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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 2.
Detection of plasmid-mediated quinolone resistance determinants and the emergence of multidrug resistance in clinical isolates of Shigella in SiXian area, China
Abstract: A total of 123 Shigella isolates were collected from SiXian area in Anhui, China. Screening was carried out by polymerase chain reaction (PCR) amplification of plasmid-mediated quinolone resistance (PMQR) determinants. Different β-blactamases genes, plasmid-borne blaAmpC, 16S rRNA methylase genes, integrons, and mutations in quinolone resistance-determining regions were analysed by PCR for the PMQR-positive isolates.
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Yu-lin Zhu, Hai-Fei Yang, Yan-yan Liu, Li-fen Hu, Jun Cheng, Ying Ye, Jia-bin Li Tags: Notes Source Type: research
GeneXpert® for smear-negative pulmonary tuberculosis: does it play a role in low-burden countries?
Abstract: We performed a retrospective analysis of costs and time to treatment (TT) of 150 culture-confirmed TB cases: 100 sputum smear (SS) (+) and 50 SS(−). This group underwent GeneXpert® (GX) assay. Expenditures and TT of SS(−)/GX(+) cases were inferred from the SS(+) group. GX detected 68% of SS(−) cases.
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Laura Muñoz, Raquel Moure, Nuria Porta, Lucia Gonzalez, Rosario Guerra, Fernando Alcaide, Miguel Santin Tags: Notes Source Type: research
Noninvasive tool for the diagnosis of polyomavirus BK–associated nephropathy in renal transplant recipients
Abstract: Noninvasive methods can facilitate early diagnosis of BK virus (BKV) replication and guide the evaluation of BKV-associated nephropathy (BKVAN). We developed 3 noninvasive methods for BKVAN screening including quantitative polymerase chain reaction (PCR) assay for BKV DNA load in urine and plasma, and quantitative assay of urine cytology by light microscopy or electron microscopy, and used these assays concurrently with renal transplant biopsies for the evaluation of 338 patients. BKVAN was diagnosed in 24 (7.1%) of 338 renal recipients. The median level of the 3 methods was the highest in pattern B of BKVAN (P <...
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Gang Huang, Wen-fang Chen, Chang-xi Wang, Ji-guang Fei, Su-xiong Deng, Jiang Qiu, Li-zhong Chen Tags: Virology Source Type: research
Antigen-specific CD4- and CD8-positive signatures in different phases of Mycobacterium tuberculosis infection
Abstract: Current diagnostic standards for Mycobacterium tuberculosis (MTB) infection do not distinguish between active and latent tuberculosis (TB). To identify specific biomarkers characterizing the different forms of TB infection, we investigated in parallel with the QuantiFERON -TB Gold In-Tube (QFT-IT) the use of flow cytometry measuring CD4 and CD8 MTB-specific immune response in 17 active-TB patients, 21 health care workers (HCW), 14 recent contacts of TB patients (RC-TB), and 10 bacille Calmette Guerin (BCG)–vaccinated healthy controls (BCG-HC).A correlation (r = 0.4526, P = 0.0002) was found only between the amo...
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Maria Nikolova, Roumiana Markova, Rumiana Drenska, Maria Muhtarova, Yana Todorova, Velichko Dimitrov, Hristo Taskov, Cesare Saltini, Massimo Amicosante Tags: Mycobacteriology Source Type: research
Epidemiology of pneumococcal serotype 6A and 6C among invasive and carriage isolates from Alaska, 1986–2009
Abstract: We investigated serotype 6A/6C invasive pneumococcal disease (IPD) incidence, genetic diversity, and carriage before and after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in Alaska. IPD cases (1986–2009) were identified through population-based laboratory surveillance. Isolates were initially serotyped by conventional methods, and 6C isolates were differentiated from 6A by polymerase chain reaction. Among invasive and carriage isolates initially typed as 6A, 35% and 50% were identified as 6C, respectively. IPD rates caused by serotype 6A or 6C among children
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Karen Rudolph, Michael Bruce, Dana Bruden, Tammy Zulz, Jay Wenger, Alisa Reasonover, Marcella Harker-Jones, Debby Hurlburt, Thomas Hennessy Tags: Bacteriology Source Type: research
Bacteraemias in tropical Australia: changing trends over a 10-year period
Abstract: Bacteraemia is an important cause of morbidity and mortality worldwide. This is the largest reported study of bacteraemias in Australia. The presence of organisms endemic to the tropical region and the changing trends described have significant implications for empirical antibiotic therapy. This retrospective study examined 8976 blood cultures from Townsville Hospital, a regional Australian hospital located in the tropics over a 10-year period. The rate of bacteraemic episodes during the study period was 10.12 per 1000 admissions. Intravenous devices (18.7%), immunosuppressive therapy (16.1%), and urinary tract i...
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Selina Porter, Natkunam Ketheesan, Robert Norton Tags: Bacteriology Source Type: research
The biodiversity and composition of the dominant fecal microbiota in patients with inflammatory bowel disease
Abstract: Clinical and experimental observations in animal models indicate that intestinal commensal bacteria are involved in the initiation and amplification of inflammatory bowel disease (IBD). As the majority of colonic bacteria cannot be identified by culture techniques, the aim of this study was to use sequence-based methods to investigate and characterize the composition of the dominant fecal microbiota in both patients with inflammatory bowel disease and healthy subjects. Fecal microbiota was isolated and quantified using real-time quantitative polymerase chain reaction. Denaturing gradient gel electrophoresis (DGGE...
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Sumei Sha, Bin Xu, Xin Wang, Yongguo Zhang, Honghong Wang, Xiangyun Kong, Hongwu Zhu, Kaichun Wu Tags: Bacteriology Source Type: research
High-resolution melt analysis for species identification of coagulase-negative staphylococci derived from bovine milk
In this study, we report a rapid assay for species identification of CNS using high-resolution melt analysis (HRMA) of 16S rDNA sequences. Real-time polymerase chain reaction amplification of 16S rRNA gene fragment, spanning the variable region V1 and V2, was performed with a resulting amplicon of 215 bp. A library of distinct melt curves of reference strains of 13 common CNS species was created using HRMA. Sequencing of 16S rRNA and rpoB genes, and, when needed, tuf gene, of 100 CNS isolates obtained from Canadian Bovine Mastitis Research Network was done to determine their species identity, allowing for subsequent evalua...
Source: Diagnostic Microbiology and Infectious Disease - February 14, 2013 Category: Microbiology Authors: Praseeda Ajitkumar, Herman W. Barkema, Ruth N. Zadoks, Douglas W. Morck, Frank J.U.M. van der Meer, Jeroen De Buck Tags: Bacteriology Source Type: research
Segmented Filamentous Bacteria in human ileostomy samples after high fiber intake
In this study, ileostomy samples from 10 human subjects were screened with PCR, using primers derived from sequences of SFB from rat and mouse. PCR products were obtained from samples taken from one individual at two time points. Sequencing revealed the presence of a 16S rRNA gene with high similarity (98%) to the corresponding genes from SFB of mouse and rat origin, thus indicating the presence of a human variant of SFB. The findings presented in this study will hopefully encourage research to elucidate whether this intriguing organism is a persistent member of the normal human microbiota. © 2013 Federation of European M...
Source: FEMS Microbiology Letters - February 14, 2013 Category: Microbiology Authors: Hans Jonsson Tags: Research Letter Source Type: research
Disruption of the Serine Threonine Protein Kinase H affects Phthiocerol Dimycocerosates Synthesis in Mycobacterium tuberculosis.
Abstract Mycobacterium tuberculosis possesses a complex cell wall that is unique and essential for interaction of the pathogen with its human host. Emerging evidence suggests that the biosynthesis of complex cell wall lipids is mediated by serine/threonine protein kinases (STPKs). Herein, we show, using in vivo radiolabeling, mass spectrometry, and immunostaining analyses that targeted deletion of one of the STPKs, pknH, attenuates the production of phthiocerol dimycocerosates (PDIMs), a major M. tuberculosis virulence lipid. Comparative protein expression analysis revealed that proteins in the PDIM biosynthetic pa...
Source: Microbiology - February 14, 2013 Category: Microbiology Authors: Gómez-Velasco A, Bach H, Rana AK, Cox LR, Bhatt A, Besra GS, Av-Gay Y Tags: Microbiology Source Type: research
Type 1 and Type 2 Strains of Mycoplasma pneumoniae Form Different Biofilms.
We report here that the biofilms formed by two strains of the human pathogen Mycoplasma pneumoniae differ quantitatively and qualitatively. Compared to strain UAB PO1, strain M129 grows well but forms biofilms that are less robust with towers that are less smooth at the margins. A polysaccharide containing N-acetylglucosamine is secreted by M129 into the culture medium but found in tight association with the cells of UAB PO1. The polysaccharide may have a role in biofilm formation, contributing to differences in virulence, chronicity, and treatment outcome between strains of M. pneumoniae. The UAB PO1 genome was found to b...
Source: Microbiology - February 14, 2013 Category: Microbiology Authors: Simmons WL, Daubenspeck JM, Osborne JD, Balish MF, Waites KB, Dybvig K Tags: Microbiology Source Type: research
Paenibacillus profundus sp. nov., a deep sediment bacterium that produces isocoumarin and peptide antibiotics.
Abstract A novel bacterial strain Sl 79(T) was isolated from a deep surface sediment sample obtained from the Sea of Japan and investigated by phenotypic and molecular methods. The bacterium Sl 79(T) was Gram-positive, facultatively anaerobic, spore-forming, motile and able to form two different types of colonies. It contained the major menaquinone MK-7 and anteiso-C(15:0) followed by iso-C(15:0) as predominant fatty acids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Sl 79(T) belonged to the genus Paenibacillus where it clustered to Paenibacillus apiarius NRRL NRS-1438(T) with a sequ...
Source: Archives of Microbiology - February 14, 2013 Category: Microbiology Authors: Romanenko LA, Tanaka N, Svetashev VI, Kalinovskaya NI Tags: Arch Microbiol Source Type: research
Cloning of a novel feruloyl esterase gene from rumen microbial metagenome and enzyme characterization in synergism with endoxylanases.
Abstract A feruloyl esterase (FAE) gene was isolated from a rumen microbial metagenome, cloned into E. coli, and expressed in active form. The enzyme (RuFae2) was identified as a type C feruloyl esterase. The RuFae2 alone released ferulic acid from rice bran, wheat bran, wheat-insoluble arabinoxylan, corn fiber, switchgrass, and corn bran in the order of decreasing activity. Using a saturating amount of RuFae2 for 100 mg substrate, a maximum of 18.7 and 80.0 μg FA was released from 100 mg corn fiber and wheat-insoluble arabinoxylan, respectively. Addition of GH10 endoxylanase (EX) synergistically increased the ...
Source: Journal of Industrial Microbiology and Biotechnology - February 14, 2013 Category: Microbiology Authors: Wong DW, Chan VJ, Liao H, Zidwick MJ Tags: J Ind Microbiol Biotechnol Source Type: research
High-throughput single nucleotide polymorphism-based typing of shared Pseudomonas aeruginosa strains in cystic fibrosis patients using the Sequenom iPLEX platform.
Abstract Shared strains of Pseudomonas aeruginosa are now well recognised in people with cystic fibrosis (CF) and suitable P. aeruginosa laboratory typing tools are pivotal to understanding their clinical significance and guiding infection control policies in CF clinics. We therefore compared a single nucleotide polymorphism (SNP)-based typing method using Sequenom iPLEX matrix-assisted laser desorption ionisation with time-of-flight mass spectrometry (MALDI-TOF MS) with typing methods used routinely by our laboratory. We analysed 617 P. aeruginosa isolates that included 561 isolates from CF patients collected betw...
Source: Journal of Medical Microbiology - February 14, 2013 Category: Microbiology Authors: Syrmis MW, Moser RJ, Kidd TJ, Hunt P, Ramsay KA, Bell SC, Wainwright CE, Grimwood K, Nissen MD, Sloots TP, Whiley D Tags: J Med Microbiol Source Type: research
Invasive disease caused by Haemophilus parainfluenzae III in a child with uropathy.
Abstract Urinary tract infections (UTIs) caused by Haemophilus parainfluenzae (HP), represent an insignificant percentage of this kind of pathology in children, and it has scarcely been described in medical literature. According to studies carried out with over 800 urine samples in children under 15 years old, a decrease of 50% (from 0.13%1 to 0.07%)2 is estimated in its occurrence over the last two decades. This can be explained by the early detection of UTIs and their early empirical treatment, because this microorganism presents high sensitivity to antibiotics. Also, the culture media where this bacteria grows i...
Source: Journal of Medical Microbiology - February 14, 2013 Category: Microbiology Authors: Ariza Jimenez AB, Moreno Perez D, Nunez Cuadros E, Urda Cardona A Tags: J Med Microbiol Source Type: research
The bionomics of Anopheles merus (Diptera: Culicidae) along the Kenyan coast
Aspects of the biology and ecology of Anopheles merus, a subspecies of Anopheles gambiae sl., are discussed. An. merus is found only along the East coast of Africa. Evidence-based findings from this study on its resting, feeding and transmission potential will be useful for the planning of control strategies for malaria vectors. Image: Sea water left behind after a tide in Garithe along the Kenyan coast, which is a typical breeding site of Anopheles merus.
Source: Parasites and Vectors - February 14, 2013 Category: Microbiology Authors: Pamela KipyabBattan KhaembaJoseph MwangangiCharles Mbogo Source Type: research
Nucleotide substitutions in dengue virus serotypes from Asian and American countries: insights into intracodon recombination and purifying selection
Conclusion: The study provides the first evidence for intracodon recombination in DENV and suggests that within codon genetic recombination has a significant role in maintaining extensive purifying selection of DENV in natural populations. Our study also suggests that fixation of beneficial mutations may lead to virus evolution via translational selection of specific sites in the DENV genome.
Source: BMC Microbiology - Latest articles - February 14, 2013 Category: Microbiology Authors: Susanta BehuraDavid Severson Source Type: research
Vibrio fischeri exhibit the growth advantage in stationary-phase phenotype
Canadian Journal of Microbiology, Volume 0, Issue 0, Page 1-6, e-First articles.
Source: Canadian Journal of Microbiology - February 13, 2013 Category: Microbiology Tags: article Source Type: research
Stratified Communities of Active Archaea in Shallow Sediments of the Pearl River Estuary, Southern China.
In this study, the archaeal diversity above, within, and beneath the sulfate-methane transition zone (SMTZ) in the Pearl River Estuary sediment core was described. The majority of the clones obtained from the metabolically active fraction of the archaeal community were most closely related to miscellaneous crenarchaeotal group and terrestrial miscellaneous euryarchaeotal group. Notably, although the Pearl River Estuary sediment belong to high methane and high organic carbon environment, sequences affiliated with methanotrophic and methanogenic archaea were detected as minor group in 16S rRNA clone libraries. No obvious evi...
Source: Current Microbiology - February 13, 2013 Category: Microbiology Authors: Chen J, Wang F, Jiang L, Yin X, Xiao X Tags: Curr Microbiol Source Type: research
Phylogenetic Analysis of Burkholderia Species by Multilocus Sequence Analysis.
In this study, we undertook a multilocus sequence analysis of 77 type and reference strains of Burkholderia using atpD, gltB, lepA, and recA genes in combination with the 16S rRNA gene sequence and employed maximum likelihood and neighbor-joining criteria to test this further. The phylogenetic analysis revealed, with high supporting values, distinct lineages within the genus Burkholderia. The two large groups were named A and B, whereas the B. rhizoxinica/B. endofungorum, and B. andropogonis groups consisted of two and one species, respectively. The group A encompasses several plant-associated and saprophytic bacterial spe...
Source: Current Microbiology - February 13, 2013 Category: Microbiology Authors: Estrada-de Los Santos P, Vinuesa P, Martínez-Aguilar L, Hirsch AM, Caballero-Mellado J Tags: Curr Microbiol Source Type: research
Engineering E. coli for triglyceride accumulation through native and heterologous metabolic reactions.
In this study, Escherichia coli was engineered to synthesize and accumulate triglycerides. Triglycerides were produced from cell wall phospholipid precursors through engineered expression of two enzymes, phosphatidic acid phosphatase (PAP) and diacylglycerol acyltransferase (DGAT). A liquid chromatography-mass spectrometry (LC-MS) method was developed to analyze the production of triglycerides by the engineered E. coli strains. This proof-of-concept study demonstrated a yield of 1.1 mg/L triglycerides (2 g/L dry cell weight) in lysogeny broth medium containing 5 g/L glucose at 8 h following induction of PAP and DGAT exp...
Source: Applied Microbiology and Biotechnology - February 13, 2013 Category: Microbiology Authors: Rucker J, Paul J, Pfeifer BA, Lee K Tags: Appl Microbiol Biotechnol Source Type: research
Clustering subspecies of Aeromonas salmonicida using IS630 typing
Conclusions: HCN-IS630-RFLP is a powerful tool for subtyping of A. salmonicida. The high stability of IS630 insertions in A. salmonicida subsp. salmonicida indicates that it might have played a role in pathoadaptation of A. salmonicida which has reached an optimal configuration in the highly virulent and specific fish pathogen A. salmonicida subsp. salmonicida.
Source: BMC Microbiology - Latest articles - February 13, 2013 Category: Microbiology Authors: Nicole StuderJoachim FreyPhilippe Vanden Bergh Source Type: research
Characterization of polyhydroxyalkanoates accumulated by a moderately halophilic salt pan isolate Bacillus megaterium strain H16
ConclusionThree moderately halophilic isolates (strain H15, H16 and H26) capable of accumulating PHA were isolated from solar salterns of Ribandar Goa, India, and identified as B. megaterium based on phenotypic and genotypic characterization. Strain H16 accumulated polyhydroxybutyrate in the presence and absence of NaCl up to 40% of its CDW. Significance and Impact of the StudyThis strain would be better suited for production of PHA at industrial level due to its tolerance to high concentration of NaCl.
Source: Journal of Applied Microbiology - February 13, 2013 Category: Microbiology Authors: B.B. Salgaonkar, K. Mani, J.M. Braganca Tags: Original Article Source Type: research
Characterization of bacteriocin bificin C6165: a novel bacteriocin
ConclusionsBificin C6165 is indeed a novel bacteriocin and it exhibited remarkable potency for Alicyclobacillus control. Significance and Impact of the StudyApplication of bacteriocins in preservation of fruit juices has seldom been studied. Bificin C6165 may be an alternative method to control juice spoilage by this Alicyclobacillus acidoterrestris and meet increasing consumer demand for nature and artificial chemical additive‐free food products.
Source: Journal of Applied Microbiology - February 13, 2013 Category: Microbiology Authors: J. Pei, Y. Yuan, T. Yue Tags: Original Article Source Type: research
Real‐time PCR‐based rapid and culture‐independent detection of Salmonella in dairy milk – addressing some core issues
In this study, methodologies were developed for cost‐effective, rapid and user‐friendly culture‐independent detection of Salmonella in milk by real‐time PCR. The SYBR Green‐based real‐time PCR assay was standardized with primers targeting the Salmonella enterotoxin gene (stn) that have been earlier used for its detection by conventional PCR. Inclusivity tests generated the specific amplifications with a Tm corresponding to 81 ± 0·5°C. The specificity of the reaction was evaluated with a panel of 36 non‐Salmonella strains. Standard curves generated, with different number of cells of this organism in milk,...
Source: Letters in Applied Microbiology - February 13, 2013 Category: Microbiology Authors: S. Riyaz‐Ul‐Hassan, V. Verma, G.N. Qazi Tags: Original Article Source Type: research
Microbiology: Antibiotic strikes new target
Nature 494, 7436 (2013). doi:10.1038/494151d Highly read on aac.asm.org in JanuaryAn antibiotic that disables protein synthesis seems to inhibit the growth of several strains of drug-resistant bacteria that are known to cause hospital infections.Dickon Alley at Anacor Pharmaceuticals in Palo Alto, California, and his colleagues synthesized the
Source: Nature - February 13, 2013 Category: Research Tags: Research Highlights Source Type: research
S-Adenosyl-L-Methionine protects the probiotic yeast, Saccharomyces boulardii, from acid-induced cell death
Conclusions: In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone.
Source: BMC Microbiology - Latest articles - February 13, 2013 Category: Microbiology Authors: Vincent CascioDaniel GittingsKristen MerloniMatthew HurtonDavid LapradeNicanor Austriaco Source Type: research
Gross blood in stools of premature neonates, a clinical and microbiological follow‐up study
ConclusionsGross blood in the stools of premature infants without other clinical signs of infection can be an innocuous and self‐limiting symptom. This cohort of preterm infants receiving breast milk supplemented with probiotics showed no alterations in gut microecology to be associated with the symptom.©2013 The Author(s)/Acta Pædiatrica ©2013 Foundation Acta Pædiatrica
Source: Acta Paediatrica - February 12, 2013 Category: Pediatrics Authors: Raakel Luoto, Jesus Rodriguez‐Diaz, Maria Carmen Collado, Seppo Salminen, Erika Isolauri, Liisa Lehtonen Tags: Regular Article Source Type: research
An improved qPCR protocol for rapid detection and quantification of Clostridium difficile in cattle feces
Abstract Clostridium difficile (CD) can cause a significant and transmissible disease in animals and humans, with poorly understood epidemiology. Animals have been suggested as a possible source of infection and environment contamination. It is necessary that a precise and rapid diagnostic tool is available for the detection of CD from clinical and/or environmental samples. A quantitative real‐time PCR (qPCR) protocol for CD detection defined by Penders et al. (2005) was modified. The modified protocol, supported by a novel extraction method, was tested on CD spiked cattle feces and clinical fecal samples from calves. Qu...
Source: FEMS Microbiology Letters - February 12, 2013 Category: Microbiology Authors: Petra Bandelj, Katarina Logar, Alenka M. Usenik, Modest Vengust, Matjaz Ocepek Tags: Research Letter Source Type: research
Induction of resistance in Mycobacterium smegmatis
Canadian Journal of Microbiology, Volume 0, Issue 0, Page 1-4, e-First articles.
Source: Canadian Journal of Microbiology - February 12, 2013 Category: Microbiology Tags: article Source Type: research
Biosynthesis of extracellular and intracellular gold nanoparticles by Aspergillus fumigatus and A. flavus.
Abstract Green chemistry is a boon for the development of safe, stable and ecofriendly nanostructures using biological tools. The present study was carried out to explore the potential of selected fungal strains for biosynthesis of intra- and extracellular gold nanostructures. Out of the seven cultures, two fungal strains (SBS-3 and SBS-7) were selected on the basis of development of dark pink colour in cell free supernatant and fungal beads, respectively indicative of extra- and intracellular gold nanoparticles production. Both biomass associated and cell free gold nanoparticles were characterized using X-ray diff...
Source: Antonie van Leeuwenhoek - February 12, 2013 Category: Microbiology Authors: Gupta S, Bector S Tags: Antonie Van Leeuwenhoek Source Type: research
Contributions of biosurfactants to natural or induced bioremediation.
Abstract The number of studies dedicated to evaluating the influence of biosurfactants on bioremediation efficiency is constantly growing. Although significant progress regarding the explanation of mechanisms behind biosurfactant-induced effects could be observed, there are still many factors which are not sufficiently elucidated. This corresponds to the fact that although positive influence of biosurfactants is often reported, there are also numerous cases where no or negative effect was observed. This review summarizes the recent finding in the field of biosurfactant-amended bioremediation, focusing mainly on a c...
Source: Applied Microbiology and Biotechnology - February 12, 2013 Category: Microbiology Authors: Lawniczak L, Marecik R, Chrzanowski L Tags: Appl Microbiol Biotechnol Source Type: research
Novel insights into the fungal oxidation of monoaromatic and biarylic environmental pollutants by characterization of two new ring cleavage enzymes.
Abstract The phenol-degrading yeast Trichosporon mucoides can oxidize and detoxify biarylic environmental pollutants such as dibenzofuran, diphenyl ether and biphenyl by ring cleavage. The degradation pathways are well investigated, but the enzymes involved are not. The high similarity of hydroxylated biphenyl derivatives and phenol raised the question if the enzymes of the phenol degradation are involved in ring cleavage or whether specific enzymes are necessary. Purification of enzymes from T. mucoides with catechol cleavage activity demonstrated the existence of three different enzymes: a classical catechol-1,2-...
Source: Applied Microbiology and Biotechnology - February 12, 2013 Category: Microbiology Authors: Schlüter R, Lippmann R, Hammer E, Gesell Salazar M, Schauer F Tags: Appl Microbiol Biotechnol Source Type: research
Risk factors for a low linezolid trough plasma concentration in acute infections: time to adjust linezolid dose.
Conclusions: A linezolid C(min) <2 mg/L was found in 29.5% of cases, and the risk was significantly higher among those with an eGF >80 ml/min. and in infections due to S. aureus. In patients with severe sepsis, loading dose or continuous infusion and drug monitoring could improve the pharmacodynamic parameters associated with linezolid efficacy. PMID: 23403416 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Morata L, Cuesta M, Rojas JF, Rodriguez S, Brunet M, Casals G, Cobos N, Hernandez C, Martínez JA, Mensa J, Soriano A Tags: Antimicrob Agents Chemother Source Type: research
Comparative population analysis of Klebsiella pneumoniae with extended-spectrum β-lactamases colonizing patients in rehabilitation centers in four countries.
f the MOSAR WP2 & WP5 study groups Abstract The international project MOSAR was conducted in five rehabilitation centers; patients were screened for rectal carriage of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Among 229 Klebsiella pneumoniae isolates four clonal groups (CG) or complexes (CC) prevailed: CG17 in France, CG101 in Italy, CG15 in Spain, and CC147 in Israel. ESBLs, mainly CTX-Ms, were produced by 226 isolates; three isolates expressed AmpC-like cephalosporinases. High genetic diversity of K. pneumoniae populations was observed, with specific characteristics at each center. ...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Baraniak A, Izdebski R, Fiett J, Sadowy E, Adler A, Kazma M, Salomon J, Lawrence C, Rossini A, Salvia A, Vidal Samso J, Fierro J, Paul M, Lerman Y, Malhotra-Kumar S, Lammens C, Goossens H, Hryniewicz W, Brun-Buisson C, Carmeli Y, Gniadkowski M, on behalf Tags: Antimicrob Agents Chemother Source Type: research
Natural History of Yersinia pestis Pneumonia in Aerosol-Challenged BALB/c Mice.
Abstract After a relatively short untreated interval, pneumonic plague has a mortality approaching 100%. We employed a murine model of aerosol challenge with Y. pestis to investigate the early course of pneumonic plague in lung, blood and spleen. We fit a mathematical model to all data simultaneously. The model fit to the data was acceptable. The number of organisms in the lung at baseline was estimated at 135 (median) - 1184 (mean) CFU/g. Doubling time was estimated at 1.5-1.7 hr. Between hrs 1and 12 post-exposure, counts declined, but then increased by hr 24, a finding hypothesized to be due to innate immunity. T...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Heine HS, Chuvala L, Riggins R, Hurteau G, Cirz R, Cass R, Louie A, Drusano GL Tags: Antimicrob Agents Chemother Source Type: research
Tigecycline Does Not Prolong QTc Intervals in Healthy Subjects.
Abstract We evaluated the effect of tigecycline (50 mg and 200 mg doses) on QTc intervals and assessed safety and tolerability in a randomized, placebo-controlled, four-period crossover study of 48 (44 male) healthy volunteers aged 22-53 years. Fed subjects received tigecycline 50 mg or 200 mg, or placebo in a blinded fashion or an open-label oral dose of moxifloxacin 400 mg after 1 L of intravenous fluid. Serial electrocardiograms were recorded before, and for 96 H after, dosing. Blood samples for tigecycline pharmacokinetics were collected after each recording. QTc intervals were corrected using Fridericia's corr...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Korth-Bradley JM, McGovern PC, Salageanu J, Matschke K, Plotka A, Pawlak S Tags: Antimicrob Agents Chemother Source Type: research
Antimicrobial susceptibilities of clinical isolates of HACEK organisms.
We report the antimicrobial susceptibilities of 70 clinical HACEK isolates to 18 antimicrobials. All isolates were susceptible to ceftriaxone and levofloxacin, indicating that these agents remain appropriate empiric choices for the treatment of infections with this group of organisms. PMID: 23403420 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Coburn B, Toye B, Rawte P, Jamieson FB, Farrell DJ, Patel SN Tags: Antimicrob Agents Chemother Source Type: research
A Novel Benzoxazole Inhibitor of Dengue Virus Replication that Targets the NS3 Helicase.
Abstract Dengue virus (DENV) is the predominant mosquito-borne viral pathogen that infects humans with an estimated 50-100 million infections per year worldwide. Over the past 50 years, the incidence of dengue disease has increased dramatically and the virus is now endemic in more than 100 countries. Moreover, multiple serotypes of DENV are now found in the same geographic region, increasing the likelihood of more severe forms of disease. Despite extensive research, there are still no approved vaccines or therapeutics commercially available to treat DENV infection. Here we report the results of a high-throughput sc...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Byrd CM, Grosenbach DW, Berhanu A, Dai D, Jones KF, Cardwell KB, Schneider C, Yang G, Tyavanagimatt S, Harver C, Wineinger KA, Page J, Stavale E, Stone MA, Fuller KP, Lovejoy C, Leeds JM, Hruby DE, Jordan R Tags: Antimicrob Agents Chemother Source Type: research
The proteolysis of mecA repressor is essential for the expression of methicillin resistance by Staphylococcus aureus.
Abstract Recently, we have demonstrated that the cognate regulatory locus of mecA gene in MRSA is in fact a three-component system, containing the novel mecR2 gene coding for an anti-repressor. MecR2 interacts with the repressor MecI, disturbing its binding to the mecA promoter and fostering its proteolysis. Here, we engineered a point mutation in the putative cleavage site of MecI and demonstrated that MecI proteolysis is strictly required for the optimal expression of β-lactam resistance. PMID: 23403422 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Arêde P, Oliveira DC Tags: Antimicrob Agents Chemother Source Type: research
A reprofiled drug, auranofin, is effective against metronidazole-resistant Giardia lamblia.
Abstract Giardiasis is one of the most common causes of diarrheal disease worldwide. Treatment is primarily with 5-nitro antimicrobials, particularly metronidazole. Resistance to metronidazole has been described and treatment failures can occur in up to 20% of cases, making development of alternative antigiardials an important goal. To this end, we have screened a chemical library of 746 approved human drugs and 164 additional bioactive compounds for activity against Giardia lamblia. We identified 56 compounds that caused significant inhibition of G. lamblia growth and attachment. Of these, 15 were previously repor...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Tejman-Yarden N, Miyamoto Y, Leitsch D, Santini J, Debnath A, Gut J, McKerrow JH, Reed SL, Eckmann L Tags: Antimicrob Agents Chemother Source Type: research
Effects of Antibiotics on Bacterial Species Composition and Metabolic Activities in Chemostats Containing Defined Populations of Human Gut Microorganisms.
Abstract The composition and metabolic activities of the human colonic microbiota are modulated by a number of external factors, including diet and antibiotic therapy. Changes in the structure and metabolism of the gut microbiota may have long term consequences for host health. The large intestine harbors a complex microbial ecosystem comprising several hundreds of different bacterial species, which complicates investigations on intestinal physiology and ecology. To facilitate such studies, a highly simplified microbiota was used in this investigation consisting of 14 anaerobic and facultatively anaerobic organisms...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Newton DF, Macfarlane S, Macfarlane GT Tags: Antimicrob Agents Chemother Source Type: research
Increased Peritoneal Dialysis Exit Site Infections using topical antiseptic Polhexamethylenbiguinide (PHMB) vs Mupirocin: Results of the safety interim analysis of an open label prospective randomised study.
We present early interim safety analysis of an open label randomised study comparing Polhexamethylenbiguinide (PHMB) vs Mupirocin. 106 patients randomised to 53 in each group were followed up for a mean 12.68 months/patient. On safety analysis the PHMB group had a significantly greater ESI rate vs Mupirocin (OR 0.26, 95% CI: 0.09-0.80) leading to discontinuation of the trial. PMID: 23403425 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Findlay A, Serrano C, Punzalan S, Fan SL Tags: Antimicrob Agents Chemother Source Type: research
GRL-0519, A NOVEL OXATRICYCLIC-LIGAND-CONTAINING NONPEPTIDIC HIV-1 PROTEASE INHIBITOR (PI), POTENTLY SUPPRESSES THE REPLICATION OF A WIDE SPECTRUM OF MULTI-PI-RESISTANT HIV-1 VARIANTS IN VITRO.
Abstract We here report that GRL-0519, a novel non-peptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) containing tris-tetrahydrofuranylurethane (tris-THF) and a sulfonamide isostere, is highly potent against laboratory HIV-1 strains and primary clinical isolates (EC(50): 0.0005 - 0.0007 μM) with minimal cytotoxicity (CC(50): 44.6 μM). GRL-0519 blocked the infectivity and replication of HIV-1(NL4-3) variants selected by up to 5 μM concentration of ritonavir, lopinavir, or atazanavir (EC(50): 0.0028 - 0.0033 μM). GRL-0519 was also potent against multi-PI-resistant clinical HIV-1 variants...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Amano M, Tojo Y, Salcedo-Gómez PM, Campbell JR, Das D, Aoki M, Xu CX, Rao KV, Ghosh AK, Mitsuya H Tags: Antimicrob Agents Chemother Source Type: research
Activity of Daptomycin with or without 25% Ethanol compared to combinations of Minocycline, EDTA, and 25% Ethanol against Methicillin-Resistant Staphylococcus aureus Isolates Embedded in Biofilm.
Abstract Central venous catheters commonly develop central line-associated blood stream infections. In-vitro antibiotic lock therapy (ALT) was performed on 10 MRSA clinical isolates imbedded in biofilm. After five days of four hour dwell daily exposures to daptomycin 2.5 mg/ml in 25% ethanol or minocycline 3 mg/ml + 25% ethanol + 30 mg/ml EDTA resulted in significantly greater elimination of MRSA colonization as compared to treatment with minocycline alone. PMID: 23403427 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Estes R, Theusch J, Beck A, Pitrak D, Mullane K Tags: Antimicrob Agents Chemother Source Type: research
Persistence of Resistant Variants in HCV Infected Patients Treated with the NS5A Replication Complex Inhibitor Daclatasvir (DCV, BMS-790052).
Abstract Daclatasvir (DCV, BMS-790052) is an HCV NS5A Replication Complex Inhibitor (RCI) with picomolar to low nanomolar potency and broad genotypic coverage in vitro. Viral RNA declines have been observed in the clinic for both IFN-α/RBV and IFN/RBV-free regimens that include DCV. Follow-up specimens (up to 6 months) from selected subjects treated with DCV in the 14-day monotherapy studies were analyzed for genotype and phenotype. Variants were detected by clonal sequencing in specimens from baseline, and were readily detected by population sequencing following viral RNA breakthrough and post-treatment. The majo...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Wang C, Sun JH, O' Boyle DR, Nower P, Valera L, Roberts S, Fridell RA, Gao M Tags: Antimicrob Agents Chemother Source Type: research
The Bis(indolyl)imidazole Alkaloid Nortopsentin A Exhibits Antiplasmodial Activity.
Abstract A library of enriched marine natural product fractions was screened for their antiplasmodial activity using the SYBR green-I fluorescence-based assay. Fractions derived from a sponge of the genus Spongosorites exhibited potent inhibition of Plasmodium falciparum growth. This genus of sponge has been reported to contain the nortopsentin and topsentin class of bis-indole imidazole alkaloids. This is the first report of nortopsentin A inhibiting parasite growth at the trophozoite stage at submicromolar IC(50) value. PMID: 23403429 [PubMed - as supplied by publisher]
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Alvarado S, Roberts BF, Wright AE, Chakrabarti D Tags: Antimicrob Agents Chemother Source Type: research
Monte Carlo Simulations Based on Phase 1 Studies Predict Target Attainment of Ceftobiprole in Nosocomial Pneumonia Patients : a Validation Study.
In this study the initial estimates of exposure from MCS were compared with actual exposure data in patients treated with ceftobiprole in a phase 3 nosocomial pneumonia study (NTC00210964). Results of MCS using population PK data from ceftobiprole derived from 12 healthy volunteers were used (Mouton et al. AAC, 2004 48:1713). Actual individual exposures in patients were derived after building a population pharmacokinetic model and used to calculate the individual exposure to ceftobiprole (percentage of time the unbound concentration exceeds the MIC, %fT>MIC) for a range of MIC-values. For the ranges of %fTMIC used to de...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Muller AE, Schmitt-Hoffmann AH, Punt N, Mouton JW Tags: Antimicrob Agents Chemother Source Type: research
Single-Dose Safety, Tolerability, and Pharmacokinetics of the Antibiotic GSK1322322, a Novel Peptide Deformylase Inhibitor.
Abstract GSK1322322 is a potent inhibitor of peptide deformylase, an essential bacterial enzyme required for protein maturation. GSK1322322 is active against community-acquired skin and respiratory tract pathogens, including methicillin-resistant Staphylococcus aureus, multidrug-resistant Streptococcus pneumoniae, and atypical pathogens. This phase I, randomized, double-blind, placebo-controlled, 2-part, single-dose, dose-escalation study (first time in humans) evaluated the safety, tolerability, and pharmacokinetics of GSK1322322 (powder-in-bottle formulation) in healthy volunteers. In part A, dose escalation incl...
Source: Antimicrobial Agents and Chemotherapy - February 12, 2013 Category: Microbiology Authors: Naderer OJ, Dumont E, Zhu J, Kurtinecz M, Jones LS Tags: Antimicrob Agents Chemother Source Type: research