Publications

spatially selective colonization of the arthropod intestine through activation of vibrio cholerae biofilm formation.	vibrio cholerae is an estuarine bacterium and the human pathogen responsible for the diarrheal disease cholera. in the environment, arthropods are proposed to be carriers and reservoirs of v. cholerae. however, the molecular basis of the association between v. cholerae and viable arthropods has not been elucidated previously. here, we show that the v. cholerae vibrio polysaccharide (vps)-dependent biofilm is highly activated upon entry into the arthropod intestine and is specifically required fo ...	2011	22106284
Synthesis and Antimicrobial Evaluation of New Pyrano[4,3-b]pyran and Pyrano[3,2-c]chromene Derivatives Bearing a 2-Thiophenoxyquinoline Nucleus.	A new series of pyrano[4,3-b]pyran 4a-i and pyrano[3,2-c]chromene 6a-r derivatives bearing a 2-thiophenoxyquinoline nucleus were synthesized by reaction of 2-(4-(un)-substituted thiophenoxy)quinoline-3-carbaldehydes 2a-i with 6-methyl-4-hydroxypyran-2-one 3 and 4-hydroxy-6-(un)-substituted-2H-chromen-2-one 5a-b respectively and malononitrile at room temperature in the presence of KOH as a basic catalyst. All the compounds were screened against three Gram-positive bacteria (Streptococcus pneumoni ...	2011	22105795
Cloning, expression, purification, crystallization and preliminary X-ray analysis of the 31 kDa Vibrio cholerae heat-shock protein VcHsp31.	The Gram-negative bacterium Vibrio cholerae, which is responsible for the diarrhoeal disease cholera in humans, induces the expression of numerous heat-shock genes. VcHsp31 is a 31 kDa putative heat-shock protein that belongs to the DJ-1/PfpI superfamily, functioning as both a chaperone and a protease. VcHsp31 has been cloned, overexpressed and purified by Ni(2+)-NTA affinity chromatography followed by gel filtration. Crystals of VcHsp31 were grown in the presence of PEG 6000 and MPD; they belon ...	2011	22102237
The Vibrio cholerae mannitol transporter is regulated post-transcriptionally by the MtlS small RNA.	Vibrio cholerae continues to pose a health threat in many developing nations and regions of the world struck by natural disasters. It is a pathogen that rapidly adapts to aquatic environments and the human small intestine. Small regulatory RNAs (sRNAs) may contribute to this adaptability. Specifically, the mannitol operon sRNA (MtlS; previously IGR7) is transcribed antisense to the 5' untranslated region of the mtl operon, encoding the mannitol-specific phosphotransferase system. Mannitol is a ...	2011	22101846
recombinant production of cathelicidin-derived antimicrobial peptides in escherichia coli using an inducible autocleaving enzyme tag.	antimicrobial peptides (amps), such as the linear amphipathic cathelicidins, are produced widely in the natural world and are active against a broad range of pathogenic microorganisms. their potential as a new range of antibiotics has prompted numerous studies of amp structure and function. most such studies are performed with chemically synthesised peptides, but a simple and rapid biosynthetic route would offer a more cost-effective alternative for the production of amps and analysis of their s ...	2011	22100429
drug-resistance mechanisms in vibrio cholerae o1 outbreak strain, haiti, 2010.	to increase understanding of drug-resistant vibrio cholerae, we studied selected molecular mechanisms of antimicrobial drug resistance in the 2010 haiti v. cholerae outbreak strain. most resistance resulted from acquired genes located on an integrating conjugative element showing high homology to an integrating conjugative element identified in a v. cholerae isolate from india.	2011	22099122
Toxigenic Vibrio cholerae O1 in water and seafood, Haiti.	During the 2010 cholera outbreak in Haiti, water and seafood samples were collected to detect Vibrio cholerae. The outbreak strain of toxigenic V. cholerae O1 serotype Ogawa was isolated from freshwater and seafood samples. The cholera toxin gene was detected in harbor water samples.	2011	22099121
Characterization of toxigenic Vibrio cholerae from Haiti, 2010-2011.	In October 2010, the US Centers for Disease Control and Prevention received reports of cases of severe watery diarrhea in Haiti. The cause was confirmed to be toxigenic Vibrio cholerae, serogroup O1, serotype Ogawa, biotype El Tor. We characterized 122 isolates from Haiti and compared them with isolates from other countries. Antimicrobial drug susceptibility was tested by disk diffusion and broth microdilution. Analyses included identification of rstR and VC2346 genes, sequencing of ctxAB and tc ...	2011	22099116
comparative genomics of vibrio cholerae from haiti, asia, and africa.	cholera was absent from the island of hispaniola at least a century before an outbreak that began in haiti in the fall of 2010. pulsed-field gel electrophoresis (pfge) analysis of clinical isolates from the haiti outbreak and recent global travelers returning to the united states showed indistinguishable pfge fingerprints. to better explore the genetic ancestry of the haiti outbreak strain, we acquired 23 whole-genome vibrio cholerae sequences: 9 isolates obtained in haiti or the dominican repub ...	2011	22099115
Cholera--modern pandemic disease of ancient lineage.	Cholera has affected humans for at least a millennium and persists as a major cause of illness and death worldwide, with recent epidemics in Zimbabwe (2008-2009) and Haiti (2010). Clinically, evidence exists of increasing severity of disease linked with emergence of atypical Vibrio cholerae organisms that have incorporated genetic material from classical biotype strains into an El Tor biotype background. A key element in transmission may be a recently recognized hyperinfectious phase, which pers ...	2011	22099113
clonal origins of vibrio cholerae o1 el tor strains, papua new guinea, 2009-2011.	we used multilocus sequence typing and variable number tandem repeat analysis to determine the clonal origins of vibrio cholerae o1 el tor strains from an outbreak of cholera that began in 2009 in papua new guinea. the epidemic is ongoing, and transmission risk is elevated within the pacific region.	2011	22099099
molecular subtyping in cholera outbreak, laos, 2010.	a cholera outbreak in laos in july 2010 involved 237 cases, including 4 deaths. molecular subtyping indicated relatedness between the vibrio cholerae isolates in this and in a 2007 outbreak, uncovering a clonal group of v. cholerae circulating in the mekong basin. our finding suggests the subtyping methods will affect this relatedness.	2011	22099098
the population and evolutionary dynamics of vibrio cholerae and its bacteriophage: conditions for maintaining phage-limited communities.	although bacteriophage have been reported to be the most abundant organisms on earth, little is known about their contribution to the ecology of natural communities of their host bacteria. most importantly, what role do these viral parasitoids play in regulating the densities of bacterial populations? to address this question, we use experimental communities of vibrio cholerae and its phage in continuous culture, and we use mathematical models to explore the population dynamic and evolutionary c ...	2011	22089867
pathoadaptive conditional regulation of the type vi secretion system in vibrio cholerae o1 strains.	the most recently discovered secretion pathway in gram-negative bacteria, the type vi secretion system (t6ss), is present in many species and is considered important for the survival of non-o1 non-o139 vibrio cholerae in aquatic environments. until now, it was not known whether there is a functionally active t6ss in wild-type v. cholerae o1 strains, the cause of cholera disease in humans. here, we demonstrate the presence of a functionally active t6ss in wild-type v. cholerae o1 strains, as evid ...	2011	22083711
In vitro evaluation of antibacterial activity of Asparagopsis taxiformis from the Straits of Messina against pathogens relevant in aquaculture.	Ethanol extracts of Asparagopsis taxiformis collected from the Straits of Messina (Italy) were screened for antibacterial activity against pathogenic shellfish and fish bacteria previously isolated from local marine and brackish environments. Genetic labelling by DNA barcoding allowed us to identify the algal population as a biogeographical strain conspecific to A. taxiformis. The extract obtained in May showed the broadest antibacterial activity against all tested pathogenic bacteria, especiall ...	2012	22078751
functional roles of a tetraloop/receptor interacting module in a cyclic di-gmp riboswitch.	riboswitches are a class of structural rnas that regulate transcription and translation through specific recognition of small molecules. riboswitches are attractive not only as drug targets for novel antibiotics but also as modular tools for controlling gene expression. sequence comparison of a class of riboswitches that sense cyclic di-gmp (type-i c-di-gmp riboswitches) revealed that this type of riboswitch frequently shows a gaaa loop/receptor interaction between p1 and p3 elements. in the cry ...	2011	22074990
Phenotypic and genetic analyses of 111 clinical and environmental O1, O139, and non-O1/O139 Vibrio cholerae strains from different geographical areas.	SUMMARYA total of 111 clinical and environmental O1, O139 and non-O1/O139 Vibrio cholerae strains isolated between 1978 and 2008 from different geographical areas were typed using a combination of methods: antibiotic susceptibility, biochemical test, serogroup, serotype, biotype, sequences containing variable numbers of tandem repeats (VNTRs) and virulence genes ctxA and tcpA amplification. As a result of the performed typing work, the strains were organized into four clusters: cluster A1 includ ...	2011	22074599
protein domain of unknown function 3233 is a translocation domain of autotransporter secretory mechanism in gamma proteobacteria.	vibrio cholerae, the enteropathogenic gram negative bacteria is one of the main causative agents of waterborne diseases like cholera. about 1/3(rd) of the organism's genome is uncharacterised with many protein coding genes lacking structure and functional information. these proteins form significant fraction of the genome and are crucial in understanding the organism's complete functional makeup. in this study we report the general structure and function of a family of hypothetical proteins, dom ...	2011	22073138
Characterization of anticancer, antimicrobial, antioxidant properties and chemical compositions of Peperomia pellucida leaf extract.	Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then charact ...	2011	22071643
different types of cell death induced by enterotoxins.	the infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. in addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. blocking these enterotoxins with synthetic drugs and vac ...	2010	22069678
a role for quorum sensing in regulating innate immune responses mediated by vibrio cholerae outer membrane vesicles (omvs).	outer membrane vesicles (omvs) are released from many gram-negative bacteria. omvs interact with and are taken up by human cells. we and others have now showed that omvs contain peptidoglycan, which is sensed mainly by the pattern-recognition receptor nod1 in the cytoplasm of host cells. vibrio cholerae is clinically important as one of the causative agents of severe dehydrating diarrhea in humans. we showed that non-o1 non-o139 v. cholerae (novc) strains of v. cholera produce omvs. of note, we ...	2011	22067940
rapid detection by multiplex pcr of genomic islands, prophages and integrative conjugative elements in v. cholerae 7th pandemic variants.	vibrio cholerae poses a threat to human health, and new epidemic variants have been reported so far. seventh pandemic v. cholerae strains are characterized by highly related genomic sequences but can be discriminated by a large set of genomic islands, phages and integrative conjugative elements. classical serotyping and biotyping methods do not easily discriminate among new variants arising worldwide, therefore the establishment of new methods for their identification is required. we developed a ...	2012	22062086
environmental and epidemiological surveillance of vibrio cholerae in a cholera-endemic region in india with freshwater environs.	to conduct epidemiological and ecological surveillance of cholera in freshwater environments.	2012	22054549
the crystal structure of aphb, a virulence gene activator from vibrio cholerae, reveals residues that influence its response to oxygen and ph.	expression of the two critical virulence factors of vibrio cholerae, toxin-coregulated pilus and cholera toxin, is initiated at the tcpph promoter by the regulators apha and aphb. apha is a winged helix dna-binding protein that enhances the ability of aphb, a lysr-type transcriptional regulator, to activate tcpph expression. we present here the 2.2 å x-ray crystal structure of full-length aphb. as reported for other lysr-type proteins, aphb is a tetramer with two distinct subunit conformations. ...	2011	22053934
[acute gastroenteritis caused by a vibrio cholerae non-o1, non-o139 strain harboring a genetic region homologous to the vpai-7 pathogenicity island].	pathogenic vibrio cholerae isolates, the etiologic agents of cholera, generally express one of two o antigens (o1 or o139). most environmental isolates are nonpathogenic and are referred to as "non-o1, non-o139". however some v. cholerae non-o1, non-o139 strains are clearly pathogenic and have caused outbreaks or sporadic cases of gastroenteritis and extraintestinal infections in humans. we report a case of acute gastroenteritis by a v. cholerae non-o1, non-o139 harboring a genetic region homolo ...	2011	22051624
erratum: variation in epitopes of the b subunit of vibrio cholerae non-o1 and vibrio mimicus cholera toxins.		1990	22049941
antibiotic susceptibility patterns of vibrio cholerae isolates.	cholera is one of the most common diarrhoeal diseases in nepal. etiological agent of cholera is vibrio cholerae which removes essential body fluids, salts and vital nutrients, which are necessary for life causing dehydration and malnutrition. emerging antimicrobial resistant is common. the aim of the present study was to determine the antibiotic susceptibility pattern of cholera patients in nepal.	2010	22049830
Exploration of in vitro time point quantitative evaluation of newly synthesized benzimidazole and benzothiazole derivatives as potential antibacterial agents.	Present communication deals with the in vitro time point quantitative antibacterial evaluation of newly synthesized 1,2-disubstituted benzimidazoles (3a-p) and 2-substituted benzothiazoles (5a-h) against Gram-positive bacteria Staphylococcus aureus, Bacillus cereus, and Gram-negative bacteria Vibrio cholerae, Shigella dysenteriae and Escherichia coli. These compounds were synthesized under mild reaction conditions using Al(2)O(3)-Fe(2)O(3) nanocrystals as heterogeneous catalyst. Bio-evaluation s ...	2011	22047695
Vibriocidal assays to determine the antibody titer of patient sera samples.	The vibriocidal titer assay can be used to detect antibodies against Vibrio cholerae in serum samples, serving as an indicator of prior infection and potential protection against cholera. The assay can be utilized in research and clinical settings to test the effectiveness of vaccines, and also in epidemiological studies relevant to cholera transmission and surveillance. This unit outlines the steps involved in conducting an easily interpreted colorimetric vibriocidal titer assay with a relative ...	2011	22045586
invasive vibrio cholerae non-o1 non-0139 infection in a thalassemic child.	invasive, extra-intestinal infection with vibrio cholerae non-o1, non-o139 is rare especially among children. herein the authors report a 12-year-old girl with underlying beta-thalassemia status post-splenectomy presenting with v. cholerae non-o1, non-o139 gastroenteritis with concomitant septicemia. the pathogen was identified from stool and blood culture and the patient recovered uneventfully after antimicrobial and supportive therapy. a review and comparison of clinical manifestations and out ...	2011	22043781
bacterial aetiology of diarrhoeal diseases and antimicrobial resistance in dhaka, bangladesh, 2005-2008.	summaryinfectious diarrhoea caused by bacterial pathogens contributes to the high level of mortality in developing countries like bangladesh. following standard bacteriological procedures, a total of 14 428 bacterial pathogens were isolated from 56 132 stool samples and rectal swabs collected from diarrhoeal patients between 2005 and 2008. the rate of isolation and antimicrobial susceptibility data were retrospectively analysed for these isolates and among them vibrio spp. (42·9%) were the most ...	2011	22040529
structural characterization of inhibitors with selectivity against members of a homologous enzyme family.	the aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. as this critical pathway is only present in plants and microbes, any disruptions will be fatal to these organisms. an early pathway enzyme, l-aspartate-β-semialdehyde dehydrogenase, produces a key intermediate at the first branch point of this pathway. developing potent and selective inhibitors against several orthologs in the l-aspart ...	2012	22039970
determination of the crystal structure and active residues of fabv, the enoyl-acp reductase from xanthomonas oryzae.	enoyl-acp reductase (enr) catalyses the last reduction reaction in the fatty acid elongation cycle in bacteria and is a good antimicrobial target candidate. fabv is the most recently discovered class of enr, but we lack information about the atomic structure and the key residues involved in reductase activity except for the known conserved tyrosine and lysine residues in the y-x(8)-k active site motif.	2011	22039545
authors' response: on sialic acid transport and utilization by vibrio cholerae.	authors' response: on sialic acid transport and utilization by vibrio cholerae.	2011	22034486
Extracellular nucleases and extracellular DNA play important roles in Vibrio cholerae biofilm formation.	Biofilms are a preferred mode of survival for many microorganisms including Vibrio cholerae, the causative agent of the severe secretory diarrhoeal disease cholera. The ability of the facultative human pathogen V. cholerae to form biofilms is a key factor for persistence in aquatic ecosystems and biofilms act as a source for new outbreaks. Thus, a better understanding of biofilm formation and transmission of V. cholerae is an important target to control the disease. So far the Vibrio exopolysacc ...	2011	22032623
efficacy of a low-cost, inactivated whole-cell oral cholera vaccine: results from 3 years of follow-up of a randomized, controlled trial.	killed oral cholera vaccines (ocvs) have been licensed for use in developing countries, but protection conferred by licensed ocvs beyond two years of follow-up has not been demonstrated in randomized, clinical trials.	2011	22028938
High Frequency of a Novel Filamentous Phage, VCY, within an Environmental Vibrio cholerae Population.	Environmental Vibrio cholerae strains isolated from a coastal brackish pond (Oyster Pond, Woods Hole, MA) carried a novel filamentous phage, VCY, which can exist as a host genome integrative form (IF) and a plasmid-like replicative form (RF). Outside the cell, the phage displays a morphology typical of Inovirus, with filamentous particles ~1.8 µm in length and 7 nm in width. Four independent RF isolates had identical genomes, except for 8 single nucleotide polymorphisms clustered in two regions. ...	2012	22020507
death of the tonb shuttle hypothesis.	a complex of exbb, exbd, and tonb couples cytoplasmic membrane (cm) proton motive force (pmf) to the active transport of large, scarce, or important nutrients across the outer membrane (om). tonb interacts with om transporters to enable ligand transport. several mechanical models and a shuttle model explain how tonb might work. in the mechanical models, tonb remains attached to the cm during energy transduction, while in the shuttle model the tonb n terminus leaves the cm to deliver conformation ...	2011	22016747
Multi-drug resistant Vibrio cholerae O1 variant El Tor isolated in northern Vietnam between 2007 and 2010.	There has been a re-emergence of cholera outbreaks in northern Vietnam since 2007. To understand the molecular epidemiological relatedness and antibiotic susceptibility profile of responsible V. cholerae O1 outbreak strains, a representative collection of 100 V. cholerae O1 strains was characterized. V. cholerae O1 strains isolated from diarrheal patients in northern Vietnam between 2007 and 2010 were investigated for antibiotic susceptibility, and characterized by phenotypic and genotypic tests ...	2011	22016560
examining the role of rv2895c (viub) in iron acquisition in mycobacterium tuberculosis.	iron acquisition is essential for mycobacterium tuberculosis (mtb) virulence. understanding the molecular mechanisms used by mtb to scavenge iron during infection might reveal new targets for antimicrobial development. rv2895c, a homolog of viub from vibrio cholerae has been postulated to be involved in iron-siderophore uptake and utilization in mtb. this study examines the requirement of rv2895c for adaptation of mtb to iron limitation. we show that rv2895c is dispensable for normal replication ...	2011	22015175
vibrio cholerae infection, novel drug targets and phage therapy.	vibrio cholerae is the causative agent of the diarrheal disease cholera. although antibiotic therapy shortens the duration of diarrhea, excessive use has contributed to the emergence of antibiotic resistance in v. cholerae. mobile genetic elements have been shown to be largely responsible for the shift of drug resistance genes in bacteria, including some v. cholerae strains. quorum sensing communication systems are used for interaction among bacteria and for sensing environmental signals. sequen ...	2011	22004038
non-canonical inflammasome activation targets caspase-11.	caspase-1 activation by inflammasome scaffolds comprised of intracellular nucleotide-binding oligomerization domain (nod)-like receptors (nlrs) and the adaptor asc is believed to be essential for production of the pro-inflammatory cytokines interleukin (il)-1β and il-18 during the innate immune response. here we show, with c57bl/6 casp11 gene-targeted mice, that caspase-11 (also known as caspase-4) is critical for caspase-1 activation and il-1β production in macrophages infected with escherichia ...	2011	22002608
small molecule probes of the receptor binding site in the vibrio cholerae cai-1 quorum sensing circuit.	based on modification of separate structural features of the vibrio cholerae quorum sensing signal, (s)-3-hydroxytridecan-4-one (cai-1), three focused compound libraries have been synthesized and evaluated for biological activity. modifications to the acyl tail and α-hydroxy ketone typically provided agonists with activities correlated to tail length and conservative changes to the hydroxy ketone. among the molecules identified within this collection of agonists is am-cai-1 (b11), which is among ...	2011	22001326
systematic review: the use of proton pump inhibitors and increased susceptibility to enteric infection.	background: the use of proton pump inhibitors (ppis) is increasing worldwide. suppression of gastric acid alters the susceptibility to enteric bacterial pathogens. aim this systematic review was undertaken to examine the relationship between ppi use and susceptibility to enteric infections by a specific pathogen based on published literature and to discuss the potential mechanisms of ppi enhanced pathogenesis of enteric infections. methods pubmed, ovid medline databases were searched. search t ...	2011	21999643
outbreak of cholera in the republic of congo and the democratic republic of congo, and cholera worldwide.	cholera is an acute intestinal disease caused by infection of the vibrio cholerae bacterium. often manifested as a constant diarrhoeal disease, cholera is associated with significant mortality as well as economic loss due to the strain on health care. cholera often affects nations with lower economic status. the recent outbreak of cholera in the republic of congo and the democratic republic of congo has affected thousands of people. here we review the past cholera epidemiology, molecular mec ...	2011	21997936
south asia instead of nepal may be the origin of the haitian cholera outbreak strains.		2011	21990616
Fine-tuning control of phoBR expression in Vibrio cholerae by binding of phoB to multiple pho boxes.	The control of Vibrio cholerae phoBR expression by PhoB involves its binding to Pho boxes at -35 (box 1), -60 (box 2), and -80 (box 3) from the putative phoB translation start site. These loci were located in the sense (box 1) and antisense (boxes 2 and 3) strands of the phoBR regulatory region, and PhoB binds to these individual boxes with distinct affinities. Fusions of sequences containing different combinations of these boxes upstream of the lacZ reporter in a plasmid demonstrated that only ...	2011	21984792
Characterization and regulation of the 2,3-butanediol pathway in Serratia marcescens.	Serratia marcescens has been proved to be a potential strain for industrial 2,3-butanediol production for its high yield, productivity, and other advantages. In this study, the genes slaA, slaB, slaC, and slaR were successfully cloned which were further confirmed to be encoding acetolactate decarboxylase, acetolactate synthase, 2,3-butanediol dehydrogenase, and a LysR-like regulator, respectively. Unlike in Klebsiella sp. or Klebsiella pneumonie and Vibrio sp. or Vibrio cholerae, the gene slaC i ...	2011	21983710
cholera.		2011	21980704
On sialic acid transport and utilization by Vibrio cholerae.		2011	21980116
two cases of vibrio cholerae non-o1/non-o139 septicaemia with favourable outcome in lebanon.		2011	21977578
emergence of vibrio cholerae serotype hikojima in northern tamil nadu.		2011	21976808
natural transformation of vibrio fischeri requires tfox and tfoy.	recent evidence has indicated that natural genetic transformation occurs in vibrio cholerae, and that it requires both induction by chitin oligosaccharides, like chitohexaose, and expression of a putative regulatory gene designated tfox. using sequence and phylogenetic analyses we have found two tfox paralogues in all sequenced genomes of the genus vibrio. like v. cholerae, when grown in chitohexaose, cells of v. fischeri are able to take up and incorporate exogenous dna. chitohexaose-independen ...	2010	21966921
interplay among cyclic diguanylate, hapr, and the general stress response regulator (rpos) in the regulation of vibrio cholerae hemagglutinin/protease.	vibrio cholerae secretes the zn-dependent metalloprotease hemagglutinin (ha)/protease (mucinase), which is encoded by hapa and displays a broad range of potential pathogenic activities. expression of ha/protease has a stringent requirement for the quorum-sensing regulator hapr and the general stress response regulator rpos. here we report that the second messenger cyclic diguanylic acid (c-di-gmp) regulates the production of ha/protease in a negative manner. overexpression of a diguanylate cycla ...	2011	21965573
positive regulation of the vibrio cholerae porin ompt by iron and fur.	the transcription factor fur regulates the expression of a number of genes in vibrio cholerae in response to changes in the level of available iron. fur usually acts as a repressor, but here we show that fur positively regulates the expression of ompt, which encodes a major outer membrane porin. ompt levels increased when the bacteria were grown in medium containing relatively high levels of iron, and this effect required fur. the level of ompt mrna also is increased in the presence of iron and ...	2011	21965571
Use of a DNA microarray for detection and identification of bacterial pathogens associated with fishery products.	We established a microarray for the simultaneous detection and identification of diverse putative pathogens often associated with fishery products by targeting specific genes of Listeria monocytogenes, Salmonella, Shigella, Staphylococcus aureus, Streptococcus pyogenes, Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus, and Yersinia enterocolitica and the 16S-23S rRNA gene internal transcribed spacer (ITS) region of Proteus mirabilis and Proteus vulgaris. The microarray contained 26 sp ...	2011	21965411
Genome sequence of the human pathogen Vibrio cholerae Amazonia.	Vibrio cholerae O1 Amazonia is a pathogen that was isolated from cholera-like diarrhea cases in at least two countries, Brazil and Ghana. Based on multilocus sequence analysis, this lineage belongs to a distinct profile compared to strains from El Tor and classical biotypes. The genomic analysis revealed that it contains Vibrio pathogenicity island 2 and a set of genes related to pathogenesis and fitness, such as the type VI secretion system, present in choleragenic V. cholerae strains.	2011	21952545
molecular cloning and characterization of mannitol-1-phosphate dehydrogenase from vibrio cholerae.	vibrio cholerae utilizes mannitol through an operon of the phosphoenolpyruvate-dependent phosphotransferase (pts) type. a gene, mtld, encoding mannitol-1-phosphate dehydrogenase was identified within the 3.9 kb mannitol operon of v. cholerae. the mtld gene was cloned from v. cholerae o395, and the recombinant enzyme was functionally expressed in e. coli as a 6×his-tagged protein and purified to homogeneity. the recombinant protein is a monomer with a molecular mass of 42.35 kda. the purified rec ...	2011	21952367
vash is a transcriptional regulator of the type vi secretion system functional in endemic and pandemic vibrio cholerae.	the gram-negative bacterium vibrio cholerae is the etiological agent of cholera, a disease characterized by the release of high volumes of watery diarrhea. many medically important proteobacteria, including v. cholerae, carry one or multiple copies of the gene cluster that encodes the bacterial type vi secretion system (t6ss) to confer virulence or interspecies competitiveness. structural similarity and sequence homology between components of the t6ss and the cell-puncturing device of t4 bacteri ...	2011	21949076
bacteriological assessment of drinking water supply options in coastal areas of bangladesh.	this study was conducted to assess the bacteriological quality of alternative drinking water supply options in southwest coastal areas of bangladesh. a total of 90 water samples were collected during both dry and wet seasons from household based rainwater harvesting systems (rwhss), community based rain water harvesting systems (crwhss), pond-sand filters (psfs) and ponds. the samples were evaluated for faecal coliform, escherichia coli and heterotrophic plate count, as well as vibrio cholerae, ...	2011	21942205
Variants of Vibrio cholerae O1 El Tor from Zambia showed new genotypes of ctxB: a reply to Marin & Vicente.		2011	21939580
variants of vibrio cholerae o1 el tor from zambia showed new genotypes of ctxb.		2011	21939579
Potential role of chitinases and chitin-binding proteins in host-microbial interactions during the development of intestinal inflammation.	The small and large intestines contain an abundance of luminal antigens derived from food products and enteric microorganisms. The function of intestinal epithelial cells is tightly regulated by several factors produced by enteric bacteria and the epithelial cells themselves. Epithelial cells actively participate in regulating the homeostasis of intestine, and failure of this function leads to abnormal and host-microbial interactions resulting in the development of intestinal inflammation. Major ...	2011	21938682
expression of the cholera toxin b subunit (ct-b) in maize seeds and a combined mucosal treatment against cholera and traveler's diarrhea.	the non-toxic b subunit (ct-b) of cholera toxin from vibrio cholerae is a strong immunogen and amplifies the immune reaction to conjugated antigens. in this work, a synthetic gene encoding for ct-b was expressed under control of a γ-zein promoter in maize seeds. levels of ct-b in maize plants were determined via ganglioside dependent elisa. the highest expression level recorded in t(1) generation seeds was 0.0014% of total aqueous soluble protein (tasp). expression level of the same event in the ...	2011	21938449
amplified fragment length polymorphism of clinical and environmental vibrio cholerae from a freshwater environment in a cholera-endemic area, india.	the region around chandigarh in india has witnessed a resurgence of cholera. however, isolation of v. cholerae o1 from the environment is infrequent. therefore, to study whether environmental nono1-nono139 isolates, which are native to the aquatic ecosystem, act as precursors for pathogenic o1 strains, their virulence potential and evolutionary relatedness was checked.	2011	21936962
Structural and functional studies on the interaction of GspC and GspD in the type II secretion system.	Type II secretion systems (T2SSs) are critical for secretion of many proteins from Gram-negative bacteria. In the T2SS, the outer membrane secretin GspD forms a multimeric pore for translocation of secreted proteins. GspD and the inner membrane protein GspC interact with each other via periplasmic domains. Three different crystal structures of the homology region domain of GspC (GspC(HR)) in complex with either two or three domains of the N-terminal region of GspD from enterotoxigenic Escherichi ...	2011	21931548
integration of cyclic di-gmp and quorum sensing in the control of vpst and apha in vibrio cholerae.	vibrio cholerae transitions between aquatic environmental reservoirs and infection in the gastrointestinal tracts of human hosts. the second-messenger molecule cyclic di-gmp (c-di-gmp) and quorum sensing (qs) are important signaling systems that enable v. cholerae to alternate between these distinct environments by controlling biofilm formation and virulence factor expression. here we identify a conserved regulatory mechanism in v. cholerae that integrates c-di-gmp and qs to control the expressi ...	2011	21926235
ecology and genetic structure of a northern temperate vibrio cholerae population related to toxigenic isolates.	although vibrio cholerae is an important human pathogen, little is known about its populations in regions where the organism is endemic but where cholera disease is rare. a total of 31 independent isolates confirmed as v. cholerae were collected from water, sediment, and oysters in 2008 and 2009 from the great bay estuary (gbe) in new hampshire, a location where the organism has never been detected. environmental analyses suggested that abundance correlates most strongly with rainfall events, as ...	2011	21926213
Serum sialic acid levels in Vibrio cholera serotype Hikojima infected Nigerian patients.	Vibro cholera neuraminidase is known to cleave sialic acid in the gut to expose receptors for cholera enterotoxin. This study determined if cholera neuraminidase crosses significantly into the circulation of patients with cholera to cause cleavage of sialic acid on circulating blood cells.	2011	21922855
Spinosad and neem seed kernel extract as bio-controlling agents for malarial vector, Anopheles stephensi and non-biting midge, Chironomus circumdatus.	Midge egg masses are reported to support non-pathogenic strains of the cholera pathogen, Vibrio cholera (V. cholera). Mosquito born diseases have been reported to cause millions of death worldwide. The present research reveals the toxicity effect of spinosad and neem seed kernel extract (NSKE) against different larval stages of Anopheles stephensi (An. stephensi) and Chironomus circumdatus (Ch. circumdatus).	2011	21914538
genetic analysis of anti-amoebae and anti-bacterial activities of the type vi secretion system in vibrio cholerae.	a type vi secretion system (t6ss) was recently shown to be required for full virulence of vibrio cholerae o37 serogroup strain v52. in this study, we systematically mutagenized each individual gene in t6ss locus and characterized their functions based on expression and secretion of the hemolysin co-regulated protein (hcp), virulence towards amoebae of dictyostelium discoideum and killing of escherichia coli bacterial cells. we group the 17 proteins characterized in the t6ss locus into four categ ...	2011	21909372
protection activity of a novel probiotic strain of bacillus subtilis against salmonella enteritidis infection.	the activity of 240 bacterial isolates screened from the gastrointestinal tracts of native chickens were evaluated for use as a potential probiotic in food animal production in order to protect against animal diseases and reduce pathogenic contamination of human food products. in observing the antagonistic activity of 117 bacilli isolates, 10 of these isolates exhibited higher growth inhibition of seven foodborne pathogens, including salmonella enteritidis, salmonella typhimurium, escherichia co ...	2011	21907374
safety and immunogenicity study of a killed bivalent (o1 and o139) whole-cell oral cholera vaccine shanchol, in bangladeshi adults and children as young as 1 year of age.	safety and immunogenicity study of an oral, killed, bivalent whole-cell, cholera vaccine, shanchol was carried out in bangladeshi participants. this study was conducted prior to initiating a feasibility study in bangladesh.	2011	21907255
Whole genome PCR scanning reveals the syntenic genome structure of toxigenic Vibrio cholerae strains in the O1/O139 population.	Vibrio cholerae is commonly found in estuarine water systems. Toxigenic O1 and O139 V. cholerae strains have caused cholera epidemics and pandemics, whereas the nontoxigenic strains within these serogroups only occasionally lead to disease. To understand the differences in the genome and clonality between the toxigenic and nontoxigenic strains of V. cholerae serogroups O1 and O139, we employed a whole genome PCR scanning (WGPScanning) method, an rrn operon-mediated fragment rearrangement analysi ...	2011	21904621
Characterization of Cholix toxin-induced apoptosis in HeLa cells.	Cholix toxin (Cholix) is a novel ADP-ribosylating cytotoxin produced by Vibrio cholerae, which utilizes eukaryotic elongation factor 2 as a substrate and acts by a mechanism similar to that of diphtheria toxin and Pseudomonas exotoxin A. First it was found that Cholix-treated HeLa cells exhibited caspase-dependent apoptosis, whereas intestinal cells such as Caco-2, HCT116, and RKO did not. Here we investigated Cholix-induced cell death signaling pathways in HeLa cells. Cholix-induced cytochrome ...	2011	21903588
a model for vibrio cholerae colonization of the human intestine.	vibrio cholerae is a strict human pathogen that causes the disease cholera. it is an old-world pathogen that has re-emerged as a new threat since the early 1990s. v. cholerae colonizes the upper, small intestine where it produces a toxin that leads to watery diarrhea, characterizing the disease (kahn et al., 1988). the dynamics of colonization by the bacteria of the intestines are largely unknown. although a large initial infectious dose is required for infection, data suggests that only a small ...	2011	21903104
a communal bacterial adhesin anchors biofilm and bystander cells to surfaces.	while the exopolysaccharide component of the biofilm matrix has been intensively studied, much less is known about matrix-associated proteins. to better understand the role of these proteins, we undertook a proteomic analysis of the v. cholerae biofilm matrix. here we show that the two matrix-associated proteins, bap1 and rbma, perform distinct roles in the biofilm matrix. rbma strengthens intercellular attachments. in contrast, bap1 is concentrated on surfaces where it serves to anchor the biof ...	2011	21901100
lplunc1 modulates innate immune responses to vibrio cholerae.	recent studies demonstrate that long palate, lung, and nasal epithelium clone 1 protein (lplunc1) is involved in immune responses to vibrio cholerae, and that variations in the lplunc1 promoter influence susceptibility to severe cholera in humans. however, no functional role for lplunc1 has been identified.	2011	21900486
biological characterization of two marine bdellovibrio-and-like organisms isolated from daya bay of shenzhen, china and their application in the elimination of vibrio parahaemolyticus in oyster.	bdellovibrio-and-like organisms (balos) are a group of highly motile delta-proteobacteria that prey on other gram-negative bacteria. however, nothing is known of the application potential of marine balos in safeguarding seafood safety. here, biological characterization of two marine balos strains and their application in the elimination of vibrio parahaemolyticus in oyster (crassostrea ariakensis) at the laboratory scale were investigated. balos strains bdh12 and bdhsh06 were isolated from sedim ...	2011	21899909
simple, direct conjugation of bacterial o-sp-core antigens to proteins: development of cholera conjugate vaccines.	bacterial o-sp-core antigens can be conjugated to proteins in the same, simple way as synthetic, linker-equipped carbohydrates by applying squaric acid chemistry. introduction of spacers (linkers) to either o-sp-core antigens or protein carriers, which is involved in commonly applied protocols, is not required. the newly developed method described here consists of preparation of a squaric acid monoester derivative of o-sp-core antigen, utilizing the amino group inherent in the core, and reaction ...	2011	21899371
vibrio cholerae o1 lineages driving cholera outbreaks during seventh cholera pandemic in ghana.	in recent years, the frequency of cholera epidemics across africa has increased significantly with thousands of people dying each year. however, there still exists a lack of information concerning the vibrio cholerae o1 lineages driving early and contemporary epidemics since the seventh cholera pandemic started in the continent. this compromises the understanding of the forces determining the epidemiology of cholera in africa and its control. this study aimed to analyze a collection of v. choler ...	2011	21896336
microwave assisted synthesis and antimicrobial evaluation of new fused pyran derivatives bearing 2-morpholinoquinoline nucleus.	a new series of fused pyran derivatives 5a-x bearing 2-morpholinoquinoline nucleus has been synthesized under microwave irradiation by a reaction of 2-morpholinoquinoline-3-carbaldehyde 2a-c, malononitrile 3 and compounds 4a-h in presence of naoh as basic catalyst. all the compounds were screened against three gram positive bacteria (streptococcus pneumoniae, clostridium tetani, bacillus subtilis), three gram negative bacteria (salmonella typhi, vibrio cholerae, escherichia coli) and two fungi ( ...	2011	21890359
A cholera outbreak associated with drinking contaminated well water.	Cholera has been a significant public health challenge in many communities. An outbreak of acute diarrheal illness occurred among participants in a wedding ceremony in a village in Qazvin, Iran, in 2008. We conducted an epidemiological, environmental and microbiological investigation to determine the causative agent, source and extent of this outbreak.	2011	21888459
localization of ubiquinone-8 in the na+-pumping nadh:quinone oxidoreductase from vibrio cholerae.	na(+) is the second major coupling ion at membranes after protons, and many pathogenic bacteria use the sodium-motive force to their advantage. a prominent example is vibrio cholerae, which relies on the na(+)-pumping nadh:quinone oxidoreductase (na(+)-nqr) as the first complex in its respiratory chain. the na(+)-nqr is a multisubunit, membrane-embedded nadh dehydrogenase that oxidizes nadh and reduces quinone to quinol. existing models describing redox-driven na(+) translocation by the na(+)-nq ...	2011	21885438
termination of vibrio cholerae virulence gene expression is mediated by proteolysis of the major virulence activator, toxt.	vibrio cholerae is the causative agent of cholera, a severe diarrhoeal illness. v. cholerae produces two major virulence factors: the cholera toxin, which directly causes diarrhoea, and the toxin-coregulated pilus, which is required for intestinal colonization. production of these virulence factors is dependent on the major virulence regulator, toxt. under virulence-inducing growth conditions, transcription factors toxr and tcpp initially activate transcription of toxt. however, once toxt has be ...	2011	21883522
Characterization of Vibrio cholerae O1 El Tor biotype variant clinical isolates from Bangladesh and Haiti, including a molecular genetic analysis of virulence genes.	Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various lev ...	2011	21880975
Functional characterization of VC1929 of Vibrio cholerae El Tor: role in mannose-sensitive haemagglutination, virulence and utilization of sialic acid.	The nonadhesive mutant CD11 of Vibrio cholerae El Tor, defective in expression of mannose-sensitive haemagglutinin, lacks a protein when compared with its parent strain. Determination of the amino acid sequence revealed the identity of the protein as the product of VC1929, which is annotated to encode a protein, DctP, involved in the transport of C4-dicarboxylates. We cloned the dctP gene in pUC19 vector and expressed it in mutant CD11. Expression of DctP in the resulting complemented strain res ...	2011	21873407
Whole genome sequencing of environmental Vibrio cholerae O1 from 10 nanograms of DNA using short reads.	Multiple Displacement Amplification (MDA) of DNA using f29 (phi29) DNA polymerase amplifies DNA several billion-fold, which has proved to be potentially very useful for evaluating genome information in a culture-independent manner. Whole genome sequencing using DNA from a single prokaryotic genome copy amplified by MDA has not yet been achieved due to the formation of chimeras and skewed amplification of genomic regions during the MDA step, which then precludes genome assembly. We have hereby ad ...	2011	21871929
evidence for several waves of global transmission in the seventh cholera pandemic.	vibrio cholerae is a globally important pathogen that is endemic in many areas of the world and causes 3-5 million reported cases of cholera every year. historically, there have been seven acknowledged cholera pandemics; recent outbreaks in zimbabwe and haiti are included in the seventh and ongoing pandemic. only isolates in serogroup o1 (consisting of two biotypes known as 'classical' and 'el tor') and the derivative o139 can cause epidemic cholera. it is believed that the first six cholera pan ...	2011	21866102
Population genetics of Vibrio cholerae from Nepal in 2010: evidence on the origin of the Haitian outbreak.	Cholera continues to be an important cause of human infections, and outbreaks are often observed after natural disasters, such as the one following the 2010 earthquake in Haiti. Once the cholera outbreak was confirmed, rumors spread that the disease was brought to Haiti by a battalion of Nepalese soldiers serving as United Nations peacekeepers. This possible connection has never been confirmed. We used whole-genome sequence typing (WGST), pulsed-field gel electrophoresis (PFGE), and antimicrobia ...	2011	21862630
developing novel antisecretory drugs to treat infectious diarrhea.	diarrhea, a disease of poverty and poor sanitation, kills an estimated two million children each year. oral rehydration therapy is a very simple and inexpensive treatment that has significantly reduced mortality from secretory diarrhea caused by rotavirus, cholera and enterotoxigenic escherichia coli. the efficacy and adoption of oral rehydration therapy would be enhanced by a drug that reduces fluid loss associated with these diseases and alleviates disease symptoms. secretion and absorption by ...	2011	21859305
tolc affects virulence gene expression in vibrio cholerae.	a vibrio cholerae tolc mutant showed increased toxt expression in m9 medium, but not in the presence of four amino acids that induce cholera toxin production, and in lb with high osmolarity but not high ph or temperature. tolc did not affect expression of other regulatory genes in the toxr regulon.	2011	21856848
characterization of pathogenicity island prophage in clinical and environmental strains of vibrio cholerae.	in this study 86 isolates of vibrio cholerae were analysed for their adhesive properties and the presence of pathogenicity island genes. with the exception of three isolates, all of the other clinical isolates (92.5%) contained an intact tcp (toxin-co-regulated pilus) gene cluster. in contrast, 95% of all environmental non-o1-non-o139 isolates were negative for the tcp gene cluster. the majority of clinical isolates (82.5%) possessed the complete vibrio pathogenicity island (vpi) gene cluster an ...	2011	21852526
studies on the synthesis of lewis-y oligosaccharides.	lewis-y histo-blood group oligosaccharides are tumour-associated antigens prevalent in several different types of cancer, and they may also be secondary ligands for bacterial toxins from escherichia coli and vibrio cholerae. the key step in the synthesis of these sterically congested oligosaccharides involves difucosylation of partially protected lactosamine derivatives. existing methods require either prolonged reaction times or elaborate glycosyl donors to ensure high stereoselectivity. herein ...	2011	21851931
differentiation among the vibrio cholerae serotypes o1, o139, o141 and non-o1, non-o139, non-o141 using specific monoclonal antibodies with dot blotting.	seven different monoclonal antibodies (mabs) specific to only vibrio cholerae were produced using a combination of five representative serotypes of v. cholerae for immunization. the first three mabs (vc-93, vc-82 and vc-223) were specific to the v. cholerae serogroup o1 with different avidity for the serotypes o1 inaba and o1 ogawa. the fourth and the fifth mabs were specific to v. cholerae o139 (vc-812) or o141 (vc-191) serogroups, respectively. the sixth mab (vc-26) bound to all three serogrou ...	2011	21851839
[comparative evaluation of protein hydrolysates in designing their based universal culture medium for the diagnosis of plague and cholera].	various protein hydrolysates made in russia and foreign countries were comparatively evaluated to use them to design a universal agarized culture medium for the diagnosis of plague and cholera. pancreatic baker's yeast broth was found to be most effective among the test media.	2011	21851013
Natural cholera infection-derived immunity in an endemic setting.	Live oral cholera vaccines may protect against cholera in a manner similar to natural cholera infections. However, information on which to base these vaccines is limited.	2011	21849288
hemolysin induces toll-like receptor (tlr)-independent apoptosis and multiple tlr-associated parallel activation of macrophages.	vibrio cholerae hemolysin (hlya) displays bipartite property while supervising macrophages (mφ). the pore-forming toxin causes profound apoptosis within 3 h of exposure and in parallel supports activation of the defying mφ. hlya-induced apoptosis of mφ remains steady for 24 h, is toll-like receptor (tlr)-independent, and is driven by caspase-9 and caspase-7, thus involving the mitochondrial or intrinsic pathway. cell activation is carried forward by time dependent up-regulation of varying tlrs. ...	2011	21846723
rna-seq-based monitoring of infection-linked changes in vibrio cholerae gene expression.	pathogens adapt to the host environment by altering their patterns of gene expression. microarray-based and genetic techniques used to characterize bacterial gene expression during infection are limited in their ability to comprehensively and simultaneously monitor genome-wide transcription. we used massively parallel cdna sequencing (rna-seq) techniques to quantitatively catalog the transcriptome of the cholera pathogen, vibrio cholerae, derived from two animal models of infection. transcripts ...	2011	21843873
influence of iron-chelated growth conditions on outer membrane protein production and virulence of vibrio tubiashii.	growth of two vibrio tubiashii strains under iron-chelated conditions resulted in the production of a hydroxymate-like siderophore, and expression of outer membrane proteins with homologies to proteins in vibrio cholerae and vibrio vulnificus which were not seen in cells grown under non-chelated growth conditions. pcr analysis using primers based on listonella anguillarum's ferric uptake repressor protein (fur) gene detected a 316-ábp fur gene homolog which also had sequence homology to the fur ...	2011	21839393