MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Trends in Microbiology' source. Mon, 06 Feb 2012 21:32:22 +0100 http://www.medworm.com/index.php?rid=5638417&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22264657%26dopt%3DAbstract Authors: Zhu L, Zhu Y, Zhang Y, Li Y Abstract Microbial fermentations and bioconversions play a central role in the production of pharmaceuticals, enzymes and chemicals. To meet the demands of industrial production, it is desirable that microbes maintain a maximized carbon flux towards target metabolites regardless of fluctuations in intracellular or extracellular environments. This requires cellular systems that maintain functional stability and dynamic homeostasis in a given physiological state, or manipulate transitions between different physiological states. Stable maintenance or smooth transition can be achieved through engineering of dynamic controllability, modular and hierarchical organization, or functional redundancy, three key features of biological robustness in a cellu... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5638417 Thu, 19 Jan 2012 05:00:00 +0100 5638417 http://www.medworm.com/index.php?rid=5620105&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22257962%26dopt%3DAbstract Authors: Lee MS, Hu AY Abstract Influenza vaccines are currently produced through egg-based methods, with one drawback being that this system is slow to respond to the surging global demand during an influenza pandemic. Alternative influenza vaccine production strategies, such as using a cell-based strategy, should be considered in pandemic situations. PMID: 22257962 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5620105 Mon, 16 Jan 2012 05:00:00 +0100 5620105 http://www.medworm.com/index.php?rid=5598284&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22239910%26dopt%3DAbstract Authors: Reynolds MG, Damon IK Abstract The recent observation of a surge in human monkeypox in the Democratic Republic of the Congo (DRC) prompts the question of whether cessation of smallpox vaccination is driving the phenomenon, and if so, why is re-emergence not universal throughout the historic geographic range of the virus? Research addressing the virus's mechanisms for immune evasion and induction, as well as that directed at elucidating the genes involved in pathogenesis in different viral lineages (West African vs Congo Basin), provide insights to help explain why emergence appears to be geographically limited. Novel vaccines offer one solution to curtail the spread of this disease. PMID: 22239910 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5598284 Tue, 10 Jan 2012 05:00:00 +0100 5598284 http://www.medworm.com/index.php?rid=5548164&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22197327%26dopt%3DAbstract Authors: Blanco LP, Evans ML, Smith DR, Badtke MP, Chapman MR Abstract Amyloid is a distinct β-sheet-rich fold that many proteins can acquire. Frequently associated with neurodegenerative diseases in humans, including Alzheimer's, Parkinson's and Huntington's diseases, amyloids are traditionally considered the product of protein misfolding. However, the amyloid fold is now recognized as a ubiquitous part of normal cellular biology. Functional amyloids have been identified in nearly all facets of cellular life, with microbial functional amyloids leading the way. Unlike disease-associated amyloids, functional amyloids are assembled by dedicated, directed pathways and ultimately perform a physiological function that benefits the organism. The evolved amyloid assembly and disassembly ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5548164 Thu, 22 Dec 2011 05:00:00 +0100 5548164 http://www.medworm.com/index.php?rid=5548165&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22196375%26dopt%3DAbstract Authors: Kirzinger MW, Stavrinides J Abstract Host specificity is an important concept that underlies the interaction of all clinically and agriculturally relevant microbes with their hosts. Changes in the host specificity of animal pathogens, in particular, are often of greatest concern due to their immediate and unexpected impact on human health. Host switching or host jumps can often be traced to modification of key microbial pathogenicity factors that facilitate the formation of particular host associations. An increase in the number of genome-level studies has begun revealing that almost any type of change, from the simplest to the most complex, can potentially impact host specificity. This review highlights examples of host specificity determinants of viruses, bacteria and fu... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5548165 Wed, 21 Dec 2011 05:00:00 +0100 5548165 http://www.medworm.com/index.php?rid=5512294&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22169461%26dopt%3DAbstract Authors: Paganelli FL, Willems RJ, Leavis HL Abstract Enterococcus faecalis and Enterococcus faecium are among the leading causative agents of nosocomial infections and are infamous for their resistance to many antibiotics. They cause difficult-to-treat infections, often originating from biofilm-mediated infections associated with implanted medical devices or endocarditis. Biofilms protect bacteria against antibiotics and phagocytosis, and physical removal of devices or infected tissue is often needed but is frequently not possible. Currently there are no clinically available compounds that disassemble biofilms. In this review we discuss all known structural and regulatory genes involved in enterococcal biofilm formation, the compounds directed against biofilm formation that have b... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512294 Mon, 12 Dec 2011 05:00:00 +0100 5512294 http://www.medworm.com/index.php?rid=5512296&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154163%26dopt%3DAbstract Authors: Carter GP, Rood JI, Lyras D Abstract During the past decade, there has been a striking increase in Clostridium difficile nosocomial infections worldwide predominantly due to the emergence of epidemic or hypervirulent isolates, leading to an increased research focus on this bacterium. Particular interest has surrounded the two large clostridial toxins encoded by most virulent isolates, known as toxin A and toxin B. Toxin A was thought to be the major virulence factor for many years; however, it is becoming increasingly evident that toxin B plays a much more important role than anticipated. It is clear that further experiments are required to accurately determine the relative roles of each toxin in disease, especially in more clinically relevant current epidemic isolates. ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512296 Wed, 07 Dec 2011 05:00:00 +0100 5512296 http://www.medworm.com/index.php?rid=5512295&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22154164%26dopt%3DAbstract Authors: White CL, Gober JW Abstract The discovery that the bacterial cell shape determinant MreB is related to actin spurred new insights into bacterial morphogenesis and development. The trafficking and mechanical roles of the eukaryotic cytoskeleton were hypothesized to have a functional ancestor in MreB based on evidence implicating MreB as an organizer of cell wall synthesis. Genetic, biochemical and cytological studies implicate MreB as a coordinator of a large multi-protein peptidoglycan (PG) synthesizing holoenzyme. Recent advances in microscopy and new biochemical evidence, however, suggest that MreB may function differently than previously envisioned. This review summarizes our evolving knowledge of MreB and attempts to refine the generalized model of the proteins organiz... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512295 Wed, 07 Dec 2011 05:00:00 +0100 5512295 http://www.medworm.com/index.php?rid=5512298&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22153752%26dopt%3DAbstract Authors: Watanabe Y, Ibrahim MS, Suzuki Y, Ikuta K Abstract Highly pathogenic avian influenza A virus subtype H5N1 has been endemic in some bird species since its emergence in 1996 and its ecology, genetics and antigenic properties have continued to evolve. This has allowed diverse virus strains to emerge in endemic areas with altered receptor specificity, including a new H5 sublineage with enhanced binding affinity to the human-type receptor. The pandemic potential of H5N1 viruses is alarming and may be increasing. We review here the complex dynamics and changing nature of the H5N1 virus that may contribute to the emergence of pandemic strains. PMID: 22153752 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512298 Mon, 05 Dec 2011 05:00:00 +0100 5512298 http://www.medworm.com/index.php?rid=5512297&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22153753%26dopt%3DAbstract Authors: Meurens F, Summerfield A, Nauwynck H, Saif L, Gerdts V Abstract An animal model to study human infectious diseases should accurately reproduce the various aspects of disease. Domestic pigs (Sus scrofa domesticus) are closely related to humans in terms of anatomy, genetics and physiology, and represent an excellent animal model to study various microbial infectious diseases. Indeed, experiments in pigs are much more likely to be predictive of therapeutic treatments in humans than experiments in rodents. In this review, we highlight the numerous advantages of the pig model for infectious disease research and vaccine development and document a few examples of human microbial infectious diseases for which the use of pigs as animal models has contributed to the acquisition of n... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512297 Mon, 05 Dec 2011 05:00:00 +0100 5512297 http://www.medworm.com/index.php?rid=5512299&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22112388%26dopt%3DAbstract Authors: Lewis CM, Obregón-Tito A, Tito RY, Foster MW, Spicer PG Abstract The Human Microbiome Project (HMP) is following in the footsteps of the Human Genome Project (HGP), which will include exciting discoveries, but also potential disappointment and resentment over the lack of medical applications. There is a wiser path for the HMP. This path includes a greater attention to rare variation, an early commitment to an ethical inclusion of indigenous communities, and a recruitment strategy in which medical benefits are de-emphasized. PMID: 22112388 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512299 Mon, 21 Nov 2011 05:00:00 +0100 5512299 http://www.medworm.com/index.php?rid=5512300&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099004%26dopt%3DAbstract Authors: Lipke PN, Garcia MC, Alsteens D, Ramsook CB, Klotz SA, Dufrêne YF Abstract Budding yeasts adhere to biotic or abiotic surfaces and aggregate to form biofilms, using wall-anchored glycoprotein adhesins. The process is paradoxical: adhesins often show weak binding to specific ligands, yet mediate remarkably strong adherence. Single-molecule atomic force microscopy (AFM), genomics, biochemistry and cell biology have recently explained the puzzle, with Candida albicans Als adhesins as the paradigm. The strength of adhesion results partly from force-activated amyloid-like clustering of hundreds of adhesin molecules to form arrays of ordered multimeric binding sites. The various protein domains of eukaryotic adhesins cooperate to facilitate this fascinating new mechanism of act... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512300 Wed, 16 Nov 2011 05:00:00 +0100 5512300 http://www.medworm.com/index.php?rid=5512301&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22088901%26dopt%3DAbstract Authors: Juge N Abstract The gastrointestinal tract (GIT) is lined by a layer of mucus formed by mucin glycoproteins. This layer constitutes a physical and chemical barrier between the intestinal contents and the underlying epithelia. In addition to this protective role, mucins harbor glycan-rich domains that provide preferential binding sites for pathogens and commensal bacteria. Although mucus-microbial interactions in the GIT play a crucial role in determining the outcome of relationships of both commensal and pathogens with the host, the adhesins and ligands involved in the interaction are poorly delineated. This review focuses on the current knowledge of microbial adhesins to gastrointestinal mucus and mucus components. PMID: 22088901 [PubMed - as supplied by publisher] (S... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5512301 Mon, 14 Nov 2011 05:00:00 +0100 5512301 http://www.medworm.com/index.php?rid=5418653&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22078325%26dopt%3DAbstract Authors: Nordmann P, Poirel L, Walsh TR, Livermore DM Abstract Carbapenems were the last β-lactams retaining near-universal anti-Gram-negative activity, but carbapenemases are spreading, conferring resistance. New Delhi metallo-β-lactamase (NDM) enzymes are the latest carbapenemases to be recognized and since 2008 have been reported worldwide, mostly in bacteria from patients epidemiologically linked to the Indian subcontinent, where they occur widely in hospital and community infections, and also in contaminated urban water. The main type is NDM-1, but minor variants occur. NDM enzymes are present largely in Enterobacteriaceae, but also in non-fermenters and Vibrionaceae. Dissemination predominantly involves transfer of the bla(NDM-1) gene among promiscuous plasmids and clonal o... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5418653 Wed, 09 Nov 2011 05:00:00 +0100 5418653 http://www.medworm.com/index.php?rid=5379140&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22032828%26dopt%3DAbstract Authors: Evans JD, Schwarz RS Abstract The biology and health of the honey bee Apis mellifera has been of interest to human societies for centuries. Research on honey bee health is surging, in part due to new tools and the arrival of colony-collapse disorder (CCD), an unsolved decline in bees from parts of the United States, Europe, and Asia. Although a clear understanding of what causes CCD has yet to emerge, these efforts have led to new microbial discoveries and avenues to improve our understanding of bees and the challenges they face. Here we review the known honey bee microbes and highlight areas of both active and lagging research. Detailed studies of honey bee-pathogen dynamics will help efforts to keep this important pollinator healthy and will give general insights into bo... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5379140 Tue, 25 Oct 2011 04:00:00 +0100 5379140 http://www.medworm.com/index.php?rid=5379141&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22030243%26dopt%3DAbstract Authors: Lebeer S, Claes IJ, Vanderleyden J Abstract Lipoteichoic acid (LTA) mutants of lactobacilli suppress inflammation in animal models of experimental colitis. The fact that a single mutation of an administered Lactobacillus strain can result in enhanced probiotic efficacy is surprising given the genetic diversity and complexity of the intestinal niche, but at the same time exciting from a microbiological, immunological and gastroenterological point of view. In this Opinion article, we discuss the possible impacts of LTA modification in probiotic bacteria in the context of the current knowledge regarding the proinflammatory capacity of LTA, structure-activity relationships of LTA, intestinal LTA recognition in healthy and colitis conditions and anti-inflammatory molecules of l... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5379141 Mon, 24 Oct 2011 04:00:00 +0100 5379141 http://www.medworm.com/index.php?rid=5379142&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22018741%26dopt%3DAbstract Authors: Guy L, Ettema TJ Abstract Although most hypotheses to explain the emergence of the eukaryotic lineage are conflicting, some consensus exists concerning the requirement of a genomic fusion between archaeal and bacterial components. Recent phylogenomic studies have provided support for eocyte-like scenarios in which the alleged 'archaeal parent' of the eukaryotic cell emerged from the Crenarchaeota/Thaumarchaeota. Here, we provide evidence for a scenario in which this archaeal parent emerged from within the 'TACK' superphylum that comprises the Thaumarchaeota, Crenarchaeota and Korarchaeota, as well as the recently proposed phylum 'Aigarchaeota'. In support of this view, functional and comparative genomics studies have unearthed an increasing number of features that are uniq... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5379142 Thu, 20 Oct 2011 04:00:00 +0100 5379142 http://www.medworm.com/index.php?rid=5325288&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000206%26dopt%3DAbstract Authors: Baines JD Abstract Herpes simplex virus (HSV) is an important pathogenic agent that causes recurrent oral and genital lesions, blindness and encephalitis. It is a member of the family Herpesviridae, which contains three subfamilies (alpha- beta- and gammaherpesvirinae) whose members infect humans to cause a variety of ailments, from benign rashes to nasopharyngeal carcinoma. Although this review focuses on HSV, the assembly steps that occur in the nucleus and the proteins involved are highly conserved among all family members, which suggests that antiviral agents that block these steps might be effective against many different herpesviruses and their associated diseases. Despite this potential, a broadly effective compound has yet to be realized, in part because many of th... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5325288 Thu, 13 Oct 2011 04:00:00 +0100 5325288 http://www.medworm.com/index.php?rid=5325289&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21983544%26dopt%3DAbstract Authors: Al-Quadan T, Price CT, London N, Schueler-Furman O, Abukwaik Y Abstract Post-translational lipidation by prenylation of the CaaX-box C-terminal motif in eukaryotic proteins facilitates anchoring of hydrophilic proteins, such as Ras and Rab, to membranes. A large cadre of bacterial effectors injected into host cells is anchored to host membranes by unknown mechanisms. As already documented for Legionella and Salmonella, we propose a common paradigm of microbial exploitation of the host prenylation machinery for anchoring of injected effectors to host membranes. This is supported by numerous potential microbial CaaX-box-containing proteins identified using refined bioinformatic tools. We also propose utilization of the CaaX motif as a membrane-targeting tag for proteins expr... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5325289 Fri, 07 Oct 2011 04:00:00 +0100 5325289 http://www.medworm.com/index.php?rid=5296165&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21978843%26dopt%3DAbstract Authors: Robinson MJ, Erlwein O, McClure MO Abstract The xenotropic murine leukaemia virus-related virus (XMRV), a gammaretrovirus, was discovered in prostate cancer tumours by Virochip technology in 2006. It was subsequently detected in chronic fatigue patients in 2009. The association between XMRV and chronic fatigue has proved to be controversial. No study has confirmed these findings and many have refuted them. Here, we present the evidence for our contention that XMRV is not a human pathogen. PMID: 21978843 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5296165 Tue, 04 Oct 2011 04:00:00 +0100 5296165 http://www.medworm.com/index.php?rid=5276545&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21959253%26dopt%3DAbstract Authors: Teitzel G PMID: 21959253 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5276545 Sat, 01 Oct 2011 04:00:00 +0100 5276545 http://www.medworm.com/index.php?rid=5276546&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21955402%26dopt%3DAbstract Authors: Neish AS, Naumann M Abstract Virtually all eukaryotes have developed defense mechanisms to efficiently counter potential threats from prokaryotic microorganisms; an example is the conserved nuclear factor-kappaB (NF-κB) signaling system. However, bacterial pathogens and commensals have in turn evolved highly effective counter mechanisms to modulate this immune regulatory circuit. Modifications in ubiquitin, ubiquitin-like (Ubl) proteins such as neural precursor cell expressed, developmentally down-regulated 8 (NEDD8) and other post-translational modifications (PTMs) in the NF-κB system represent attractive targets for microbial manipulation. In this review, we describe recent advances in understanding the different strategies that bacteria have evolved to interfere with ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5276546 Mon, 26 Sep 2011 04:00:00 +0100 5276546 http://www.medworm.com/index.php?rid=5276547&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945420%26dopt%3DAbstract Authors: Garrett RA, Vestergaard G, Shah SA Abstract CRISPR (clustered regularly interspaced short palindromic repeats)-based immune systems are essentially modular with three primary functions: the excision and integration of new spacers, the processing of CRISPR transcripts to yield mature CRISPR RNAs (crRNAs), and the targeting and cleavage of foreign nucleic acid. The primary target appears to be the DNA of foreign genetic elements, but the CRISPR/Cmr system that is widespread amongst archaea also specifically targets and cleaves RNA in vitro. The archaeal CRISPR systems tend to be both diverse and complex. Here we examine evidence for exchange of functional modules between archaeal systems that is likely to contribute to their diversity, particularly of their nucleic acid targ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5276547 Thu, 22 Sep 2011 04:00:00 +0100 5276547 http://www.medworm.com/index.php?rid=5245977&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21924910%26dopt%3DAbstract Authors: Ouellet H, Johnston JB, Montellano PR Abstract Mycobacterium tuberculosis (Mtb) is an intracellular pathogen that infects 10 million people worldwide and kills 2 million people every year. The uptake and utilization of nutrients by Mtb within the host cell is still poorly understood, although lipids play an important role in Mtb persistence. The recent identification of a large regulon of cholesterol catabolic genes suggests that Mtb can use host sterol for infection and persistence. In this review, we report on recent progress in elucidation of the Mtb cholesterol catabolic reactions and their potential utility as targets for tuberculosis therapeutic agents. PMID: 21924910 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5245977 Thu, 15 Sep 2011 04:00:00 +0100 5245977 http://www.medworm.com/index.php?rid=5218175&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21893414%26dopt%3DAbstract Authors: Cowan DA, Chown SL, Convey P, Tuffin M, Hughes K, Pointing S, Vincent WF Abstract The Antarctic continent is frequently cited as the last pristine continent on Earth. However, this view is misleading for several reasons. First, there has been a rapid increase in visitors to Antarctica, with large increases at research bases and their environs and to sites of major tourist interest (e.g. historical sites and concentrations of megafauna). Second, although substantial efforts are made to avoid physical disturbance and contamination by chemical, human and other wastes at these sites, little has been done to prevent the introduction of non-indigenous microorganisms. Here, we analyse the extent and significance of anthropogenic introduction of microbial 'contaminants' to the Ant... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5218175 Sat, 03 Sep 2011 04:00:00 +0100 5218175 http://www.medworm.com/index.php?rid=5192446&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21880492%26dopt%3DAbstract Authors: Chaturvedi V, Chaturvedi S Abstract Cryptococcus gattii and Cryptococcus neoformans are causal agents of cryptococcosis, which manifests as pneumonia and meningitis. C. gattii has recently received widespread attention owing to outbreaks in British Columbia, Canada and the US Pacific Northwest. The biology of this tree-dwelling yeast is relatively unexplored, and there are few clues about how it causes infections in humans and animals. In this review, we summarize recent discoveries about C. gattii genetics and its ecological niche and highlight areas ripe for future exploration. Increased focus on epidemiology, ecological modeling and host-pathogen interactions is expected to yield a better understanding of this enigmatic yeast, and ultimately lead to better measures for ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5192446 Sun, 28 Aug 2011 23:00:00 +0100 5192446 http://www.medworm.com/index.php?rid=5192447&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21872475%26dopt%3DAbstract Authors: Zaneveld JR, Parfrey LW, Van Treuren W, Lozupone C, Clemente JC, Knights D, Stombaugh J, Kuczynski J, Knight R Abstract High-throughput sequencing technologies provide new opportunities to address longstanding questions about habitat adaptation in microbial organisms. How have microbes managed to adapt to such a wide range of environments, and what genomic features allow for such adaptation? We review recent large-scale studies of habitat adaptation, with emphasis on those that utilize phylogenetic techniques. On the basis of current trends, we summarize methodological challenges faced by investigators, and the tools, techniques and analytical approaches available to overcome them. Phylogenetic approaches and detailed information about each environmental sample will be cru... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5192447 Wed, 24 Aug 2011 23:00:00 +0100 5192447 http://www.medworm.com/index.php?rid=5192449&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21871806%26dopt%3DAbstract Authors: Rizzetto L, Cavalieri D Abstract Modelling the networks sustaining the fruitful coexistence between fungi and their mammalian hosts is becoming increasingly important to control emerging fungal pathogens. In a 'systems biology' perspective, the microbiota and host should be seen as an ecosystem, and disease considered as an alteration of the equilibrium. This review addresses host-fungus interaction with a special focus on systems biology approaches to investigate the mechanisms developed by Candida albicans and Aspergillus fumigatus to circumvent host immune responses during fungal infections. Such genome-wide integrative approaches hold the promise to significantly improve our ability to understand which fungal traits can be considered potential threats and the regulator... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5192449 Tue, 23 Aug 2011 23:00:00 +0100 5192449 http://www.medworm.com/index.php?rid=5192448&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21871807%26dopt%3DAbstract Authors: Gowen CM, Fong SS Abstract Harnessing the immense natural diversity of biological functions for economical production of fuel has enormous potential benefits. Inevitably, however, the native capabilities for any given organism must be modified to increase the productivity or efficiency of a biofuel bioprocess. From a broad perspective, the challenge is to sufficiently understand the details of cellular functionality to be able to prospectively predict and modify the cellular function of a microorganism. Recent advances in experimental and computational systems biology approaches can be used to better understand cellular level function and guide future experiments. With pressure to quickly develop viable, renewable biofuel processes a balance must be maintained between obta... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5192448 Tue, 23 Aug 2011 23:00:00 +0100 5192448 http://www.medworm.com/index.php?rid=5155757&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21855346%26dopt%3DAbstract Authors: Harriott MM, Noverr MC Abstract Candida albicans is the most prevalent human fungal pathogen, with an ability to inhabit diverse host niches and cause disease in both immunocompetent and immunocompromised individuals. C. albicans also readily forms biofilms on indwelling medical devices and mucosal tissues, which serve as an infectious reservoir that is difficult to eradicate, and can lead to lethal systemic infections. Biofilm formation occurs within a complex milieu of host factors and other members of the human microbiota. Polymicrobial interactions will probably dictate the cellular and biochemical composition of the biofilm, as well as influence clinically relevant outcomes, such as drug and host resistance and virulence. In this manuscript, we review C. albicans infe... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5155757 Wed, 17 Aug 2011 23:00:00 +0100 5155757 http://www.medworm.com/index.php?rid=5155747&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21855347%26dopt%3DAbstract Authors: Friedel CC, Haas J Abstract Novel high-throughput technologies such as yeast two-hybrid and RNA interference (RNAi) screens provide the tools to study interactions between viral proteins and the host on a genomic scale. In this review, we provide an overview of studies in which these technologies were applied and of computational approaches for the analysis of the identified viral interactors in the context of the host cell. The results of these studies illustrate the advantages of integrative systems biology approaches in the investigation of viral pathogens. PMID: 21855347 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5155747 Wed, 17 Aug 2011 23:00:00 +0100 5155747 http://www.medworm.com/index.php?rid=5141013&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21831640%26dopt%3DAbstract Authors: Comas I, Gagneux S Abstract Despite being a curable disease, tuberculosis (TB) killed more people in 2009 than during any previous year in history. Progress in TB research has been slow, and remains burdened by important gaps in our knowledge of the basic biology of Mycobacterium tuberculosis, the causative agent of TB, and its interaction with the human host. Fortunately, major systems biology initiatives have recently been launched that will help fill some of these gaps. However, to fully comprehend TB and control this disease globally, current systems biological approaches will not suffice. The influence of host and pathogen diversity, changes in human demography, and socioeconomic and environmental factors will also need to be considered. Such a multidisciplinary appro... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5141013 Sun, 07 Aug 2011 23:00:00 +0100 5141013 http://www.medworm.com/index.php?rid=5141014&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21820313%26dopt%3DAbstract Authors: Dagan T Abstract Phylogenomics is aimed at studying functional and evolutionary aspects of genome biology using phylogenetic analysis of whole genomes. Current approaches to genome phylogenies are commonly founded in terms of phylogenetic trees. However, several evolutionary processes are non tree-like in nature, including recombination and lateral gene transfer (LGT). Phylogenomic networks are a special type of phylogenetic network reconstructed from fully sequenced genomes. The network model, comprising genomes connected by pairwise evolutionary relations, enables the reconstruction of both vertical and LGT events. Modeling genome evolution in the form of a network enables the use of an extensive toolbox developed for network research. The structural properties of phylog... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5141014 Tue, 02 Aug 2011 23:00:00 +0100 5141014 http://www.medworm.com/index.php?rid=5141015&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21816616%26dopt%3DAbstract Authors: Trivedi K, Tang CM, Exley RM Abstract Despite advances against infectious diseases over the past century, Neisseria meningitidis remains a major causative agent of meningitis and septicaemia worldwide. Its adaptation for survival in the human nasopharynx makes the meningococcus a highly successful commensal bacterium. Recent progress has been made in understanding the mechanisms that enable neisserial colonisation, in terms of the role of type IV pili, the impact of other adhesins, biofilm formation, nutrient acquisition and resistance to host immune defences. Refinements in cell-based and in vivo models will lead to improved understanding of the colonisation process, and hopefully to more effective vaccines and therapeutic strategies. PMID: 21816616 [PubMed - as suppl... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5141015 Mon, 01 Aug 2011 23:00:00 +0100 5141015 http://www.medworm.com/index.php?rid=5097439&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21795047%26dopt%3DAbstract Authors: Baur AS After two decades of research the Nef protein of human immunodeficiency virus (HIV) remains a mysterious protein with an indisputable role in HIV pathogenesis. The ability to downregulate CD4 and major histocompatibility complex class I (MHC-I) was the first ascribed function of Nef and, whereas the number of downmodulated receptors by Nef is rising, so are the explanations for how their downregulation could contribute to HIV pathogenesis. At the same time there is increasing evidence that Nef not only induces endocytosis but also exocytosis, namely of cytokines and microvesicles that contain Nef itself. Because endocytosis and exocytosis are connected events, this is not surprising - and raises the intriguing possibility that HIV aims at secretion rather than ingestio... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5097439 Sun, 24 Jul 2011 23:00:00 +0100 5097439 http://www.medworm.com/index.php?rid=5097480&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21784640%26dopt%3DAbstract Authors: Boles BR, Horswill AR Staphylococcus aureus and Staphylococcus epidermidis are a frequent cause of biofilm-associated infections that are a tremendous burden on our healthcare system. Staphylococcal biofilms exhibit extraordinary resistance to antimicrobial killing, limiting the efficacy of antibiotic therapy, and surgical intervention is often required to remove infected tissues or implanted devices. Recent work has provided new insight into the molecular basis of biofilm development in these opportunistic pathogens. Extracellular bacterial products, environmental conditions, and polymicrobial interactions have all been shown to influence profoundly the ability of these bacteria to colonize and disperse from clinically relevant surfaces. We review new developments in staphylo... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5097480 Thu, 21 Jul 2011 23:00:00 +0100 5097480 http://www.medworm.com/index.php?rid=5097452&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21784641%26dopt%3DAbstract Authors: Ferreira DM, Jambo KC, Gordon SB Pneumococcal conjugate vaccines have had unprecedented success in controlling vaccine-type invasive pneumococcal disease. As serotype replacement and the complexity of designing vaccines to multiple capsular polysaccharides ultimately pose a threat to these vaccines, the development of alternative protein vaccines is important. Protein vaccines offer the promise of extended serotype coverage, reduced cost, and improved protection against otitis media and pneumococcal pneumonia. As placebo-controlled trials are not currently ethically justifiable, human pneumococcal challenge models using prevention of carriage as a test endpoint offer an attractive link between preclinical studies and clinical efficacy trials. Experimental human pneumococcal ca... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5097452 Thu, 21 Jul 2011 23:00:00 +0100 5097452 http://www.medworm.com/index.php?rid=5051356&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21775143%26dopt%3DAbstract This article explores strategies for merging the human microbiome data with multiple additional datasets (e.g. host single nucleotide polymorphisms and host gene expression) and for integrating patient-based data with results from experimental animal models to gain deeper understanding of how host-microbe interactions impact disease. PMID: 21775143 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5051356 Sun, 17 Jul 2011 23:00:00 +0100 5051356 http://www.medworm.com/index.php?rid=5051357&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21763141%26dopt%3DAbstract Authors: Jefferies JM, Clarke SC, Webb JS, Kraaijeveld AR Pathogens increasingly evade current vaccines, and new strategies to control them are needed. There is mounting evidence that replacement of vaccine serotypes of Streptococcus pneumoniae with non-vaccine serotypes has taken place following widespread use of limited-serotype conjugate vaccines. New strategies to control vaccine evasion are needed and understanding evolutionary theory is important for the development of such approaches. Hosts are under selection pressure to evolve resistance against pathogens whereas pathogens are under selection pressure to evolve counter-resistance against the resistance mechanism of their host. Evolutionary changes in both host and pathogen lead to a continuous turnover of host and pathogen gen... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5051357 Tue, 12 Jul 2011 23:00:00 +0100 5051357 http://www.medworm.com/index.php?rid=5000813&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21726793%26dopt%3DAbstract Authors: Teitzel G PMID: 21726793 [PubMed - in process] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5000813 Thu, 30 Jun 2011 23:00:00 +0100 5000813 http://www.medworm.com/index.php?rid=5000814&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21705222%26dopt%3DAbstract Authors: Tan M, Jiang X The discovery of human histo-blood group antigens (HBGAs) as receptors or ligands of noroviruses (NoVs) raises a question about the potential role of host factors in the evolution and diversity of NoVs. Recent structural analysis of selected strains in the two major genogroups of human NoVs (GI and GII) demonstrated highly conserved HBGA binding interfaces within the two groups but not between them, indicating convergent evolution of GI and GII NoVs. GI and GII NoVs are probably introduced to humans from different non-human hosts with the HBGAs as a common niche. Each genogroup has further diverged into multiple sub-lineages (genotypes) through selections by the polymorphic HBGAs of the hosts. An elucidation of such pathogen-host interaction, including determina... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=5000814 Thu, 23 Jun 2011 23:00:00 +0100 5000814 http://www.medworm.com/index.php?rid=4954852&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21684749%26dopt%3DAbstract Authors: Holmes E, Li JV, Athanasiou T, Ashrafian H, Nicholson JK There is growing awareness of the importance of the gut microbiome in health and disease, and recognition that the microbe to host metabolic signalling is crucial to understanding the mechanistic basis of their interaction. This opens new avenues of research for advancing knowledge on the aetiopathologic consequences of dysbiosis with potential for identifying novel microbially-related drug targets. Advances in both sequencing technologies and metabolic profiling platforms, coupled with mathematical integration approaches, herald a new era in characterizing the role of the microbiome in metabolic signalling within the host and have far reaching implications in promoting health in both the developed and developing world. ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954852 Thu, 16 Jun 2011 23:00:00 +0100 4954852 http://www.medworm.com/index.php?rid=4954857&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664817%26dopt%3DAbstract Authors: Winder CL, Dunn WB, Goodacre R Metabolomics can play a particularly important role in elucidating novel anabolic and catabolic pathways in bacteria and fungi, and in understanding the dynamics of metabolism. In these approaches, an isotopically labelled substrate, with an artificially high abundance of isotopic label, is fed to the microorganism under study. The products become isotopically labelled, and can be measured using a combination of mass spectrometry and nuclear magnetic resonance spectroscopy. This mass isotopomer analysis is referred to as time and relative differences in systems (TARDIS)-based analysis, as it measures and quantifies the temporal sequential emergence of these labelled products. In this review, we cover this topic from an experimental point of view ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954857 Wed, 08 Jun 2011 23:00:00 +0100 4954857 http://www.medworm.com/index.php?rid=4954856&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664818%26dopt%3DAbstract Authors: Zhang F, Keasling J Many metabolic pathways in microbial hosts have been created, modified and engineered to produce useful molecules. The titer and yield of a final compound is often limited by the inefficient use of cellular resources and imbalanced metabolism. Engineering sensory-regulation devices that regulate pathway gene expression in response to the environment and metabolic status of the cell have great potential to solve these problems, and enhance product titers and yields. This review will focus on recent developments in biosensor design, and their applications for controlling microbial behavior. PMID: 21664818 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954856 Wed, 08 Jun 2011 23:00:00 +0100 4954856 http://www.medworm.com/index.php?rid=4954855&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664819%26dopt%3DAbstract Authors: Breidenstein EB, de la Fuente-Núñez C, Hancock RE Pseudomonas aeruginosa is often resistant to multiple antibiotics and consequently has joined the ranks of 'superbugs' due to its enormous capacity to engender resistance. It demonstrates decreased susceptibility to most antibiotics due to low outer membrane permeability coupled to adaptive mechanisms and can readily achieve clinical resistance. Newer research, using mutant library screens, microarray technologies and mutation frequency analysis, has identified very large collections of genes (the resistome) that when mutated lead to resistance as well as new forms of adaptive resistance that can be triggered by antibiotics themselves, in in vivo growth conditions or complex adaptations such as biofilm growth or swarming moti... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954855 Wed, 08 Jun 2011 23:00:00 +0100 4954855 http://www.medworm.com/index.php?rid=4954854&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664820%26dopt%3DAbstract Authors: Gomelsky M, Hoff WD Until recently, bacterial responses to changes in light environments were regarded as specialized adaptations in a small number of phototrophs. However, the genomes of many photosynthetic and chemotrophic bacteria not known to have photophysiological responses also encode photoreceptor proteins. What new trends in the biological responses triggered by these photoreceptors are emerging? Here, we review several instances where members of different blue-light receptor classes (LOV, BLUF and PYP) photoregulate a lifestyle choice between the motile single-cellular state and the multicellular surface-attached community state (biofilm) by a range of mechanisms including bacterial two-component systems, the second messenger cyclic di-GMP and direct interactions of ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954854 Wed, 08 Jun 2011 23:00:00 +0100 4954854 http://www.medworm.com/index.php?rid=4954853&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664821%26dopt%3DAbstract Authors: Bird LJ, Bonnefoy V, Newman DK Before cyanobacteria invented oxygenic photosynthesis and O(2) and H(2)O began to cycle between respiration and photosynthesis, redox cycles between other elements were used to sustain microbial metabolism on a global scale. Today these cycles continue to occur in more specialized niches. In this review we focus on the bioenergetic aspects of one of these cycles - the iron cycle - because iron presents unique and fascinating challenges for cells that use it for energy. Although iron is an important nutrient for nearly all life forms, we restrict our discussion to energy-yielding pathways that use ferrous iron [Fe(II)] as an electron donor or ferric iron [Fe(III)] as an electron acceptor. We briefly review general concepts in bioenergetics, focusi... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954853 Wed, 08 Jun 2011 23:00:00 +0100 4954853 http://www.medworm.com/index.php?rid=4954858&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21664137%26dopt%3DAbstract Authors: van Belkum MJ, Martin-Visscher LA, Vederas JC Circular bacteriocins are antimicrobial peptides produced by a variety of Gram-positive bacteria. They are part of a growing family of ribosomally synthesized peptides with a head-to-tail cyclization of their backbone that are found in mammals, plants, fungi and bacteria and are exceptionally stable. These bacteriocins permeabilize the membrane of sensitive bacteria, causing loss of ions and dissipation of the membrane potential. Most circular bacteriocins probably adopt a common 3D structure consisting of four or five α-helices encompassing a hydrophobic core. This review compares the various structures, as well as the gene clusters that encode circular bacteriocins, and discusses the biogenesis of this unique class of bacterioci... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4954858 Tue, 07 Jun 2011 23:00:00 +0100 4954858 http://www.medworm.com/index.php?rid=4905688&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21640592%26dopt%3DAbstract Authors: Boyce KJ, Andrianopoulos A The family of Ste20-related kinases is conserved from yeast to mammals and includes the p21 activated kinases (PAKs) and germinal centre kinases (GCKs). These kinases have been shown to be involved in signaling through mitogen activated protein kinase (MAPK) pathways and in morphogenesis through the regulation of cytokinesis and actin-dependent polarized growth. This review concentrates on the role of Ste20-related kinases in fungi where recent research has revealed roles for both PAKs and GCKs in the regulation of cytokinesis and in previously unidentified roles in promoting hyphal growth and differentiation of asexual development structures. In particular, the importance of PAKs during pathogenesis will be examined. PMID: 21640592 [PubMed - as ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4905688 Tue, 31 May 2011 23:00:00 +0100 4905688 http://www.medworm.com/index.php?rid=4855858&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21600774%26dopt%3DAbstract Authors: Rohmer L, Hocquet D, Miller SI It is interesting to speculate that the evolutionary drive for microbes to develop pathogenic characteristics was to access the nutrient resources that animals provided. Animal environments that pathogens colonize have likely driven the evolution of new bacterial characteristics to maximize these new nutritional opportunities. This review focuses on genomic and functional aspects of pathogen metabolism that allow efficient utilization of nutrient resources provided by animals. Similar to genes encoding specific virulence traits, genes encoding metabolic functions have been horizontally acquired by pathogens to provide a selective advantage in host tissues. Selective advantage in host tissues can also be gained by loss of function mutations that a... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4855858 Tue, 17 May 2011 23:00:00 +0100 4855858 http://www.medworm.com/index.php?rid=4855859&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21570293%26dopt%3DAbstract Authors: Yu Y, Clippinger AJ, Alwine JC Human cytomegalovirus (HCMV) infection causes dramatic alterations of intermediary metabolism, similar to those found in tumor cells. In infected cells, glucose carbon is not completely broken down by the tricarboxylic acid (TCA) cycle for energy; instead, it is used biosynthetically. This process requires increased glucose uptake, increased glycolysis and the diversion of glucose carbon, in the form of citrate, from the TCA cycle for use in HCMV-induced fatty acid biosynthesis. The diversion of citrate from the TCA cycle (cataplerosis) requires induction of enzymes to promote glutaminolysis, the conversion of glutamine to α-ketoglutarate to maintain the TCA cycle (anaplerosis) and ATP production. Such changes could result in heretofore uncharac... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4855859 Tue, 10 May 2011 23:00:00 +0100 4855859 http://www.medworm.com/index.php?rid=4855860&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21561773%26dopt%3DAbstract Authors: Rhee KY, Carvalho LP, Bryk R, Ehrt S, Marrero J, Park SW, Schnappinger D, Venugopal A, Nathan C Recent advances in liquid chromatography and mass spectrometry have enabled the highly parallel, quantitative measurement of metabolites within a cell and the ability to trace their biochemical fates. In Mycobacterium tuberculosis (Mtb), these advances have highlighted major gaps in our understanding of central carbon metabolism (CCM) that have prompted fresh interpretations of the composition and structure of its metabolic pathways and the phenotypes of Mtb strains in which CCM genes have been deleted. High-throughput screens have demonstrated that small chemical compounds can selectively inhibit some enzymes of Mtb's CCM while sparing homologs in the host. Mtb's CCM has thus emerg... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4855860 Sun, 08 May 2011 23:00:00 +0100 4855860 http://www.medworm.com/index.php?rid=4803896&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21549606%26dopt%3DAbstract Authors: Selosse MA PMID: 21549606 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4803896 Tue, 03 May 2011 23:00:00 +0100 4803896 http://www.medworm.com/index.php?rid=4803897&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21531564%26dopt%3DAbstract Authors: Meyerson NR, Sawyer SL Recent studies have identified ancient virus genomes preserved as fossils within diverse animal genomes. These fossils have led to the revelation that a broad range of mammalian virus families are older and more ubiquitous than previously appreciated. Long-term interactions between viruses and their hosts often develop into genetic arms races where both parties continually jockey for evolutionary dominance. It is difficult to imagine how mammalian hosts have kept pace in the evolutionary race against rapidly evolving viruses over large expanses of time, given their much slower evolutionary rates. However, recent data has begun to reveal the evolutionary strategy of slowly-evolving hosts. We review these data and suggest a modified arms race model where t... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4803897 Thu, 28 Apr 2011 23:00:00 +0100 4803897 http://www.medworm.com/index.php?rid=4803898&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21530270%26dopt%3DAbstract Authors: Heaton NS, Randall G Viruses have evolved complex and dynamic interactions with their host cell. In recent years we have gained insight into the expanding roles for host lipids in the virus life cycle. In particular, viruses target lipid signaling, synthesis, and metabolism to remodel their host cells into an optimal environment for their replication. This review highlights examples from different viruses that illustrate the importance of these diverse virus-lipid interactions. PMID: 21530270 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4803898 Wed, 27 Apr 2011 23:00:00 +0100 4803898 http://www.medworm.com/index.php?rid=4803899&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21511478%26dopt%3DAbstract Authors: Lee B, Ataman ZA Henipavirus is a new genus of Paramyxoviridae that uses protein-based receptors (ephrinB2 and ephrinB3) for virus entry. Paramyxovirus entry requires the coordinated action of the fusion (F) and attachment viral envelope glycoproteins. Receptor binding to the attachment protein triggers F to undergo a conformational cascade that results in membrane fusion. The accumulation of structural and functional studies on many paramyxoviral fusion and attachment proteins, including the recent elucidation of structures of Nipah virus (NiV) and Hendra virus (HeV) G glycoproteins bound and unbound to cognate ephrinB receptors, indicate that henipavirus entry and fusion could differ mechanistically from paramyxoviruses that use glycan-based receptors. PMID: 21511478 [Pu... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4803899 Mon, 18 Apr 2011 23:00:00 +0100 4803899 http://www.medworm.com/index.php?rid=4803900&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21478019%26dopt%3DAbstract Authors: Malou N, Raoult D Immuno-PCR (iPCR) is a method that combines the advantages of both enzyme-linked immunosorbent assay and PCR and is a powerful method for detecting low quantities of protein antigens. Despite its potential, for a long time iPCR was an underutilized method as evidenced by the low number of publications on its routine application. The introduction of ready-to-use reagents, the large choice in linker molecule, reduction of protocol time and the development of new systems is opening the way for iPCR to become a routine method for use as a microbial diagnostic. To understand how iPCR could become an indispensible microbial diagnostic, we review the evolution of iPCR, from its first classical format with numerous drawbacks to more sophisticated systems developed to... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4803900 Wed, 06 Apr 2011 23:00:00 +0100 4803900 http://www.medworm.com/index.php?rid=4697419&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21458996%26dopt%3DAbstract Authors: Romero D, Kolter R Nearly 12 years after promising results suggested that antibiofilm agents might be developed into novel therapeutics, there are no such products on the market. In our opinion, the reasons for this have been predominantly economic. Recent developments, however, suggest that there could still be emerging opportunities for the developments of such products. PMID: 21458996 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4697419 Wed, 30 Mar 2011 23:00:00 +0100 4697419 http://www.medworm.com/index.php?rid=4697418&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21458997%26dopt%3DAbstract Authors: Thoulouze MI, Alcover A The recent finding that the human T-cell leukemia virus type 1 (HTLV-1) encases itself in a carbohydrate-rich adhesive extracellular 'cocoon', which enables its efficient and protected transfer between cells, unveiled a new infectious entity and a novel mechanism of viral transmission. These HTLV-1 structures are observed at the surface of T cells from HTLV-1-infected patients and are reminiscent of bacterial biofilms. The virus controls the synthesis of the matrix, which surrounds the virions and attaches them to the T cell surface. We propose that, similar to bacterial biofilms, viral biofilms could represent 'viral communities' with enhanced infectious capacity and improved spread compared with 'free' viral particles, and might constitute a key reser... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4697418 Wed, 30 Mar 2011 23:00:00 +0100 4697418 http://www.medworm.com/index.php?rid=4697420&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21458273%26dopt%3DAbstract Authors: Singh SP, Montgomery BL Similar to other bacteria, cyanobacteria exist in a wide-ranging diversity of shapes and sizes. However, three general shapes are observed most frequently: spherical, rod and spiral. Bacteria can also grow as filaments of cells. Some filamentous cyanobacteria have differentiated cell types that exhibit distinct morphologies: motile hormogonia, nitrogen-fixing heterocysts, and spore-like akinetes. Cyanobacterial cell shapes, which are largely controlled by the cell wall, can be regulated by developmental and/or environmental cues, although the mechanisms of regulation and the selective advantage(s) of regulating cellular shape are still being elucidated. In this review, recent insights into developmental and environmental regulation of cell shape in cyan... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4697420 Tue, 29 Mar 2011 23:00:00 +0100 4697420 http://www.medworm.com/index.php?rid=4637992&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21411325%26dopt%3DAbstract Authors: Silva S, Negri M, Henriques M, Oliveira R, Williams DW, Azeredo J Most cases of candidosis have been attributed to Candida albicans, but recently non-C. albicans Candida species have been identified as frequent human pathogens. Candida pathogenicity has been attributed to several factors, including adhesion to medical devices and/or host cells, biofilm formation, and secretion of hydrolytic enzymes (proteases, phospholipases and haemolysins). Although 'new'Candida species are emerging, there is still a lack of information about their pathogenicity. This review discusses recent advances in our knowledge of Candida glabrata, Candida parapsilosis and Candida tropicalis virulence factors, specifically those of adhesion and biofilm formation, which are key components in Candida pat... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4637992 Mon, 14 Mar 2011 00:00:00 +0100 4637992 http://www.medworm.com/index.php?rid=4578642&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21388812%26dopt%3DAbstract Authors: Rodenhuis-Zybert IA, Wilschut J, Smit JM Cleavage of the precursor membrane (prM) protein is required for the activation of flavivirus infectivity. However, many studies have shown that, for dengue virus in particular, prM cleavage and maturation is inefficient. Heterogeneity of wild-type dengue virus preparations with regard to the presence of uncleaved prM in the virion is mirrored in the substantial levels of prM-specific antibodies that are produced following dengue infection. What might be the evolutionary advantage for the virus to produce so many prM-containing particles? In this review we summarize the latest achievements of dengue research that contribute to a better understanding of the role of prM-containing virions in the pathogenesis of dengue. PMID: 21388812 ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578642 Mon, 07 Mar 2011 00:00:00 +0100 4578642 http://www.medworm.com/index.php?rid=4578643&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21377881%26dopt%3DAbstract Authors: Caffrey M The HIV envelope proteins glycoprotein 120 (gp120) and glycoprotein 41 (gp41) play crucial roles in HIV entry, therefore they are of extreme interest in the development of novel therapeutics. Studies using diverse methods, including structural biology and mutagenesis, have resulted in a detailed model for envelope-mediated entry, which consists of multiple conformations, each a potential target for therapeutic intervention. In this review, the challenges, strategies and progress to date for developing novel entry inhibitors directed at disrupting HIV gp120 and gp41 function are discussed. PMID: 21377881 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578643 Fri, 04 Mar 2011 00:00:00 +0100 4578643 http://www.medworm.com/index.php?rid=4578644&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21371889%26dopt%3DAbstract Authors: Schuelein R, Everingham P, Kwok T Helicobacter pylori (Hp) employs a multi-component type IV secretion system (T4SS) to secrete the effector protein CagA into the cytosol of infected host cells. A longstanding challenge has been to identify the host cell receptor(s) involved. Two recent studies have independently unveiled human β(1) integrin as the receptor but are divided over which T4SS proteins bind to β(1) integrin. Here we revisit the two models in light of previous findings and recent progress in the field. More concerted efforts are required to fully understand the complex T4SS mechanisms that underpin Hp pathogenesis. PMID: 21371889 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578644 Tue, 01 Mar 2011 00:00:00 +0100 4578644 http://www.medworm.com/index.php?rid=4578645&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21354799%26dopt%3DAbstract Authors: Kumamoto CA, Pierce JV Candida albicans, an opportunistic fungal pathogen and a component of the normal flora of the gastrointestinal tract, is a frequent colonizer of humans. Is C. albicans capable of sensing the immune status of its host, a process we term immunosensing, and, if so, how? C. albicans causes serious disease only in immunocompromised hosts and therefore the ability to immunosense would be advantageous to an organism. We propose a speculative model whereby, during colonization, C. albicans produces phenotypic variants that vary in relative concentration depending on host status. One variant is optimized for persistence as a commensal, whereas the other variant has higher capacity to initiate pathogenic interactions. When the ratio of the two variants changes, th... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578645 Fri, 25 Feb 2011 00:00:00 +0100 4578645 http://www.medworm.com/index.php?rid=4578646&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353779%26dopt%3DAbstract Authors: Cheng AG, Dedent AC, Schneewind O, Missiakas D Staphylococcus aureus is an important human pathogen that causes skin and soft tissue abscesses. Abscess formation is not unique to staphylococcal infection and purulent discharge has been widely considered a physiological feature of healing and tissue repair. Here we present a different view, whereby S. aureus deploys specific virulence factors to promote abscess lesions that are distinctive for this pathogen. In support of this model, only live S. aureus is able to form abscesses, requiring genes that act at one or more of four discrete stages during the development of these infectious lesions. Protein A and coagulases are distinctive virulence attributes for S. aureus, and humoral immune responses specific for these polypeptide... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578646 Thu, 24 Feb 2011 00:00:00 +0100 4578646 http://www.medworm.com/index.php?rid=4578649&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353564%26dopt%3DAbstract Authors: Schroeder N, Mota LJ, Méresse S Salmonella virulence relies on its capacity to replicate inside various cell types in a membrane-bound compartment, the Salmonella-containing vacuole (SCV). A unique feature of Salmonella-infected cells is the presence of tubular structures originating from and connected to the SCV, which often extend throughout the cell cytoplasm. These tubules include the well-studied Salmonella-induced filaments (SIFs), enriched in lysosomal membrane proteins. However, recent studies revealed that the Salmonella-induced tubular network is more extensive than previously thought and includes three types of tubules distinct from SIFs: sorting nexin tubules, Salmonella-induced secretory carrier membrane protein 3 (SCAMP3) tubules and lysosome-associated membrane... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578649 Wed, 23 Feb 2011 00:00:00 +0100 4578649 http://www.medworm.com/index.php?rid=4578648&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353565%26dopt%3DAbstract Authors: Baron EJ, Lewis H In the current era of public scientific 'debate' such as the scientific merit of climate change, it should come as no surprise that a bacterium would have its 15minutes of political limelight. Furthermore, a few dedicated citizens can truly influence the lives of many by changing the law of the land. For microbiologists, who often complain that our contributions go unnoticed and that we have no political power, this story serves to prove otherwise. PMID: 21353565 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578648 Wed, 23 Feb 2011 00:00:00 +0100 4578648 http://www.medworm.com/index.php?rid=4578647&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353566%26dopt%3DAbstract Authors: Kanabrocki J To support increased research in the USA aimed at discovering products and technologies to combat infectious diseases, significant investment has been made to develop the appropriate laboratory infrastructure where these investigations can be conducted safely and securely. A key element to the success of this effort is the integration of these laboratories into their surrounding communities. PMID: 21353566 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4578647 Wed, 23 Feb 2011 00:00:00 +0100 4578647 http://www.medworm.com/index.php?rid=4525288&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21333542%26dopt%3DAbstract Authors: Bhatt S, Romeo T, Kalman D Bacteria evolve their capacity to cause disease by acquiring virulence genes that are usually clustered in discrete genetic modules termed pathogenicity islands (PAI). Stable integration of PAIs into pre-existing transcriptional networks coordinates expression from PAIs with ancestral genes in response to diverse environmental cues. Such transcriptional controls are evident in the regulation of the locus of enterocyte effacement (LEE), a PAI of enteropathogenic and enterohemorrhagic Escherichia coli. However, recent reports indicate that global post-transcriptional and post-translational regulators, including CsrA, Hfq and ClpXP, fine-tune the transcriptional output from the LEE. In this opinion article, we highlight recent advances in the understand... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4525288 Wed, 16 Feb 2011 00:00:00 +0100 4525288 http://www.medworm.com/index.php?rid=4525289&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21330137%26dopt%3DAbstract Authors: Chinnadurai G The E1A gene of species C human adenovirus is an intensely investigated model viral oncogene that immortalizes primary cells and mediates oncogenic cell transformation in cooperation with other viral or cellular oncogenes. Investigations using E1A proteins have illuminated important paradigms in cell proliferation and about the functions of cellular proteins such as the retinoblastoma protein. Studies with E1A have led to the unexpected discovery that E1A also suppresses cell transformation and oncogenesis. Here, I review our current understanding of the transforming and tumor-suppressive functions of E1A, and how E1A studies led to the discovery of a related tumor-suppressive function in benign human papillomaviruses. The potential role of these opposing functio... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4525289 Tue, 15 Feb 2011 00:00:00 +0100 4525289 http://www.medworm.com/index.php?rid=4470638&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21310617%26dopt%3DAbstract Authors: Bull RA, White PA Since the late 1990s norovirus (NoV) strains belonging to a single genotype (GII.4) have caused at least four global epidemics. To date, the higher epidemiological fitness of the GII.4 strains has been attributed to a faster rate of evolution within the virus capsid, resulting in the ability to escape herd immunity. Four key factors have been proposed to influence the rate of evolution in NoV. These include host receptor recognition, sequence space, duration of herd immunity, and replication kinetics. In this review we discuss recent advancements in our understanding of these four mechanisms in relation to GII.4 evolution. PMID: 21310617 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4470638 Tue, 08 Feb 2011 00:00:00 +0100 4470638 http://www.medworm.com/index.php?rid=4470639&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296575%26dopt%3DAbstract Authors: Dejager L, Pinheiro I, Dejonckheere E, Libert C Sepsis is a serious medical condition characterized by dysregulated systemic inflammatory responses followed by immunosuppression. To study the pathophysiology of sepsis, diverse animal models have been developed. Polymicrobial sepsis induced by cecal ligation and puncture (CLP) is the most frequently used model because it closely resembles the progression and characteristics of human sepsis. Here we summarize the role of several immune components in the pathogenesis of sepsis induced by CLP. However, several therapies proposed on the basis of promising results obtained by CLP could not be translated to the clinic. This demonstrates that experimental sepsis models do not completely mimic human sepsis. We propose several strategie... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4470639 Fri, 04 Feb 2011 00:00:00 +0100 4470639 http://www.medworm.com/index.php?rid=4470640&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21277778%26dopt%3DAbstract Authors: Veyrier FJ, Dufort A, Behr MA When studied from the perspective of non-tuberculous mycobacteria (NTM) it is apparent that Mycobacterium tuberculosis has undergone a biphasic evolutionary process involving genome expansion (gene acquisition and duplication) and reductive evolution (deletions). This scheme can instruct descriptive and experimental studies that determine the importance of ancestral events (including horizontal gene transfer) in shaping the present-day pathogen. For example, heterologous complementation in an NTM can test the functional importance of M. tuberculosis-specific genetic insertions. An appreciation of both phases of M. tuberculosis evolution is expected to improve our fundamental understanding of its pathogenicity and facilitate the evaluation of novel... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4470640 Fri, 28 Jan 2011 00:00:00 +0100 4470640 http://www.medworm.com/index.php?rid=4400208&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21239171%26dopt%3DAbstract Authors: Reguera G It is widely accepted that microorganisms are social beings. Whereas communication via chemical signals (e.g. quorum sensing) has been the focus of most investigations, the use of physical signals for microbial cell-cell communication has received only limited attention. In this article, I postulate that physical modes of microbial communication could be widespread in nature. This is based on experimental evidence on the microbial emission and response to three physical signals: sound waves, electromagnetic radiation and electric currents. These signals propagate rapidly, and even at very low intensities, they provide useful mechanisms when a rapid response is required. I also make some suggestions for promising future research avenues that could provide novel and un... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4400208 Fri, 14 Jan 2011 00:00:00 +0100 4400208 http://www.medworm.com/index.php?rid=4400211&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21227698%26dopt%3DAbstract Authors: Ryan RP, Dow JM Many pathogenic bacteria use cell-cell signaling to regulate the expression of factors contributing to virulence. Bacteria produce signals of diverse structural classes. The signal molecule known as diffusible signal factor (DSF) is a cis-unsaturated fatty acid that was first described in the plant pathogen Xanthomonas campestris. Recent work has shown that structurally related molecules produced by the unrelated bacteria Burkholderia cenocepacia and Pseudomonas aeruginosa regulate virulence, biofilm formation and antibiotic tolerance in these important human pathogens. Furthermore, DSF family signals have been shown to be involved in interspecies signaling that modulates bacterial behavior. An understanding of these diverse signaling mechanisms could suggest s... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4400211 Mon, 10 Jan 2011 00:00:00 +0100 4400211 http://www.medworm.com/index.php?rid=4400210&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21227699%26dopt%3DAbstract Authors: Zehr JP Discrepancies between estimates of oceanic N(2) fixation and nitrogen (N) losses through denitrification have focused research on identifying N(2)-fixing cyanobacteria and quantifying cyanobacterial N(2) fixation. Previously unrecognized cultivated and uncultivated unicellular cyanobacteria have been discovered that are widely distributed, and some have very unusual properties. Uncultivated unicellular N(2)-fixing cyanobacteria (UCYN-A) lack major metabolic pathways including the tricarboxylic acid cycle and oxygen-evolving photosystem II. Genomes of the oceanic N(2)-fixing cyanobacteria are highly conserved at the DNA level, and genetic diversity is maintained by genome rearrangements. The major cyanobacterial groups have different physiological and ecological constra... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4400210 Mon, 10 Jan 2011 00:00:00 +0100 4400210 http://www.medworm.com/index.php?rid=4400209&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21227700%26dopt%3DAbstract Authors: Edwards AM, Massey RC Staphylococcus aureus is a major cause of bacteraemia, which frequently leads to infective endocarditis, osteomyelitis, septic arthritis and metastatic abscess formation. The development of these secondary infections is due to bacterial dissemination from the blood into surrounding tissues and is associated with significantly increased morbidity and mortality. Despite the importance of S. aureus extravasation in disease progression, there is relatively little understanding of the molecular mechanisms by which this pathogen crosses the endothelial barrier and establishes new sites of infection. Recent work has identified a number of putative routes by which S. aureus can escape the bloodstream. In this article we review these new developments and set them ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4400209 Mon, 10 Jan 2011 00:00:00 +0100 4400209 http://www.medworm.com/index.php?rid=4334173&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21216598%26dopt%3DAbstract Authors: Herfs M, Hubert P, Moutschen M, Delvenne P Throughout adult life, new developmental commitment of adult stem cells causes reversible epithelial replacements in various mucosal surfaces, including the uterine cervix and the anal canal. Located at the squamocolumnar junctions, these metaplastic conversions are associated with chronic inflammation and deregulated expression of soluble and cell-membrane factors important for antiviral immune response. In this paper, we propose that these histological and immunological features increase the susceptibility of these metaplastic microenvironments to human papillomavirus and human immunodeficiency virus infections. Identification of the anatomical sites and cell populations within the anogenital tract, which is the site primary infecte... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4334173 Fri, 07 Jan 2011 00:00:00 +0100 4334173 http://www.medworm.com/index.php?rid=4334174&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21215638%26dopt%3DAbstract Authors: Yang J, Tauschek M, Robins-Browne RM This review highlights the exciting new finding that small molecule inducers have been found for some members of the AraC family of transcriptional regulators (AFTRs) that control the expression of virulence genes of pathogenic bacteria. Although effector-mediated activation of AFTRs involved in the regulation of sugar and alkylbenzoate catabolism (e.g. AraC and XylS) is well understood, until recently little was known about effector-mediated regulation of virulence gene expression. This led to the belief that regulation of virulence by AFTRs does not involve the direct recognition of chemical environmental signals. More recently, however, a growing number of virulence-associated AFTRs have been found to directly sense environmental chemica... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4334174 Wed, 05 Jan 2011 00:00:00 +0100 4334174 http://www.medworm.com/index.php?rid=4334175&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21195621%26dopt%3DAbstract Authors: McDonald SM, Patton JT The rotavirus (RV) genome comprises 11 segments of double-stranded RNA (dsRNA) and is contained within a non-enveloped, icosahedral particle. During assembly, a highly coordinated selective packaging mechanism ensures that progeny RV virions contain one of each genome segment. Cis-acting signals thought to mediate assortment and packaging are associated with putative panhandle structures formed by base-pairing of the ends of RV plus-strand RNAs (+RNAs). Viral polymerases within assembling core particles convert the 11 distinct +RNAs to dsRNA genome segments. It remains unclear whether RV +RNAs are assorted before or during encapsidation, and the functions of viral proteins during these processes are not resolved. However, as reviewed here, recent insight... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4334175 Thu, 30 Dec 2010 00:00:00 +0100 4334175 http://www.medworm.com/index.php?rid=4334176&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21185193%26dopt%3DAbstract Authors: Bravo IG, de Sanjosé S, Gottschling M PMID: 21185193 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4334176 Wed, 22 Dec 2010 00:00:00 +0100 4334176 http://www.medworm.com/index.php?rid=4334177&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21177108%26dopt%3DAbstract Authors: Teplitski M, Warriner K, Bartz J, Schneider KR Recent outbreaks of vegetable-borne gastrointestinal illnesses across the globe demonstrate that human enteric pathogens can contaminate produce at any stage of production. Interactions of enterics with native plant-associated microbiota influence the microbiological safety of produce by affecting the attachment, persistence and proliferation of human pathogens on plants. Supermarket surveys have revealed that bacteria, but not fungi or mechanical damage, promote the growth of Salmonella enterica on produce. Field and laboratory studies have indicated that some plant pathogenic bacteria and fungi facilitate the entry and internalization of human pathogens in plants. Conversely, some phytobacteria, including those involved in bioco... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4334177 Mon, 20 Dec 2010 00:00:00 +0100 4334177 http://www.medworm.com/index.php?rid=4275763&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21167717%26dopt%3DAbstract Authors: King GM Terrestrial carbon sequestration represents an important option for partially mitigating anthropogenic CO(2) emissions. Evidence suggests that terrestrial ecosystems can be managed for carbon sequestration, but it is not certain to what extent the microbes within them can be manipulated. Challenges include identifying which specific microbes and mechanisms contribute to sequestered carbon; understanding how microbial communities respond over large spatial and long temporal scales to crucial environmental variables; and developing management strategies suitable for large spatial and long temporal scales. The growing recognition that microbes produce proteins that limit organic matter degradation suggests targets for basic research. Directly manipulating microbes to sequ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4275763 Wed, 15 Dec 2010 00:00:00 +0100 4275763 http://www.medworm.com/index.php?rid=4275764&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21163649%26dopt%3DAbstract Authors: Zlotnick A, Mukhopadhyay S Assembly of virus capsids and surface proteins must be regulated to ensure that the resulting complex is an infectious virion. In this review, we examine assembly of virus capsids, focusing on hepatitis B virus and bacteriophage MS2, and formation of glycoproteins in the alphaviruses. These systems are structurally and biochemically well-characterized and are simplest-case paradigms of self-assembly. Published data suggest that capsid and glycoprotein assembly is subject to allosteric regulation, that is regulation at the level of conformational change. The hypothesis that allostery is a common theme in viruses suggests that deregulation of capsid and glycoprotein assembly by small molecule effectors will be an attractive antiviral strategy, as has b... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4275764 Tue, 14 Dec 2010 00:00:00 +0100 4275764 http://www.medworm.com/index.php?rid=4275765&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146993%26dopt%3DAbstract Authors: Bartenschlager R, Penin F, Lohmann V, André P A hallmark of the hepatitis C virus (HCV) replication cycle is its tight link with host cell lipid synthesis. This is best illustrated by the peculiar pathway used for the assembly of infectious HCV particles. Research in the past few years has shown that formation of HC-virions is closely connected to lipid droplets that could serve as an assembly platform. Moreover, HCV particle production appears to be strictly linked to very-low-density lipoproteins. In this review, we focus on new insights into the molecular aspects of the architecture and assembly of this unique type of virus particle. PMID: 21146993 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4275765 Fri, 10 Dec 2010 00:00:00 +0100 4275765 http://www.medworm.com/index.php?rid=4275766&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21144754%26dopt%3DAbstract Authors: Van Doorslaer K, Bernard HU, Chen Z, de Villiers EM, Hausen HZ, Burk RD PMID: 21144754 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4275766 Mon, 06 Dec 2010 00:00:00 +0100 4275766 http://www.medworm.com/index.php?rid=4250784&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21130655%26dopt%3DAbstract Authors: Anesio AM, Bellas CM There is an increasing body of evidence to show that viruses are important drivers of microbial evolution and that they can store a great deal of the Earth's microbial diversity in their genomes. Examination of microbial diversity in polar regions has revealed a higher than expected diversity of viruses, bacteria and eukaryotic microbes. Further, the few available studies in polar regions reveal that viral control of microbial mortality is important in these habitats. In this opinion article, we argue that strong relationships between viruses and their hosts in a range of polar habitats could be key in explaining why polar regions are in fact hot spots of microbial diversity and evolution. Further, we argue that periodic glaciations, and particularly the N... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4250784 Thu, 02 Dec 2010 00:00:00 +0100 4250784 http://www.medworm.com/index.php?rid=4250783&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21130656%26dopt%3DAbstract Authors: Karuppiah V, Berry JL, Derrick JP Gram-negative bacteria need to maintain the integrity of their outer membrane while also regulating the secretion of toxins and other macromolecules. A variety of dedicated outer membrane proteins (OMPs) facilitate this process. Recent structural work has shown that some of these proteins adopt classical β-barrel transmembrane structures and rely on structural changes within the barrel lumen to allow passage of substrate proteins. Other secretion systems have OMP components which use transmembrane α-helices and appear to function in a different way. Here we review a selection of recent structural studies which have major ramifications for our understanding of the passage of macromolecules across the outer membrane. PMID: 21130656 [PubMed... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4250783 Thu, 02 Dec 2010 00:00:00 +0100 4250783 http://www.medworm.com/index.php?rid=4250785&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21129975%26dopt%3DAbstract Authors: Ekins S, Freundlich JS, Choi I, Sarker M, Talcott C We are witnessing the growing menace of both increasing cases of drug-sensitive and drug-resistant Mycobacterium tuberculosis strains and the challenge to produce the first new tuberculosis (TB) drug in well over 40 years. The TB community, having invested in extensive high-throughput screening efforts, is faced with the question of how to optimally leverage these data to move from a hit to a lead to a clinical candidate and potentially, a new drug. Complementing this approach, yet conducted on a much smaller scale, cheminformatic techniques have been leveraged and are examined in this review. We suggest that these computational approaches should be optimally integrated within a workflow with experimental approaches to accele... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4250785 Wed, 01 Dec 2010 00:00:00 +0100 4250785 http://www.medworm.com/index.php?rid=4250786&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21123072%26dopt%3DAbstract Authors: Pallen MJ The scientific community is comfortable with recognising mitochondria as organelles that happen to be descendants of bacteria. Here, I playfully explore the arguments for and against a phylogenetic fundamentalism that states that mitochondria are bacteria and should be given their own taxonomic family, the Mitochondriaceae. I also explore the consequences of recognizing mitochondria as bacteria for our understanding of the systemic response to trauma and for the prospects of creating transgenic mitochondria. PMID: 21123072 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4250786 Mon, 29 Nov 2010 00:00:00 +0100 4250786 http://www.medworm.com/index.php?rid=4217810&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21112786%26dopt%3DAbstract Authors: Paredes-Sabja D, Setlow P, Sarker MR Under conditions that are not conducive to growth, such as nutrient depletion, many members of the orders Bacillales and Clostridiales can sporulate, generating dormant and resistant spores that can survive in the absence of nutrients for years under harsh conditions. However, when nutrients are again present, these spores can return to active growth through the process of germination. Many of the components of the spore germination machinery are conserved between spore forming members of the Bacillales and Clostridiales orders. However, recent studies have revealed significant differences between the germination of spores of Clostridium perfringens and that of spores of a number of Bacillus species, both in the proteins and in the signal t... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4217810 Fri, 26 Nov 2010 00:00:00 +0100 4217810 http://www.medworm.com/index.php?rid=4166032&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21071229%26dopt%3DAbstract Authors: Vos M Bacterial strains are currently grouped into species based on overall genomic similarity and sharing of phenotypes deemed ecologically important. Many believe this polyphasic taxonomy is in need of revision because it lacks grounding in evolutionary theory, and boundaries between species are arbitrary. Recent taxonomy efforts using multilocus sequence typing (MLST) data are based on the identification of distinct phylogenetic clusters. However, these approaches face the problem of deciding the phylogenetic level at which clusters are representative of evolutionary or taxonomically distinct units. In this review, I propose classifying two phylogenetic clusters as separate species only when they have statistically significantly diverged as a result of adaptive evolution. M... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4166032 Tue, 09 Nov 2010 00:00:00 +0100 4166032 http://www.medworm.com/index.php?rid=4166033&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21055948%26dopt%3DAbstract Authors: Alizon S, Luciani F, Regoes RR Many viruses and bacteria are known to evolve rapidly over the course of an infection. However, epidemiological studies generally assume that within-host evolution is an instantaneous process. We argue that the dynamics of within-host evolution has implications at the within-host and at the between-host levels. We first show that epidemiologists should consider within-host evolution, notably because it affects the genotype of the pathogen that is transmitted. We then present studies that investigate evolution at the within-host level and examine the extent to which these studies can help to understand infection traits involved in the epidemiology (e.g. transmission rate, virulence, recovery rate). Finally, we discuss how new techniques for data a... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4166033 Wed, 03 Nov 2010 00:00:00 +0100 4166033 http://www.medworm.com/index.php?rid=4166034&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21050765%26dopt%3DAbstract Authors: Bodily J, Laimins LA Human papillomaviruses (HPVs) are the etiologic agents of cervical and other epithelial cancers. Persistence of infections by high-risk HPV types is the single greatest risk factor for malignant progression. Although prophylactic vaccines have been developed that target high-risk HPV types, there is a continuing need to understand better the virus-host interactions that underlie persistent benign infection and progression to cancer. In this review we summarize the molecular events that facilitate the differentiation-dependent HPV life cycle, how the life cycle is organized to facilitate virus persistence, and how the activities of HPV regulatory proteins result in malignancy. PMID: 21050765 [PubMed - as supplied by publisher] (Source: Trends in Microbi... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4166034 Mon, 01 Nov 2010 00:00:00 +0100 4166034 http://www.medworm.com/index.php?rid=4139537&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21036616%26dopt%3DAbstract Authors: Soll DR The evolution of new signal transductions pathways is poorly understood. Here I present a rare glimpse into the evolution of one such pathway, namely the white-cell pheromone response pathway in Candida albicans. In this pathway, the upper portion has been derived intact from the ancestral pathway for mating, the targeted transcription factor from an ancestral filamentation or biofilm pathway, and the upregulated genes from an ancestral biofilm pathway. Each component of this pathway, therefore, has been derived from a conserved pathway. I suggest that the evolution of this new pathway provides one possible paradigm for the evolution of other signal transduction pathways in new cell types. PMID: 21036616 [PubMed - as supplied by publisher] (Source: Trends in Microb... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4139537 Fri, 29 Oct 2010 00:00:00 +0100 4139537 http://www.medworm.com/index.php?rid=4139539&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21035345%26dopt%3DAbstract Authors: Eleftherianos I, Ffrench-Constant RH, Clarke DJ, Dowling AJ, Reynolds SE Bacterial pathogens either hide from or modulate the host's immune response to ensure their survival. Photorhabdus is a potent insect pathogenic bacterium that uses entomopathogenic nematodes as vectors in a system that represents a useful tool for probing the molecular basis of immunity. During the course of infection, Photorhabdus multiplies rapidly within the insect, producing a range of toxins that inhibit phagocytosis of the invading bacteria and eventually kill the insect host. Photorhabdus bacteria have recently been established as a tool for investigating immune recognition and defense mechanisms in model hosts such as Manduca and Drosophila. Such studies pave the way for investigations of gene in... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4139539 Wed, 27 Oct 2010 00:00:00 +0100 4139539 http://www.medworm.com/index.php?rid=4139538&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21035346%26dopt%3DAbstract Authors: Etxebeste O, Garzia A, Espeso EA, Ugalde U Asexual development in Aspergillus nidulans begins in superficial hyphae as the programmed emergence of successive pseudohyphal modules, collectively known as the conidiophore, and is completed by a layer of specialized cells (phialides) giving rise to chains of aerial spores. A discrete number of regulatory factors present in hyphae play different stage-specific roles in pseudohyphal modules, depending on their cellular localization and protein-protein interactions. Their multiple roles include the timely activation of a sporulation-specific pathway that governs phialide and spore formation. Such functional versatility provides for a new outlook on morphogenetic change and the ways we should study it. PMID: 21035346 [PubMed - as ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4139538 Wed, 27 Oct 2010 00:00:00 +0100 4139538 http://www.medworm.com/index.php?rid=4107866&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20971645%26dopt%3DAbstract Authors: Cappitelli F, Pasquariello G, Tarsitani G, Sorlini C Paper, like all other cultural heritage materials, degrades over time, but conservation slows down the rate of its deterioration. There is a long history of cooperation between microbiologists and conservators of libraries and archival materials, but current approaches addressing paper deterioration need urgent reassessment to take full advantage of modern microbiological methodologies. The present article discusses what we believe are the current priority research areas in assessing microbial risk to paper heritage, and reports studies on a 13th century Italian manuscript and on Leonardo da Vinci's Atlantic Codex which illustrate the problems and challenges encountered when dealing with microbial investigations of paper art... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4107866 Thu, 21 Oct 2010 23:00:00 +0100 4107866 http://www.medworm.com/index.php?rid=4107867&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20965729%26dopt%3DAbstract Authors: Permanyer M, Ballana E, Esté JA The major pathway for HIV internalization in CD4+ T cells has been thought to be the direct fusion of virus and cell membranes, because the cell surface is the point of entry of infectious particles. However, the exact contribution of endocytic pathways to the infection of CD4+ T lymphocytes is unknown, and the mechanisms involved in endocytosis of HIV particles are unclear. Recent evidence suggests that endocytosis of cell-free and cell-associated virus particles could lead to effective virus entry and productive infections. Such observations have, in turn, spurred a debate on the relevance of endosomal entry as a mechanism of escape from the immune system and HIV entry inhibitors. In this paper, we review the endocytosis of HIV and discuss it... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4107867 Mon, 18 Oct 2010 23:00:00 +0100 4107867 http://www.medworm.com/index.php?rid=4088256&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20961764%26dopt%3DAbstract Authors: Schwarz S, Hood RD, Mougous JD The identification of bacterial secretion systems capable of translocating substrates into eukaryotic cells via needle-like appendages has opened fruitful and exciting areas of microbial pathogenesis research. The recent discovery of the type VI secretion system (T6SS) was met with early speculation that it too acts as a 'needle' that pathogens aim at host cells. New reports demonstrate that certain T6SSs are potent mediators of interbacterial interactions. In light of these findings, we examined earlier data indicating its role in pathogenesis. We conclude that although T6S can, in rare instances, directly influence interactions with higher organisms, the broader physiological significance of the system is likely to provide defense against simpl... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4088256 Sun, 17 Oct 2010 23:00:00 +0100 4088256 http://www.medworm.com/index.php?rid=4088257&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20951592%26dopt%3DAbstract Authors: Sun GW, Gan YH Burkholderia pseudomallei is a highly versatile pathogen capable of infecting many species of animals and plants. It is the causative agent of melioidosis, a medically important infectious disease in humans with a wide spectrum of disease manifestations. Its versatility as a pathogen is reflected in its huge 7.2Mb genome and the many virulence mechanisms it possesses, including three different type III secretion systems (T3SSs). Recent elucidation of the regulatory network of T3SS3 and the characterization of several T3SS proteins have enabled us to construct a model of the B. pseudomallei T3SS3 apparatus and evaluate the role it plays in disease pathogenesis. PMID: 20951592 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4088257 Wed, 13 Oct 2010 23:00:00 +0100 4088257 http://www.medworm.com/index.php?rid=4003616&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20863705%26dopt%3DAbstract Authors: Backert S, Naumann M Infection of gastric epithelial cells with Helicobacter pylori induces strong proinflammatory responses by activating nuclear transcription factors NF-κB and AP-1. Several reports indicate that multiple bacterial factors and cellular molecules are involved in this signaling. Injected peptidoglycan, CagA or OipA and urease, and at least 16 different signaling cascades have been implicated in H. pylori-induced proinflammatory signaling. Many of these reports are contradictory, thus generating a highly puzzling scenario. Here we discuss the pros and cons of the multiple signaling activities in the induction of proinflammatory responses and associated problems, and give suggestions for finding ways out of this dilemma. PMID: 20863705 [PubMed - as suppli... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=4003616 Sun, 19 Sep 2010 23:00:00 +0100 4003616 http://www.medworm.com/index.php?rid=3973495&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20832319%26dopt%3DAbstract Authors: Glennie SJ, Williams NA, Heyderman RS In many developing countries, populations are under considerable pressure from high bacterial exposure on mucosal surfaces. Immune dysregulation in this setting is multifactorial and is driven by a range of environmental factors, undernutrition and coinfections such as measles, malaria and HIV. Disruption or subversion of respiratory-tract and intestinal epithelial barriers leads to increased invasion by mucosal pathogens and a high frequency of life-threatening bacterial disease. It is our opinion that a process of epithelial barrier dysfunction and immune dysregulation at these mucosal surfaces leads to the much higher rates of pneumonia, meningitis and severe sepsis seen in resource-limited countries. PMID: 20832319 [PubMed - as sup... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3973495 Tue, 07 Sep 2010 23:00:00 +0100 3973495 http://www.medworm.com/index.php?rid=3973494&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20832320%26dopt%3DAbstract Authors: Alexander RP, Lowenthal AC, Harshey RM, Ottemann KM Microbes have chemotactic signaling systems that enable them to detect and follow chemical gradients in their environments. The core of these sensory systems consists of chemoreceptor proteins coupled to the CheA kinase via the scaffold or coupler protein CheW. Some bacterial chemotaxis systems replace or augment CheW with a related protein, CheV, which is less well understood. CheV consists of a CheW domain fused to a receiver domain that is capable of being phosphorylated. Our review of the literature, as well as comparisons of the CheV and CheW sequence and structure, suggest that CheV proteins conserve CheW residues that are crucial for coupling. Phosphorylation of the CheV receiver domain might adjust the efficiency of i... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3973494 Tue, 07 Sep 2010 23:00:00 +0100 3973494 http://www.medworm.com/index.php?rid=3973493&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20832321%26dopt%3DAbstract Authors: Tian B, Hua Y Bacteria from the phylum Deinococcus-Thermus are known for their resistance to extreme stresses including radiation, oxidation, desiccation and high temperature. Cultured Deinococcus-Thermus bacteria are usually red or yellow pigmented because of their ability to synthesize carotenoids. Unique carotenoids found in these bacteria include deinoxanthin from Deinococcus radiodurans and thermozeaxanthins from Thermus thermophilus. Investigations of carotenogenesis will help to understand cellular stress resistance of Deinococcus-Thermus bacteria. Here, we discuss the recent progress toward identifying carotenoids, carotenoid biosynthetic enzymes and pathways in some species of Deinococcus-Thermus extremophiles. In addition, we also discuss the roles of carotenoids in ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3973493 Tue, 07 Sep 2010 23:00:00 +0100 3973493 http://www.medworm.com/index.php?rid=3973492&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20832322%26dopt%3DAbstract Authors: Solieri L Recent advances in yeast mitogenomics have significantly contributed to our understanding of the diversity of organization, structure and topology in the mitochondrial genome of budding yeasts. In parallel, new insights on mitochondrial DNA (mtDNA) inheritance in the model organism Saccharomyces cerevisiae highlighted an integrated scenario where recombination, replication and segregation of mtDNA are intricately linked to mitochondrial nucleoid (mt-nucleoid) structure and organelle sorting. In addition to this, recent discoveries of bifunctional roles of some mitochondrial proteins have interesting implications on mito-nuclear genome interactions and the relationship between mtDNA inheritance, yeast fitness and speciation. This review summarizes the current knowledg... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3973492 Tue, 07 Sep 2010 23:00:00 +0100 3973492 http://www.medworm.com/index.php?rid=3955251&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20739182%26dopt%3DAbstract Authors: Bravo IG, de Sanjosé S, Gottschling M A significant fraction of human cancers is associated with infections by different papillomaviruses (PVs). In other vertebrates, the presence of specific PVs is also associated with different neoplasias. The popular view of PVs conceives them to be largely static and relies on generalized assumptions that have rarely been rigorously tested such as: virus-host codivergence, strict tissue tropism and host-specificity, their very low mutation rate and the absence of recombination. Here, we want to stress the need and the medical importance of understanding the evolutionary history and present-day dynamics of PVs. Understanding the way that PV genomes have evolved will clarify the link between a given genotype and the phenotypic and clinica... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3955251 Sun, 22 Aug 2010 23:00:00 +0100 3955251 http://www.medworm.com/index.php?rid=3900288&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20729086%26dopt%3DAbstract Authors: Mandel MJ Animals are symbiotic superorganisms, composed of eukaryotic cells and specific microbial residents that perform essential functions for their host. As humans, we are beginning to appreciate the diversity and function of our own microbiota, but model systems are leading the field in illustrating the molecular mechanisms that allow specific relationships to be recapitulated during each host generation. This review focuses on models in which genetic screens, coupled with genomics, imaging, phylogenetics and population biology, have begun to allow a remarkably detailed investigation into the molecular dissection of the evolution of host specificity in animal symbionts. PMID: 20729086 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3900288 Thu, 19 Aug 2010 23:00:00 +0100 3900288 http://www.medworm.com/index.php?rid=3890812&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20724161%26dopt%3DAbstract This article reviews examples of viruses and bacteria known or thought to induce epigenetic changes in host cells, and how this might contribute to disease. The heritable nature of these processes in gene regulation suggests that they could play important roles in chronic diseases associated with microbial persistence; they might also explain so-called 'hit-and-run' phenomena in infectious disease pathogenesis. PMID: 20724161 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3890812 Mon, 16 Aug 2010 23:00:00 +0100 3890812 http://www.medworm.com/index.php?rid=3855180&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20688520%26dopt%3DAbstract Authors: Evans DT, Serra-Moreno R, Singh RK, Guatelli JC The interferon-inducible, transmembrane protein BST-2 (CD317, tetherin) directly holds fully formed enveloped virus particles to the cells that produce them, inhibiting their spread. BST-2 inhibits members of the retrovirus, filovirus, arenavirus and herpesvirus families. These viruses encode a variety of proteins to degrade BST-2 and/or direct it away from its site of action at the cell surface. Viral antagonism has subjected BST-2 to positive selection, leading to species-specific differences that presented a barrier to the transmission of simian immunodeficiency viruses (SIVs) to humans. This barrier was crossed by HIV-1 when its Vpu protein acquired activity as a BST-2 antagonist. Here, we review this new host-pathogen relati... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3855180 Mon, 02 Aug 2010 23:00:00 +0100 3855180 http://www.medworm.com/index.php?rid=3824165&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20674365%26dopt%3DAbstract Authors: Rodríguez-Carmona E, Villaverde A The development of innovative medicines and personalized biomedical approaches require the identification and implementation of new biocompatible materials produced by methodologically simple and cheap fabrication methods. The biological fabrication of materials, mostly carried out by microorganisms, has historically provided organic compounds with wide-spectrum biomedical applications, including hyaluronic acid, poly(gamma-glutamic acid) and polyhydroxyalkanoates. Additionally, the implementation of new methodological platforms such as metabolic engineering and systems biology have facilitated the controlled production of natural nanoparticles produced by bacteria, including metallic deposits of Au, Ag, Cd, Zn or Fe, virus-like particles o... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3824165 Wed, 28 Jul 2010 23:00:00 +0100 3824165 http://www.medworm.com/index.php?rid=3824164&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20674366%26dopt%3DAbstract Authors: Fiore CL, Jarett JK, Olson ND, Lesser MP Many marine organisms have coevolved symbiotic relationships with nitrogen-fixing bacteria in nitrogen limited environments such as coral reefs. In addition, some of these organisms also harbor microbes that carry out nitrification and denitrification. Prokaryotes involved in nitrogen fixation and other nitrogen transformations are symbionts in a range of eukaryotic hosts in the marine environment including shipworms, diatoms, corals and sponges. Molecular genetic approaches, and other analytical techniques, have provided exciting new insights into symbiont diversity and the relationship between host and symbiont. We review the current state of knowledge of these symbioses and highlight important avenues for future studies. PMID: 20... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3824164 Wed, 28 Jul 2010 23:00:00 +0100 3824164 http://www.medworm.com/index.php?rid=3804433&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20667738%26dopt%3DAbstract Authors: Mellies JL, Lawrence-Pine ER Investigators have recently turned to the soil nematode Caenorhabditis elegans as a small animal infection model to study infectious disease. To extrapolate findings concerning bacterial pathogenesis from non-mammals to mammals, virulence factors should be conserved in function, independent of the infection model. Emerging from these studies is the observation that bacterial virulence regulatory networks function in a conserved manner across multiple hosts, including nematodes, mice and plants. Several regulatory networks have been implicated in nematode innate immune function and are being exploited in the C. elegans infection model to develop novel chemical therapies against bacterial pathogens. PMID: 20667738 [PubMed - as supplied by publish... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3804433 Sun, 25 Jul 2010 23:00:00 +0100 3804433 http://www.medworm.com/index.php?rid=3804463&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20656493%26dopt%3DAbstract Authors: Fischer M, Zhang QY, Hubbard RE, Thomas GH Substrate-binding protein (SBP)-dependent secondary transporters are ubiquitous in prokaryotes yet poorly characterised. Recently, the structures of over 10 prokaryotic SBPs have been solved, which we compare here to consider their impact on our understanding of transporter function and evolution. Seven structures are from tripartite ATP-independent periplasmic (TRAP) transporters of the DctP-type, which have similar overall structures distinct from SBPs used by ATP-binding cassette (ABC) transporters, despite recognising a range of substrates. A defining feature of substrate recognition in the DctP-TRAP SBPs is the formation of a salt bridge between a highly conserved arginine and a carboxylate group in the substrate, suggesting that... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3804463 Thu, 22 Jul 2010 23:00:00 +0100 3804463 http://www.medworm.com/index.php?rid=3804462&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20663673%26dopt%3DAbstract Authors: Fang J, Zhang L, Bazylinski DA The deep-sea piezosphere accounts for approximately 75% of the total ocean volume and hosts active and diverse biological communities. Evidence obtained thus far suggests that the microbial biomass present in the piezosphere is significant. Continued international interest in exploring the deep ocean provides impetus to increase our understanding of the deep-sea piezosphere and of the influence of piezophilic microbial communities on the global ocean environment and on biogeochemical cycling occurring in the deep sea. Here, we review the diversity, metabolic characteristics, geomicrobiology and biogeochemistry of the deep-sea piezophiles. PMID: 20663673 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3804462 Sun, 18 Jul 2010 23:00:00 +0100 3804462 http://www.medworm.com/index.php?rid=3777406&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20638846%26dopt%3DAbstract Authors: Kretzschmar M, Gabriela M Gomes M, Coutinho RA, Koopman JS Molecular typing and mathematical modeling have gone through rapid development in the past decade. Both offer new insights into the epidemiology of infectious diseases, thereby contributing to a better understanding of transmission dynamics. Infectious disease surveillance and control benefit from the optimum use of these techniques. In this paper, we review recent developments and propose methods to integrate pathogen ecology and molecular evolution based on their common dependence on the underlying host contact patterns. PMID: 20638846 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3777406 Thu, 15 Jul 2010 23:00:00 +0100 3777406 http://www.medworm.com/index.php?rid=3777407&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20637628%26dopt%3DAbstract Authors: Sutcliffe IC Improved understanding of the bacterial phylogenetic tree has allowed the distinction of at least 25 phyla with cultured representatives. This review surveys the diversity of cell envelope types present in these phyla and emphasises that it is important to define bacterial cell envelopes according to whether they have one (monoderm) or two (diderm) cellular membranes and, in the latter case, lipopolysaccharide as well. A comparative genomics approach, facilitated by the recent vast expansion in genome sequence information, is used here to survey the distribution of key lipopolysaccharide biosynthesis enzymes across the bacterial world and to consider alternative diderm cell envelope architectures. These data add to our understanding of microbial diversity and it i... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3777407 Tue, 13 Jul 2010 23:00:00 +0100 3777407 http://www.medworm.com/index.php?rid=3760041&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20630762%26dopt%3DAbstract Authors: Dupres V, Alsteens D, Andre G, Dufrêne YF How cell envelope constituents are spatially organised and how they interact with the environment are key questions in microbiology. Unlike other bioimaging tools, atomic force microscopy (AFM) provides information about the nanoscale surface architecture of living cells and about the localization and interactions of their individual constituents. These past years have witnessed remarkable advances in our use of the AFM molecular toolbox to observe and force probe microbial cells. Recent milestones include the real-time imaging of the nanoscale organization of cell walls, the quantification of subcellular chemical heterogeneities, the mapping and functional analysis of individual cell wall constituents and the analysis of the mechan... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3760041 Sun, 11 Jul 2010 23:00:00 +0100 3760041 http://www.medworm.com/index.php?rid=3734074&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20598889%26dopt%3DAbstract Authors: Spang A, Hatzenpichler R, Brochier-Armanet C, Rattei T, Tischler P, Spieck E, Streit W, Stahl DA, Wagner M, Schleper C Globally distributed archaea comprising ammonia oxidizers of moderate terrestrial and marine environments are considered the most abundant archaeal organisms on Earth. Based on 16S rRNA phylogeny, initial assignment of these archaea was to the Crenarchaeota. By contrast, features of the first genome sequence from a member of this group suggested that they belong to a novel phylum, the Thaumarchaeota. Here, we re-investigate the Thaumarchaeota hypothesis by including two newly available genomes, that of the marine ammonia oxidizer Nitrosopumilus maritimus and that of Nitrososphaera gargensis, a representative of another evolutionary lineage within this group pr... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3734074 Wed, 30 Jun 2010 23:00:00 +0100 3734074 http://www.medworm.com/index.php?rid=3734076&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20598544%26dopt%3DAbstract Authors: Mingorance J, Rivas G, Vélez M, Gómez-Puertas P, Vicente M FtsZ, the best-known prokaryotic division protein, assembles at midcell with other proteins forming a ring during septation. Widely conserved in bacteria, FtsZ represents the ancestor of tubulin. In the presence of GTP it forms polymers able to associate into multi-stranded flexible structures. FtsZ research is aimed at determining the role of the Z-ring in division, describing the polymerization and potential force-generating mechanisms and evaluating the roles of nucleotide exchange and hydrolysis. Systems to reconstruct the FtsZ ring in vitro have been described and some of its mechanical properties have been reproduced using in silico modeling. We discuss current research in FtsZ, some of the controversies, a... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3734076 Tue, 29 Jun 2010 23:00:00 +0100 3734076 http://www.medworm.com/index.php?rid=3734075&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20598545%26dopt%3DAbstract Authors: Newton AC, Fitt BD, Atkins SD, Walters DR, Daniell TJ Microbe-host interactions can be categorised as pathogenic, parasitic or mutualistic, but in practice few examples exactly fit these descriptions. New molecular methods are providing insights into the dynamics of microbe-host interactions, with most microbes changing their relationship with their host at different life-cycle stages or in response to changing environmental conditions. Microbes can transition between the trophic states of pathogenesis and symbiosis and/or between mutualism and parasitism. In plant-based systems, an understanding of the true ecological niche of organisms and the dynamic state of their trophic interactions with their hosts has important implications for agriculture, including crop rotation, dis... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3734075 Tue, 29 Jun 2010 23:00:00 +0100 3734075 http://www.medworm.com/index.php?rid=3702013&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20573513%26dopt%3DAbstract Authors: Platt TG, Fuqua C The expression of many bacterial phenotypes is regulated according to the concentration of chemical cues that they or other bacteria produce, a process often termed quorum sensing (QS). Many aspects of the environment can affect cue concentration. Thus these molecules might be indirect proxies for any one or combination of environmental factors. Recent research suggests that the adaptive significance of QS varies depending on its evolutionary and ecological context. Consequently, some researchers have proposed new terms, each emphasizing different adaptive functions, for the QS process. However, these new terms generate potential for a semantic quagmire and perpetuate the questionable notion that we can identify a single, dominant environmental feature to whi... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3702013 Sun, 20 Jun 2010 23:00:00 +0100 3702013 http://www.medworm.com/index.php?rid=3660078&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20542698%26dopt%3DAbstract Authors: Stackebrandt E Implementation of quality measures, compliance with the Convention on Biological Diversity (CBD), and adoption of latest bioinformatics tools are among the main steps to be taken by microbial culture collections in order to provide resources for the emerging area of the knowledge-based bioeconomy. These measures have to be introduced side by side with the deposition of increasingly phylogenetically and physiologically diverse microbiological organisms. However, the necessary expansion of human resources and infrastructure is moving slowly, if at all. Furthermore, considering that the vast majority of microbial isolates do not find their way into public collections, a strategy should be devised to encourage researchers to deposit a higher fraction of strains. It ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3660078 Sun, 06 Jun 2010 23:00:00 +0100 3660078 http://www.medworm.com/index.php?rid=3556674&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20452218%26dopt%3DAbstract Authors: Didelot X, Maiden MC Genetic exchange plays a defining role in the evolution of many bacteria. The recent accumulation of nucleotide sequence data from multiple members of diverse bacterial genera has facilitated comparative studies that have revealed many features of this process. Here we focus on genetic exchange that has involved homologous recombination and illustrate how nucleotide sequence data have furthered our understanding of: (i) the frequency of recombination; (ii) the impact of recombination in different parts of the genome; and (iii) patterns of gene flow within bacterial populations. Summarizing the results obtained for a range of bacteria, we survey evidence indicating that the extent and nature of recombination vary widely among microbiological species and oft... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3556674 Wed, 05 May 2010 23:00:00 +0100 3556674 http://www.medworm.com/index.php?rid=3556673&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20452219%26dopt%3DAbstract Authors: Sayce AC, Miller JL, Zitzmann N The re-emergence of dengue virus as a significant human pathogen has lead to an increasing need for effective antivirals. Development of therapeutic agents with the ability to attenuate both the duration and severity of disease in patients after infection is particularly desirable in dengue endemic resource-poor settings. The reliance of dengue virus on endogenous processes during the late stages of infection prompts the development of molecules to interfere with and exploit these dependencies as potential antiviral therapies. Here we focus on the importance of N-linked glycan processing in infectious virion morphogenesis. PMID: 20452219 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3556673 Wed, 05 May 2010 23:00:00 +0100 3556673 http://www.medworm.com/index.php?rid=3556672&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20452220%26dopt%3DAbstract Authors: de Oliveira DE, Ballon G, Cesarman E The nuclear factor (NF)-kappaB signaling pathway is pivotal for immune system function. Not surprisingly, pathogenic microorganisms have developed strategies to subvert it. Two examples are Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV), oncogenic gammaherpesviruses that establish a lifelong latent infection in their human hosts. The modulation of NF-kappaB signaling by EBV and KSHV is not only important for viral infection, but also contributes to the development of malignant neoplasia. This review explores the current knowledge of NF-kappaB modulation by EBV and KSHV, focusing on connections between viral biology and human carcinogenesis. PMID: 20452220 [PubMed - as supplied by publisher] (Source: Trends in Microbiolog... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3556672 Wed, 05 May 2010 23:00:00 +0100 3556672 http://www.medworm.com/index.php?rid=3468178&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20382022%26dopt%3DAbstract Authors: Tiaden A, Spirig T, Hilbi H Bacteria produce diffusible, small signaling molecules termed autoinducers to promote cell-cell communication. Recently, a novel class of signaling molecules, the alpha-hydroxyketones (AHKs), was discovered in the facultative human pathogens Legionella pneumophila and Vibrio cholerae. In this review, we summarize and compare findings on AHK signaling in these bacteria. The L. pneumophila lqs (Legionella quorum sensing) and V. cholerae cqs (cholera quorum sensing) gene clusters synthesize and detect Legionella autoinducer 1 (3-hydroxypentadecan-4-one) or cholera autoinducer-1 (3-hydroxytridecan-4-one), respectively. In addition to the autoinducer synthase and cognate sensor kinase encoded in the cqs locus, the lqs cluster also harbors a prototypic re... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3468178 Wed, 07 Apr 2010 23:00:00 +0100 3468178 http://www.medworm.com/index.php?rid=3468177&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20382023%26dopt%3DAbstract This article summarizes recent results from this approach that include the identification of the function of unknown genes, connections between cofactors biosynthesis and thiamine biosynthesis, and how metabolites from one biosynthetic pathway can be used in thiamine biosynthesis. PMID: 20382023 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3468177 Wed, 07 Apr 2010 23:00:00 +0100 3468177 http://www.medworm.com/index.php?rid=3468176&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20382024%26dopt%3DAbstract We describe emerging functional interactions between the Ccm components categorized into three conserved modules, and present a mechanistic view of the molecular basis of ubiquitous vinyl-2 approximately Cys(1) and vinyl-4 approximately Cys(2) heme b-apocytochrome thioether bonds in c-type cytochromes. PMID: 20382024 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3468176 Wed, 07 Apr 2010 23:00:00 +0100 3468176 http://www.medworm.com/index.php?rid=3468179&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20381355%26dopt%3DAbstract Authors: Cockell CS Geomicrobiology investigates the interactions of microorganisms with geological substrates, and this branch of microbiology has enormous potential in the exploration and settlement of space. Microorganisms can be used to extract useful elements from extraterrestrial materials for industrial processes or for use as nutrients in life support systems. In addition, microorganisms could be used to create soil from lunar and Martian rocks. Furthermore, understanding the interactions of microorganisms with rocks is essential for identifying mineral biomarkers to be used in the search for life on other planetary bodies. Increasing space exploration activities make geomicrobiology an important applied science beyond Earth. PMID: 20381355 [PubMed - as supplied by publishe... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3468179 Tue, 06 Apr 2010 23:00:00 +0100 3468179 http://www.medworm.com/index.php?rid=3457132&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20378353%26dopt%3DAbstract Authors: Kline KA, Dodson KW, Caparon MG, Hultgren SJ Bacterial pili have long been recognized as mediators of initial host-pathogen interactions important for the progression of Gram-negative bacterial diseases. An appreciation of the role of pili on virulence in Gram-positive bacteria and the unique properties of their biogenesis is a rapidly emerging area of research. In this review, we focus on recent advances in one of the longest-studied Gram-negative pilus systems, the chaperone/usher assembled pili, along with the newcomer to the field, the sortase-assembled pili of Gram-positive bacteria. In both systems, a wealth of new structural and molecular details has emerged recently. In light of this, we explore similarities between chaperone/usher and sortase-assembled pilus biogenesi... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3457132 Mon, 05 Apr 2010 23:00:00 +0100 3457132 http://www.medworm.com/index.php?rid=3433699&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20359893%26dopt%3DAbstract Authors: Wade WF, O'Toole GA Antibodies and immune effectors (IE) are crucial for protecting humans from Gram-negative bacteria. Antibodies can bind outer membrane or cell surface (e.g. flagella) structures, thereby preventing adhesion, disrupting specific virulence functions, or targeting bacteria for phagocytosis. IE (antimicrobial peptides, cytokines and hormones) impinge on bacterial infections and regulate immune responses. A developing paradigm is that bacteria 'recognize' antibodies and IE, which alert them to challenging environments, promoting resistance phenotypes and increased virulence. A broader understanding of the interactions between bacteria and antibodies and IE will help define their relative contributions to pathogenesis, and perhaps indicate how we could use antibo... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3433699 Mon, 29 Mar 2010 23:00:00 +0100 3433699 http://www.medworm.com/index.php?rid=3420924&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20347595%26dopt%3DAbstract Authors: Smeesters PR, McMillan DJ, Sriprakash KS Interaction of the M-protein of group A Streptococcus (GAS) with it numerous host binding partners might assist the bacteria in evading host immune responses. Although the extensive diversity of this protein has been highlighted by different GAS typing schemes, most of the structural and functional information has been obtained from a limited number of types. Increasing numbers of epidemiological, clinical and biological reports suggest that the structure and function of the M protein is less conserved than previously thought. This review focuses on the known interactions between M proteins and host ligand proteins, emphasizing that our understanding of this well-studied molecule is fragmented. PMID: 20347595 [PubMed - as supplied b... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3420924 Fri, 26 Mar 2010 00:00:00 +0100 3420924 http://www.medworm.com/index.php?rid=3412705&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20338765%26dopt%3DAbstract Authors: Raymond B, Johnston PR, Nielsen-Leroux C, Lereclus D, Crickmore N Bacillus thuringiensis (Bt) is an insecticidal bacterium that has successfully been used as a biopesticide for many years. It is usually referred to as a soil-dwelling organism, as a result of the prevalence of its spores in this environment, but one that can act as an opportunistic pathogen under appropriate conditions. Our understanding of the biology of this organism has been challenged further by the recent publication of two reports that claim that Bt requires the co-operation of commensal bacteria within the gut of a susceptible insect for its virulence. It is our opinion that Bt is not primarily a saprophyte and does not require the assistance of commensal bacteria but is a true pathogen in its own right ... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3412705 Tue, 23 Mar 2010 00:00:00 +0100 3412705 http://www.medworm.com/index.php?rid=3386171&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20299224%26dopt%3DAbstract Authors: Dunthorn M, Katz LA Facultative sexuality is assumed to have occurred in the ancestor of all extant eukaryotes, but the distribution and maintenance of sex among microbial eukaryotes is still under debate. In this paper, we address the purported asexuality in colpodean ciliates as an exemplary lineage. Colpodeans are a primarily terrestrial clade thought to have arisen up to 900 MYA and contain one known derived sexual species. We conclude that the putative asexuality of this lineage is an observational artifact. We suggest that the same might hold for other microbial eukaryotes, and that many are secretively sexual as well. Theoretical work from the distantly related plants and animals suggests that both the evolutionary success of ancient asexuals and the reversal of the los... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3386171 Tue, 16 Mar 2010 00:00:00 +0100 3386171 http://www.medworm.com/index.php?rid=3347328&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20207544%26dopt%3DAbstract This article provides a perspective on the current status of drug therapy for invasive fungal diseases, together with priorities for the future development of novel compounds. Key opportunities for new drugs include production of orally bioavailable agents for the treatment of invasive aspergillosis, invasive candidiasis, cryptococcal meningitis and mucosal and urinary Candida infections. Orally bioavailable agents for the treatment of chronic pulmonary and allergic aspergillosis are also required, as well as new potent drugs against a range of medically important moulds. Antifungal resistance is a problem in certain contexts, but is generally less of a problem than bacterial infections. Earlier and more complete mycological diagnosis and improvements in underlying risk estimation will imp... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3347328 Fri, 05 Mar 2010 00:00:00 +0100 3347328 http://www.medworm.com/index.php?rid=3336222&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20202845%26dopt%3DAbstract Authors: Hakami RM, Ruthel G, Stahl AM, Bavari S Owing in part to recently heightened concern over bioterrorism, interest in the mechanism of action of botulinum neurotoxin (BoNT) and development of effective therapeutic strategies has dramatically increased. The emergence of BoNT as an effective treatment for a variety of neurological disorders and its growing use in the cosmetic industry have also increased interest in developing effective countermeasures. Although recent attempts to create effective vaccines appear promising, the multitude of clinical and cosmetic uses of BoNT make mass vaccination against the toxin undesirable and impractical, leading to intensified efforts to develop effective therapeutics to combat large-scale intoxications. In this review, we examine the relevan... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3336222 Tue, 02 Mar 2010 00:00:00 +0100 3336222 http://www.medworm.com/index.php?rid=3336221&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20202846%26dopt%3DAbstract Authors: Chen Y, Murrell JC The application of metagenomics, the culture-independent capture and subsequent analysis of genomic DNA from the environment, has greatly expanded our knowledge of the diversity of microbes and microbial protein families; however, the metabolic functions of many microorganisms remain largely unknown. DNA stable-isotope probing (DNA-SIP) is a recently developed method in which the incorporation of stable isotope from a labelled substrate is used to identify the function of microorganisms in the environment. The technique has now been used in conjunction with metagenomics to establish links between microbial identity and particular metabolic functions. The combination of DNA-SIP and metagenomics not only permits the detection of rare low-abundance species from... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3336221 Tue, 02 Mar 2010 00:00:00 +0100 3336221 http://www.medworm.com/index.php?rid=3336220&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20202847%26dopt%3DAbstract Authors: Pflüger-Grau K, Görke B In addition to the sugar phosphotransferase system (sugar PTS) dedicated to carbohydrate uptake, many Gram-negative bacteria possess a so-called nitrogen PTS (PTS(Ntr)). Although fulfilling very different functions, both systems can communicate with each other by phosphate exchange. PTS(Ntr) regulates diverse processes implicated in metabolism of nitrogen and carbon, and is essential for virulence in some bacteria. Additionally, it plays a role in potassium homeostasis by regulating the expression and activity of a high- and a low-affinity K(+) transporter, respectively. In this article, we review recent advances in the understanding of the regulatory roles of PTS(Ntr) in various organisms. PMID: 20202847 [PubMed - as supplied by publisher... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3336220 Tue, 02 Mar 2010 00:00:00 +0100 3336220 http://www.medworm.com/index.php?rid=3303253&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20176487%26dopt%3DAbstract Authors: Johnson EM In the past three years, remarkable discoveries have added three new human polyomaviruses (KI virus (KIV), WU virus (WUV) and Merkel cell virus (MCV)) to a class that previously had only two disease-causing members (BK virus (BKV) and JC virus (JCV)) identified. Two monkey polyomaviruses, simian virus (SV)40 and B-cell lymphotropic polyomavirus (LPV) are also present in humans. KIV and WUV lack the agnoprotein coding sequence and regulatory micro (mi)RNA clusters of BKV, JCV and SV40. MCV lacks the agnoprotein sequence but generates miRNAs. KIV, WUV and MCV are all widespread in humans. Although they have distinctive tissue tropisms, all these viruses are probably acquired in childhood. Of these viruses, only MCV has thus far been strongly linked to cancer. Marshall... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3303253 Sat, 20 Feb 2010 00:00:00 +0100 3303253 http://www.medworm.com/index.php?rid=3291446&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20167493%26dopt%3DAbstract Authors: Tucker NP, Le Brun NE, Dixon R, Hutchings MI Nitric oxide (NO) is a toxic, free radical gas with diverse biological roles in eukaryotes and bacteria, being involved in signalling, vasodilation, blood clotting and immunity and as an intermediate in microbial denitrification. Several bacterial transcriptional regulators sense this molecule and regulate the expression of genes involved in both NO detoxification and NO damage repair. However, a recently discovered NO sensing repressor, named NsrR, has gained attention because of its suggested role as a global regulator of the bacterial NO stress response. Recent advances in biochemical and transcriptomic studies of NsrR make it timely to review the current evidence for NsrR as a global regulator and to speculate on the recent cont... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3291446 Tue, 16 Feb 2010 00:00:00 +0100 3291446 http://www.medworm.com/index.php?rid=3186816&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20083406%26dopt%3DAbstract Authors: Kent BN, Bordenstein SR The discovery of an extraordinarily high level of mobile elements in the genome of Wolbachia, a widespread arthropod and nematode endosymbiont, suggests that this bacterium could be an excellent model for assessing the evolution and function of mobile DNA in specialized bacteria. In this paper, we discuss how studies on the temperate bacteriophage WO of Wolbachia have revealed unexpected levels of genomic flux and are challenging previously held views about the clonality of obligate intracellular bacteria. We also discuss the roles this phage might play in the Wolbachia-arthropod symbiosis and infer how this research can be translated to combating human diseases vectored by arthropods. We expect that this temperate phage will be a preeminent model syste... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3186816 Sat, 16 Jan 2010 00:00:00 +0100 3186816 http://www.medworm.com/index.php?rid=3186817&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20080407%26dopt%3DAbstract Authors: Harrison PW, Lower RP, Kim NK, Young JP In addition to the main chromosome, approximately one in ten bacterial genomes have a 'second chromosome' or 'megaplasmid'. Here, we propose that these represent a single class of elements that have a distinct and consistent set of properties, and suggest the term 'chromid' to distinguish them from both chromosomes and plasmids. Chromids carry some core genes, and their nucleotide composition and codon usage are very similar to those of the chromosomes they are associated with. By contrast, they have plasmid replication and partitioning systems and the majority of their genes confer accessory functions. Chromids seem particularly rich in genus-specific genes and appear to be 'reinvented' at the origin of a new genus. PMID: 20080407 [... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3186817 Fri, 15 Jan 2010 00:00:00 +0100 3186817 http://www.medworm.com/index.php?rid=3179191&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20071175%26dopt%3DAbstract Authors: Feng Y, Zhang H, Ma Y, Gao GF Streptococcus suis is recognized as a major swine pathogen and an emerging zoonotic agent. Two large-scale outbreaks of severe S. suis epidemics occurred in China in 1998 and 2005 that posed serious concerns to public health and challenged the conventional conception that opportunistic infections of S. suis serotype 2 (SS2) in humans were only sporadic cases. An extensive, collaborative study on Chinese SS2 variants, which exhibit strong invasiveness and high pathogenicity, has resulted in the description of a new disease form of streptococcal toxic shock syndrome (STSS) and a putative pathogenicity island (termed 89K). The abbreviation of STSS is used for the severe disease caused by both Staphylococci and Streptococci. The main virulence factors... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3179191 Mon, 11 Jan 2010 00:00:00 +0100 3179191 http://www.medworm.com/index.php?rid=3164511&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060721%26dopt%3DAbstract Authors: Vollmer W, Seligman SJ Peptidoglycan forms a net-like sacculus made of glycan strands crosslinked by peptides. The length of the glycan strands and the degree of crosslinkage vary with bacterial species, strains and growth conditions. Several models for the three-dimensional architecture of peptidoglycan have been proposed, some of which have been tested experimentally. The new data support a layered model in Gram-negative bacteria, and a more elaborate peptidoglycan architecture, with bands made of coiled bundles of glycan strands, in the rod-shaped Bacillus subtilis. However, many questions remain unanswered and, therefore, more data and more models are required to decipher the complex cell wall architecture in bacteria. PMID: 20060721 [PubMed - as supplied by publisher]... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3164511 Thu, 07 Jan 2010 00:00:00 +0100 3164511 http://www.medworm.com/index.php?rid=3164509&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060722%26dopt%3DAbstract Authors: Niederweis M, Danilchanka O, Huff J, Hoffmann C, Engelhardt H The cell wall is a major virulence factor of Mycobacterium tuberculosis and contributes to its intrinsic drug resistance. Recently, cryo-electron microscopy showed that mycobacterial cell wall lipids form an unusual outer membrane. Identification of the components of the uptake and secretion machinery across this membrane will be crucial for understanding the physiology and pathogenicity of M. tuberculosis and for the development of better anti-tuberculosis drugs. Although the genome of M. tuberculosis appears to encode over 100 putative outer membrane proteins, only a few have been identified and characterized. Here, we summarize the current knowledge on the structure of the mycobacterial outer membrane and its kno... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3164509 Thu, 07 Jan 2010 00:00:00 +0100 3164509 http://www.medworm.com/index.php?rid=3164507&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060723%26dopt%3DAbstract Authors: Medjahed H, Gaillard JL, Reyrat JM Mycobacterium abscessus, a relative of Koch's bacillus (the bacterium that causes tuberculosis), has recently emerged as the cause of an increasing number of both community- and hospital-acquired infections in humans; it also constitutes a serious threat for cystic fibrosis patients. This situation is worsened by its exceptionally high natural and acquired antibiotic resistance that complicates treatment. Although a rapid grower, it shares some traits with Koch's bacillus, including the ability to induce a persistent lung disease associated with caseous lesions, a landmark of Mycobacterium tuberculosis infection. Its genome sequence and microarrays are now available, and efficient genetic tools have recently been developed. Here we consider t... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3164507 Thu, 07 Jan 2010 00:00:00 +0100 3164507 http://www.medworm.com/index.php?rid=3164513&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060299%26dopt%3DAbstract Authors: Decho AW, Norman RS, Visscher PT Much laboratory-based information exists on quorum sensing, a type of bacterial cell-to-cell communication that depends upon exchanges of molecular signals between neighboring cells. However, little is known about how this and other microbial sensing systems operate in nature. Geochemical and biological modifications of signals probably occur in extracellular environments, and these could disrupt intended communication if signals are no longer recognized. However, as we discuss here, signal alterations might result in other outcomes: if a modified signal is able to interact with a different receptor then further environmental information can be gained by the receiving cells. We also postulate that quorum sensing occurs within cell clusters, whe... Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3164513 Wed, 06 Jan 2010 00:00:00 +0100 3164513 http://www.medworm.com/index.php?rid=3164512&cid=s_36143_77_f&fid=36143&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060300%26dopt%3DAbstract This article describes personal experiences of research-led teaching at Manchester Metropolitan University (UK) which have been used successfully to encourage creativity and other employability skills in both large and smaller classroom settings, and through individual student project work. PMID: 20060300 [PubMed - as supplied by publisher] (Source: Trends in Microbiology) Trends in Microbiology journals http://www.medworm.com/rss/comments.php?id=3164512 Wed, 06 Jan 2010 00:00:00 +0100 3164512