MedWorm: Gastroenteritis

Monoclonal Antibodies Against the Escherichia coli DNA Repair Protein RadA/Sms

Hybridoma — Wed, 08 Feb 2012 16:36:55 +0100

Hybridoma Feb 2012, Vol. 31, No. 1: 25-31. (Source: Hybridoma)

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New Insight Into 2011 E. coli Outbreaks In Europe Provided By Whole-Genome Sequencing

Health News from Medical News Today — Wed, 08 Feb 2012 09:00:00 +0100

Using whole-genome sequencing, a team led by researchers from Harvard School of Public Health (HSPH) and the Broad Institute has traced the path of the E. coli outbreak that sickened thousands and killed over 50 people in Germany in summer 2011 and also caused a smaller outbreak in France. It is one of the first uses of genome sequencing to study the dynamics of a food-borne outbreak and provides further evidence that genomic tools can be used to investigate future outbreaks and provide greater insight into the emergence and spread of infectious diseases... (Source: Health News from Medical News Today)

Chronic fatigue syndrome after Giardia enteritis: clinical characteristics, disability and long-term sickness absence.

BMC Gastroenterology — Wed, 08 Feb 2012 05:00:00 +0100

Conclusion: After giardiasis enteritis at least 5% developed clinical characteristics and functional impairment comparable to previously described post-infectious fatigue syndrome. (Source: BMC Gastroenterology)

Harmful Bacteria On Raw Chicken Reduced By A Zap Of Cold Plasma

Health News from Medical News Today — Tue, 07 Feb 2012 08:00:00 +0100

A new study by food safety researchers at Drexel University demonstrates that plasma can be an effective method for killing pathogens on uncooked poultry. The proof-of-concept study was published in the Journal of Food Protection. Although recent high-profile outbreaks of foodborne illness have involved contaminated fresh produce, the most common source of harmful bacteria in food is uncooked poultry and other meat products. The bacteria responsible for most foodborne illnesses, Campylobacter and Salmonella, are found on upwards of 70 percent of chicken meat tested... (Source: Health News from Medical News Today)

Cefpodoxime vs Ciprofloxacin for Short-Course Treatment of Acute Uncomplicated Cystitis: A Randomized Trial [Original Contribution]

JAMA — Tue, 07 Feb 2012 05:00:00 +0100

Conclusions Among women with uncomplicated cystitis, a 3-day regimen of cefpodoxime compared with ciprofloxacin did not meet criteria for noninferiority for achieving clinical cure. These findings, along with concerns about possible adverse ecological effects associated with other broad-spectrum β-lactams, do not support the use of cefpodoxime as a first-line fluoroquinolone-sparing antimicrobial for acute uncomplicated cystitis. Trial Registration clinicaltrials.gov Identifier: NCT00194532 (Source: JAMA)

IcsA autotransporter passenger promotes increased fusion protein expression on the cell surface

Microbial Cell Factories — Tue, 07 Feb 2012 02:08:30 +0100

Conclusions: The export mechanism of autotransporters is not well understood but accumulating evidence suggest a critical role for the native effector or alpha domain in facilitating its own export via interactions with the translocation or beta domain. This is the first report directly comparing expression of heterologous proteins fused to the full length IcsA autotransporter and fusion to the beta domain alone. Protein expression and surface presentation of the fusion proteins were dramatically improved when fused to IcsA rather than IcsAbeta. Future studies involved in designing autotransporters as cell surface display vehicles would benefit from including the native alpha domain. This work also provides further evidence for a key interaction between the autotransporter alpha and beta d...

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Anti-ganglioside antibody internalization attenuates motor nerve terminal injury in a mouse model of acute motor axonal neuropathy

Journal of Clinical Investigation — Mon, 06 Feb 2012 18:32:05 +0100

In the Guillain-Barré syndrome subform acute motor axonal neuropathy (AMAN), Campylobacter jejuni enteritis triggers the production of anti-ganglioside Abs (AGAbs), leading to immune-mediated injury of distal motor nerves. An important question has been whether injury to the presynaptic neuron at the neuromuscular junction is a major factor in AMAN. Although disease modeling in mice exposed to AGAbs indicates that complement-mediated necrosis occurs extensively in the presynaptic axons, evidence in humans is more limited, in comparison to the extensive injury seen at nodes of Ranvier. We considered that rapid AGAb uptake at the motor nerve terminal membrane might attenuate complement-mediated injury. We found that PC12 rat neuronal cells rapidly internalized AGAb, which were traffi...

Whole-genome sequencing of 2011 E. coli outbreaks in Europe provides new insight

EurekAlert! - Social and Behavioral Science — Mon, 06 Feb 2012 05:00:00 +0100

(Harvard School of Public Health) Using whole-genome sequencing, a team led by researchers from Harvard School of Public Health and the Broad Institute has traced the path of the E. coli outbreak that sickened thousands and killed over 50 people in Germany in summer 2011 and also caused a smaller outbreak in France. (Source: EurekAlert! - Social and Behavioral Science)

A strategy of gene overexpression based on tandem repetitive promoters in Escherichia coli

Microbial Cell Factories — Mon, 06 Feb 2012 05:00:00 +0100

Conclusions: The transcription strength of the MCPtacs promoter cluster can be greatly improved by increasing the tandem repeats number of the core-tac-promoter. By integrating the desired gene together with the MCPtacs promoter cluster into the chromosome of E. coli, we can achieve high and stale overexpression with only a small size. This strategy has an application potential in many fields and can be extended to other bacteria. (Source: Microbial Cell Factories)

E. Coli O157:H7 Population Reduction from Alfalfa Seeds with Malic Acid and Thiamine Dilauryl Sulfate and Quality Evaluation of the Resulting Sprouts

Journal of Food Science — Mon, 06 Feb 2012 05:00:00 +0100

The objectives of this research were to examine the efficacy of malic acid (MA) and thiamine dilauryl sulfate (TDS) combined treatments on the inactivation of E. coli O157:H7 on alfalfa seeds, to study the growth of the remaining E. coli cells during sprouting, and to evaluate the sprout quality. When 10 g of inoculated alfalfa seeds were washed in a 10% MA‐1% TDS solution, a complete elimination of E. coli was achieved. The same result was observed by washing the seeds in a 20000 ppm Ca(OCl)2 solution. However, when the seed size was increased to 50 g while maintaining the same seed‐to‐sanitizer ratio, both the MA + TDS and the 20000 ppm chlorine washes failed to completely inactivate the E. coli cells on the seeds. Nevertheless, the 10% MA‐1% TDS solution was significantly more e...

A direct detection of Escherichia coli genomic DNA using gold nanoprobes

Journal of Nanobiotechnology — Mon, 06 Feb 2012 05:00:00 +0100

Conclusion: This work gives entry into a new class of DNA/gold nanoparticles hybrid materials which might have optical property that can be controlled for application in diagnostics. We note that it should be possible to extend this strategy easily for developing new types of DNA biosensor for point of care detection. The salient feature of this approach includes low-cost, robust reagents and simple colorimetric detection of pathogen. (Source: Journal of Nanobiotechnology)

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Recognition of prokaryotic promoters based on a novel variable-window Z-curve method

Nucleic Acids Research — Mon, 06 Feb 2012 05:00:00 +0100

Transcription is the first step in gene expression, and it is the step at which most of the regulation of expression occurs. Although sequenced prokaryotic genomes provide a wealth of information, transcriptional regulatory networks are still poorly understood using the available genomic information, largely because accurate prediction of promoters is difficult. To improve promoter recognition performance, a novel variable-window Z-curve method is developed to extract general features of prokaryotic promoters. The features are used for further classification by the partial least squares technique. To verify the prediction performance, the proposed method is applied to predict promoter fragments of two representative prokaryotic model organisms (Escherichia coli and Bacillus subtilis). Depe...

A model for Escherichia coli chromosome packaging supports transcription factor-induced DNA domain formation

Nucleic Acids Research — Mon, 06 Feb 2012 05:00:00 +0100

What physical mechanism leads to organization of a highly condensed and confined circular chromosome? Computational modeling shows that confinement-induced organization is able to overcome the chromosome's propensity to mix by the formation of topological domains. The experimentally observed high precision of separate subcellular positioning of loci (located on different chromosomal domains) in Escherichia coli naturally emerges as a result of entropic demixing of such chromosomal loops. We propose one possible mechanism for organizing these domains: regulatory control defined by the underlying E. coli gene regulatory network requires the colocalization of transcription factor genes and target genes. Investigating this assumption, we find the DNA chain to self-organize into several topolog...

Opposing effects of DNA on proteolysis of a replication initiator

Nucleic Acids Research — Mon, 06 Feb 2012 05:00:00 +0100

DNA replication initiation proteins (Reps) are subjected to degradation by cellular proteases. We investigated how the formation of nucleoprotein complex, involving Rep and a protease, affects Rep degradation. All known Escherichia coli AAA+ cytosolic proteases and the replication initiation protein TrfA of the broad-host-range plasmid RK2 were used. Our results revealed that DNA influences the degradation process and that the observed effects are opposite and protease specific. In the case of ClpXP and ClpYQ proteases, DNA abolishes proteolysis, while in the case of ClpAP and Lon proteases it stimulates the process. ClpX and ClpY cannot interact with DNA-bound TrfA, while the ClpAP and Lon activities are enhanced by the formation of nucleoprotein complexes involving both the protease and ...

Development of a microRNA delivery system based on bacteriophage MS2 virus‐like particles

FEBS Journal — Mon, 06 Feb 2012 05:00:00 +0100

SummaryRecently, microRNA‐mediated RNA interference (RNAi) has been developed as a useful tool in gene function analysis and gene therapy. A major obstacle in miRNA‐mediated RNAi is cellular delivery, which requires an efficient and flexible delivery system. The self‐assembly of the MS2 bacteriophage capsids has been used to develop virus‐like particles (VLPs) for RNA and drug delivery. However, MS2 VLP mediated miRNAs delivery has not yet been reported. We therefore produced the MS2 VLPs packaging model pre‐miR146a RNA by E.coli expression system and then conjugated these particles with human immunodeficiency virus‐1 (HIV‐1) Tat47‐57 peptide. The conjugated MS2 VLPs can effectively transfer the packaged pre‐miR146a RNA into various cells and tissues, with a 0.92 to 14.76...

The “Black Widow”: Arsenic and Britain’s First Serial Killer

The Poison Review — Sun, 05 Feb 2012 22:35:21 +0100

The Daily Mail (U.K.) has a fascinating story today about Mary Ann Cotton (1832 – 1873), Britain’s first serial killer. According to the author, Professor of Criminology David Wilson, a serial killer is someone who kills more than three people over a time period of more than thirty days. Cotton more than met this definition: Few have heard of the so-called “Black Widow” killer who posed as a wife, widow, mother, friend and nurse to murder perhaps as many as 21 victims [over a period of almost 20 years], living off her husbands before eventually claiming their estates. Two decades before Jack the Ripper would terrorist the streets of Whitechapel in London, Mary Ann Cotton had already become a killing machine, perhaps murdering as many as eight of her own children, se...

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Composition and antimicrobial activities of the leaf essential oil of Machilus zuihoensis from Taiwan

Revista Brasileira de Farmacognosia — Sun, 05 Feb 2012 18:30:49 +0100

This study investigated the chemical composition, and antimicrobial and anti-wood-decay fungal activities of the essential oil isolated from the leaf of endemic Machilus zuihoensis Hayata, Lauraceae, of Taiwan. The essential oil from the fresh leaves of M. zuihoensis was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of 104 compounds were identified, representing 100% of the oil. The main components identified were n-dodecanal (23.8%) and (E)-nerolidol (10.5%). The antimicrobial activity of the oil was tested by the disc diffusion method and micro-broth dilution method against ten microbial species (Bacillus cereus, Staphylococcus aureus, S. epidermidis, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomo...

Reversal of CRF- and stress-induced anorexia by an ayurvedic formulation

Revista Brasileira de Farmacognosia — Sun, 05 Feb 2012 18:30:49 +0100

Trikatu churna is one of the commonly used Ayurvedic formulations in the traditional system of medicine in India for the treatment of agnimandya, i.e. anorexia. Trikatu contains equal amounts of finely powdered rhizomes of Zingiber officinale Roscoe (Zingiberaceae) and fruits of Piper longum L. and Piper nigrum L. (Piperaceae). The chief objective of the study was to determine the antianorectic effects of three drugs individually and to compare these effects with the effect of Trikatu. The activity of the drugs was studied after anorexia was induced in rats by (1) physical stress arising from immobilization for 60 min; (2) intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS, 100 μg/kg body weight); and (3) intraperitoneal administration of fluoxetine (8 mg/kg body weight...

Orange Rinds May Help Rid Cows of E. Coli

Scientific American - Official RSS Feed — Sun, 05 Feb 2012 13:00:00 +0100

Name : Todd Callaway [More] (Source: Scientific American - Official RSS Feed)

Orange Rinds May Help Rid Cows of E. Coli

Scientific American Topic - Medical Technology — Sun, 05 Feb 2012 13:00:00 +0100

Name : Todd Callaway [More] (Source: Scientific American Topic - Medical Technology)

35 Cases of Illness Tied to Pa. Farm’s Raw Milk

RWJF News Digest - Public Health — Sun, 05 Feb 2012 11:44:57 +0100

The confirmed cases of campylobacter bacterial infection include 28 people in Pennsylvania, four in Maryland, two in West Virginia, and one in New Jersey. (Source: RWJF News Digest - Public Health)

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A structural motif is the recognition site for a new family of bacterial protein O‐glycosyltransferases

Molecular Microbiology — Sun, 05 Feb 2012 05:00:00 +0100

SummaryThe Escherichia coli Adhesin Involved in Diffuse Adherence (AIDA‐I) is a multifunctional protein that belongs to the family of monomeric autotransporters. This adhesin can be glycosylated by the AIDA‐associated heptosyltransferase (Aah). Glycosylation appears to be restricted to the extracellular domain of AIDA‐I, which comprises imperfect repeats of a 19‐amino‐acid consensus sequence and is predicted to form a β‐helix. Here, we show that Aah homologues can be found in many Gram‐negative bacteria, including Citrobacter rodentium. We demonstrated that an AIDA‐like protein is glycosylated in this species by the Aah homologue. We then investigated the substrate recognition mechanism of the E. coli Aah heptosyltransferase. We found that a peptide corresponding to one ...

Isolation and Molecular Characterization of Escherichia coli O157 from Broiler and Human Samples

Foodborne Pathogens and Disease — Sat, 04 Feb 2012 04:06:44 +0100

Foodborne Pathogens and Disease , Vol. 0, No. 0. (Source: Foodborne Pathogens and Disease)

Norovirus causes most hospital outbreaks

Health News - UPI.com — Sat, 04 Feb 2012 02:23:29 +0100

WASHINGTON, Feb. 3 (UPI) -- Norovirus, a pathogen that often causes food poisoning and gastroenteritis, is the leading cause of infectious outbreaks in U.S. hospitals, researchers said. (Source: Health News - UPI.com)

Pathogen detected in raw milk from Pa.

Health News - UPI.com — Sat, 04 Feb 2012 00:44:11 +0100

BALTIMORE, Feb. 3 (UPI) -- Maryland health officials have confirmed the presence of Campylobacter jejuni in two unopened raw milk samples purchased from a Pennsylvanian farm. (Source: Health News - UPI.com)

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An Evolving Case of Concurrent Eosinophilic Esophagitis and Eosinophilic Gastroenteritis

Digestive Diseases and Sciences — Fri, 03 Feb 2012 17:53:10 +0100

Content Type Journal ArticleCategory Stanford Multidisciplinary SeminarsPages 1-3DOI 10.1007/s10620-012-2061-3Authors Minou Le-Carlson, Department of Pediatrics, Stanford University Medical Center, Stanford, CA, USAGeorge Triadafilopoulos, Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Stanford, CA, USAReteesh K. Pai, Department of Pathology, Stanford University Medical Center, Stanford, CA, USAJohn A. Kerner, Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Stanford University Medical Center, Stanford, CA, USA Journal Digestive Diseases and SciencesOnline ISSN 1573-2568Print ISSN 0163-2116 (Source: Digestive Diseases and Sciences)

In vitro modulatory effects of flavonoids on human cytochrome P450 2C8 (CYP2C8)

Naunyn-Schmiedeberg's Archives of Pharmacology — Fri, 03 Feb 2012 17:12:17 +0100

Abstract The inhibitory effects of five flavonoids with distinct chemical classes (flavones [luteolin], flavonols [quercetin and quercitrin], and flavanones [hesperetin and hespiridin]) on cDNA-expressed CYP2C8 were investigated. CYP2C8 was co-expressed with NADPH-cytochrome P450 reductase in Escherichia coli and used to characterise potency and mechanism of these flavonoids on the isoform. Tolbutamide 4-methylhydroxylase, a high-performance liquid chromatography-based assay, was selected as marker activity for CYP2C8. Our results indicated that the flavonoids inhibited CYP2C8 with different potency. The order of inhibitory activities was quercetin > luteolin > hesperetin > hesperidin > quercitrin. All of these compounds however exhibited mechanism-based inhibit...

A two reservoir model to predict Escherichia coli losses to water from pastures grazed by dairy cows.

Environment International — Fri, 03 Feb 2012 09:50:02 +0100

Authors: Muirhead RW, Monaghan RM Abstract Animal agriculture has been identified as an important source of diffuse faecal microbial pollution of water. Our current understanding of the losses of faecal microbes from grazed pasture systems is however poor. To help synthesise our current knowledge, a simple two reservoir model was constructed to represent the faecal and environmental sources of Escherichia coli found in a grazed pastoral system. The size of the faecal reservoir was modelled on a daily basis with inputs from grazing animals, and losses due to die-off of E. coli and decomposition of the faecal material. Estimates were made of transport coefficients of E. coli losses from the two reservoirs. The concentration of E. coli measured in overland flow and artificial drainage...

Renal bioenergetics during early gram-negative mammalian sepsis and angiotensin II infusion

Intensive Care Medicine — Fri, 03 Feb 2012 07:21:32 +0100

Conclusions During early hypotensive experimental Gram-negative sepsis, there was no evidence of renal bioenergetic failure despite decreased RBF. In this setting, the addition of a powerful renal vasoconstrictor does not lead to deterioration in renal bioenergetics. Content Type Journal ArticleCategory ExperimentalPages 1-8DOI 10.1007/s00134-012-2487-2Authors Clive N. May, Howard Florey Institute, Florey Neurosciences Institutes, University of Melbourne, Parkville, VIC, AustraliaKen Ishikawa, Howard Florey Institute, Florey Neurosciences Institutes, University of Melbourne, Parkville, VIC, AustraliaLi Wan, Howard Florey Institute, Florey Neurosciences Institutes, University of Melbourne, Parkville, VIC, AustraliaJohn Williams, Howard Florey Institute, Florey Neurosc...

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Outbreak of salmonella strikes UK

OnMedica Latest News — Fri, 03 Feb 2012 05:00:00 +0100

Health Protection Agency says watermelons may be the source Related items from OnMedicaE. coli linked to long-term illnessSalmonella found in kebab shop salads Environment and health link to be tested Poor patients more likely to die after heart surgery than rich'Mad cow's disease' confirmed in patient with haemophilia for first time (Source: OnMedica Latest News)

3D‐QSAR studies on the inhibitory activity of trimethoprim analogues against Escherichia coli dihydrofolate reductase

Chemical Biology and Drug Design — Fri, 03 Feb 2012 05:00:00 +0100

AbstractThree‐dimensional quantitative structure activity relationship (3D‐QSAR) study has been carried out on the Escherichia coli DHFR inhibitors 2,4‐diamino‐5‐(substituted‐benzyl)pyrimidine derivatives to understand the structural features responsible for the improved potency. In order to construct highly predictive 3D‐QSAR models, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were used. The predicted models shows statistically significant cross validated and non‐cross validated correlation coefficient of and , respectively. The final 3D‐QSAR models were validated using structurally diverse test set compounds. Analysis of the contour maps generated from CoMFA and CoMSIA methods reveals that the subst...

Markov Chain Ontology Analysis (MCOA)

BMC Bioinformatics - Latest articles — Fri, 03 Feb 2012 05:00:00 +0100

Conclusion: A methodology based on Markov chain models and network analytic metrics can help detect the relevant signal within large, highly interdependent and noisy data sets and, for applications such as enrichment analysis, has been shown to generate superior performance on both real and simulated data relative to existing state-of-the-art approaches. (Source: BMC Bioinformatics - Latest articles)

Adaptation of Salmonella enterica Hadar under static magnetic field: effects on outer membrane protein pattern

Proteome Science — Fri, 03 Feb 2012 05:00:00 +0100

Conclusions: SMF (200 mT) seems to maintain the cell envelope integrity and to submit the exposed cells to an oxidative stress. Some alterations suggest an increase of the ability of exposed cells to form biofilms. (Source: Proteome Science)

High Growth Rate Downregulates fumA mRNA Transcription but Is Dramatically Compensated by Its mRNA Stability in Escherichia coli.

Current Microbiology — Fri, 03 Feb 2012 05:00:00 +0100

This study demonstrates that increasing growth rate (k) from 0.24/h to 0.96/h causes a marked eightfold reduction in fumA transcription as assessed using the β-galactosidase activity from fumA promoter fused with a lacZ reporter. It was further confirmed using Northern blot analysis. Most interestingly, the FumA protein levels remained unchanged over the growth rate, as indicated by Western blot analysis. Therefore, whether the reduced fumA mRNA expression under the high growth rate can be overcome by increasing the stability of the fumA mRNA was tested. The half-life of fumA mRNA was established to significantly increase by fivefold when the growth rate was increased to 0.96/h. This finding suggests that the cells could turn down the expression of fumA mRNA because of increased stability...

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Necrotizing fasciitis of thigh associated with EscherichiaColi bacteremia in a patient on chronic hemodialysis

Hemodialysis International — Fri, 03 Feb 2012 05:00:00 +0100

We present a 59‐year‐old male on chronic hemodialysis (HD). We made the diagnosis of necrotizing fasciitis of the right thigh due to the crepitus from physical examination and subcutaneous emphysema from an X film. He was successfully treated with antibiotics and surgical debridement. The blood and surgical drainage cultures showed Escherichia coli, which is less commonly seen in cutaneous infection. The colonoscopic finding revealed adenomatous polyps. Necrotizing fasciitis in patients on HD requires early diagnosis and aggressive treatment to ensure the favorable clinical outcomes. (Source: Hemodialysis International)

Regulation of Myb by Cdk2 in Giardia [Microbiology]

Journal of Biological Chemistry — Fri, 03 Feb 2012 05:00:00 +0100

The protozoan Giardia lamblia parasitizes the human small intestine to cause diseases. It undergoes differentiation into infectious cysts by responding to intestinal stimulation. How the activated signal transduction pathways relate to encystation stimulation remain largely unknown. During encystation, genes encoding cyst wall proteins (CWPs) are coordinately up-regulated by a Myb2 transcription factor. Because cell differentiation is linked to cell cycle regulation, we tried to understand the role of cell cycle regulators, cyclin-dependent kinases (Cdks), in encystation. We found that the recombinant Myb2 was phosphorylated by Cdk-associated complexes and the levels of phosphorylation increased significantly during encystation. We have identified a putative cdk gene (cdk2) by searching th...

APC Regulation of GSK-3 [Cell Biology]

Journal of Biological Chemistry — Fri, 03 Feb 2012 05:00:00 +0100

Glycogen synthase kinase-3 (GSK-3) is essential for many signaling pathways and cellular processes. As Adenomatous Polyposis Coli (APC) functions in many of the same processes, we investigated a role for APC in the regulation of GSK-3-dependent signaling. We find that APC directly enhances GSK-3 activity. Furthermore, knockdown of APC mimics inhibition of GSK-3 by reducing phosphorylation of glycogen synthase and by activating mTOR, revealing novel roles for APC in the regulation of these enzymes. Wnt signaling inhibits GSK-3 through an unknown mechanism, and this results in both stabilization of β-catenin and activation of mTOR. We therefore hypothesized that Wnts may regulate GSK-3 by disrupting the interaction between APC and the Axin-GSK-3 complex. We find that Wnts rapidly induce APC...

CB2 Receptor Function and Anionic Lipids [Membrane Biology]

Journal of Biological Chemistry — Fri, 03 Feb 2012 05:00:00 +0100

Human cannabinoid type 2 (CB2) receptor expressed in Escherichia coli was purified and successfully reconstituted in the functional form into lipid bilayers composed of POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS), and cholesteryl hemisuccinate (CHS). Reconstitution was performed by detergent removal from the protein/lipid/detergent mixed micelles either on an adsorbent column, or by rapid dilution to below the critical micelle concentration of detergent followed by removal of detergent monomers on a concentrator. Proteoliposomes prepared at a protein/phospholipid/CHS molar ratio of 1/620–650/210–220 are free of detergent as shown by 1H NMR, have a homogeneous protein/lipid ratio shown by isopycnic gradient ultracentr...

Assembling Cysteine Synthase [Molecular Biophysics]

Journal of Biological Chemistry — Fri, 03 Feb 2012 05:00:00 +0100

Control of sulfur metabolism in plants and bacteria is linked, in significant measure, to the behavior of the cysteine synthase complex (CSC). The complex is comprised of the two enzymes that catalyze the final steps in cysteine biosynthesis: serine O-acetyltransferase (SAT, EC 2.3.1.30), which produces O-acetyl-l-serine, and O-acetyl-l-serine sulfhydrylase (OASS, EC 2.5.1.47), which converts it to cysteine. SAT (a dimer of homotrimers) binds a maximum of two molecules of OASS (a dimer) in an interaction believed to involve docking of the C terminus from a protomer in an SAT trimer into an OASS active site. This interaction inactivates OASS catalysis and prevents further binding to the trimer; thus, the system exhibits a contact-induced inactivation of half of each biomolecule. To better u...

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An observational study on bloodstream extended-spectrum beta-lactamase infection in critical care unit: Incidence, risk factors and its impact on outcome.

European Journal of Internal Medicine — Fri, 03 Feb 2012 00:25:53 +0100

CONCLUSION: There is a high incidence of ESBL producing organisms causing blood stream infections in critically ill patients. Transfer from other hospitals and previous antibiotic usage are important risk factors for ESBL production. However ESBL production may not be associated with a poorer outcome if appropriate early antibiotic therapy is instituted. PMID: 22284253 [PubMed - in process] (Source: European Journal of Internal Medicine)

Analysis of Giardia lamblia Interactions with Polymer Surfaces Using a Microarray Approach

Environmental Science and Technology — Thu, 02 Feb 2012 20:43:11 +0100

Environmental Science & TechnologyDOI: 10.1021/es203637e (Source: Environmental Science and Technology)

Bevacizumab: Eosinophilic gastroenteritis: case report

Reactions — Thu, 02 Feb 2012 18:34:27 +0100

(Source: Reactions)

Binding of Escherichia coli to Functionalized Gold Nanoparticles

Plasmonics — Thu, 02 Feb 2012 18:13:33 +0100

Abstract The molecular basis of the diversity of fimbrial lectins dictates the extent of adhesion in different types of Escherichia coli strains to mammalian cells. The mechanism of receptor binding by E. coli in eukaryotic cells differs based on the adhesin domains, patterns in the macromolecular structure and the ligand-binding groove. Current sensor technologies utilize biosensors that are based on the carbohydrate moieties that are involved in pathogen adhesion to host cells. Nanoparticles have been extensively used as carriers for pathogen detection. Gold nanoparticles (Au NPs) of 200 nm size were functionalized with two distinct glycoconjugates mannose (Mn–Au NPs) and Neuαc(α2-3)-Gal-(β1-4)Glc–Paa (Sg–Au NPs) in order to investigate primary and fine sugar...

Faster Diagnosis of Amebic Colitis

Consultant Live — Thu, 02 Feb 2012 12:00:00 +0100

Distinguish Amebic Colitis from E coli infection faster (Source: Consultant Live)

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Science Museum launches online games about the future of technology

Guardian Unlimited Science — Thu, 02 Feb 2012 11:09:10 +0100

Futurecade features games that ask questions about robotics, space, geo-engineering and synthetic biologyThe Science Museum has launched a suite of online games designed to raise questions about the future of medicine, robotics and technology. Developed as part of the Talk Science programme, which was initiated to encourage discussion of science in schools, the 'Futurecade' features four titles exploring areas such as geo-engineering and synthetic biology.In Batco-Lab, players must engineer E.coli bacteria to make useful products, while ensuring that no harmful mutant bacteria are accidentally unleashed on the world. Cloud Control, meanwhile, allows participants to guide Flettner ships which brighten clouds so they reflect sunlight and lower the Earth's temperature. The titles have been de...

The Leading Cause Of Infection Outbreaks In US Hospitals Is Norovirus

Health News from Medical News Today — Thu, 02 Feb 2012 09:00:00 +0100

Norovirus, a pathogen that often causes food poisoning and gastroenteritis, was responsible for 18.2 percent of all infection outbreaks and 65 percent of ward closures in U.S. hospitals during a two-year period, according to a new study published in the February issue of the American Journal of Infection Control (AJIC), the official publication of APIC - the Association for Professionals in Infection Control and Epidemiology... (Source: Health News from Medical News Today)

Shedding New Light On The Way Superbugs Such As MRSA Are Able To Become Resistant To Treatment With Antibiotics

Health News from Medical News Today — Thu, 02 Feb 2012 08:00:00 +0100

Scientists have shed new light on the way superbugs such as MRSA are able to become resistant to treatment with antibiotics. Researchers have mapped the complex molecular structure of an enzyme found in many bacteria. These molecules - known as restriction enzymes - control the speed at which bacteria can acquire resistance to drugs and eventually become superbugs. The study, carried out by an international team including scientists from the University of Edinburgh, focused on E. coli, but the results would apply to many other infectious bacteria... (Source: Health News from Medical News Today)

Construction of an infectious cDNA clone of Culex flavivirus, an insect-specific flavivirus from Culex mosquitoes

Archives of Virology — Thu, 02 Feb 2012 06:56:42 +0100

Abstract Culex flavivirus (CxFV) is an insect-specific flavivirus that has recently been detected in various Culex spp. mosquitoes worldwide. Here, we report the successful construction of a full-length infectious cDNA clone of a Tokyo strain, CxFV-NIID21. The full-length CxFV-NIID21 cDNA was cloned into the low-copy-number plasmid pMW119, which was stably amplified in Escherichia coli. Transfection of a mosquito cell line with in vitro-transcribed RNA from the cDNA clone resulted in the production of recombinant progeny virus with growth properties, cytopathogenicity, and virion morphology similar to the parental virus. Content Type Journal ArticleCategory Brief ReportPages 1-5DOI 10.1007/s00705-012-1240-zAuthors Haruhiko Isawa, Department of Medical Entomology, Natio...

Lipooligosaccharide locus classes are associated with certain Campylobacter jejuni multilocus sequence types

European Journal of Clinical Microbiology and Infectious Diseases — Thu, 02 Feb 2012 06:54:13 +0100

Abstract The lipooligosaccharide (LOS) locus class was determined using polymerase chain reaction (PCR) in 335 Finnish Campylobacter jejuni strains isolated from humans, poultry and bovines with known multilocus sequence types. The results revealed an association between clonal complexes/sequence types (STs) and LOS locus classes. Based on these results, we further predicted the LOS locus classes distribution among the STs of 209 additional C. jejuni strains from Finnish human domestically acquired infections. Non-sialylated LOS locus classes were associated with STs that comprised ≈55% of patient strains. Sialylated LOS locus classes A and B were associated with STs infrequently isolated, whereas class C was correlated with the ST-21 complex, found in ≈14% of human stra...

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The effect of various concentrations of iodine potassium iodide on the antimicrobial properties of mineral trioxide aggregate – a pilot study

Dental Traumatology — Thu, 02 Feb 2012 05:00:00 +0100

Conclusions: Substitution of IKI solutions (1%, 2%, and 4%) for water did not significantly increase the antimicrobial activity of MTA. (Source: Dental Traumatology)

Treatment of Enterohemorrhagic E. coli (EHEC) infection and Hemolytic Uremic Syndrome (HUS)

BMC Medicine — Thu, 02 Feb 2012 05:00:00 +0100

In light of the verotoxigenic E. coli (VTEC) European epidemic in 2011, Goldwater and Bettelheim comment on the complex pathogenesis of these strains and recommend a multi-targeted approach to current and future treatment strategies. (Source: BMC Medicine)

Outbreaks of virulent diarrhoeagenic Escherichia coli - are we in control?

BMC Medicine — Thu, 02 Feb 2012 05:00:00 +0100

Improvements in management strategies to control Shiga toxin-producing E. coli (STEC) outbreaks are discussed by Dirk Werber et al, who advocate early detection via careful surveillance and investigation of food source, as well as integration of molecular data. (Source: BMC Medicine)

Expression of high-affinity human antibody fragments in bacteria

Nature Protocols — Thu, 02 Feb 2012 05:00:00 +0100

This article provides an overview of expression and purification (Source: Nature Protocols)

RcsB‐BglJ activates the Escherichia coli leuO gene, encoding an H‐NS antagonist and pleiotropic regulator of virulence determinants

Molecular Microbiology — Thu, 02 Feb 2012 05:00:00 +0100

SummaryThe LysR‐type transcription factor LeuO is involved in regulation of pathogenicity determinants and stress responses in Enterobacteriaceae, and acts as antagonist of the global repressor H‐NS. Expression of the leuO gene is repressed by H‐NS, and it is upregulated in stationary phase and under amino acid starvation conditions. Here, we show that the heterodimer of the FixJ/NarL‐type transcription regulators RcsB and BglJ strongly activates expression of leuO and that RcsB‐BglJ regulates additional loci. Activation of leuO by RcsB‐BglJ is independent of the Rcs phosphorelay system. RcsB‐BglJ binds to the leuO promoter region and activates one of two leuO promoters mapped in vivo. Moreover, LeuO antagonizes activation of leuO by RcsB‐BglJ and acts as negative autoregul...

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Hsp33 confers bleach resistance by protecting elongation factor Tu against oxidative degradation in Vibrio cholerae

Molecular Microbiology — Thu, 02 Feb 2012 05:00:00 +0100

SummaryThe redox‐regulated chaperone Hsp33 protects bacteria specifically against stress conditions that cause oxidative protein unfolding, such as treatment with bleach or exposure to peroxide at elevated temperatures. To gain insight into the mechanism by which expression of Hsp33 confers resistance to oxidative protein unfolding conditions, we made use of V. cholerae strain O395 lacking the Hsp33 gene hslO. We found that this strain, which is exquisitely bleach‐sensitive, displays a temperature‐sensitive (ts) phenotype during aerobic growth, implying that V. cholerae suffers from oxidative heat stress when cultivated at 43°C. We utilized this phenotype to select for E. coli genes that rescue the ts phenotype of V. cholerae ΔhslO when overexpressed. We discovered that expression ...

A Survey of Gastrointestinal Parasites of Olive Baboons (Papio anubis) in Human Settlement areas of Mole National Park, Ghana.

The Journal of Parasitology — Thu, 02 Feb 2012 05:00:00 +0100

Authors: Ryan SJ, Brashares JS, Walsh C, Milbers K, Kilroy CM, Chapman CA Abstract Abstract Fecal samples from 55 free-ranging olive baboons (Papio anubis) in Mole National Park, Ghana, were collected June 22-July 7, 2008, and analyzed for gastrointestinal parasites. This is the first survey of baboon gastrointestinal parasites in Ghana and provides baseline data for this area. Ninety-three percent of samples were infected, leaving 7% with no parasites observed. Of those infected, there was a 76% prevalence of Strongyles, 53% Strongyloides spp., 11% Abbreviata caucasica, 62% prevalence of Balantidium coli (trophozoites and cysts identified), 4% Entomeba hystolytica/dispar and 47% unidentified protozoan parasites. Of the strongyle infections, 9% were identified as Oesophagostamum s...

Persistent Helicobacter pullorum colonization in C57BL/6NTac mice: A new mouse model for an emerging zoonosis.

Journal of Medical Microbiology — Thu, 02 Feb 2012 05:00:00 +0100

Authors: Turk ML, Cacioppo LD, Ge Z, Shen Z, Whary MT, Parry N, Boutin SR, Klein HJ, Fox JG Abstract Helicobacter pullorum, an enterohepatic Helicobacter species, is associated with gastroenteritis and hepatobiliary disease in humans and chickens. Recently a novel H. pullorum outbreak in barrier-maintained rats and mice was described. We further evaluated persistence of infection and serologic response in H. pullorum-infected female C57BL/6NTac and C3H/HeNTac mice obtained from the barrier outbreak. C57BL/6NTac mice (n=36) aged 10 to 58 weeks were confirmed to be chronically infected with H. pullorum by PCR or culture of cecum, colon and feces, with no evidence of hepatic infection; 2 of 3 C3H/HeNTac cleared H. pullorum infection by 26 weeks of age. A quantitative PCR assay based o...

Gastro-enteritis caused by Campylobacter concisus: case report and short review of literature.

Journal of Medical Microbiology — Thu, 02 Feb 2012 05:00:00 +0100

We describe a case of gastro-enteritis caused by Campylobacter concisus. The pathogenic potential of C. concisus has yet to be elucidated. Recent studies indicate an association with enteric disease in immunocompromised and inflammatory bowel disease in children. Molecular identification methods may be necessary for identifying certain Campylobacter species because of phenotypic similarity. PMID: 22301611 [PubMed - as supplied by publisher] (Source: Journal of Medical Microbiology)

Wave-Induced Mass Transport Affects Daily Escherichia coli Fluctuations in Nearshore Water

Environmental Science and Technology — Wed, 01 Feb 2012 21:24:39 +0100

Environmental Science & TechnologyDOI: 10.1021/es203847n (Source: Environmental Science and Technology)

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Time to positivity of blood culture association with clinical presentation, prognosis and ESBL-production in Escherichia coli bacteremia

European Journal of Clinical Microbiology and Infectious Diseases — Wed, 01 Feb 2012 17:11:02 +0100

Abstract The time to positivity (TTP) of blood cultures has been associated with increased mortality in bacteremia caused by several microorganisms. The aim of this study is to evaluate the relationship between TTP and prognosis, clinical presentation and extended spectrum B-lactamase (ESBL)-production in patients with Escherichia coli bacteremia. This is a retrospective observational study involving 226 adult patients with E. coli bacteremia. Data collected included underlying diseases, clinical presentation, prognosis factors, TTP, ESBL-production and outcome. Thirty-one (14%) patients had severe sepsis and 29 (13%) septic shock at presentation. Thirty-three (14%) strains were ESBL-producers. Thirty-nine (17%) patients died during admission and 17 (7.5%) within 48 hours. T...

Evaluation of antigen specific recognition and cell mediated cytotoxicity by a modified lysispot assay in a rat colon carcinoma model

Journal of Experimental and Clinical Cancer Research — Wed, 01 Feb 2012 05:00:00 +0100

Conclusions: The assay proved to be highly sensitive and specific, detecting even low frequencies of cytotoxic/activated cells and providing the evaluation of cytokine-expressing T cells as well as the extent of cytotoxicity against the target cells as independent functions. This assay may represent an important tool to be adopted in experimental settings including the development of vaccines or immune therapeutic strategies (Source: Journal of Experimental and Clinical Cancer Research)

Rapid Intravenous Rehydration in Gastroenteritis

AAP Grand Rounds — Wed, 01 Feb 2012 05:00:00 +0100

(Source: AAP Grand Rounds)

Antibiotic Therapy and Early Onset Sepsis

NeoReviews recent issues — Wed, 01 Feb 2012 05:00:00 +0100

Early onset sepsis in the newborn infant continues to be an important clinical problem for neonatologists everywhere in the world. Different routes of transmission, changes in causative agents, and potential antibiotic resistance all influence the choice of antibiotic therapy. Group B Streptococcus and Escherichia coli continue to be the major pathogens dictating antibiotic therapy in the United States. Ampicillin and gentamicin are the antibiotics used by most for empirical therapy; cephalosporins are used in certain clinical situations. In this review, we address the reasons for these choices while highlighting clinically relevant aspects of the antibiotics commonly used in the treatment of early onset sepsis in the newborn. (Source: NeoReviews recent issues)

A vast collection of microbial genes that are toxic to bacteria [RESOURCES]

Genome Research — Wed, 01 Feb 2012 05:00:00 +0100

In the process of clone-based genome sequencing, initial assemblies frequently contain cloning gaps that can be resolved using cloning-independent methods, but the reason for their occurrence is largely unknown. By analyzing 9,328,693 sequencing clones from 393 microbial genomes we systematically mapped more than 15,000 genes residing in cloning gaps and experimentally showed that their expression products are toxic to the Escherichia coli host. A subset of these toxic sequences was further evaluated through a series of functional assays exploring the mechanisms of their toxicity. Among these genes our assays revealed novel toxins and restriction enzymes, and new classes of small non-coding toxic RNAs that reproducibly inhibit E. coli growth. Further analyses also revealed abundant, short ...

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A naturally occurring nonapeptide functionally compensates the CP1 domain of leucyl-tRNA synthetase to modulate aminoacylation activity.

The Biochemical Journal — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Tan M, Yan W, Liu RJ, Wang M, Chen X, Zhou XL, Wang ED Abstract Aminoacyl-tRNA synthetases (aaRSs) establish the rules of the genetic code by catalyzing the formation of aminoacyl-tRNA. The quality control for aminoacylation reaction is achieved by editing activity, which is usually carried out by a discrete editing domain. For leucyl-tRNA synthetase (LeuRS), the connective peptide 1 (CP1) domain is the editing domain responsible for hydrolyzing mis-charged tRNA. The CP1 domain is universally present in LeuRSs except LeuRS from Mycoplasma mobile (MmLeuRS). The substitute of CP1 in MmLeuRS is a nonapeptide (MmLinker). We show here that the MmLinker, which is critical for aminoacylation activity of MmLeuRS, could confer remarkable tRNA charging activity to the inactive CP1-d...

Effects of Cranberry Extracts on Growth and Biofilm Production of Escherichia coli and Staphylococcus species

Phytotherapy Research — Wed, 01 Feb 2012 05:00:00 +0100

This study evaluated the effects of three proprietary PAC‐standardized cranberry extracts on the inhibition of bacterial growth and biofilm production against a panel of clinically relevant pathogens: Staphylococcus epidermidis, Staphylococcus aureus, clinical methicillin‐resistant S. aureus (MRSA), Staphylococcus saprophyticus and Escherichia coli. The extracts inhibited the growth of the Gram‐positive bacteria (Staphylococcus spp.) but not the Gram‐negative species (E. coli) with minimum inhibitory concentrations in the range 0.02–5 mg/mL. The extracts also inhibited biofilm production by the Gram‐positive bacteria but did not eradicate their established biofilm. These results suggest that cranberry may have beneficial effects against the growth and biofilm producing capabi...

Investigating the Effectiveness of St John's Wort Herb as an Antimicrobial Agent against Mycobacteria

Phytotherapy Research — Wed, 01 Feb 2012 05:00:00 +0100

A persistent need exists for effective treatment agents for mycobacterial infections. This research investigated the effectiveness of the Hypericum perforatum herb (commonly known as St John's wort; SJW) in its growth inhibition of mycobacteria. A SJW extract was effective at inhibiting five nonpathogenic Mycobacterium isolates and Bacillus subtilis, but not Escherichia coli. Quantitative studies of concentration sensitivity to the SJW extract were performed with minimal bactericidal concentrations (MBC) ranging from 0.33 to 2.66 mg extract/mL. The SJW compounds hyperforin (Hfn), hypericin (Hpn), and pseudohypericin (Phn) were quantified in the extract using HPLC. The SJW extract solution of 133 mg extract/mL used in this study contained 2.3 mg Hfn/mL, 0.8 mg Hpn/mL, and 2.1 mg P...

A naturally occurring nonapeptide functionally compensates the CP1 domain of leucyl-tRNA synthetase to modulate aminoacylation activity

BJ Gene — Wed, 01 Feb 2012 05:00:00 +0100

Aminoacyl-tRNA synthetases (aaRSs) establish the rules of the genetic code by catalyzing the formation of aminoacyl-tRNA. The quality control for aminoacylation reaction is achieved by editing activity, which is usually carried out by a discrete editing domain. For leucyl-tRNA synthetase (LeuRS), the connective peptide 1 (CP1) domain is the editing domain responsible for hydrolyzing mis-charged tRNA. The CP1 domain is universally present in LeuRSs except LeuRS from Mycoplasma mobile (MmLeuRS). The substitute of CP1 in MmLeuRS is a nonapeptide (MmLinker). We show here that the MmLinker, which is critical for aminoacylation activity of MmLeuRS, could confer remarkable tRNA charging activity to the inactive CP1-deleted LeuRS from Escherichia coli (EcLeuRS) and Aquifex aeolicus (AaLeuRS). Furt...

Prolonged and Mixed non‐O157 E. coli Infection in an Australian Household

Clinical Microbiology and Infection — Wed, 01 Feb 2012 05:00:00 +0100

This study illustrates the potentially complicated nature of non‐O157 STEC infections and the importance of molecular epidemiology in understanding disease clusters. (Source: Clinical Microbiology and Infection)

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The major secreted protein Msp1/p75 is O-glycosylated in Lactobacillus rhamnosus GG

Microbial Cell Factories — Wed, 01 Feb 2012 05:00:00 +0100

Conclusions: In this study we have provided the first evidence of protein O-glycosylation in the probiotic L rhamnosus GG. The major secreted protein Msp1 is glycosylated with a ConA reactive glycan at the serine residues at 106 and 107. Glycosylation is not required for the peptidoglycan hydrolase activity of Msp1 nor for Akt activation capacity in epithelial cells, but appears to be important for its stability and protection against proteases. (Source: Microbial Cell Factories)

Detection and Transmission of Dientamoeba fragilis from Environmental and Household Samples.

The American Journal of Tropical Medicine and Hygiene — Wed, 01 Feb 2012 05:00:00 +0100

This study provides evidence that environmental transmission of D. fragilis is unlikely and that pets played no role in transmission of the disease in this study. Direct transmission from infected persons is the most likely mode of transmission for D. fragilis. The study also highlights the need for household contacts to be screened, given the propensity of close contacts to become infected with the organism. PMID: 22302854 [PubMed - in process] (Source: The American Journal of Tropical Medicine and Hygiene)

Plant chitinase III Ziz m 1 stimulates multiple cytokines, most predominantly interleukin-13, from peripheral blood mononuclear cells of latex-fruit allergic patients.

Annals of Allergy, Asthma and Immunology — Wed, 01 Feb 2012 05:00:00 +0100

CONCLUSIONS: The biological function of chitinase activity is required for Ziz m 1 to induce a Th2-specific immune response. This is the first report on PBMC responses of latex-fruit syndrome subjects toward an active exogenous plant class III chitinase that can stimulate multiple cytokines, especially IL-13, from allergic subjects. This implies the role of cross-reactive food allergens in propagating allergic inflammation among allergic subjects. PMID: 22289730 [PubMed - in process] (Source: Annals of Allergy, Asthma and Immunology)

[Segmental Necrotizing Colitis in a Patient with E. coli O104:H4 Infection.]

Zeitschrift fur Gastroenterologie — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Scheppach W, Reißmann N, Breunig E, Konwisorz A, Schwarz TF, Müller JG, Tappe D Abstract A 29-year-old man presented with abdominal cramps and bloody diarrhoea. Blood tests revealed elevated C-reactive protein (21.3 mg/dL; normal range 0.01 - 0. 82 mg/dL) and white blood cells (28 200 /μL, normal range 4000 - 10 000 /μL). Stool tests were negative for enteropathogenic bacteria and Clostridium difficile toxins A/B. Ultrasound and computed tomography showed massive swelling of the transverse colon and right colonic flexure. At endoscopy, circular necrosis of the mucosa was encountered in the proximal segments of the colon whereas distal parts of the organ showed patchy inflammation of minor severity. Extended stool testing identified Escherichia coli type O10...

Domain organization of Legionella effector SetA

Cellular Microbiology — Tue, 31 Jan 2012 20:40:43 +0100

SummaryLegionella pneumophila is a human pathogen causing severe pneumonia called Legionnaires' disease. Multiple Legionella effectors are type IV‐secreted into the host cell to establish a specific vesicular compartment for pathogen replication. Recently it has been reported that the Legionella effector SetA shares sequence similarity with glycosyltransferases and interferes with vesicular trafficking of host cells (Heidtman et al., 2009, Cell Microbiol 11: 230). Here we show that SetA possesses glycohydrolase and mono‐O‐glucosyltransferase activity by using UDP‐glucose as a donor substrate. Whereas the catalytic activity is located at the N terminus of SetA, the C terminus (amino acids 401‐644) is essential for guidance of SetA to vesicular compartments of host cells. EGFP‐Se...

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Norovirus is the leading cause of infection outbreaks in US hospitals

EurekAlert! - Medicine and Health — Tue, 31 Jan 2012 05:00:00 +0100

(Elsevier Health Sciences) Norovirus, a pathogen that often causes food poisoning and gastroenteritis, was responsible for 18.2 percent of all infection outbreaks and 65 percent of ward closures in US hospitals during a two-year period, according to a new study published in the February issue of the American Journal of Infection Control, the official publication of APIC - the Association for Professionals in Infection Control and Epidemiology. (Source: EurekAlert! - Medicine and Health)

Effect of Continuous Ohmic Heating to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in Orange and Tomato Juice

Journal of Applied Microbiology — Tue, 31 Jan 2012 05:00:00 +0100

Conclusions: Continuous ohmic heating can be effective at killing foodborne pathogens on orange and tomato juice with lower degradation of quality than conventional heating.Significance and Impact of Study: These results suggest that continuous ohmic heating might be effectively used to pasteurize fruit and vegetable juice in a short operating time and that the effect of inactivation depends on applied electric field strengths, treatment time and electric conductivity.© 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology (Source: Journal of Applied Microbiology)

E. Coli Symptoms

About.com Eating Disorders — Tue, 31 Jan 2012 05:00:00 +0100

Although these infections are not common, parents should be aware of the symptoms of E. coli O157:H7 infections, which can include bloody diarrhea, fever, and stomach cramps. (Source: About.com Eating Disorders)

Low‐dose Azithromycin improves phagocytosis of bacteria by both alveolar and monocyte‐derived macrophagesin COPD subjects

Respirology — Tue, 31 Jan 2012 05:00:00 +0100

Conclusions:: The data provide further support for the long term use of low dose azithromycin as an attractive adjunct treatment option for COPD. Improved clearance of both apoptotic cells and bacteria in the airway may have a dual effect; reducing the risk of secondary necrosis and release of toxic cell contents that perpetuate inflammation as well as contributing to a reduction in the rate of exacerbations in COPD.© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology (Source: Respirology)

Efficient coupling of ATP hydrolysis to translocation by RecQ helicase [Biochemistry]

Proceedings of the National Academy of Sciences — Tue, 31 Jan 2012 05:00:00 +0100

Helicases are ubiquitous enzymes that unwind double-stranded DNA (dsDNA) to reveal single-stranded DNA (ssDNA) during essential processes such as replication, transcription, or repair. The Escherichia coli RecQ protein is a 3′ to 5′ helicase, which functions in the processes of homologous recombination and replication fork restart. Here, we analyzed the relationship between ATP hydrolysis by RecQ and its translocation on ssDNA. We monitored a single round of RecQ translocation on ssDNA by measuring the rates of inorganic phosphate release during translocation, and the dissociation of RecQ from ssDNA. We find that RecQ translocates with a rate of 16( ± 4) nucleotides/s and moves on average only 36( ± 2) nucleotides before dissociating. Fitting to an n-step kinetic model suggests t...

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In-feed antibiotic effects on the swine intestinal microbiome [Microbiology]

Proceedings of the National Academy of Sciences — Tue, 31 Jan 2012 05:00:00 +0100

Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1–11%) compa...

Noninvasive inference of the molecular chemotactic response using bacterial trajectories [Systems Biology]

Proceedings of the National Academy of Sciences — Tue, 31 Jan 2012 05:00:00 +0100

The quality of sensing and response to external stimuli constitutes a basic element in the selective performance of living organisms. Here we consider the response of Escherichia coli to chemical stimuli. For moderate amplitudes, the bacterial response to generic profiles of sensed chemicals is reconstructed from its response function to an impulse, which then controls the efficiency of bacterial motility. We introduce a method for measuring the impulse response function based on coupling microfluidic experiments and inference methods: The response function is inferred using Bayesian methods from the observed trajectories of bacteria swimming in microfluidically controlled chemical fields. The notable advantages are that the method is based on the bacterial swimming response, it is noninva...

Gene expression and functional studies of small heat shock protein 37 (MrHSP37) from Macrobrachium rosenbergii challenged with infectious hypodermal and hematopoietic necrosis virus (IHHNV).

Molecular Biology Reports — Tue, 31 Jan 2012 05:00:00 +0100

In this study, we have reported a full length of small heat shock protein 37 (designated MrHSP37) gene, identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrHSP37 is 2,425 base pairs in length, and encodes 338 amino acids. MrHSP37 contains a long heat shock protein family profile in the amino acid sequence between 205 and 288. The mRNA expressions of MrHSP37 in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). MrHSP37 is highly expressed in hepatopancreas and all the other tissues (walking leg, gills, muscle, stomach, haemocyte, intestine, pleopods, brain and eye stalk) of M. rosenberg...

Isolation and identification of a bacteriocin with antibacterial and antibiofilm activity from Citrobacter freundii.

Archives of Microbiology — Tue, 31 Jan 2012 05:00:00 +0100

This study suggests that bacteriocins can be an effective way to control surface-attached pathogenic bacteria. PMID: 22290290 [PubMed - as supplied by publisher] (Source: Archives of Microbiology)

Ethyl Pyruvate Improves Healing of Colonic Anastomosis in a Rat Model of Peritonitis.

Surgical Innovation — Tue, 31 Jan 2012 05:00:00 +0100

Conclusions. EP administration prevented intraperitoneal sepsis-induced impaired anastomotic healing of colon. PMID: 22298750 [PubMed - as supplied by publisher] (Source: Surgical Innovation)

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How New Viruses Evolve, And In Some Cases, Become Deadly

Health News from Medical News Today — Mon, 30 Jan 2012 08:00:00 +0100

Researchers at Michigan State University (MSU) have demonstrated how a new virus evolves, shedding light on how easy it can be for diseases to gain dangerous mutations. The findings appear in the journal Science. The scientists showed for the first time how the virus called "Lambda" evolved to find a new way to attack host cells, an innovation that took four mutations to accomplish. This virus infects bacteria, in particular the common E. coli bacterium... (Source: Health News from Medical News Today)

Dealing with stress: New research highlights the survival skills of disease-causing E. coli

EurekAlert! - Medicine and Health — Mon, 30 Jan 2012 05:00:00 +0100

(Arizona State University) A team of researchers at Arizona State University's Biodesign Institute investigates disease-causing E. coli strains known as APEC. By studying circular segments of bacterial DNA known as plasmids, the group uncovered some of the tricks used by these highly adaptive organisms to survive, even in the face of daunting environmental challenges. (Source: EurekAlert! - Medicine and Health)

Predicting outcomes of steady-state 13C isotope tracing experiments with Monte Carlo sampling

BMC Systems Biology - Latest articles — Mon, 30 Jan 2012 05:00:00 +0100

Conclusions: While 13C analysis is a useful tool in systems biology, high redundancy in measurements limits the information that can be obtained from each experiment. It is however possible to compute potential limitations before an experiment is run and predict whether, and to what degree, the rate of each reaction can be resolved. (Source: BMC Systems Biology - Latest articles)

A small RNA that regulates motility and biofilm formation in response to changes in nutrient availability in Escherichia coli

Molecular Microbiology — Mon, 30 Jan 2012 05:00:00 +0100

SummaryIn bacteria, many small regulatory RNAs (sRNAs) are induced in response to specific environmental signals or stresses and act by base‐pairing with mRNA targets to affect protein translation or mRNA stability. In Escherichia coli, the gene for the sRNA IS061/IsrA, here renamed McaS, was predicted to reside in an intergenic region between abgR, encoding a transcription regulator and ydaL, encoding a small MutS‐related protein. We show that McaS is a ∼ 95 nt transcript whose expression increases over growth, peaking in early‐to‐mid stationary phase, or when glucose is limiting. McaS uses three discrete single‐stranded regions to regulate mRNA targets involved in various aspects of biofilm formation. McaS represses csgD, the transcription regulator of curli biogenesis an...

Construction and completion of flux balance models from pathway databases

Bioinformatics — Mon, 30 Jan 2012 05:00:00 +0100

We present a multiple gap-filling method to accelerate the development of FBA models using a new tool, called MetaFlux, based on mixed integer linear programming (MILP). The method suggests corrections to the sets of reactions, biomass metabolites, nutrients and secretions. The method generates FBA models directly from Pathway/Genome Databases. Thus, FBA models developed in this framework are easily queried and visualized using the Pathway Tools software. Predicted fluxes are more easily comprehended by visualizing them on diagrams of individual metabolic pathways or of metabolic maps. MetaFlux can also remove redundant high-flux loops, solve FBA models once they are generated and model the effects of gene knockouts. MetaFlux has been validated through construction of FBA models for Escher...

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Development of label-free optical diagnosis for sensitive detection of influenza virus with genetically engineered fusion protein.

Talanta — Mon, 30 Jan 2012 05:00:00 +0100

Authors: Park TJ, Lee SJ, Kim DK, Heo NS, Park JY, Lee SY Abstract An active immobilization method utilizing the metal-binding property was developed and examined for its ability to facilitate the biosensing of avian influenza virus. The special biosensing performance with optical plasmonic analysis, including surface plasmon resonance (SPR) was evaluated on gold substrate and also by SPR imaging (SPRi) and localized SPR (LSPR) system where antigen-antibody interaction occurs. A complete optical analytical system was developed by integrating microarray and fabricating nanoparticles onto a single glass chip, thus allowing specific and sensitive diagnosis with subsequent binding. Reaction condition for the maximum reactivity was optimized by SPR analysis and more sensitive interactio...

One-step generation of error-prone PCR libraries using Gateway(R) technology

Microbial Cell Factories — Mon, 30 Jan 2012 05:00:00 +0100

Conclusions: The one-step method enables producing epPCR libraries of as high complexity and quality as does the regular, two-step, protocol for half the amount of work. In addition, it contributes to preserve the original complexity of the epPCR product. (Source: Microbial Cell Factories)

Efficacy of a post enrichment acid treatment for isolation of Escherichia coli O157:H7 from alfalfa sprouts.

Food Microbiology — Sun, 29 Jan 2012 21:53:47 +0100

Authors: Fedio WM, Jinneman KC, Yoshitomi KJ, Zapata R, Weagant SD Abstract The enrichment, detection and isolation procedure in the current US FDA BAM have been shown effective for Escherichia coli O157:H7 in a wide variety of foods. Recently reported modifications to the enrichment protocol, including post-enrichment immunomagnetic separation (IMS) procedures have improved sensitivity of the method for alfalfa sprouts. However, cultural isolation on selective agar plates still presents a challenge in this food matrix. The focus of this study was to reduce levels of competing microflora and enhance isolation of E. coli O157:H7 on selective agars. We optimized the use of a short acid treatment after enrichment and with post-enrichment IMS beads. The optimized acid treatments were ...

The antimicrobial properties of the lowbush blueberry (Vaccinium angustifolium) fractional components against foodborne pathogens and the conservation of probiotic Lactobacillus rhamnosus.

Food Microbiology — Sun, 29 Jan 2012 21:52:53 +0100

Authors: Lacombe A, Wu VC, White J, Tadepalli S, Andre EE Abstract The antimicrobial properties of lowbush blueberry (Vaccinium angustifolium) were studied against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Lactobacillus rhamnosus to determine which fractional components have antimicrobial effects and which microorganisms are most susceptible to these antimicrobial properties. Lowbush blueberry extract (F1) was separated using a C-18 Sep-Pak cartridge into monomeric phenolics (F2) and anthocyanins plus proanthocyanidins (F3). Fraction 3 was further separated into anthocyanins (F4) and proanthocyanidins (F5) using a LH-20 Sephadex column. Each fraction was initially screened for antimicrobial properties using agar diffusion assay. Treatments that d...

Electrochemical disinfection: An efficient treatment to inactivate Escherichia coli O157:H7 in process wash water containing organic matter.

Food Microbiology — Sun, 29 Jan 2012 21:52:20 +0100

Authors: López-Gálvez F, Posada-Izquierdo GD, Selma MV, Pérez-Rodríguez F, Gobet J, Gil MI, Allende A Abstract The efficacy of an electrochemical treatment in water disinfection, using boron-doped diamond electrodes, was studied and its suitability for the fresh-cut produce industry analyzed. Tap water (TW), and tap water supplemented with NaCl (NaClW) containing different levels of organic matter (Chemical Oxygen Demand (COD) around 60, 300, 550 ± 50 and 750 ± 50 mg/L) obtained from lettuce, were inoculated with a cocktail of Escherichia coli O157:H7 at 10(5) cfu/mL. Changes in levels of E. coli O157:H7, free, combined and total chlorine, pH, oxidation-reduction potential, COD and temperature were monitored during the treatments. In NaClW, free chlorine was produced m...

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Antimicrobial activity of cyclodextrin entrapped allyl isothiocyanate in a model system and packaged fresh-cut onions.

Food Microbiology — Sun, 29 Jan 2012 21:50:58 +0100

Authors: Piercey MJ, Mazzanti G, Budge SM, Delaquis PJ, Paulson AT, Truelstrup Hansen L Abstract The aim of this work was to determine the antimicrobial effect of allyl isothiocyanate (AIT) entrapped in alpha and beta cyclodextrin inclusion complexes (ICs). In model experiments, AIT formulations were applied to filter paper discs fixed inside the lid of Petri dishes, where the agar surface was inoculated with the target organism (Penicillium expansum, Escherichia coli or Listeria monocytogenes). Solid phase microextraction coupled with gas chromatography was used to determine static headspace concentrations of AIT formulations. The antimicrobial effect of beta IC was determined during aerobic storage of packaged fresh-cut onions at 5 °C for 20 days. AIT entrapped in beta IC exhib...

Reduction of food matrix interference by a combination of sample preparation and multi-dimensional gating techniques to facilitate rapid, high sensitivity analysis for Escherichia coli serotype O157 by flow cytometry.

Food Microbiology — Sun, 29 Jan 2012 21:49:15 +0100

Authors: Wilkes JG, Tucker RK, Montgomery JA, Cooper WM, Sutherland JB, Buzatu DA Abstract Escherichia coli serotype O157 strains, which may be found in foods, often produce enterohemorrhagic toxins. The research goal was to facilitate rapid, sensitive detection in foods of E. coli serotype O157 by flow cytometry. Sample preparation methods were developed for potential use in 15 foods. Combined with multi-dimensional gating, these methods decreased time-to-results (TTR) for determination of low-level contamination. They mitigated the effects of interfering food components, concentrated cells for analysis without growth or, when necessary, used short-term incubation. The results showed qualitative analysis that was equivalent to culture plating in accuracy and superior in sensitivi...

Application of propidium monoazide-qPCR to evaluate the ultrasonic inactivation of Escherichia coli O157:H7 in fresh-cut vegetable wash water.

Food Microbiology — Sun, 29 Jan 2012 21:48:23 +0100

Authors: Elizaquível P, Sánchez G, Selma MV, Aznar R Abstract The efficacy of sanitizing technologies in produce or in vegetable wash water is generally evaluated by plate count in selective media. This procedure is time consuming and can lead to misinterpretations because environmental conditions and sanitizing processes may affect bacterial growth or culturable capability. Thus, the aim of this study was to determine the applicability of a propidium monoazide real-time PCR (PMA-qPCR) method to monitor the inactivation by ultrasound treatment of foodborne bacteria in fresh-cut vegetable wash water. To this aim, lettuce wash water was artificially inoculated with Escherichia coli O157:H7 (10(6) CFU/mL) and treated by means of a continuous ultrasonic irradiation with a power dens...

Evaluation of shiga toxin-producing Escherichia coli (STEC) method for the detection and identification of STEC O104 strains from sprouts.

Food Microbiology — Sun, 29 Jan 2012 21:48:13 +0100

This study validated the use of a standard method to detect and recover two strains of E. coli O104 STEC at a level of approximately 1 CFU/g from sprouts. The use of additional serotype-specific real-time PCR assays and supplemental chromogenic media to assist the detection and recovery of these organisms were also evaluated. PMID: 22265319 [PubMed - in process] (Source: Food Microbiology)

Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

Advances in Pharmacological Sciences — Sun, 29 Jan 2012 18:41:46 +0100

The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight (4∘C), and subsequently cooked. The surface temperature reached 70∘C within 30 sec and 85∘C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained for C. jejuni, E. coli, and S. typhimurium, respectively. Chicken meat and refrigerated storage before cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resista...

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Peptidoglycan and lipopolysaccharide synergistically enhance bone resorption and osteoclastogenesis

Journal of Periodontal Research — Sun, 29 Jan 2012 05:00:00 +0100

Conclusion: Gram‐positive or gram‐negative PGN worked synergistically with LPS to induce bone resorption and osteoclastogenesis, possibly by co‐ordinating the effects of TLR2, NOD1, NOD2 and TLR4 signaling. (Source: Journal of Periodontal Research)

Organic solvent-tolerant elastase efficiently hydrolyzes insoluble, cross-linked, protein fiber of eggshell membranes.

Biotechnology Letters — Sun, 29 Jan 2012 05:00:00 +0100

Authors: Takenaka S, Hano S, Cheng M, Yoshida KI, Aoki K Abstract Eggshell membrane is a mechanically stable and insoluble cross-linked fibrous protein. Pseudomonas aeruginosa strain ME-4 synthesizes a metalloprotease that degrades the eggshell membrane. We cloned the encoding gene in Escherichia coli. The recombinant protease, over-expressed in E. coli, was inactive but addition of acetone to crude cell extracts restored the activity and removed many E. coli proteins. We purified the active, acetone-treated protease to homogeneity in a single chromatography step with 57% recovery. The recombinant protease partially hydrolyzed eggshell membrane and produced more soluble peptides and proteins than commercial elastase, α-chymotrypsin, and collagenase. The soluble peptides produced f...

APC gene deletions in gastric adenocarcinomas in a Chinese population: a correlation with tumour progression

Clinical and Translational Oncology — Sat, 28 Jan 2012 16:53:16 +0100

Conclusion Sporadic GCs exhibit different mechanisms of APC regulation. Content Type Journal ArticleCategory Research ArticlesPages 60-65DOI 10.1007/s12094-012-0762-xAuthors Zhengyu Fang, Biomedical Research Institute Shenzhen-PKU-HKUST Medical Center Guangdong Province, Shenzhen, People’s Republic of ChinaYi Xiong, Biomedical Research Institute Shenzhen-PKU-HKUST Medical Center Guangdong Province, Shenzhen, People’s Republic of ChinaJiana Li, Biomedical Research Institute Shenzhen-PKU-HKUST Medical Center Guangdong Province, Shenzhen, People’s Republic of ChinaLi Liu, Biomedical Research Institute Shenzhen-PKU-HKUST Medical Center Guangdong Province, Shenzhen, People’s Republic of ChinaWei Zhang, JNU-HKUST Joint Lab Ji-Nan University, Guangdong, People’s Repu...

Internal ribosome entry site mediates protein synthesis in yeast Pichia pastoris.

Biotechnology Letters — Sat, 28 Jan 2012 05:00:00 +0100

Authors: Liang S, Lin Y, Li C, Ye Y Abstract The imitation of translation, as mediated by internal ribosome entry sites, has not yet been reported in Pichia pastoris. An IRES element from Saccharomyces cerevisiae was demonstrated to direct the translation of a dicistronic mRNA in P. pastoris. The 5'-untranslated region of GPR1 mRNA, termed GPR, was cloned into a dual reporter construct containing an upstream Rhizomucor miehei lipase (RML) and a downstream β-galactosidase gene (lacZ) from Escherichia coli BL21. After being transformed into P. pastoris, the RML gene and lacZ were simultaneously expressed. The possibility of DNA rearrangement, spurious splicing, or cryptic promoter in the GPR sequence were eliminated, indicating that expression of a second ORF was IRES-dependent. The...

Adenosine deamination increases the survival under acidic conditions in Escherichia coli

Journal of Applied Microbiology — Sat, 28 Jan 2012 02:27:23 +0100

Conclusions: Our present results imply that adenosine was used to survive under extremely acidic conditions via the production of NH3.Significance and Impact of the Study: It has been proposed that amino acid decarboxylation is the major system for the resistance of E. coli to acidic stress. In the present study, the adenosine deamination was shown to induce the survival under acidic conditions, demonstrating that bacteria have alternative strategies to survive under acidic conditions besides amino acid decarboxylation.© 2012The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology (Source: Journal of Applied Microbiology)

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A two-sphere model for bacteria swimming near solid surfaces

Physics of Fluids — Sat, 28 Jan 2012 01:37:38 +0100

We present a simple model for bacteria like Escherichia coli swimming near solid surfaces. It consists of two spheres of different radii connected by a dragless rod. The effect of the flagella is taken into account by imposing a force on the tail sphere and opposite torques exerted by the rod over t ... [Phys. Fluids 24, 011901 (2012)] published Fri Jan 27, 2012. (Source: Physics of Fluids)

Evidence for a Complex Relationship between Antibiotics and Antibiotic-Resistant Escherichia Coli: From Medical Center Patients to a Receiving Environment

Environmental Science and Technology — Fri, 27 Jan 2012 18:38:29 +0100

Environmental Science & TechnologyDOI: 10.1021/es203399h (Source: Environmental Science and Technology)

[Report] The Molecular Diversity of Adaptive Convergence

Science: Current Issue — Fri, 27 Jan 2012 17:42:31 +0100

Replicate Escherichia coli lines show multiple convergent adaptations via different mutations in response to high temperature.Authors: Olivier Tenaillon, Alejandra Rodríguez-Verdugo, Rebecca L. Gaut, Pamela McDonald, Albert F. Bennett, Anthony D. Long, Brandon S. Gaut (Source: Science: Current Issue)

Impact of Growth Conditions on Transport Behavior of E. coli

RSC - J. Environ. Monit. latest articles — Fri, 27 Jan 2012 16:39:43 +0100

J. Environ. Monit., 2012, Accepted ManuscriptDOI: 10.1039/C2EM10960C, PaperIan Marcus, Carl Bolster, Kimberley L Cook, Stephen Opot, Sharon L. WalkerThe aim of this investigation is to determine the effect that growth solution has on cell surface properties and transport behavior of eleven E. coli isolates through saturated porous media....The content of this RSS Feed (c) The Royal Society of Chemistry (Source: RSC - J. Environ. Monit. latest articles)

Scleroderma digital ulcers complicated by infection with fecal pathogens

Arthritis Care and Research — Fri, 27 Jan 2012 10:29:36 +0100

ConclusionA number of effective measures involving health care personnel and hospital environment are essential in the management of digital ulcers and prevention of infectious complications. In addition, the prevalence of fecal pathogens in one‐quarter of cases, never reported previously, suggests an important role of a patient's self‐care limitations, mainly during intercurrent home medications. Consequently, methodical education on hand hygiene of both patients and relatives, frequently involved in ulcer medications, is mandatory to avoid such deleterious complications. (Source: Arthritis Care and Research)

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MSU technology spin-out company to market portable biohazard detection

EurekAlert! - Medicine and Health — Fri, 27 Jan 2012 05:00:00 +0100

(Michigan State University) A new company formed around Michigan State University nanotechnology promises to move speedy detection of deadly pathogens and toxins from the laboratory directly to the field. Food contamination and other biohazards present a growing public health concern, but laboratory analysis consumes precious time. The company, nanoRETE, will develop and commercialize an inexpensive test for handheld biosensors to detect a broad range of threats such as E. coli, Salmonella, anthrax and tuberculosis. (Source: EurekAlert! - Medicine and Health)

Substrate Specificity of ProRS INS Domain [RNA]

Journal of Biological Chemistry — Fri, 27 Jan 2012 05:00:00 +0100

Aminoacyl-tRNA synthetases catalyze the covalent attachment of amino acids onto their cognate tRNAs. High fidelity in this reaction is crucial to the accurate decoding of genetic information and is ensured, in part, by proofreading of the newly synthesized aminoacyl-tRNAs. Prolyl-tRNA synthetases (ProRS) mischarge tRNAPro with alanine or cysteine due to their smaller or similar sizes relative to cognate proline. Mischarged Ala-tRNAPro is hydrolyzed by an editing domain (INS) present in most bacterial ProRSs. In contrast, the INS domain is unable to deacylate Cys-tRNAPro, which is hydrolyzed exclusively by a freestanding trans-editing domain known as YbaK. Here, we have used computational and experimental approaches to probe the molecular basis of INS domain alanine specificity. We show tha...

Modification of Flagellar Rod Protein FlgG by C. jejuni [Membrane Biology]

Journal of Biological Chemistry — Fri, 27 Jan 2012 05:00:00 +0100

Gram-negative bacteria assemble complex surface structures that interface with the surrounding environment and are involved in pathogenesis. Recent work in Campylobacter jejuni identified a gene encoding a novel phosphoethanolamine (pEtN) transferase Cj0256, renamed EptC, that serves a dual role in modifying the flagellar rod protein, FlgG, and the lipid A domain of C. jejuni lipooligosaccharide with a pEtN residue. In this work, we characterize the unique post-translational pEtN modification of FlgG using collision-induced and electron transfer dissociation mass spectrometry, as well as a genetic approach using site-directed mutagenesis to determine the site of modification. Specifically, we show that FlgG is modified with pEtN at a single site (Thr75) by EptC and demonstrate enzyme speci...

Crystallization and preliminary X-ray analysis of the Clostridium botulinum type D nontoxic nonhaemagglutinin

Acta Crystallographica Section F — Fri, 27 Jan 2012 05:00:00 +0100

Clostridium botulinum produces botulinum neurotoxin (BoNT) as a large toxin complex assembled with nontoxic nonhaemagglutinin (NTNHA) and/or haemagglutinin components. Complex formation with NTNHA is considered to be critical in eliciting food poisoning because the complex shields the BoNT from the harsh conditions in the digestive tract. In the present study, NTNHA was expressed in Escherichia coli and crystallized. Diffraction data were collected to 3.9 Å resolution. The crystal belonged to the trigonal space group P321 or P3121/P3221, with unit-cell parameters a = b = 147.85, c = 229.74 Å. The structure of NTNHA will provide insight into the assembly mechanism that produces the unique BoNT–NTNHA complex. (Source: Acta Crystallographica Section F)

Refolding, purification and crystallization of the FrpB outer membrane iron transporter from Neisseria meningitidis

Acta Crystallographica Section F — Fri, 27 Jan 2012 05:00:00 +0100

FrpB is an integral outer membrane protein from the human pathogen Neisseria meningitidis. It is a member of the TonB-dependent transporter family and promotes the uptake of iron across the outer membrane. There is also evidence that FrpB is an antigen and hence a potential component of a vaccine against meningococcal meningitis. FrpB incorporating a polyhistidine tag was overexpressed in Escherichia coli into inclusion bodies. The protein was then solubilized in urea, refolded and purified to homogeneity. Two separate antigenic variants of FrpB were crystallized by sitting-drop vapour diffusion. Crystals of the F5-1 variant diffracted to 2.4 Å resolution and belonged to space group C2, with unit-cell parameters a = 176.5, b = 79.4, c = 75.9 Å, β = 98.3°. Crystal-packing calculatio...

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Expression, purification, crystallization and preliminary X-ray diffraction analysis of a ribokinase from the thermohalophile Halothermothrix orenii

Acta Crystallographica Section F — Fri, 27 Jan 2012 05:00:00 +0100

A ribokinase gene (rbk) from the anaerobic halothermophilic bacterium Halothermothrix orenii was cloned and overexpressed in Escherichia coli. The recombinant protein (Ho-Rbk) was purified using immobilized metal-ion affinity chromatography and crystals were obtained using the sitting-drop method. Diffraction data were collected to a resolution of 3.1 Å using synchrotron radiation. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 45.6, b = 61.1, c = 220.2, and contained two molecules per asymmetric unit. A molecular-replacement solution has been found and attempts are currently under way to build a model of the ribokinase. Efforts to improve crystal quality so that higher resolution data can be obtained are also being considered. (Source: Act...

Crystallization and preliminary X-ray diffraction analysis of orotate phosphoribosyltransferase from the human malaria parasite Plasmodium falciparum

Acta Crystallographica Section F — Fri, 27 Jan 2012 05:00:00 +0100

Orotate phosphoribosyltransferase (OPRT) catalyzes the Mg2+-dependent condensation of orotic acid (OA) with 5-α-d-phosphorylribose 1-diphosphate (PRPP) to yield diphosphate (PPi) and the nucleotide orotidine 5′-monophosphate. OPRT from Plasmodium falciparum produced in Escherichia coli was crystallized by the sitting-drop vapour-diffusion method in complex with OA and PRPP in the presence of Mg2+. The crystal exhibited tetragonal symmetry, belonging to space group P41 or P43, with unit-cell parameters a = b = 49.15, c = 226.94 Å. X-ray diffraction data were collected to 2.5 Å resolution at 100 K using a synchrotron-radiation source. (Source: Acta Crystallographica Section F)

Heterogonous expression and characterization of a plant class IV chitinase from the pitcher of the carnivorous plant Nepenthes alata

Glycobiology — Fri, 27 Jan 2012 05:00:00 +0100

A class IV chitinase belonging to the glycoside hydrolase 19 family from Nepenthes alata (NaCHIT1) was expressed in Escherichia coli. The enzyme exhibited weak activity toward polymeric substrates and significant activity toward (GlcNAc)n [β-1,4-linked oligosaccharide of GlcNAc with a polymerization degree of n (n = 4–6)]. The enzyme hydrolyzed the third and fourth glycosidic linkages from the non-reducing end of (GlcNAc)6. The pH optimum of the enzymatic reaction was 5.5 at 37°C. The optimal temperature for activity was 60°C in 50 mM sodium acetate buffer (pH 5.5). The anomeric form of the products indicated that it was an inverting enzyme. The kcat/Km of the (GlcNAc)n hydrolysis increased with an increase in the degree of polymerization. Amino acid seque...

Assessment of Microbial Quality of Commercial and Home‐Made Tiger‐Nut Beverages

Letters in Applied Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Conclusions: These results reflected that there exists a rather high contamination level in home‐made tiger‐nut beverages indicating the need to apply correct and strict HACCP system(s) during manufacturing and storage of these food products.Significance and Impact of Study: This study demonstrates the great need to carry out microbiological tests frequently in these products and even more the need to apply correct HACCP system (s). Tiger‐nut beverages are especially well‐known products in Spain, hence it is extremely important to ensure an adequate microbiological quality to guarantee consumers health.© 2012 The Authors Letters in Applied Microbiology © 2012 The Society for Applied Microbiology (Source: Letters in Applied Microbiology)

Prevalence and risk factors for Giardia duodenalis infection among children: A case study in Portugal

Parasites and Vectors — Fri, 27 Jan 2012 05:00:00 +0100

We investigated the prevalence of Giardia duodenalis infection and identified possible associated risk factors in a healthy paediatric population from Portugal. We highlight the high prevalence of G.duodenalis in these children, as well as the parents¿ education level as the main risk factor. Of interest, we also found an association between G. duodenalis and Helicobacter pylori infections. Image: Giardia duodenalis cysts stained by FICT. (Source: Parasites and Vectors)

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The genome and proteome of a Campylobacter coli bacteriophage vB_CcoM-IBB_35 reveal unusual features

Virology Journal — Fri, 27 Jan 2012 05:00:00 +0100

Conclusions: Genes encoding proteins involved in the carbohydrate metabolism along with several incidences of gene duplications, split genes with inteins and introns have been rarely found in other phage genomes yet are found in this phage. We identified the genes encoding for tail fibres and for the lytic cassette, this later, expressing enzymes for bacterial capsular polysaccharides (CPS) degradation, which has not been reported before for Campylobacter phages. (Source: Virology Journal)

Depolymerization of alginate into a monomeric sugar acid using Alg17C, an exo-oligoalginate lyase cloned from Saccharophagus degradans 2-40.

Applied Microbiology and Biotechnology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Kim HT, Chung JH, Wang D, Lee J, Woo HC, Choi IG, Kim KH Abstract Macroalgae are considered to be promising biomass for fuels and chemicals production. To utilize brown macroalgae as biomass, the degradation of alginate, which is the main carbohydrate of brown macroalgae, into monomeric units is a critical prerequisite step. Saccharophagus degradans 2-40 is capable of degrading more than ten different polysaccharides including alginate, and its genome sequence demonstrated that this bacterium contains several putative alginate lyase genes including alg17C. The gene for Alg17C, which is classified into the PL-17 family, was cloned and overexpressed in Escherichia coli. The recombinant Alg17C was found to preferentially act on oligoalginates with degrees of polymerization hi...

Whack-an-E. coli with the morbidostat

Genome Biology — Fri, 27 Jan 2012 05:00:00 +0100

Nathalie Balaban and colleagues highlight a landmark study of antibiotic resistance evolutionary trajectories, which is centered on a morbidostat (Source: Genome Biology)

Sequence Determinants Governing the Topology and Biological Activity of a Lasso Peptide, Microcin J25.

Chembiochem — Fri, 27 Jan 2012 05:00:00 +0100

In this study, we rationally designed and performed site-specific mutations in order to pinpoint the sequence determinants of the lasso topology. Structures of the resulting variants were analysed by a combination of methods (mass spectrometry, NMR spectroscopy, enzymatic digestion), and correlated to the antibacterial activity. The selected mutations resulted in the production of branched-cyclic or lasso variants. The C-terminal residues below the ring (Tyr20, Gly21) and the size of the macrolactam ring were revealed to be critical for both the lasso scaffold and bioactivity, while shortening the loop region (Tyr9-Ser18) or extending the C-terminal tail below the ring did not alter the lasso structure, but differentially affected the antibacterial activity. These results provide new insig...

Biosynthetic design and implementation towards E. coli-derived Taxol and other heterologous polyisoprene compounds.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Jiang M, Stephanopoulos G, Pfeifer BA Abstract Escherichia coli offers unparalleled engineering capacity in the context of heterologous natural product biosynthesis. However, like other heterologous hosts, cellular metabolism must be designed or re-designed to support final compound formation. This task is at once complicated and aided by the fact that the cell does not natively produce an abundance of natural products. As such, the metabolic engineer will avoid complicated interactions with native pathways closely associated with the outcome of interest, but this convenience is tempered by the need to implement the required metabolism to allow functional biosynthesis. This review will focus on engineering E. coli for the purpose of polyisoprene formation as related to tho...

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Disulfide bond formation and activation of Escherichia coli β-galactosidase under oxidizing conditions.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Seras-Franzoso J, Affentranger R, Ferrer-Navarro M, Daura X, Villaverde A, García-Fruitós E Abstract Escherichia coli β-galactosidase is probably the most widely used reporter enzyme in molecular biology, cell biology and biotechnology because of the easy detection of its activity. Its large size and tetrameric structure made this bacterial protein an interesting model for crystallographic studies and atomic mapping. In the present study, we investigate a version of Escherichia coli β-galactosidase produced under oxidizing conditions, in the cytoplasm of an Origami strain. Our data prove the activation of this microbial enzyme under oxidizing conditions and clearly show the occurrence of a disulfide bond in the β-galactosidase structure. Additionally, the formation of...

An engineered Escherichia coli silver-binding periplasmic protein promotes silver tolerance.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Hall Sedlak R, Hnilova M, Grosh C, Fong H, Baneyx F, Schwartz D, Sarikaya M, Tamerler C, Traxler B Abstract Silver toxicity is a problem that microorganisms face in medical and environmental settings. Through exposure to silver compounds, some bacteria have adapted to growth in high concentrations of silver ions. Such adapted microbes may be dangerous as pathogens, but alternatively could be potentially useful in nanomaterial manufacturing applications. While naturally adapted isolates typically utilize efflux pumps to achieve metal resistance, we have engineered a silver tolerant E. coli strain utilizing a simple silver-binding peptide motif. A silver-binding peptide, AgBP2, was identified from a combinatorial display library and fused to the C-terminus of the E. coli mal...

Functional cloning and characterization of antibiotic resistance genes from chicken gut microbiome.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Zhou W, Wang Y, Lin J Abstract Culture-independent sampling in conjunction with a functional cloning approach identified diverse antibiotic resistance genes for different classes of antibiotics in gut microbiomes from both conventionally raised and free range chickens. Many of the genes are phylogenetically distant from known resistance genes. Two unique genes that conferred ampicillin and spectinomycin resistance were also functional in Campylobacter, a distant relative of the E. coli host used to generate the genomic libraries. PMID: 22286984 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)

Molecular characterisation of the EhaG and UpaG trimeric autotransporter proteins from pathogenic Escherichia coli.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Totsika M, Wells TJ, Beloin C, Valle J, Allsopp LP, King NP, Ghigo JM, Schembri MA Abstract Trimeric autotransporter proteins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. A common feature of most TAAs is the ability to mediate adherence to eukaryotic cells or extracellular matrix (ECM) proteins via a cell-surface exposed passenger domain. Here we describe the characterization of EhaG, a TAA identified from enterohaemorrhagic E. coli (EHEC) O157:H7. EhaG is a positional orthologue of the recently characterized UpaG TAA from uropathogenic E. coli (UPEC). Similar to UpaG, EhaG localized at the bacterial cell surface and promoted cell aggregation, biofilm formation and adherence to a range of ECM proteins. However, the two orthologues displ...

Supplementation of intracellular XylR leads to co-utilization of hemicellulose sugars.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Groff D, Benke PI, Batth TS, Bokinsky G, Petzold CJ, Adams PD, Keasling JD Abstract E. coli has the potential to be a powerful biocatalyst for the conversion of lignocellulosic biomass into useful materials such as biofuels and polymers. One important challenge in using E. coli for the transformation of biomass sugars is diauxie or sequential utilization of different types of sugars. We demonstrate that by increasing the intracellular levels of the transcription factor XylR, the preferential consumption of arabinose before xylose can be eliminated. In addition, XylR augmentation must be finely tuned for robust co-utilization of these two hemicellulosic sugars. Using a novel technique for scarless gene insertion, an additional copy of xylR was inserted into the araBAD opero...

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Geraniol and geranial dehydrogenases induced in anaerobic monoterpene degradation by Castellaniella defragrans.

Applied and Environmental Microbiology — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Lüddeke F, Wülfing A, Timke M, Germer F, Weber J, Dikfidan A, Rahnfeld T, Linder D, Meyerdierks A, Harder J Abstract Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes to denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding ORF, the first bacterial gene for a geraniol dehydrogenase (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase (GeDH) is a homodimeric enzyme affiliating with the zinc-containing benzyl alcohol dehydrogenases in the medium-chain dehydrogenases/reductases (MDR) superfamily. The purified enzyme most efficient...

Study Finds Virus to Be Fast Learner on Infecting

NYT Health — Fri, 27 Jan 2012 01:28:15 +0100

Researchers report that viruses deprived of their usual channel for infiltrating the E. coli bacterium evolved a different route into the cells in little more than two weeks. (Source: NYT Health)

[Correspondence] Direct faecal PCR for diagnosis of Shiga-toxin-producing Escherichia coli

The Lancet Infectious Diseases — Thu, 26 Jan 2012 23:05:13 +0100

Martina Bielaszewska and colleagues characterised the Shiga-toxin-producing Escherichia coli (STEC) O104:H4 outbreak strain, which has been reported to cause gastroenteritis and haemolytic uraemic syndrome. They used a diagnostic protocol recommended by the Robert Koch Institute. Broth enrichment of faecal samples was followed by Shiga-toxin immunoassay or PCR to detect the genes encoding Shiga toxin (Stx) and other virulence factors, and microbiological culture was used as the gold standard. In our laboratory, we processed 754 faecal samples from 481 patients that were sent from affiliated hospitals and private practices in Bremen and Lower Saxony during the outbreak from May 23, to June 10, 2011. (Source: The Lancet Infectious Diseases)

[Correspondence] Is Escherichia coli bacteraemia preventable?

The Lancet Infectious Diseases — Thu, 26 Jan 2012 23:05:13 +0100

In response to yearly increases in Escherichia coli bacteraemia, the UK Department of Health recently launched mandatory E coli bacteraemia surveillance. Before starting this programme, the Department of Health should have reviewed historical data and contacted units, such as the Barking, Havering & Redbridge University Hospitals NHS Trust (BHRUT), that undertake bacteraemia surveillance. We have, therefore, pre-empted the surveillance findings and estimated the proportion of preventable E coli bacteraemias. (Source: The Lancet Infectious Diseases)

[Comment] Updating prevaccination rotavirus-associated mortality

The Lancet Infectious Diseases — Thu, 26 Jan 2012 23:05:12 +0100

In The Lancet Infectious Diseases, Jacqueline Tate and colleagues assess more than 40 reports published between 2008 and 2011 and recent data from WHO-coordinated Global Surveillance Networks, which established the rate of rotavirus-associated acute gastroenteritis in children younger than 5 years who were admitted to hospital in various parts of the world. From these rates and the actual numbers of childhood deaths in different countries related to all causes of diarrhoea, Tate and colleagues obtained estimates of deaths associated with rotavirus disease. (Source: The Lancet Infectious Diseases)

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In Real Time, a Virus Learns a New Way to Infect

NYT Health — Thu, 26 Jan 2012 19:26:55 +0100

Researchers report that viruses deprived of their usual channel for infiltrating the E. coli bacterium evolved a different route into the cells in little more than two weeks. (Source: NYT Health)

Evaluation of four phenotypic methods to detect plasmid-mediated AmpC β-lactamases in clinical isolates

European Journal of Clinical Microbiology and Infectious Diseases — Thu, 26 Jan 2012 06:56:38 +0100

Abstract Four phenotypic methods (three dimensional test, AmpC test, cloxacillin synergy test and cefotetan/cefotetan-cloxacillin E-test) to detect plasmid-mediated AmpC β-lactamases (pAmpC) were compared in 125 clinical Enterobacteriaceae isolates with AmpC profile: 74 E. coli (bla CMY-2: 70; bla DHA-1: 4), five K. pneumoniae (bla CMY-2: 2; bla DHA-1: 3), six P. mirabilis (bla CMY-2: 6) and 40 negative isolates for pAmpC β-lactamases. All evaluated methods showed a good sensitivity (>95%) but low values of specificity (<60%) in E. coli, explained by an increase of AmpC expression caused by chromosomal ampC promoter/attenuator mutations (−42, −18, −1, +58, predominantly). The cefotetan/cefotetan-cloxacillin or cloxacillin synergy test may be advocated as ph...

Crystallization and preliminary X-ray diffraction analysis of the metalloregulatory protein DtxR from Thermoplasma acidophilum

Acta Crystallographica Section F — Thu, 26 Jan 2012 05:00:00 +0100

The diphtheria toxin repressor (DtxR) is a metal-ion-dependent transcriptional regulator which regulates genes encoding proteins involved in metal-ion uptake to maintain metal-ion homeostasis. DtxR from Thermoplasma acidophilum was cloned and overexpressed in Escherichia coli. Crystals of N-terminally His-tagged DtxR were obtained by hanging-drop vapour diffusion and diffracted to 1.8 Å resolution. DtxR was crystallized at 296 K using polyethylene glycol 4000 as a precipitant. The crystals belonged to the orthorhombic space group P21212, with unit-cell parameters a = 61.14, b = 84.61, c = 46.91 Å, α = β = γ = 90°. The asymmetric unit contained approximately one monomer of DtxR, giving a crystal volume per mass (VM) of 2.22 Å3 Da−1 and a solvent content of 44.6%. (Source...

Crystallization and preliminary crystallographic analysis of LipC12, a true lipase isolated through a metagenomics approach

Acta Crystallographica Section F — Thu, 26 Jan 2012 05:00:00 +0100

LipC12, a true lipase from family I.1 of bacterial lipases which was previously isolated through a metagenomics approach, contains 293 amino acids. Among lipases of known three-dimensional structure, it has a sequence identity of 47% to the lipase from Pseudomonas aeruginosa PAO1. Recombinant N-terminally His6-tagged LipC12 protein was expressed in Escherichia coli, purified in a homogenous form and crystallized in several conditions, with the best crystals being obtained using 2.0 M sodium formate and 0.1 M bis-tris propane pH 7.0. X-ray diffraction data were collected to 2.70 Å resolution. The crystals belonged to the tetragonal space group P4122, with unit-cell parameters a = b = 58.62, c = 192.60 Å. (Source: Acta Crystallographica Section F)

Crystallization and preliminary X-ray crystallographic analysis of dioscorin from Dioscorea japonica

Acta Crystallographica Section F — Thu, 26 Jan 2012 05:00:00 +0100

Dioscorin, the major tuber storage protein in yam, has been reported to possess carbonic anhydrase, trypsin inhibitor, angiotensin-converting enzyme (ACE) inhibitor, free-radical scavenger, dehydroascorbate reductase and monodehydroascorbate reductase activities. Recent research has also found that dioscorin can enhance immune modulation via the toll-like receptor 4 (TLR-4) signal transduction pathway in RAW 264.7 cells, murine bone-marrow cells and human monocytes ex vivo. Resolving the structure of dioscorin would help in better understanding its activities and would provide clues to understanding the mechanism of its multiple functions. The full-length protein (residues 1–246) with an additional His6 tag at the N-terminus was expressed in Escherichia coli Rosetta (DE3) cells. After Hi...

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Crystallization and preliminary X-ray analysis of S-ribosylhomocysteinase from Streptococcus mutans

Acta Crystallographica Section F — Thu, 26 Jan 2012 05:00:00 +0100

S-Ribosylhomocysteinase (LuxS) encoded by the luxS gene from Streptococcus mutans plays a crucial role in the quorum-sensing system. LuxS was solubly expressed in Escherichia coli with high yield. The purity of the purified target protein, which was identified by SDS–PAGE and MALDI–TOF MS analysis, was >95%. The protein was crystallized using the hanging-drop vapour-diffusion method with PEG 3350 as the primary precipitant. X-ray diffraction data were collected at Beijing Synchrotron Radiation Facility (BSRF). Diffraction by the crystal extended to 2.4 Å resolution and the crystal belonged to space group C2221, with unit-cell parameters a = 55.3, b = 148.7, c = 82.8 Å. (Source: Acta Crystallographica Section F)

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of aspartyl aminopeptidase from the apeB gene of Pseudomonas aeruginosa

Acta Crystallographica Section F — Thu, 26 Jan 2012 05:00:00 +0100

Aminopeptidases (APs) are a group of exopeptidases that catalyze the removal of amino acids from the N-termini of proteins and peptides. The APs are ubiquitous in nature and are of critical biological and medical importance because of their key role in protein degradation. Pseudomonas aeruginosa aspartyl aminopeptidase (PaAAP), which is encoded by the apeB gene, was expressed in Escherichia coli, purified and crystallized using the microbatch method. A preliminary structural study has been performed using the X-ray crystallographic method. The PaAAP crystal diffracted to 2.0 Å resolution and belonged to the rhombohedral space group H3, with unit-cell parameters a = b = 133.6, c = 321.2. The unit-cell volume of the crystal is compatible with the presence of four monomers in the asym...

Antimicrobial Resistance and Virulence Factors in Escherichia coli from Swedish Dairy Calves

Acta Veterinaria Scandinavica — Thu, 26 Jan 2012 05:00:00 +0100

Conclusions: Antimicrobial resistance was common in E. coli from pre-weaned dairy calves, occurring particularly in calves from herds experiencing calf diarrhea problems. The results indicate that more factors than use of antimicrobials influence the epidemiology of resistant E. coli.Enteropathogenic E. coli seems to be an uncommon cause of neonatal calf diarrhea in Swedish dairy herds. In practice, calf diarrhea should be regarded holistically in a context of infectious agents, calf immunity, management practices etc. We therefore advice against routine antimicrobial treatment and recommend that bacteriological cultures, followed by testing for antimicrobial susceptibility and for virulence factors, are used to guide decisions on such treatment. (Source: Acta Veterinaria Scandinavica)

Role of anionic charges of osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium SL1344 in mice virulence.

Archives of Microbiology — Thu, 26 Jan 2012 05:00:00 +0100

Role of anionic charges of osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium SL1344 in mice virulence. Arch Microbiol. 2012 Jan 26; Authors: Bhagwat AA, Kannan P, Leow YN, Dharne M, Smith A Abstract opgB gene of Salmonella enterica serovar Typhimurium was identified earlier in a genome-wide screen for mice virulence (Valentine et al. in Infect Immun 66:3378-3383, 1998). Although mutation in opgB resulted in avirulent Salmonella strain, how this gene contributes to pathogenesis remains unclear. Based on DNA homology, opgB is predicted to be responsible for adding phosphoglycerate residues to osmoregulated periplasmic glucans (OPGs) giving them anionic characteristics. In Escherichia coli, yet another gene, opgC, is also...

An alkaline-active and alkali-stable pectate lyase from Streptomyces sp. S27 with potential in textile industry.

Journal of Industrial Microbiology and Biotechnology — Thu, 26 Jan 2012 05:00:00 +0100

Authors: Yuan P, Meng K, Shi P, Luo H, Huang H, Tu T, Yang P, Yao B Abstract A pectate lyase gene (pl-str) was cloned from Streptomyces sp. S27 and expressed in Escherichia coli Rosetta. The full-length pl-str consists of 972 bp and encodes for a protein of 323 amino acids without signal peptide that belongs to family PF00544. The recombinant enzyme (r-PL-STR) was purified to electrophoretic homogeneity using Ni(2+)-NTA chromatography and showed apparent molecular mass of ~35 kDa. The pH optimum of r-PL-STR was found to be 10.0, and it exhibited >70% of the maximal activity at pH 12.0. After incubation at 37°C for 1 h without substrate, the enzyme retained more than 55% activity at pH 7.0-12.0. Compared with the commercial complex enzyme Scourzyme(@)301L from Novozymes, pur...

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Outbreak of haemolytic uraemic syndrome due to Shiga toxin-producing Escherichia coli O104:H4 among French tourists returning from Turkey, September 2011

Eurosurveillance latest news — Thu, 26 Jan 2012 00:00:00 +0100

(Source: Eurosurveillance latest news)

A Case Study on the Economic Impact of Optimal Breastfeeding

Maternal and Child Health Journal — Wed, 25 Jan 2012 18:09:10 +0100

Abstract To develop a framework, using Louisiana as a case study, for estimating the potential cost savings to individual states if families were able to meet current recommendations for breastfeeding. Using cost-analyses methods, cost savings, as well as, case and death reductions of infant illnesses and deaths on four selected infant diseases (respiratory tract infections, gastroenteritis, necrotizing enterocolitis, and Sudden Infant Death Syndrome) were calculated utilizing the most recent data of breastfeeding and low/very low birth weight rates in Louisiana. To estimate the incidence of a disease in exclusive breastfed infants and formula fed infants respectively, we used the following formula: x = s/br + 1 − b. Here “x” is the incid...

Molecular characterization of β-lactam-resistant Escherichia coli isolated from Fu River, China

World Journal of Microbiology and Biotechnology — Wed, 25 Jan 2012 18:07:41 +0100

Abstract The present study aims to demonstrate the β-lactam resistance phenotypes and genotypes of Escherichia coli isolates from the Fu River in Chengdu, southwestern China. We obtained 108 E. coli isolates from nine sampling sites during May and December 2010. The total bacterial count varied from 79 colony-forming units (CFU)/ml to 14,550 CFU/ml, and coliform group number from 13 to 1,435 MPN/ml. Among the 108 isolates, 0–31.48% were resistant to β-lactams and β-lactam inhibitors, 1.85–7.40% to aminoglycoside, 1–20% to fluoroquinolone, and 50% to trimethoprim- sulfamethoxazole. The total bacterial count and antimicrobial resistance of different sites were significantly correlated (P < 0.05). Among the 34 ampicillin-resistant isolates, polymerase ...

New Discoveries In Cell Aging

Health News from Medical News Today — Wed, 25 Jan 2012 08:00:00 +0100

A group of researchers led by the Institute of Biotechnology and Biomedicine (IBB) and Universitat Autonoma de Barcelona (UAB) can now quantify with precision the effect of protein aggregation on cell aging processes using Escherichia coli bacteria and the molecule which triggers Alzheimer's disease as models. Scientists demonstrated that the effect can be predicted before it occurs. Protein aggregation is related to several diseases, including neurodegenerative diseases... (Source: Health News from Medical News Today)