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predatory bacteriovorax communities ordered by various prey species.the role of predation in altering microbial communities has been studied for decades but few examples are known for bacterial predators. bacteriovorax are halophilic prokaryotes that prey on susceptible gram-negative bacteria. we recently reported novel observations on the differential selection of bacteriovorax phylotypes by two different prey, vibrio parahaemolyticus and vibrio vulnificus. however, the conclusion is restricted by the limited number of prey tested. in this study, we have conduc ...201222461907
isolation, identification, and characterization of vibrio cholerae from the danube river in slovakia.the occurrence of vibrio cholerae, an important aquatic pathogen, was assessed in the surface water of the danube river near bratislava. the isolates were distinguished by biochemical tests and grouped by ardra to three clusters corresponding to three species (v. cholerae, vibrio metschnikovii, and aeromonas spp.). the identification of v. cholerae was confirmed by multiplex pcr using primer pairs targeted to ompw gene (membrane protein), ctxa gene (toxicity gene), and toxr gene (regulatory gene ...201222457232
cholera ante portas - the re-emergence of cholera in kinshasa after a ten-year hiatus.cholera is an endemic disease in certain well-defined areas in the east of the democratic republic of congo (drc). the west of the country, including the mega-city kinshasa, has been free of cases since mid 2001 when the last outbreak ended.201222453903
occurrence of vibrio cholerae in municipal and natural waters and incidence of cholera in azerbaijan.cholera, a waterborne disease caused by vibrio cholerae, is an autochthonous member of the aquatic environment and predominantly reported from developing countries. technical reports and proceedings were reviewed to determine the relationship between occurrence of v. cholerae in natural waters, including sources of municipal water, and cases of cholera in azerbaijan. water samples collected from different environmental sources from 1970 to 1998 were tested for v. cholerae and 0.73% (864/117,893) ...201122451165
structural characterization of cfa/iii and longus type ivb pili from enterotoxigenic escherichia coli.the type iv pili are helical filaments found on many gram-negative pathogenic bacteria, with multiple diverse roles in pathogenesis, including microcolony formation, adhesion, and twitching motility. many pathogenic enterotoxigenic escherichia coli (etec) isolates express one of two type iv pili belonging to the type ivb subclass: cfa/iii or longus. here we show a direct correlation between cfa/iii expression and etec aggregation, suggesting that these pili, like the vibrio cholerae toxin-coregu ...201222447901
replication regulation of vibrio cholerae chromosome ii involves initiator binding to the origin both as monomer and as dimer.the origin region of vibrio cholerae chromosome ii (chrii) resembles plasmid origins that have repeated initiator-binding sites (iterons). iterons are essential for initiation as well as preventing over-initiation of plasmid replication. in chrii, iterons are also essential for initiation but over-initiation is prevented by sites called 39-mers. both iterons and 39-mers are binding sites of the chrii specific initiator, rctb. here, we have isolated rctb mutants that permit over-initiation in the ...201222447451
immunomodulation of t-cell responses with vibrio cholerae o135 capsular polysaccharide and its protein conjugate, novel cholera vaccine study models.we studied t-cell immune responses to surface capsular polysaccharide (cps) of vibrio cholerae o135 and its protein conjugate. cps and cps-bovine serum albumin (bsa) activation and presentation are characterized with induced alterations in expression and upregulation of membrane antigens cd25, cd11b, cd16/32, mhcii and cd45 on blood- and spleen-derived t cells. expression of the early activation marker cd25 revealed efficient cps-bsa conjugate activation especially of cd4(+) cd3(+) and cd8(+) cd ...201222443716
targeting bacterial toxins.protein toxins constitute the main virulence factors of several species of bacteria and have proven to be attractive targets for drug development. lead candidates that target bacterial toxins range from small molecules to polymeric binders, and act at each of the multiple steps in the process of toxin-mediated pathogenicity. despite recent and significant advances in the field, a rationally designed drug that targets toxins has yet to reach the market. this review presents the state of the art i ...201222441768
memory b cell and other immune responses in children receiving two doses of an oral killed cholera vaccine compared to responses following natural cholera infection in bangladesh.current oral cholera vaccines induce lower protective efficacy and shorter duration of protection against cholera than wild-type infection provides, and this difference is most pronounced in young children. despite this, there are limited data comparing immune responses in children following wild-type disease versus vaccination, especially with regard to memory responses associated with long-term immunity. here, we report a comparison of immune responses in young children (2 to 5 years of age; n ...201222441386
ifn-γ renders human intestinal epithelial cells responsive to lipopolysaccharide of vibrio cholerae by down-regulation of dmbt1.although intestinal epithelial cells (iecs) are continuously exposed to high densities of enteric bacteria, they are not highly responsive to microbe-associated molecular patterns (mamps). however, inflammatory cytokines such as interferon-γ (ifn-γ) are potentially capable of priming iecs to enhance responsiveness to mamps. in this study, we observed that heat-killed vibrio cholerae (hkvc) and its lipopolysaccharide (lps) poorly induced il-8 production in a human iec line, ht-29. however, both h ...201222437006
optimal protein extraction methods from diverse sample types for protein profiling by using two-dimensional electrophoresis (2de).there is a great diversity of protein samples types and origins, therefore the optimal procedure for each sample type must be determined empirically. in order to obtain a reproducible and complete sample presentation which view as many proteins as possible on the desired 2de gel, it is critical to perform additional sample preparation steps to improve the quality of the final results, yet without selectively losing the proteins. to address this, we developed a general method that is suitable for ...201122433892
the drosophila protein mustard tailors the innate immune response activated by the immune deficiency pathway.in this study, we describe a drosophila melanogaster transposon insertion mutant with tolerance to vibrio cholerae infection and markedly decreased transcription of diptericin as well as other genes regulated by the immune deficiency innate immunity signaling pathway. we present genetic evidence that this insertion affects a locus previously implicated in pupal eclosion. this genetic locus, which we have named mustard (mtd), contains a lysm domain, often involved in carbohydrate recognition, and ...201222427641
oral vaccination with lactococcus lactis expressing the vibrio cholerae wzm protein to enhance mucosal and systemic immunity.a gene associated with lipopolysaccharide (lps) transport was cloned from a local clinical vibrio cholerae o1 strain of the ogawa serotype by using the lactococcus lactis nisin-controlled expression (nice) system. the v. cholerae wzm gene, which codes for an integral membrane transporter protein, was expressed and targeted to the cytoplasmic membrane, and was crudely isolated through simple centrifugation and sds solubilization. to examine seroreactivity of this construct, rabbits were orally fe ...201222426330
effect of quercetin on vibrio cholerae induced nuclear factor-κb activation and interleukin-8 expression in intestinal epithelial cells.vibrio cholerae, the etiological agent of cholera, colonizes the small intestine, produces an enterotoxin and causes acute inflammatory response at intestinal epithelial cell surface. pretreatment of intestinal epithelial cells with quercetin reduces the level of v. cholerae induced il-8 in dose and time dependent manner as determined by elisa and rt-pcr. immunofluorescence studies showed that quercetin suppresses the translocation of p50 subunit of nf-κb. in vivo, quercetin administration produ ...201222421109
aglycone-focused randomization of 2-difluoromethylphenyl-type sialoside suicide substrates for neuraminidases.a selective and potent inhibitor of neuraminidases, a hydrolase that is responsible for processing sialylated glycoconjugates, is a promising drug candidate for various infective diseases. the current study demonstrates that the use of an aglycone-focused library of 2-difluoromethylphenyl α-sialosides is an effective technique to find potent and selective mechanism-based labeling reagents for neuraminidases. the focused library was constructed from a 4-azide-2-difluoromethylphenyl sialoside (2) ...201222410247
crystal structure of a concentrative nucleoside transporter from vibrio cholerae at 2.4 å.nucleosides are required for dna and rna synthesis, and the nucleoside adenosine has a function in a variety of signalling processes. transport of nucleosides across cell membranes provides the major source of nucleosides in many cell types and is also responsible for the termination of adenosine signalling. as a result of their hydrophilic nature, nucleosides require a specialized class of integral membrane proteins, known as nucleoside transporters (nts), for specific transport across cell mem ...201222407322
larazotide acetate regulates epithelial tight junctions in vitro and in vivo.tight junctions (tjs) control paracellular permeability and apical-basolateral polarity of epithelial cells, and can be regulated by exogenous and endogenous stimuli. dysregulated permeability is associated with pathological conditions, such as celiac disease and inflammatory bowel disease. herein we studied the mechanism by which larazotide acetate, an 8-mer peptide and tj regulator, inhibits the cellular changes elicited by gliadin fragments, at-1002, and cytokines. previously, we demonstrated ...201222401908
characterization of exogenous bacterial oligosaccharyltransferases in escherichia coli reveals the potential for o-linked protein glycosylation in vibrio cholerae and burkholderia thailandensis.bacterial protein glycosylation systems from varying species have been functionally reconstituted in escherichia coli. both n- and o-linked glycosylation pathways, in which the glycans are first assembled onto lipid carriers and subsequently transferred to acceptor proteins by an oligosaccharyltransferase (otase), have been documented in bacteria. the identification and characterization of novel otases with different properties may provide new tools for engineering glycoproteins of biotechnologi ...201222391990
an epidemic outbreak of vibrio cholerae el tor 01 serotype ogawa biotype in a lalpur town, jamnagar, india.on december 19, 2010, 57 cases of gastroenteritis were reported in the community health center of lalpur town. a rapid response team was sent to investigate the outbreak on december 21, 2010.201522387643
sequence analyses of type iv pili from vibrio cholerae, vibrio parahaemolyticus, and vibrio vulnificus.bacterial surface structures called pili have been studied extensively for their role as possible colonization factors. most sequenced vibrio genomes predict a variety of pili genes in these organisms, including several types of type iv pili. in particular, the mannose-sensitive hemagglutinin (msha) and the pila pili, also known as the chitin-regulated pilus (chirp), are type iva pili commonly found in vibrio genomes and have been shown to play a role in the colonization of vibrio species in the ...201222383120
characterization of vibrio cholerae o139 of an aquatic isolate in northern vietnam.during the cholera survey in namdinh province (northern vietnam) in july, 2010, one strain of vibrio cholerae o139 was isolated from 7 environmental water samples positive for ctxa, toxr,vco139 genes and named as v. cholerae o139, nd1 strain. this strain was lysogenic harbouring a genome similar to the filamentous phage fs1. the replicative form dna of this phage (named as nd1-fs1, 6856 bp) was sequenced and compared with the other filamentous phages. the filamentous phage nd1-fs1 integrates int ...201222371817
type vi secretion requires a dynamic contractile phage tail-like structure.type vi secretion systems are bacterial virulence-associated nanomachines composed of proteins that are evolutionarily related to components of bacteriophage tails. here we show that protein secretion by the type vi secretion system of vibrio cholerae requires the action of a dynamic intracellular tubular structure that is structurally and functionally homologous to contractile phage tail sheath. time-lapse fluorescence light microscopy reveals that sheaths of the type vi secretion system cycle ...201222367545
the single nqrb and nqrc subunits in the na(+)-translocating nadh: quinone oxidoreductase (na(+)-nqr) from vibrio cholerae each carry one covalently attached fmn.the na(+)-translocating nadh:quinone oxidoreductase (na(+)-nqr) is the prototype of a novel class of flavoproteins carrying a riboflavin phosphate bound to serine or threonine by a phosphodiester bond to the ribityl side chain. this membrane-bound, respiratory complex also contains one non-covalently bound fad, one non-covalently bound riboflavin, ubiquinone-8 and a [2fe-2s] cluster. here, we report the quantitative analysis of the full set of flavin cofactors in the na(+)-nqr and characterize t ...201222366169
structural variation of the superintegron in the toxigenic vibrio cholerae o1 el tor.to understand the genetic structures and variations of the superintegron (si) in vibrio cholerae isolated in the seventh cholera pandemic.201122365393
resistotypes of vibrio cholerae 01 ogawa biotype el tor in kathmandu, nepal.cholera continued to be a major diarrheal illness in nepal and antibiotic resistance has appeared as a serious problem in cholera management. the study aimed at analyzing the distribution pattern of the resistotypes (r-types) of vibrio cholerae in the kathmandu valley, nepal. during june 2008 to january 2009, 210 diarrheal specimens received at national public health laboratory from suspected cholera patients were subjected to standard bacteriological investigation including biotyping and seroty ...201122364087
a rapid and reliable species-specific identification of clinical and environmental isolates of vibrio cholerae using a three-test procedure and reca polymerase chain reaction.vibrio cholerae, the cause of cholera, is one of the leading causes of morbidity and mortality in many developing countries. most laboratories initially rely on biochemical tests for a presumptive identification of these strains, followed by a polymerase chain reaction (pcr)-based method to confirm their identification. the aim of this study is to establish a rapid and reliable identification scheme for v. cholerae using a minimal, but highly specific number of biochemical tests and a pcr assay.201222361759
structure of the vibrio cholerae type ivb pilus and stability comparison with the neisseria gonorrhoeae type iva pilus.type iv pili are multifunctional filaments displayed on many bacterial pathogens. members of the type iva pilus subclass are found on a diverse group of human pathogens, whereas type ivb pili are found almost exclusively on enteric bacteria. the type iva and ivb subclasses are distinguished by differences in the pilin subunits, including the fold of the globular domain. to understand the implications of the distinct pilin folds, we compared the stabilities of pilin subunits and pilus filaments f ...201222361030
[in vitro induction of transmissive resistance to tetracycline, chloramphenicol and ampicillin chloramphenicol in vibrio cholera non-o1/non-o139 serogroups isolated within 1990-2005].inducible character of resistance to tetracycline, chloramphenicol and ampicillin was investigated in 20 strains of vibrio cholera non-o1/non-o139 serogroups isolated from inhabitants of uzbekistan in 1990 (10 strains, ctx+) and in 2001 (5 strains, ctx-) and from inhabitants of kalmykiya within 2003-2005 (5 strains, ctx-). eight of the 20 isolates showed not only capacity for induction of the antibiotic resistance, but also its possible self transfer to escherichia coli and reverse crosses in el ...201122359864
a high-throughput screen identifies a new natural product with broad-spectrum antibacterial activity.due to the inexorable invasion of our hospitals and communities by drug-resistant bacteria, there is a pressing need for novel antibacterial agents. here we report the development of a sensitive and robust but low-tech and inexpensive high-throughput metabolic screen for novel antibiotics. this screen is based on a colorimetric assay of ph that identifies inhibitors of bacterial sugar fermentation. after validation of the method, we screened over 39,000 crude extracts derived from organisms that ...201222359585
transcutaneous immunization with a vibrio cholerae o1 ogawa synthetic hexasaccharide conjugate following oral whole-cell cholera vaccination boosts vibriocidal responses and induces protective immunity in mice.a shortcoming of currently available oral cholera vaccines is their induction of relatively short-term protection against cholera compared to that afforded by wild-type disease. we were interested in whether transcutaneous or subcutaneous boosting using a neoglycoconjugate vaccine made from a synthetic terminal hexasaccharide of the o-specific polysaccharide of vibrio cholerae o1 (ogawa) coupled to bovine serum albumin as a carrier (cho-bsa) could boost lipopolysaccharide (lps)-specific and vibr ...201222357651
development and evaluation of a pcr assay for tracking the emergence and dissemination of haitian variant ctxb in vibrio cholerae o1 strains isolated from kolkata, india.a pcr-based assay was developed to discriminate the classical, el tor, and haitian types of ctxb alleles. our retrospective study using this newly developed pcr showed that haitian ctxb first appeared in kolkata during april 2006, and 93.3% of strains isolated during 2011 carried the new allele. dendrogram analysis showed a pulsed-field gel electrophoresis (pfge) pattern of the new variant strains isolated recently that was distinct from the pfge pattern of the strains carrying classical ctxb th ...201222357499
the vibrio cholerae pst2 phosphate transport system is upregulated in biofilms and contributes to biofilm-induced hyperinfectivity.vibrio cholerae is the causative agent of the deadly diarrheal disease cholera. as part of its life cycle, v. cholerae persists in marine environments, where it forms surface-attached communities commonly described as biofilms. evidence indicates that these biofilms constitute the infectious form of the pathogen during outbreaks. previous work has shown that biofilm-derived v. cholerae cells, even when fully dispersed from the biofilm matrix, are vastly more infectious than planktonic (free-livi ...201222354023
recent patents on antibacterial, antifungal and antiviral properties of tea.teas have beneficial effects on human health including cardioprotective, anticarcinogenic, antibacterial, antiviral and antifungal activity. the precise antimicrobial spectrum of tea is difficult to be defined due to variation in the methods of testing that have been used. antibacterial effects of tea have been demonstrated against a number of microorganisms including staphylococcus aureus, vibrio cholerae, escherichia coli, shigella spp., salmonella spp., bacillus spp., klebsiella spp. and pseu ...201222353001
clinical characteristics and predictors of positive stool culture in adult patients with acute gastroenteritis.to identify the presenting features and spectrum of pathogens in adult patients with acute diarrhoea and to determine the predictors of stool culture positivity.201222352095
antibiofilm activity of α-amylase from bacillus subtilis s8-18 against biofilm forming human bacterial pathogens.the extracellular α-amylase enzyme from bacillus subtilis s8-18 of marine origin was proved as an antibiofilm agent against methicillin-resistant staphylococcus aureus (mrsa), a clinical strain isolated from pharyngitis patient, vibrio cholerae also a clinical isolate from cholera patient and pseudomonas aeruginosa atcc10145. the spectrophotometric and microscopic investigations revealed the potential of α-amylase to inhibit biofilm formation in these pathogens. at its bic level, the crude enzym ...201222350933
strategies to overexpress enterotoxigenic escherichia coli (etec) colonization factors for the construction of oral whole-cell inactivated etec vaccine candidates.enterotoxigenic escherichia coli (etec) is an important cause of diarrheal disease and deaths among children in developing countries and the major cause of traveler's diarrhea (td). since surface protein colonization factors (cfs) of etec are important for pathogenicity and immune protection is mainly mediated by locally produced iga antibodies in the gut, much effort has focused on the development of an oral cf-based vaccine. the most extensively studied etec candidate vaccine is the rctb-cf et ...201222350259
[intracerebral abscess after infection with non-toxigenic vibrio cholerae].we present the first case of intracerebral abscess after blood-borne infection with non-toxigenic vibrio cholerae (non-01). the patient was a 66 year-old woman who was infected after swimming in danish seawater during an unusually hot summer. she had predisposing haemochromatosis and a skin lesion on the ankle. we treated the patient with meropenem and ciprofloxacin for six weeks followed by ciprofloxacin for four weeks, and she recovered with hemiparesis and speech impairment. marine vibrio spe ...201222348672
interleukin-8 gene regulation in epithelial cells by vibrio cholerae: role of multiple promoter elements, adherence and motility of bacteria and host mapks.interleukin (il)-8 is an important mediator in neutrophil-mediated acute inflammation. we previously demonstrated that incubation of intestinal epithelial cells with vibrio cholerae o395 resulted in increased il-8 mrna expression and il-8 secretion, which was associated with the adherence and motility of bacteria. however, the mechanisms responsible for transcriptional regulation of the il-8 gene in epithelial cells during v. cholerae infections were not explored. transient transfection analysis ...201222348317
sialic acid catabolism and transport gene clusters are lineage specific in vibrio vulnificus.sialic or nonulosonic acids are nine-carbon alpha ketosugars that are present in all vertebrate mucous membranes. among bacteria, the ability to catabolize sialic acid as a carbon source is present mainly in pathogenic and commensal species of animals. previously, it was shown that several vibrio species carry homologues of the genes required for sialic acid transport and catabolism, which are genetically linked. in vibrio cholerae on chromosome i, these genes are carried on the vibrio pathogeni ...201222344665
bacteria and their toxins tamed for immunotherapy.bacterial toxins share the ability to enter host cells to target various intracellular proteins and to modulate host immune responses. over the last 20 years, toxins and their mutated variants, as well as live attenuated bacteria, have been exploited for vaccination and immunotherapy of various infectious, malignant and autoimmune diseases. the ability of bordetella pertussis adenylate cyclase toxin to translocate its adenylate cyclase domain across the host cell membrane, as well as the pathway ...201222339216
[surveillance program on and the distribution related to the virulence-associated genes of vibrio cholerae in estuary of pearl river].to understand the distribution, molecular characteristics and virulence genes of the o1 and o139 vibrio cholerae isolates from the pearl river estuary water.201122336609
the role of aquatic reservoir fluctuations in long-term cholera patterns.we propose and analyze an important extension of standard cholera epidemiological models, explicitly accounting for fluctuations of water availability to the human community under study. the seasonality of water input in the reservoir drives the variation of concentration of vibrio cholerae. two compartments are added to the susceptible-infected-bacteria model. first, the recovered individuals, which, over many seasons, lose their immunity to the disease and replenish the susceptible group. seco ...201122325012
viability kinetics, induction, resuscitation and quantitative real-time polymerase chain reaction analyses of viable but nonculturable vibrio cholerae o1 in freshwater microcosm.to study the induction of a viable but nonculturable (vbnc) state in vibrio cholerae o1 in freshwater, in response to cold temperatures (4°c) and starvation.201222324483
microbial biosafety of pilot-scale bioreactor treating mtbe and tba-contaminated drinking water supply.a pilot-scale sand-based fluidized bed bioreactor (fbbr) was utilized to treat both methyl tert-butyl ether (mtbe) and tert-butyl alcohol (tba) from a contaminated aquifer. to evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, escherichia coli, salmonella and shigella spp., campylobacter jejuni, aeromonas hydrophila, legionella pneumophila, vibrio cholerae, yersinia ...201222321859
[molecular characteristics and antibiotic resistances of vibrio cholerae o1 isolates in hangzhou in 2009].to study the molecular characteristics and antibiotic resistances of vibrio cholerae (v. cholerae) o1 isolates in hangzhou in 2009.201122321588
role of shrimp chitin in the ecology of toxigenic vibrio cholerae and cholera transmission.seasonal plankton blooms correlate with occurrence of cholera in bangladesh, although the mechanism of how dormant vibrio cholerae, enduring interepidemic period in biofilms and plankton, initiates seasonal cholera is not fully understood. in this study, laboratory microcosms prepared with estuarine mathbaria water (mw) samples supported active growth of toxigenic v. cholerae o1 up to 7 weeks as opposed to 6 months when microcosms were supplemented with dehydrated shrimp chitin chips (cc) as the ...201122319512
zooplankton's role in the distributional status of autochthonous vibrio cholerae: a case study using principal component analysis.miscellaneous statistical approaches were applied to illustrate the influence exerted by different zooplankton groups on the survival and distributional status of autochthonous vibrio cholerae in two diverse marine environments, veli and kochi, former with low nutrient loading and later with high nutrient loading. the data set has been factorised using principal component analysis (pca) for extracting linear relationships existing among a set of variables. box plots were derived from the pca dat ...201022312802
bundle-forming pilus locus of aeromonas veronii bv. sobria.little is known about the colonization mechanisms of aeromonas spp. previous work has suggested that the type iv bundle-forming pilus (bfp) is an aeromonad intestinal colonization factor. this study provides the first genetic characterization of this structure. to define the role of bfp in aeromonas veronii bv. sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (msha) of vibrio chole ...201222311923
chromosome dynamics in multichromosome bacteria.on the basis of limited information, bacteria were once assumed to have no more than one chromosome. in the era of genomics, it has become clear that some, like eukaryotes, have more than one chromosome. multichromosome bacteria provide opportunities to investigate how split genomes emerged, whether the individual chromosomes communicate to coordinate their replication and segregation, and what selective advantages split genomes might provide. our current knowledge of these topics comes mostly f ...201222306663
transition state analysis of vibrio cholerae sialidase-catalyzed hydrolyses of natural substrate analogues.a series of isotopically labeled natural substrate analogues (phenyl 5-n-acetyl-α-d-neuraminyl-(2→3)-β-d-galactopyranosyl-(1→4)-1-thio-β-d-glucopyranoside; neu5acα2,3lacβsph, and the corresponding 2→6 isomer) were prepared chemoenzymatically in order to characterize, by use of multiple kinetic isotope effect (kie) measurements, the glycosylation transition states for vibrio cholerae sialidase-catalyzed hydrolysis reactions. the derived kies for neu5acα2,3lacβsph for the ring oxygen ((18)v/k), le ...201222296330
hsp33 confers bleach resistance by protecting elongation factor tu against oxidative degradation in vibrio cholerae.the 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 vibrio cholerae strain o395 lacking the hsp33 gene hslo. we found that this strain, which is exquisitely bleach-sensitive, displays a temperature- ...201222296329
ligand and antagonist driven regulation of the vibrio cholerae quorum-sensing receptor cqss.quorum sensing, a bacterial cell-cell communication process, controls biofilm formation and virulence factor production in vibrio cholerae, a human pathogen that causes the disease cholera. the major v. cholerae autoinducer is (s)-3-hydroxytridecan-4-one (cai-1). a membrane bound two-component sensor histidine kinase called cqss detects cai-1, and the cqss → luxu → luxo phosphorelay cascade transduces the information encoded in cai-1 into the cell. because the cai-1 ligand is known and because t ...201222295878
genotypic and pfge/mlva analyses of vibrio cholerae o1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in thailand.vibrio cholerae o1 el tor dominated the seventh cholera pandemic which occurred in the 1960s. for two decades, variants of v. cholerae o1 el tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic el tor biotype. this study aims to characterize v. cholerae o1 isolates from outbreaks in thailand with special reference to genotypic variations over time.201222292065
unique iron coordination in iron-chelating molecule vibriobactin helps vibrio cholerae evade mammalian siderocalin-mediated immune response.iron is essential for the survival of almost all bacteria. vibrio cholerae acquires iron through the secretion of a catecholate siderophore called vibriobactin. at present, how vibriobactin chelates ferric ion remains controversial. in addition, the mechanisms underlying the recognition of ferric vibriobactin by the siderophore transport system and its delivery into the cytoplasm specifically have not been clarified. in this study, we report the high-resolution structures of the ferric vibriobac ...201222291019
connecting environment and genome plasticity in the characterization of transformation-induced sos regulation and carbon catabolite control of the vibrio cholerae integron integrase.the human pathogen vibrio cholerae carries a chromosomal superintegron (si). the si contains an array of hundreds of gene cassettes organized in tandem which are stable under conditions when no particular stress is applied to bacteria (such as during laboratory growth). rearrangements of these cassettes are catalyzed by the activity of the associated integron integrase. understanding the regulation of integrase expression is pivotal to fully comprehending the role played by this genetic reservoi ...201222287520
the histone-like nucleoid structuring protein (h-ns) is a repressor of vibrio cholerae exopolysaccharide biosynthesis (vps) genes.the capacity of vibrio cholerae to form biofilms has been shown to enhance its survival in the aquatic environment and play important roles in pathogenesis and disease transmission. in this study, we demonstrated that the histone-like nucleoid structuring protein is a repressor of exopolysaccharide (vps) biosynthesis genes and biofilm formation.201222287003
vibrio cholerae autoinducer cai-1 interferes with pseudomonas aeruginosa quorum sensing and inhibits its growth.the human pathogen vibrio cholerae uses several small molecules to coordinate gene expression in a process termed quorum sensing (qs), and its main autoinducer is cai-1. we have examined the activity of this signaling molecule in three other species of bacteria. interestingly, while showing an inhibitory effect on qs in the opportunistic pathogen p. aeruginosa at low micromolar concentrations, it caused also growth inhibition at higher concentrations. in contrast, the two other bacteria were una ...201222270383
culture-independent real-time pcr reveals extensive polymicrobial infections in hospitalized diarrhoea cases in kolkata, india.clin microbiol infect abstract: culture-independent identification of diarrhoeal aetiological agents was performed using dna harvested from diarrhoeal stool specimens with sybr-green-based real-time pcr targeting vibrio cholerae, vibrio parahaemolyticus, campylobacter spp., shigella spp. and three different pathotypes of diarrhoeagenic escherichia coli. conventional culture-dependent methods detected bacterial enteropathogens in 68 of 122 diarrhoeal stool specimens. of 68 specimens, 59 (86.8%) h ...201122268636
genome engineering in vibrio cholerae: a feasible approach to address biological issues.although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. owing to its bi-chromosomal genome architecture and its importance in public health, vibrio cholerae, the causative agent of cholera, has become a preferred model to study bacteria with multipartite genomes. however, most in vivo studies in v. cholerae hav ...201222253612
the vibrio cholerae colonization factor gbpa possesses a modular structure that governs binding to different host surfaces.vibrio cholerae is a bacterial pathogen that colonizes the chitinous exoskeleton of zooplankton as well as the human gastrointestinal tract. colonization of these different niches involves an n-acetylglucosamine binding protein (gbpa) that has been reported to mediate bacterial attachment to both marine chitin and mammalian intestinal mucin through an unknown molecular mechanism. we report structural studies that reveal that gbpa possesses an unusual, elongated, four-domain structure, with domai ...201222253590
csra modulates luxr transcript levels in vibrio fischeri.the quorum-sensing and csra regulons of vibrios control overlapping cellular functions during growth. hence, the potential exists for regulatory network interactions between the pathways that enable them to be coordinately controlled. in vibrio cholerae, csra indirectly modulates the activity of luxo in the quorum-sensing signaling pathway. in this study, it was demonstrated that in vibrio fischeri, csra causes an increase in the transcript levels of a downstream quorum-sensing regulatory gene, ...201222250984
a 29-mer site regulates transcription of the initiator gene as well as function of the replication origin of vibrio cholerae chromosome ii.the region responsible for replication of vibrio cholerae chromosome ii (chrii) resembles those of plasmids that have repeated initiator binding sites (iterons) and an autorepressed initiator gene. chrii has additional features: its iterons require full methylation for initiator (rctb) binding, which makes them inactive for a part of the cell cycle when they are hemi-methylated. rctb also binds to a second kind of site, called 39-mers, in a methylation independent manner. this binding is inhibit ...201222248922
toxr of vibrio cholerae affects biofilm, rugosity and survival with acanthamoeba castellanii.vibrio cholerae causes the diarrheal disease cholera and utilizes different survival strategies in aquatic environments. v. cholerae can survive as free-living or in association with zooplankton and can build biofilm and rugose colonies. the bacterium expresses cholera toxin (ct) and toxin-coregulated pilus (tcp) as the main virulence factors. these factors are co-regulated by a transcriptional regulator toxr, which modulates expression of outer membrane proteins (ompu) and (ompt). the aims of t ...201222248371
nhap1 is a k+(na+)/h+ antiporter required for growth and internal ph homeostasis of vibrio cholerae at low extracellular ph.vibrio cholerae has adapted to a wide range of salinity, ph and osmotic conditions, enabling it to survive passage through the host and persist in the environment. among the many proteins responsible for bacterial survival under these diverse conditions, we have identified vc-nhap1 as a k(+)(na(+))/h(+) antiporter essential for v. cholerae growth at low environmental ph. deletion of the v. cholerae nhap1 gene caused growth inhibition when external potassium was either limited (100 mm and below ...201222241048
elevated levels of the norspermidine synthesis enzyme nspc enhance vibrio cholerae biofilm formation without affecting intracellular norspermidine concentrations.biofilm formation in vibrio cholerae is in part regulated by norspermidine, a polyamine synthesized by the enzyme carboxynorspermidine decarboxylase (nspc). the absence of norspermidine in the cell leads to a marked reduction in v. cholerae biofilm formation by an unknown mechanism. in this work, we show that overexpression of nspc results in large increases in biofilm formation and vps gene expression as well as a significant decrease in motility. interestingly, increased nspc levels do not lea ...201222239666
defying stereotypes: the elusive search for a universal model of lysr-type regulation.lysr-type transcriptional regulators (lttrs) compose the largest family of homologous regulators in bacteria. considering their prevalence, it is not surprising that lttrs control diverse metabolic functions. arguably, the most unexpected aspect of lttrs is the paucity of available structural information. solubility issues are notoriously problematic, and structural studies have only recently begun to flourish. in this issue of molecular microbiology, taylor et al. (2012) present the structure o ...201222235937
the "first" case of cholera in haiti: lessons for global health.cholera is an acute watery diarrheal disease caused by infection with vibrio cholerae. the disease has a high fatality rate when untreated and outbreaks of cholera have been increasing globally in the past decade, most recently in haiti. we present the case of a 28-year-old haitian male with a history of severe untreated mental health disorder that developed acute fatal watery diarrhea in mid-october 2010 in central haiti after drinking from the local river. we believe he is the first or among t ...201222232448
crystallization and preliminary x-ray crystallographic studies of a new class of enoyl-(acyl-carrier protein) reductase, fabv, from vibrio fischeri.enoyl-(acyl-carrier protein) reductase (enr) catalyzes the last step of the fatty-acid elongation cycle of the bacterial fatty-acid biosynthesis (fas ii) pathway. recently, a new class of enr has been identified from vibrio cholerae and was named fabv. in order to understand the molecular mechanism of the new class of enr at the structural level, fabv from v. fischeri was overexpressed, purified and crystallized. diffraction data were collected to 2.7 å resolution from a native crystal. the crys ...201122232178
arctic actinomycetes as potential inhibitors of vibrio cholerae biofilm.the aim of this study was to identify novel biofilm inhibitors from actinomycetes isolated from the arctic against vibrio cholerae, the causative agent of cholera. the biofilm inhibitory activity of actinomycetes was assessed using biofilm assay and was confirmed using air-liquid interphase coverslip assay. the potential isolates were identified using 16s rrna gene sequencing. of all, three isolates showed significant biofilm inhibition against v. cholerae. the results showed that 20% of the act ...201222231452
fluorometric estimation of surface associated microbial abundance.surface associated microbes have historically been difficult to accurately and effectively enumerate. in the current study, we propose a rapid and simple method for estimating abundance of surface associated microbial cells by fluorescence of sybrgreen stained bacteria and in vivo chlorophyll a fluorescence of benthic diatoms in 24 and 48-well microtiter plates. the effectiveness of this high-throughput technique is demonstrated by assessing sensitivity of a clinical strain of vibrio cholerae, a ...201122230233
quorum-sensing non-coding small rnas use unique pairing regions to differentially control mrna targets.quorum sensing is a mechanism of cell-cell communication that bacteria use to control collective behaviours including bioluminescence, biofilm formation and virulence factor production. in the vibrio harveyi and vibrio cholerae quorum-sensing circuits, multiple non-coding small regulatory rnas called the quorum-regulated small rnas (qrr srnas) function to establish the global quorum-sensing gene expression pattern by modulating translation of multiple mrnas encoding quorum-sensing regulatory fac ...201222229925
wbet sequence typing and is1004 profiling of vibrio cholerae isolates.to investigate the molecular basis for serotype variation in vibrio cholerae o1 and the genetic relatedness amongst different serotypes isolated from 2004 to 2008 in iran.201222225492
epidemiological investigation of an outbreak of acute diarrheal disease: a shoe leather epidemiology.health care problems faced by migrant construction workers are always neglected. fifteen patients were admitted with the complaints of loose motion and pain in the abdomen from a labor settlement at a construction site near our city. three stool samples revealed darting motility.201122224000
chitin colonization, chitin degradation and chitin-induced natural competence of vibrio cholerae are subject to catabolite repression.although vibrio cholerae is a human pathogen its primary habitat are aquatic environments. in this environment, v. cholerae takes advantage of the abundance of zooplankton, whose chitinous exoskeletons provide a nutritious surface. chitin also induces the developmental programme of natural competence in several species of the genus vibrio. because the chitin surface can serve as the sole carbon source for v. cholerae, the link between carbon catabolite repression and chitin-induced natural compe ...201222222000
real-time pcr and nasba for rapid and sensitive detection of vibrio cholerae in ballast water.transport of ballast water is one major factor in the transmission of aquatic organisms, including pathogenic bacteria. the imo-guidelines of the convention for the control and management of ships' ballast water and sediments, states that ships are to discharge <1 cfu per 100 ml ballast water of toxigenic vibrio cholerae, emphasizing the need to establish test methods. to our knowledge, there are no methods sensitive and rapid enough available for cholera surveillance of ballast water. in this s ...201222221710
individuals with le(a+b-) blood group have increased susceptibility to symptomatic vibrio cholerae o1 infection.human genetic factors such as blood group antigens may affect the severity of infectious diseases. presence of specific abo and lewis blood group antigens has been shown previously to be associated with the risk of different enteric infections. the aim of this study was to determine the relationship of the lewis blood group antigens with susceptibility to cholera, as well as severity of disease and immune responses to infection.201122216364
cholera in united states associated with epidemic in hispaniola.cholera is rare in the united states (annual average 6 cases). since epidemic cholera began in hispaniola in 2010, a total of 23 cholera cases caused by toxigenic vibrio cholerae o1 have been confirmed in the united states. twenty-two case-patients reported travel to hispaniola and 1 reported consumption of seafood from haiti.201122204035
Bacterial chromosome segregation.Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid i ...201222201788
[a case of liver abscess and bacteremia caused by vibrio cholerae non-o1].vibrio cholerae non-o1 have caused several well-studied food-borne outbreaks of gastroenteritis and also have been responsible for sporadic cases of otitis media, wound infection, and bacteremia. few cases of liver abscess caused by vibrio cholerae non-o1 have been reported. a 73-year-old man with underlying diabetes mellitus was admitted with nausea, vomiting, dyspepsia and febrile sensation. we identified vibrio cholerae non-o1 in his blood cultures and multiple hepatic microabscess on abdomin ...201122198234
intracranial v. cholerae sialidase protects against excitotoxic neurodegeneration.converging evidence shows that gd3 ganglioside is a critical effector in a number of apoptotic pathways, and gm1 ganglioside has neuroprotective and noötropic properties. targeted deletion of gd3 synthase (gd3s) eliminates gd3 and increases gm1 levels. primary neurons from gd3s-/- mice are resistant to neurotoxicity induced by amyloid-β or hyperhomocysteinemia, and when gd3s is eliminated in the app/psen1 double-transgenic model of alzheimer's disease the plaque-associated oxidative stress and i ...201122195039
association of heavy rainfall on genotypic diversity in v. cholerae isolates from an outbreak in india.the outbreak of waterborne disease cholera has been associated with rainfall and flooding events by contamination of potable water with environmental vibrio cholerae. the continuation of the epidemic in a region, however, is often due to secondary transmission of the initial outbreak strain through human waste. this paper reports, on the contrary, a rapid shift of genotype from one v. cholerae strain to another one in an epidemic region. v. cholerae isolated from patients during 2005 cholera epi ...201122194751
interaction of the histone-like nucleoid structuring protein (h-ns) and the general stress response regulator rpos at vibrio cholerae promoters that regulate motility and hemagglutinin (ha)/protease expression.the bacterium vibrio cholerae colonizes the human small intestine and secretes cholera toxin (ct) to cause the rice-watery diarrhea characteristic of this illness. the ability of this pathogen to colonize the small bowel, express ct, and return to the aquatic environment is controlled by a complex network of regulatory proteins. two global regulators that participate in this process are the histone-like nucleoid structuring protein (h-ns) and the general stress response regulator rpos. in this s ...201122194453
cholera: lessons from haiti and beyond.cholera is an acute, severe diarrheal disease caused by vibrio cholerae that affects millions of people each year. without prompt rehydration, death can occur within hours of the onset of symptoms. in october 2010, cholera emerged in haiti, and the resulting large epidemic continues today. as of august 29, 2011, more than 439,000 cases have been reported in haiti, with over 6,200 deaths. this review covers important features of epidemiology, pathogenesis, treatment and prevention of cholera, wit ...201122179934
[etiological surveillance and analysis of infectious diarrhea in beijing in year 2010].to explore the pathogenic form, epidemic features and serotype distribution of the pathogenic bacteria causing infectious diarrhea in beijing.201122177306
Detection and characterization of pathogenic vibrios in shellfish by a Ligation Detection Reaction-Universal Array approach.Vibrios are a group of major foodborne pathogens widely distributed in marine environment. Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus are the pathogenic species of Vibrio that pose the greatest threat to human health. However, other vibrios, e.g. Vibrio alginolyticus, Vibrio mimicus and Grimontia hollisae, apparently less relevant in the group of foodborne pathogens, have been sporadically found in outbreaks. For seafood safety and economic purposes, a rapid and powerful met ...201122177227
the membrane proteins, siaq and siam, form an essential stoichiometric complex in the sialic acid trap transporter siapqm (vc1777-1779) from vibrio cholerae.tripartite atp-independent periplasmic (trap) transporters are widespread in bacteria but poorly characterised. they contain three subunits, a small membrane protein, a large membrane protein and a substrate binding protein (sbp). while the function of the sbp is well-established, the membrane components have only been studied in detail for the sialic acid trap transporter siapqm from haemophilus influenzae, where the membrane proteins are genetically fused. herein we report the first in vitro ...201122167185
Possible laboratory contamination leads to incorrect reporting of Vibrio cholerae O1 and initiates an outbreak response.V. cholerae O1 was reported from a river water specimen in South Africa. A public health response followed in order to prevent an outbreak. Further investigation determined this to be a pseudo-alert of V. cholerae O1, possibly linked to laboratory contamination. Following culture of bacteria from the water specimen, the testing laboratory possibly contaminated the culture with a V. cholerae O1 reference strain and then mistakenly reported isolation of V. cholerae O1.201122162543
an overview of cholera vaccines and their public health implications.the current cholera pandemic now involves almost the entire developing world and represents an important global challenge. though improved water and sanitation remain the mainstays of cholera prevention efforts, major improvements to infrastructure continue to be a goal far out of reach for many of those affected and near-term interventions, including vaccines, need consideration.201122157363
immunization of mice with vibrio cholerae outer-membrane vesicles protects against hyperinfectious challenge and blocks transmission.background. vibrio cholerae excreted by cholera patients is "hyperinfectious" (hi), which can be modeled by passage through infant mice. immunization of adult female mice with v. cholerae outer-membrane vesicles (omvs) passively protects suckling mice from challenge. although v. cholerae is unable to colonize protected pups, the bacteria survive passage and have the potential to be transmitted to susceptible individuals. here, we investigated the impact of omv immunization and the hi state on v. ...201122147790
Molecular Techniques in Ecohealth Research Toolkit: Facilitating Estimation of Aggregate Gastroenteritis Burden in an Irrigated Periurban Landscape.Assessment of microbial hazards associated with certain environmental matrices, livelihood strategies, and food handling practices are constrained by time-consuming conventional microbiological techniques that lead to health risk assessments of narrow geographic or time scope, often targeting very few pathogens. Health risk assessment based on one or few indicator organisms underestimates true disease burden due a number of coexisting causative pathogens. Here, we employed molecular techniques i ...201122146856
development of a sensitive rrna-targeted reverse transcription-quantitative polymerase chain reaction for detection of vibrio cholerae/mimicus, v. parahaemolyticus/alginolyticus and campylobacter jejuni/coli.a sensitive rrna-targeted reverse transcription-quantitative polymerase chain reaction (rt-qpcr) method was developed for detection of vibrio cholerae/mimicus, v. parahaemolyticus/alginolyticus and campylobacter jejuni/coli by using specific primers. counts of the enteric pathogens spiked in human stools were quantified at the lower detection limit of 10(3) cells /g of stools by rt-qpcr, in marked contrast with conventional quantitative polymerase chain reaction (qpcr) at the detection limit of ...201122146006
[characteristics of vibrio cholerae nono1/nono139 serogroup strains that caused diseases in population of rostov region].genotype characteristic and determination of serological properties of vibrio cholerae nono1/nono139 strains that caused diseases in population of rostov region from 2000 to 2009.201122145343
[detection of "hybrid" vibrio cholerae eltor strains during epidemic complications in syberia and far east].biotyping of vibrio cholerae eltor isolated during epidemic complications of cholera in syberia and far east by phenotypic and genotypic properties complex.201122145342
[determination of dna content in individual vibrjo cholerae cells by using flow cytofluorimetry method: comparative analysis of inhomogeneity in cells of strains with various biological properties].comparative analysis of dna content in individual cells of vibrio cholerae strains with various biological properties.201122145341
The effects of amino acid supplementation on porin expression and ToxR levels in Vibrio cholerae.Vibrio cholerae responds to environmental changes by altering the protein composition of its outer membrane. In rich medium, V. cholerae expresses almost exclusively the outer membrane porin OmpU, whereas in minimal medium, OmpT is the dominant porin. Supplementing a minimal medium with a mixture of asparagine, arginine, glutamic acid and serine (NRES) promotes OmpU production and OmpT repression similar to levels seen in rich media. Here we show that the altered Omp profile is not due to a grow ...201122144480
Overexpression, purification, crystallization and preliminary X-ray analysis of CheY4 from Vibrio cholerae O395.Chemotaxis and motility greatly influence the infectivity of Vibrio cholerae, although the role of chemotaxis genes in V. cholerae pathogenesis is poorly understood. In contrast to the single copy of CheY found in Escherichia coli and Salmonella typhimurium, four CheYs (CheY1-CheY4) are present in V. cholerae. While insertional disruption of the cheY4 gene results in decreased motility, insertional duplication of this gene increases motility and causes enhanced expression of the two major virule ...201122139188
crystallization and preliminary x-ray crystallographic studies of vibe, a vibriobactin-specific 2,3-dihydroxybenzoate-amp ligase from vibrio cholerae.vibriobactin synthetases (vibabcdefh) catalyze the biosynthesis of vibriobactin in the pathogenic bacterium vibrio cholerae. vibe, a vibriobactin-specific 2,3-dihydroxybenzoate-amp ligase, plays a critical role in the transfer of 2,3-dihydroxybenzoate to the aryl carrier protein domain of holo vibb. here, the cloning, protein expression and purification, crystallization and preliminary x-ray crystallographic analysis of vibe from v. cholerae are reported. the vibe crystal diffracted to 2.3 å res ...201122139167
Identification of virulence factors in Vibrio cholerae isolated from Iraq during the 2007-2009 outbreak.Thousands of people were infected with Vibrio cholerae during the outbreak in Iraq in 2007-2009. Vibrio cholerae was shown to be variable in its content of virulence determinants and in its antibiotic sensitivity. This study was designed to isolate and characterize clinical and environmental V. cholerae isolates and to determine antibiotic sensitivity, enzyme and toxin production, and the presence of virulence genes. Eighty clinical and five environmental bacterial isolates were collected an ...201122133188
developing next generation antimicrobials by intercepting ai-2 mediated quorum sensing.bacteria have been evolving antibiotic resistance since their discovery in the early twentieth century. most new antibiotics are derivatives of older generations and there are now bacteria that are virtually resistant to almost all antibiotics. this poses a global threat to human health and has been classified as a clinical "super-challenge", which has necessitated research into new antimicrobials that inhibit bacterial virulence while minimizing selective pressures that lead to the emergence of ...201122112397
the 2008 cholera epidemic in zimbabwe: experience of the icddr,b team in the field.during august 2008-june 2009, an estimated 95,531 suspected cases of cholera and 4,282 deaths due to cholera were reported during the 2008 cholera outbreak in zimbabwe. despite the efforts by local and international organizations supported by the zimbabwean ministry of health and child welfare in the establishment of cholera treatment centres throughout the country, the case-fatality rate (cfr) was much higher than expected. over two-thirds of the deaths occurred in areas without access to treat ...201122106761
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