Publications

regulated intramembrane proteolysis of the virulence activator tcpp in vibrio cholerae is initiated by the tail-specific protease (tsp).	vibrio cholerae uses a multiprotein transcriptional regulatory cascade to control expression of virulence factors cholera toxin and toxin-co-regulated pilus. two proteins in this cascade are toxr and tcpp - unusual membrane-localized transcription factors with relatively undefined periplasmic domains and transcription activator cytoplasmic domains. tcpp and toxr function with each other and two other membrane-localized proteins, tcph and toxs, to activate transcription of toxt, encoding the dire ...	2015	25999037
intestinal colonization dynamics of vibrio cholerae.	to cause the diarrheal disease cholera, vibrio cholerae must effectively colonize the small intestine. in order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. the bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. in this review, we discuss recent developments and known aspects of the early stag ...	2015	25996593
ctxφ replication depends on the histone-like hu protein and the uvrd helicase.	the vibrio cholerae bacterium is the agent of cholera. the capacity to produce the cholera toxin, which is responsible for the deadly diarrhea associated with cholera epidemics, is encoded in the genome of a filamentous phage, ctxφ. rolling-circle replication (rcr) is central to the life cycle of ctxφ because amplification of the phage genome permits its efficient integration into the genome and its packaging into new viral particles. a single phage-encoded huh endonuclease initiates rcr of the ...	2015	25992634
rpos and quorum sensing control expression and polar localization of vibrio cholerae chemotaxis cluster iii proteins in vitro and in vivo.	the diarrheal pathogen vibrio cholerae contains three gene clusters that encode chemotaxis-related proteins, but only cluster ii appears to be required for chemotaxis. here, we present the first characterization of v. cholerae's 'cluster iii' chemotaxis system. we found that cluster iii proteins assemble into foci at bacterial poles, like those formed by cluster ii proteins, but the two systems assemble independently and do not colocalize. cluster iii proteins are expressed in vitro during stati ...	2015	25989366
integrating small molecule signalling and h-ns antagonism in vibrio cholerae, a bacterium with two chromosomes.	h-ns is a well-established silencer of virulence gene transcription in the human pathogen vibrio cholerae. biofilm formation aids v. cholerae in colonizing both its host and its external environments, and h-ns silences biofilm gene expression. cyclic-di-guanosine monophosphate acts through the dna binding proteins vpsr and vpst to overcome h-ns-mediated repression of biofilm genes, driving a transition between a planktonic and a colonial/biofilm lifestyle. the h-ns binding pattern has now been c ...	2015	25988304
atp-association to intrabacterial nanotransportation system in vibrio cholerae.	vibrio cholerae colonizes the lumen of the proximal small intestine, which has an alkaline environment, and secretes cholera toxin (ct) through a type ii secretion machinery. v. cholerae possesses the intrabacterial nanotransportation system (ibnots) for transporting ct from the inner portion toward the peripheral portion of the cytoplasm, and this system is controlled by extrabacterial ph. association of atp with ibnots has not yet been examined in detail. in this study, we demonstrated by immu ...	2015	25986680
highly active and stable oxaloacetate decarboxylase na⁺ pump complex for structural analysis.	the oxaloacetate decarboxylase primary na(+) pump (oad) produces energy for the surviving of some pathogenic bacteria under anaerobic conditions. oad composes of three subunits: oad-α, a biotinylated soluble subunit and catalyzes the decarboxylation of oxaloacetate; oad-β, a transmembrane subunit and functions as a na(+) pump; and oad-γ, a single transmembrane α-helical anchor subunit and assembles oad-α/β/γ complex. the molecular mechanism of oad complex coupling the exothermic decarboxylation ...	2015	25986323
repression by h-ns of genes required for the biosynthesis of the vibrio cholerae biofilm matrix is modulated by the second messenger cyclic diguanylic acid.	expression of vibrio cholerae genes required for the biosynthesis of exopolysacchide (vps) and protein (rbm) components of the biofilm matrix is enhanced by cyclic diguanylate (c-di-gmp). in a previous study, we reported that the histone-like nucleoid structuring (h-ns) protein represses the transcription of vpsa, vpsl and vpst. here we demonstrate that the regulator vpst can disrupt repressive h-ns nucleoprotein complexes at the vpsa and vpsl promoters in the presence of c-di-gmp, while h-ns co ...	2015	25982817
complete genome assemblies for two single-chromosome vibrio cholerae isolates, strains 1154-74 (serogroup o49) and 10432-62 (serogroup o27).	here, we report the completed genome sequences for two non-o1/non-o139 vibrio cholerae isolates. each isolate has only a single chromosome, as opposed to the normal paradigm of two chromosomes found in all other v. cholerae isolates.	2015	25977434
a case of non-o1/non-o139 vibrio cholerae septicemia and meningitis in a neonate.	a case of septicemia with meningitis due to non-o1/non-o139 vibrio cholerae in a neonate is reported. the genotype and phenotype of the isolate were examined in relation to the major virulence genes. the isolate was shown to be non-toxin but cytotoxin-producing, distinguished from the dominant clone of non-o1/non-o139v. cholerae by multilocus sequence typing.	2015	25975654
detection of vibrio cholerae by isothermal cross-priming amplification combined with nucleic acid detection strip analysis.	vibrio cholerae is a water- and food-borne human pathogen, and v. cholerae serotypes o1 and o139 have attracted attention because of their severe pathogenesis. however, non-o1, non-o139 cholera vibrios (ncvs) were also recently recognized as having virulence properties. in this study, we developed a cross-priming amplification (cpa) method for the detection of all serotypes of v. cholerae. the specificity of the cpa method was tested using a panel of 60 different bacterial strains. all of the v. ...	2015	25962828
occurrence of vibrio parahaemolyticus, vibrio cholerae, and vibrio vulnificus in the aquacultural environments of taiwan.	the occurrence of vibrio parahaemolyticus, vibrio vulnificus, and vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern taiwan was examined by the membrane filtration and colony hybridization method. the halophilic v. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log cfu/g. v. cholerae was found in both the seawater and freshwater ponds but preferentially in ...	2015	25951392
type 3 secretion system island encoded proteins required for colonization by non-o1/non-o139 serogroup v. cholerae.	vibrio cholerae is a genetically diverse species, and pathogenic strains can encode different virulence factors that mediate colonization and secretory diarrhea. although the toxin co-regulated pilus (tcp) is the primary colonization factor in epidemic causing v. cholerae strains, other strains do not encode tcp and instead promote colonization via the activity of a type three secretion system (t3ss). using the infant mouse model and t3ss-positive o39 serogroup strain am-19226, we sought to dete ...	2015	25939511
stereoselective syntheses of the conjugation-ready, downstream disaccharide and phosphorylated upstream, branched trisaccharide fragments of the o-ps of vibrio cholerae o139.	n-bromosuccinimide-mediated 4,6-o-benzylidene ring opening in 8-azido-3,6-dioxaoctyl 4,6-o-benzylidene-2-deoxy-2-trichloroacetamido-β-d-glucopyranoside afforded the corresponding 4-o-benzoyl-6-bromo-6-deoxy analogue, which was coupled with 3,4,6-tri-o-acetyl-2-o-benzyl-α-d-galactopyranosyl chloride to give the 1,2-cis α-linked disaccharide as the major product. conventional hydroxyl group manipulation in the latter and products of further conversions gave the desired, functionalized disaccharide ...	2015	25928584
gbpa as a novel qpcr target for the species-specific detection of vibrio cholerae o1, o139, non-o1/non-o139 in environmental, stool, and historical continuous plankton recorder samples.	the vibrio cholerae n-acetyl glucosamine-binding protein a (gbpa) is a chitin-binding protein involved in v. cholerae attachment to environmental chitin surfaces and human intestinal cells. we previously investigated the distribution and genetic variations of gbpa in a large collection of v. cholerae strains and found that the gene is consistently present and highly conserved in this species. primers and probe were designed from the gbpa sequence of v. cholerae and a new taq-based qpcr protocol ...	2015	25915771
whole-genome sequence comparisons reveal the evolution of vibrio cholerae o1.	the analysis of the whole-genome sequences of vibrio cholerae strains from previous and current cholera pandemics has demonstrated that genomic changes and alterations in phage ctx (particularly in the gene encoding the b subunit of cholera toxin) were major features in the evolution of v. cholerae. recent studies have revealed the genetic mechanisms in these bacteria by which new variants of v. cholerae are generated from type-specific strains; these mechanisms suggest that certain strains are ...	2015	25913612
hybrid vibrio cholerae el tor lacking sxt identified as the cause of a cholera outbreak in the philippines.	cholera continues to be a global threat, with high rates of morbidity and mortality. in 2011, a cholera outbreak occurred in palawan, philippines, affecting more than 500 people, and 20 individuals died. vibrio cholerae o1 was confirmed as the etiological agent. source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. in this study, three v. cholerae o1 isolates from a philippines cholera outbreak were sequenced and their genomes ana ...	2015	25900650
antimicrobial drug resistance of vibrio cholerae, democratic republic of the congo.	we analyzed 1,093 vibrio cholerae isolates from the democratic republic of the congo during 1997-2012 and found increasing antimicrobial drug resistance over time. our study also demonstrated that the 2011-2012 epidemic was caused by an el tor variant clonal complex with a single antimicrobial drug susceptibility profile.	2015	25897570
living in the matrix: assembly and control of vibrio cholerae biofilms.	nearly all bacteria form biofilms as a strategy for survival and persistence. biofilms are associated with biotic and abiotic surfaces and are composed of aggregates of cells that are encased by a self-produced or acquired extracellular matrix. vibrio cholerae has been studied as a model organism for understanding biofilm formation in environmental pathogens, as it spends much of its life cycle outside of the human host in the aquatic environment. given the important role of biofilm formation in ...	2015	25895940
multidrug resistant vibrio cholerae o1 from clinical and environmental samples in kathmandu city.	cholera, an infectious disease caused by vibrio cholerae, is a major public health problem and is a particularly burden in developing countries including nepal. although the recent worldwide outbreaks of cholera have been due to v. cholerae el tor, the classical biotypes are still predominant in nepal. serogroup o1 of the v. cholerae classical biotype was the primary cause of a cholera outbreak in kathmandu in 2012. thus, this study was designed to know serotypes and biotypes of v. cholerae stra ...	2015	25888391
the vieb auxiliary protein negatively regulates the viesa signal transduction system in vibrio cholerae.	vibrio cholerae is a facultative pathogen that lives in the aquatic environment and the human host. the ability of v. cholerae to monitor environmental changes as it transitions between these diverse environments is vital to its pathogenic lifestyle. one way v. cholerae senses changing external stimuli is through the three-component signal transduction system, viesab, which is encoded by the viesab operon. the viesab system plays a role in the inverse regulation of biofilm and virulence genes by ...	2015	25887601
evaluation of the medicinal properties of cyrtocarpa procera kunth fruit extracts.	the fruit of cyrtocarpa procera is used to treat stomach diseases by people living in san rafael, coxcatlan, puebla. this work investigated the antibacterial, antioxidant, cytotoxic and anti-inflammatory activities of the fruit produced by this species.	2015	25887560
endopeptidase-mediated beta lactam tolerance.	in many bacteria, inhibition of cell wall synthesis leads to cell death and lysis. the pathways and enzymes that mediate cell lysis after exposure to cell wall-acting antibiotics (e.g. beta lactams) are incompletely understood, but the activities of enzymes that degrade the cell wall ('autolysins') are thought to be critical. here, we report that vibrio cholerae, the cholera pathogen, is tolerant to antibiotics targeting cell wall synthesis. in response to a wide variety of cell wall--acting ant ...	2015	25884840
(p)ppgpp, a small nucleotide regulator, directs the metabolic fate of glucose in vibrio cholerae.	when v. cholerae encounters nutritional stress, it activates (p)ppgpp-mediated stringent response. the genes rela and relv are involved in the production of (p)ppgpp, whereas the spot gene encodes an enzyme that hydrolyzes it. herein, we show that the bacterial capability to produce (p)ppgpp plays an essential role in glucose metabolism. the v. cholerae mutants defective in (p)ppgpp production (i.e. δrelaδrelv and δrelaδrelvδspot mutants) lost their viability because of uncontrolled production o ...	2015	25882848
electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere label for detection of vibrio cholerae.	vibrio cholerae is a gram-negative bacterium that causes cholera, a diarrheal disease. cholera is widespread in poor, under-developed or disaster-hit countries that have poor water sanitation. hence, a rapid detection method for v. cholerae in the field under these resource-limited settings is required. in this paper, we describe the development of an electrochemical genosensor assay using lyophilized gold nanoparticles/latex microsphere (aunps-psa) reporter label. the reporter label mixture was ...	2015	25882423
biological characterization of v. cholerae-specific bacteriophages isolated from water sources in georgia.	vibrio cholerae, a widely spread bacterium in various marine, fresh, and brackish water environments, can cause a devastating diarrheal disease - cholera and also mild forms of gastroenteritis. bacterial viruses are natural controllers of bacterial population density in water systems. the goal of this study was to isolate and characterize v. cholerae-specific bacteriophages occurring in the georgian coastal zone of the black sea and inland water reservoirs in the eastern part of georgia. during ...	2015	25879562
establishment and characterization of a continuous cell line from thymus of striped snakehead, channa striatus (bloch 1793).	the establishment and characterization of a continuous cell line from the thymus of air-breathing fish channa striatus are described. the cell line, designated c. striatus thymus (cst), has been subcultured over 71 times and shows optimal growth at 28°c in leibovitz's-15 (l-15) medium supplemented with 20% fetal bovine serum. the cst cells exhibited low plating efficiency which improved with increase in seeding density. the karyotype analysis revealed that cst cells have a normal diploid karyoty ...	2015	25877070
genomic location of the major ribosomal protein gene locus determines vibrio cholerae global growth and infectivity.	the effects on cell physiology of gene order within the bacterial chromosome are poorly understood. in silico approaches have shown that genes involved in transcription and translation processes, in particular ribosomal protein (rp) genes, localize near the replication origin (oric) in fast-growing bacteria suggesting that such a positional bias is an evolutionarily conserved growth-optimization strategy. such genomic localization could either provide a higher dosage of these genes during fast g ...	2015	25875621
serine 26 in the pomb subunit of the flagellar motor is essential for hypermotility of vibrio cholerae.	vibrio cholerae is motile by means of its single polar flagellum which is driven by the sodium-motive force. in the motor driving rotation of the flagellar filament, a stator complex consisting of subunits poma and pomb converts the electrochemical sodium ion gradient into torque. charged or polar residues within the membrane part of pomb could act as ligands for na+, or stabilize a hydrogen bond network by interacting with water within the putative channel between poma and pomb. by analyzing a ...	2015	25874792
quadruple quorum-sensing inputs control vibrio cholerae virulence and maintain system robustness.	bacteria use quorum sensing (qs) for cell-cell communication to carry out group behaviors. this intercellular signaling process relies on cell density-dependent production and detection of chemical signals called autoinducers (ais). vibrio cholerae, the causative agent of cholera, detects two ais, cai-1 and ai-2, with two histidine kinases, cqss and luxq, respectively, to control biofilm formation and virulence factor production. at low cell density, these two signal receptors function in parall ...	2015	25874462
enzyme-based microfluidic chip coupled to graphene electrodes for the detection of d-amino acid enantiomer-biomarkers.	an electrochemical microfluidic strategy for the separation and enantiomeric detection of d-methionine (d-met) and d-leucine (d-leu) is presented. these d-amino acids (d-aas) act as biomarkers involved in relevant diseases caused by vibrio cholerae. on a single layout microfluidic chip (mc), highly compatible with extremely low biological sample consumption, the strategy allowed the controlled microfluidic d-aa separation and the specific reaction between d-amino acid oxidase (daao) and each d-a ...	2015	25870911
molecular characterization of iscr1-mediated blaper-1 in a non-o1, non-o139 vibrio cholerae strain from china.	we report the detection of per-1 extended-spectrum β-lactamase (esbl) in a clinical non-o1, non-o139 vibrio cholerae strain from china. iscr1-mediated bla(per-1) was embedded in a complex in4 family class 1 integron belonging to the lineage of tn1696 on a conjugative inca/c plasmid. a free 8.98-kb circular molecule present with the iscr1-bla(per-1)-truncated 3'-conserved sequence (cs) structure was detected in this isolate. these findings may provide insight into the mobilization of bla(per-1).	2015	25870070
in silico phylogenetic analysis of vibrio cholerae isolates based on three housekeeping genes.	vibrio cholera, a gram-negative bacterium, has been categorised into clinical and environmental species. phylogenetic studies have been performed to investigate the relationships of the v. cholerae populations in worldwide. in this study, phylogenetic relationship between v. cholerae isolates from iran and other regions of the world was determined, based on three housekeeping genes analysis. results for iranian strains showed that congruency of asd and hlya phylogenetic trees were remarkably hig ...	2015	25869320
enhanced resistance to several abiotic stresses in vibrio cholerae during starvation.	in this study, we investigated whether vibrio cholerae cells exposed to nutrient-limited conditions developed resistance to abiotic stresses because of which most, if not all, starved cells turn coccoid in shape and exhibited marked resistance to freezing, low ph, and chlorine, but not against bile.	2015	25866118
plant-based production of two chimeric monoclonal igg antibodies directed against immunodominant epitopes of vibrio cholerae lipopolysaccharide.	we have produced and characterized two chimeric human igg1 monoclonal antibodies that bind different immunodominant epitopes on vibrio cholerae lipopolysaccharide (lps). mab 2d6 igg1 recognizes ogawa o-polysaccharide antigen, while mab zac-3 igg1 recognizes core/lipid a moiety of ogawa and inaba lps. both antibodies were expressed using a nicotiana benthamiana-based rapid antibody-manufacturing platform (ramp) and evaluated in vitro for activities associated with immunity to v. cholerae, includi ...	2015	25865265
nitric oxide is a potent inhibitor of the cbb(3)-type heme-copper oxidases.	c-type heme-copper oxidases terminate the respiratory chain in many pathogenic bacteria, and will encounter elevated concentrations of no produced by the immune defense of the host. thus, a decreased sensitivity to no in c-type oxidases would increase the survival of these pathogens. here we have compared the inhibitory effect of no in c-type oxidases to that in the mitochondrial a-type. we show that o2-reduction in both the rhodobacter sphaeroides and vibrio cholerae c-type oxidases is strongly ...	2015	25862499
clonal dissemination of a single vibrio cholerae o1 biotype el tor strain in sistan-baluchestan province of iran during 2013.	although much is known about the mechanisms affecting cholera spread, cholera outbreaks occur annually in iran. the aim of this study was to characterize and assess the clonal correlation of strains obtained from an outbreak in 2013 in iran. thirty-three strains of vibrio cholerae were isolated from stool sample of patients majority of them belonged to afghan nationality. pcr and sequencing analysis was performed to characterize virulence and resistance associates genes and cassettes. clonality ...	2015	25862465
liposome reconstitution and transport assay for recombinant transporters.	secondary active transporters are responsible for the cellular uptake of many biologically important molecules, including neurotransmitters, nutrients, and drugs. because of their physiological and clinical importance, a method for assessing their transport activity in vitro is necessary to gain a better understanding of how these transporters function at the molecular level. in this chapter, we describe a protocol for reconstituting the concentrative nucleoside transporter from vibrio cholerae ...	2015	25857791
increased isolation frequency of toxigenic vibrio cholerae o1 from environmental monitoring sites in haiti.	since the identification of the first cholera case in 2010, the disease has spread in epidemic form throughout the island nation of haiti; as of 2014, about 700,000 cholera cases have been reported, with over 8,000 deaths. while case numbers have declined, the more fundamental question of whether the causative bacterium, vibrio cholerae has established an environmental reservoir in the surface waters of haiti remains to be elucidated. in a previous study conducted between april 2012 and march 20 ...	2015	25853552
biocompatible capped iron oxide nanoparticles for vibrio cholerae detection.	we report the studies relating to fabrication of an efficient immunosensor for vibrio cholerae detection. magnetite (iron oxide (fe(3)o(4))) nanoparticles (nps) have been synthesized by the co-precipitation method and capped by citric acid (ca). these nps were electrophoretically deposited onto indium-tin-oxide (ito)-coated glass substrate and used for immobilization of monoclonal antibodies against vibrio cholerae (ab) and bovine serum albumin (bsa) for vibrio cholerae detection using an electr ...	2015	25850702
role of methylthioadenosine/s-adenosylhomocysteine nucleosidase in vibrio cholerae cellular communication and biofilm development.	in vibrio cholerae, the genes required for biofilm development are repressed by quorum sensing at high cell density due to the accumulation in the medium of two signaling molecules, cholera autoinducer 1 (cai-1) and autoinducer 2 (ai-2). a significant fraction of toxigenic v. cholerae isolates, however, exhibit dysfunctional quorum sensing pathways. it was reported that transition state analogs of the enzyme methylthioadenosine/s-adenosylhomocysteine nucleosidase (mtnn) required to make ai-2 inh ...	2015	25849889
purification, crystallization and preliminary x-ray analysis of the periplasmic haem-binding protein hutb from vibrio cholerae.	the mechanism of haem transport across the inner membrane of pathogenic bacteria is currently insufficiently understood at the molecular level and no information is available for this process in vibrio cholerae. to obtain structural insights into the periplasmic haem-binding protein hutb from v. cholerae (vchutb), which is involved in haem transport through the hutbcd haem-transport system, at the atomic level, vchutb was cloned, overexpressed and crystallized using 1.6 m ammonium sulfate as a p ...	2015	25849499
proteolysis of virulence regulator toxr is associated with entry of vibrio cholerae into a dormant state.	vibrio cholerae o1 is a natural inhabitant of aquatic environments and causes the diarrheal disease, cholera. two of its primary virulence regulators, tcpp and toxr, are localized in the inner membrane. tcpp is encoded on the vibrio pathogenicity island (vpi), a horizontally acquired mobile genetic element, and functions primarily in virulence gene regulation. tcpp has been shown to undergo regulated intramembrane proteolysis (rip) in response to environmental conditions that are unfavorable for ...	2015	25849031
control of bacterial exoelectrogenesis by c-amp-gmp.	major changes in bacterial physiology including biofilm and spore formation involve signaling by the cyclic dinucleotides c-di-gmp and c-di-amp. recently, another second messenger dinucleotide, c-amp-gmp, was found to control chemotaxis and colonization by vibrio cholerae. we have identified a superregulon of genes controlled by c-amp-gmp in numerous deltaproteobacteria, including geobacter species that use extracellular insoluble metal oxides as terminal electron acceptors. this exoelectrogenic ...	2015	25848023
gemm-i riboswitches from geobacter sense the bacterial second messenger cyclic amp-gmp.	cyclic dinucleotides are an expanding class of signaling molecules that control many aspects of bacterial physiology. a synthase for cyclic amp-gmp (cag, also referenced as 3'-5', 3'-5' cgamp) called dncv is associated with hyperinfectivity of vibrio cholerae but has not been found in many bacteria, raising questions about the prevalence and function of cag signaling. we have discovered that the environmental bacterium geobacter sulfurreducens produces cag and uses a subset of gemm-i class ribos ...	2015	25848022
mechanisms of inflammasome activation by vibrio cholerae secreted toxins vary with strain biotype.	activation of inflammasomes is an important aspect of innate immune responses to bacterial infection. recent studies have linked vibrio cholerae secreted toxins to inflammasome activation by using murine macrophages. to increase relevance to human infection, studies of inflammasome-dependent cytokine secretion were conducted with the human thp-1 monocytic cell line and corroborated in primary human peripheral blood mononuclear cells (pbmcs). both el tor and classical strains of v. cholerae activ ...	2015	25847959
dynamics of vibrio cholerae abundance in austrian saline lakes, assessed with quantitative solid-phase cytometry.	in order to elucidate the main predictors of vibrio cholerae dynamics and to estimate the risk of vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (card-fish/spc) was applied in comparison to cultivation for water samples from the lake neusiedler see, austria and three shallow alkaline lakes over a period of 20 months. vibrio cholerae attached to crustacean zooplankton was quantified via fish and ...	2015	25847810
[improvement of laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera vibrio biovar el tor].	improvement of laboratory diagnostics of cholera taking into the account appearance of hybrid variants of cholera vibrio el tor biovar in the 1990s.	2015	25842952
[cholera vibrio biofilm: production, characterization and role in reservation of causative agent in water environment].	experimental production, characterization and evaluation of the role of cholera vibrio biofilm.	2015	25842946
enzymatic electrochemical detection of epidemic-causing vibrio cholerae with a disposable oligonucleotide-modified screen-printed bisensor coupled to a dry-reagent-based nucleic acid amplification assay.	in this study, we developed a nucleic acid-sensing platform in which a simple, dry-reagent-based nucleic acid amplification assay is combined with a portable multiplex electrochemical genosensor. preparation of an amplification reaction mix targeting multiple dna regions of interest is greatly simplified because the lyophilized reagents need only be reconstituted with ultrapure water before the dna sample is added. the presence of single or multiple target dnas causes the corresponding single-st ...	2015	25835520
complete topology of the rnf complex from vibrio cholerae.	rnf is a redox-driven ion (na(+) and in one case possibly h(+)) transporter present in many prokaryotes. it has been proposed that rnf performs a variety of reactions in different organisms, delivering low-potential reducing equivalents for specific cellular processes. rnf shares strong homology with the na(+)-pumping respiratory enzyme na(+)-nqr, although there are significant differences in subunit and redox cofactor composition. here we report a topological analysis of the six subunits of rnf ...	2015	25831459
a cis-regulatory antisense rna represses translation in vibrio cholerae through extensive complementarity and proximity to the target locus.	as with all facultative pathogens, vibrio cholerae must optimize its cellular processes to adapt to different environments with varying carbon sources and to environmental stresses. more specifically, in order to metabolize mannitol, v. cholerae must regulate the synthesis of mtla, a mannitol transporter protein produced exclusively in the presence of mannitol. we previously showed that a cis-acting small rna (srna) expressed by v. cholerae, mtls, appears to post-transcriptionally downregulate t ...	2015	25826566
"quorum non-sensing": social cheating and deception in vibrio cholerae.	quorum sensing (qs) is widely used by bacteria to coordinate behavior in response to external stimuli. in vibrio cholerae, this process is important for environmental survival and pathogenesis, though, intriguingly, a large percentage of natural isolates are qs deficient. here, we show that qs-deficient mutants can spread as social cheaters by ceasing production of extracellular proteases under conditions requiring their growth. we further show that mutants stimulate biofilm formation and are ov ...	2015	25819968
dimeric wh2 repeats of vopf sequester actin monomers into non-nucleating linear string conformations: an x-ray scattering study.	vopf and vopl are highly similar virulence-factors of vibrio cholerae and vibrio parahaemolyticus respectively that disrupt the host's actin cytoskeleton, using a unique organization in dimerized wh2 repeats. association of dimerized wh2 domains with the barbed face of actin confers multifunctional activities to vopf in vitro, including g-actin sequestration and filament nucleation, barbed end tracking and uncapping. here, small angle x-ray scattering (saxs) measurements of complexes of vopf wit ...	2015	25818509
whole-genome sequencing of a vibrio cholerae el tor strain isolated in the imported cholera focus in siberia.	the draft genome sequence of vibrio cholerae o1 strain i-1263, isolated from a patient in the imported focus in siberia, was determined. the established structural features of the mobile genetic elements indicate stage-by-stage formation of a highly pathogenic v. cholerae clone and promote understanding of the mechanisms of evolutionary pathogen transformations.	2015	25814617
meddling vibrio cholerae murmurs: a neoteric advancement in cholera research.	cholera, a known diarrheal disease is associated with various risk factors like hypovolemic shock, rice watery stools, and death in developing countries. the overuse of antibiotics to treat cholera imposed a selective pressure for the emergence and spread of multi-drug resistant vibrio cholerae strains. the failure of conventional antimicrobial therapy urged the researchers to find an alternative therapy that could meddle the cholera murmurs (quorum sensing). it seems to effectively overcome the ...	2015	25805898
high production of neuraminidase by a vibrio cholerae non-o1 strain--the first possible alternative to toxigenic producers.	vibrio cholerae neuraminidase (vcna) is widely used in biochemical and medical research, in processes for preparing homogenous sialoconjugates, and in the pharmaceutical industry. its production by non-toxigenic strains is quite desirable, in order to avoid the expensive safety measures. here, we report the first method for highly effective production of a novel, purified v. cholerae extracellular neuraminidase from a non-toxigenic strain. the enzyme is highly active, and its properties, as well ...	2015	25805019
scanning the landscape of genome architecture of non-o1 and non-o139 vibrio cholerae by whole genome mapping reveals extensive population genetic diversity.	historically, cholera outbreaks have been linked to v. cholerae o1 serogroup strains or its derivatives of the o37 and o139 serogroups. a genomic study on the 2010 haiti cholera outbreak strains highlighted the putative role of non o1/non-o139 v. cholerae in causing cholera and the lack of genomic sequences of such strains from around the world. here we address these gaps by scanning a global collection of v. cholerae strains as a first step towards understanding the population genetic diversity ...	2015	25794000
identification and characterisation of a novel plasmid-mediated quinolone resistance gene, qnrvc7, in vibrio cholerae of seafood origin.		2015	25769785
multidrug-resistant vibrio cholerae o1 was responsible for a cholera outbreak in 2013 in bagalkot, north karnataka.	cholera is a major cause of illness in the developing world. during the monsoon season, small sporadic clusters of cholera cases are reported on an annual basis in karnataka, india. during the monsoons of 2013, there was a cholera outbreak in badami, a remote area of bagalkot district in karnataka. the multi-drug-resistant vibrio cholerae o1 serotype ogawa was found to be responsible for this outbreak. on 5 august 2013, a 30-year-old woman presented with severe dehydration and watery diarrhea at ...	2015	25766606
toxigenic vibrio cholerae identified in estuaries of tanzania using pcr techniques.	the current study assessed the occurrence of the vibrio cholerae serogroups o1 and o139 in environmental samples along salinity gradients in three selected estuaries of tanzania both through culture independent methods and by cultured bacteria. occurrence of v. cholerae was determined by pcr targeting the v. cholerae outer membrane protein gene ompw. furthermore, the presence of toxigenic strains and serogroups o1 and o139 was determined using multiplex pcr with specific primers targeting the ch ...	2015	25743072
correction for herrera et al., the vibrio cholerae vpra-vprb two-component system controls virulence through endotoxin modification.		2015	25736885
mechanism for inhibition of vibrio cholerae toxt activity by the unsaturated fatty acid components of bile.	the gram-negative curved bacillus vibrio cholerae causes the severe diarrheal illness cholera. during host infection, a complex regulatory cascade results in production of toxt, a dna-binding protein that activates the transcription of major virulence genes that encode cholera toxin (ct) and toxin-coregulated pilus (tcp). previous studies have shown that bile and its unsaturated fatty acid (ufa) components reduce virulence gene expression and therefore are likely important signals upon entering ...	2015	25733618
identifying the most sensitive and specific sign and symptom combinations for cholera: results from an analysis of laboratory-based surveillance data from haiti, 2012-2013.	since october 2010, over 700,000 cholera cases have been reported in haiti. we used data from laboratory-based surveillance for diarrhea in haiti to evaluate the sensitivity, specificity, and positive (ppv) and negative predictive values (npv) of the cholera case definitions recommended by the world health organization (who). from april 2012 to may 2013, we tested 1,878 samples from hospitalized patients with acute watery diarrhea; 1,178 (62.7%) yielded vibrio cholerae o1. the sensitivity and sp ...	2015	25732682
a novel triplex quantitative pcr strategy for quantification of toxigenic and nontoxigenic vibrio cholerae in aquatic environments.	vibrio cholerae is a severe human pathogen and a frequent member of aquatic ecosystems. quantification of v. cholerae in environmental water samples is therefore fundamental for ecological studies and health risk assessment. beside time-consuming cultivation techniques, quantitative pcr (qpcr) has the potential to provide reliable quantitative data and offers the opportunity to quantify multiple targets simultaneously. a novel triplex qpcr strategy was developed in order to simultaneously quanti ...	2015	25724966
structure of the type vi secretion system contractile sheath.	bacteria use rapid contraction of a long sheath of the type vi secretion system (t6ss) to deliver effectors into a target cell. here, we present an atomic-resolution structure of a native contracted vibrio cholerae sheath determined by cryo-electron microscopy. the sheath subunits, composed of tightly interacting proteins vipa and vipb, assemble into a six-start helix. the helix is stabilized by a core domain assembled from four β strands donated by one vipa and two vipb molecules. the fold of i ...	2015	25723169
in silico screening of antibacterial compounds from herbal sources against vibrio cholerae.	the prolonged use of antibiotic viz., tetracycline, quinolones, ampicillin, etc., to reduce the infection of cholera, may failed due to the emergence of new vibrio cholerae antibiotics resistant strains. moreover, these antibiotics even restricted for patient suffering from severe dehydration. hence, there is a call to find an alternative therapeutics against v. cholerae. the natures serve different herbs in its lap which might contain several natural therapeutic compounds almost all diseases. c ...	2015	27013793
sentinel surveillance detects low circulation of vibrio cholerae serotype inaba in haiti, 2011-2012.	over 700,000 cases of cholera were reported in haiti between october 2010 and february 2015. in november 2011, the cuban medical team serving in haiti established a laboratory-supported sentinel surveillance system for cholera in 10 public hospitals (one in each of haiti's 10 departments), to estimate the proportion of hospitalized patients with cholera and detect emergence of new vibrio cholerae serotypes. each month, the first ten stool samples collected from patients admitted with acute water ...	2015	26947158
low detection of vibrio cholerae carriage in healthcare workers returning to 12 latin american countries from haiti.	summary this investigation was undertaken to characterize the prevalence of intestinal vibrio cholerae in healthcare workers (hcws) returning from haiti due to the ongoing cholera epidemic. eight hundred and fifty asymptomatic hcws of the cuban medical brigade, who planned to leave haiti, were studied by laboratory screening of stool culture for v. cholerae. a very low percentage (0.23%) of toxigenic v. cholerae serogroup o1, serotype ogawa was found. to the best of our knowledge, this study rep ...	2015	25016919
piezoresistive microcantilever-based dna sensor for sensitive detection of pathogenic vibrio cholerae o1 in food sample.	pathogenic vibrio cholerae produces a cholera toxin which is the cause of a severe diarrheal disease called "cholera". available detection methods, including standard bacteriological test and immuno-based detection, are specific to the suspected pathogenic v. cholerae o1 and o139, but they are not specific to the cholera toxin producible strain. this work combined the polymerase chain reaction (pcr) of cholera toxin gene, ctxa gene, and microcantilever-based dna sensor to improve the sensitivity ...	2015	25113053
adhesion as a weapon in microbial competition.	microbes attach to surfaces and form dense communities known as biofilms, which are central to how microbes live and influence humans. the key defining feature of biofilms is adhesion, whereby cells attach to one another and to surfaces, via attachment factors and extracellular polymers. while adhesion is known to be important for the initial stages of biofilm formation, its function within biofilm communities has not been studied. here we utilise an individual-based model of microbial groups to ...	2015	25290505
nontoxigenic vibrio cholerae non-o1/o139 isolate from a case of human gastroenteritis in the u.s. gulf coast.	an occurrence of vibrio cholerae non-o1/o139 gastroenteritis in the u.s. gulf coast is reported here. genomic analysis revealed that the isolate lacked known virulence factors associated with the clinical outcome of a v. cholerae infection but did contain putative genomic islands and other accessory virulence factors. many of these factors are widespread among environmental strains of v. cholerae, suggesting that there might be additional virulence factors in non-o1/o139 v. cholerae yet to be de ...	2015	25339398
host intestinal signal-promoted biofilm dispersal induces vibrio cholerae colonization.	vibrio cholerae causes human infection through ingestion of contaminated food and water, leading to the devastating diarrheal disease cholera. v. cholerae forms matrix-encased aggregates, known as biofilms, in the native aquatic environment. while the formation of v. cholerae biofilms has been well studied, little is known about the dispersal from biofilms, particularly upon entry into the host. in this study, we found that the exposure of mature biofilms to physiologic levels of the bile salt t ...	2015	25368110
application of chitosan microparticles for reduction of vibrio species in seawater and live oysters (crassostrea virginica).	human vibrio infections associated with consumption of raw shellfish greatly impact the seafood industry. vibrio cholerae-related disease is occasionally attributed to seafood, but v. vulnificus and v. parahaemolyticus are the primary targets of postharvest processing (php) efforts in the united states, as they pose the greatest threat to the industry. most successful php treatments for vibrio reduction also kill the molluscs and are not suitable for the lucrative half-shell market, while nonlet ...	2015	25381244
evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of vibrio cholerae.	we evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (ms) for the identification of vibrio cholerae. ms identified all 42 isolates of v. cholerae o1 and o139 and 7 of 9 non-o1/o139 isolates. ms correctly discriminated between all aeromonas and v. cholerae isolates. overall, ms performed as well as or better than biochemical methods.	2015	25392355
environmental surveillance for toxigenic vibrio cholerae in surface waters of haiti.	epidemic cholera was reported in haiti in 2010, with no information available on the occurrence or geographic distribution of toxigenic vibrio cholerae in haitian waters. in a series of field visits conducted in haiti between 2011 and 2013, water and plankton samples were collected at 19 sites. vibrio cholerae was detected using culture, polymerase chain reaction, and direct viable count methods (dfa-dvc). cholera toxin genes were detected by polymerase chain reaction in broth enrichments of sam ...	2015	25385860
crystal structure of apo and ligand bound vibrio cholerae ribokinase (vc-rk): role of monovalent cation induced activation and structural flexibility in sugar phosphorylation.		2015	25408351
vibrio cholerae cytolysin: structure-function mechanism of an atypical β-barrel pore-forming toxin.		2015	25408339
chironomid microbiome.	chironomids are abundant insects in freshwater habitats. they undergo a complete metamorphosis of four life stages: eggs, larvae, and pupae in water, and a terrestrial adult stage. chironomids are known to be pollution-tolerant, but little is known about their resistance mechanisms to toxic substances. here we review current knowledge regarding the chironomid microbiome. chironomids were found as natural reservoirs of vibrio cholerae and aeromonas spp. a stable bacterial community was found in t ...	2015	25421389
hypoxia-induced localization of chemotaxis-related signaling proteins in vibrio cholerae.	vibrio cholerae has three sets of chemotaxis-related signaling proteins, of which only system ii has been shown to be involved in chemotaxis. here, we examined localization of green fluorescent protein (gfp)-fused components of system i. the histidine kinase (chea1) and the adaptor (chew0) of system i localized to polar and lateral membrane regions with standing incubation (microaerobic conditions), but their localization was lost after shaking (aerobic conditions). a transmembrane receptor of s ...	2015	25420689
vca1008: an anion-selective porin of vibrio cholerae.	a putative porin function has been assigned to vca1008 of vibrio cholerae. its coding gene, vca1008, is expressed upon colonization of the small intestine in infant mice and human volunteers, and is essential for infection. in vitro, vca1008 is expressed under inorganic phosphate limitation and, in this condition, vca1008 is the major outer membrane protein of the bacterium. here, we provide the first functional characterization of vca1008 reconstituted into planar lipid bilayers. our main findi ...	2015	25462170
pentavalent outer membrane vesicles of vibrio cholerae induce adaptive immune response and protective efficacy in both adult and passive suckling mice models.	recently, we demonstrated oral immunizations with single serotype outer membrane vesicles of vibrio cholerae induced serogroup specific protective immunity in the ritard model. in our present study, we advanced our research by formulating multi-serotype outer membrane vesicles, mixing the omvs of five virulent v. cholerae strains. four doses of oral immunization with cholera pentavalent outer membrane vesicles (cpmvs) induced v. cholerae specific b and t cell responses. cpmvs-immunized mice gene ...	2015	25461799
crystal structure of the bacterial type vi secretion system component tssl from vibrio cholerae.	the type vi secretion system (t6ss), commonly found in gram-negative bacteria, is responsible for exporting effector proteins. the t6ss has been reported to be cytotoxic to host cells. while the components and assembly of the t6ss complex have been largely assessed, structural data on t6ss components from virulent bacteria is remarkably insufficient. here, we report the crystal structure of vibrio cholerae tssl (vctssl), a core component of t6ss. in spite of a relatively low sequence identity, t ...	2015	25471186
novel readout method for molecular diagnostic assays based on optical measurements of magnetic nanobead dynamics.	we demonstrate detection of dna coils formed from a vibrio cholerae dna target at picomolar concentrations using a novel optomagnetic approach exploiting the dynamic behavior and optical anisotropy of magnetic nanobead (mnb) assemblies. we establish that the complex second harmonic optical transmission spectra of mnb suspensions measured upon application of a weak uniaxial ac magnetic field correlate well with the rotation dynamics of the individual mnbs. adding a target analyte to the solution ...	2015	25539065
transmembrane oligomeric form of vibrio cholerae cytolysin triggers tlr2/tlr6-dependent proinflammatory responses in monocytes and macrophages.	vibrio cholerae cytolysin (vcc) kills target eukaryotic cells by forming transmembrane oligomeric β-barrel pores. once irreversibly converted into the transmembrane oligomeric form, vcc acquires an unusual structural stability and loses its cytotoxic property. it is therefore possible that, on exertion of its cytotoxic activity, the oligomeric form of vcc retained in the disintegrated membrane fractions of the lysed cells would survive within the host cellular milieu for a long period, without c ...	2015	25431887
vibrio cholerae martx toxin heterologous translocation of beta-lactamase and roles of individual effector domains on cytoskeleton dynamics.	the vibrio cholerae martxvc toxin delivers three effector domains to eukaryotic cells. to study toxin delivery and function of individual domains, the rtxa gene was modified to encode toxin with an in-frame beta-lactamase (bla) fusion. the hybrid rtxa::bla toxin was type i secreted from bacteria; and then bla was translocated into eukaryotic cells and delivered by autoprocessing, demonstrating that the martxvc toxin is capable of heterologous protein transfer. strains that produce hybrid rtxa::b ...	2015	25427654
influence of diffusion on the stability of equilibria in a reaction-diffusion system modeling cholera dynamic.	a reaction-diffusion system modeling cholera epidemic in a non-homogeneously mixed population is introduced. the interaction between population and toxigenic vibrio cholerae concentration in contaminated water has been taken into account. the existence of biologically meaningful equilibria is investigated together with their linear and nonlinear stability. using the data collected during the haiti cholera epidemic, a numerical simulation is performed.	2015	25424418
assessing clonal correlation of epidemic vibrio cholerae isolates during 2011 in 16 provinces of iran.	a total of 1,187 vibrio cholerae isolates were received during 2011 cholera outbreaks from 16 provinces in different geographical location to iranian reference health laboratory. a random selection was performed, and 61 isolates were subjected to further investigations. cholera cases were come up from may with nine cases and reached to its maximum rate at august (57 cases) and continued to october after which a fall occurred in september. all of the isolates were susceptible to three antimicrobi ...	2015	25424344
a small unstructured region in vibrio cholerae toxt mediates the response to positive and negative effectors and toxt proteolysis.	vibrio cholerae is the causative agent of the severe diarrheal disease cholera. the production of the virulence factors that are required for human disease is controlled by a complex network of transcriptional and posttranscriptional regulators. toxt is the transcription regulator that directly controls the production of the two major virulence factors, toxin-coregulated pilus (tcp) and cholera toxin (ct). the solved crystal structure of toxt revealed an unstructured region in the n-terminal dom ...	2015	25422303
a study on the existence of vibrio cholerae non-o1 in the river.	the aim of the present study is vibrio cholerae non-o1 existing in river. bacteria are known to inhabit all kinds of environment. vibrionaceae is widely distributed in environmental water. vibrio spp. have been identified as a cause of toxicity in fish and shellfish. one condition affecting the survival of pathogenic microorganisms in environmental water is the salt concentration, and they have been reported to inhabit brackish water. however, v. cholerae non-o1 has also been detected in fresh w ...	2015	25500964
detection of vibrio cholerae o1 and o139 in environmental waters of rural bangladesh: a flow-cytometry-based field trial.	presence of vibrio cholerae serogroups o1 and o139 in the waters of the rural area of matlab, bangladesh, was investigated with quantitative measurements performed with a portable flow cytometer. the relevance of this work relates to the testing of a field-adapted measurement protocol that might prove useful for cholera epidemic surveillance and for validation of mathematical models. water samples were collected from different water bodies that constitute the hydrological system of the region, a ...	2015	25496520
turn-on optomagnetic bacterial dna sequence detection using volume-amplified magnetic nanobeads.	detection of a vibrio cholerae dna-sequence using an optomagnetic read-out exploiting the dynamic behavior of magnetic nanobeads along with two turn-on data analysis approaches is demonstrated. the optomagnetic method uses a weak uniaxial ac magnetic field of varying frequency applied perpendicular to the optical path and measures the modulation of laser light passing through a cuvette containing the sample with oligonucleotide-tagged magnetic beads and macromolecular coils of single-stranded dn ...	2015	25483917
development of benzo[1,4]oxazines as biofilm inhibitors and dispersal agents against vibrio cholerae.	bacterial biofilms are estimated to be associated with over 65 percent of all nosocomial infections. however, no therapeutics have been approved by the fda which directly mediate biofilm formation or persistence. herein we report oxazine as a highly potent inhibitor, disperser and in the presence of the appropriate antibiotic eradicator of v. cholerae biofilms.	2015	25479128
lolb gene, a valid alternative for qpcr detection of vibrio cholerae in food and environmental samples.	in recent years a new genetic target for vibrio cholerae detection has been reported, but its application was limited to clinical samples. this target, lolb, has never been applied to either food or environmental samples. in the present study the development, as well as the evaluation and pre-validation, of a real-time pcr method based on lolb, is described. the method included a newly designed hydrolysis probe to enhance its specificity. after comparison against other molecular and traditional ...	2015	25475326
solar-photocatalytic disinfection of vibrio cholerae by using ag@zno core-shell structure nanocomposites.	disinfection of gram-negative bacterium vibrio cholerae 569b in aqueous matrix by solar-photocatalysis mediated by ag@zno core-shell structure nanocomposite particles was investigated. silver nanoparticles are synthesized by the reduction of silver perchlorate followed by precipitation of zinc oxide shell and are employed in the photocatalytic disinfection of the model pathogen. effect of photocatalyst loading and reaction temperature on the disinfection kinetics was studied. disinfection effici ...	2015	25523714
in vitro and in vivo antimicrobial efficacy of natural plant-derived compounds against vibrio cholerae of o1 el tor inaba serotype.	in this study, we investigated antibacterial activities of 20 plant-derived natural compounds against gram-negative enteric pathogens. we found that both flavonoids and non-flavonoids, including honokiol and magnolol, possess specific antibacterial activities against v. cholerae, but not against other species of gram-negative bacterium which we tested. using various antibacterial assays, we determined that there was a dose-dependent bactericidal and biofilm inhibitory activity of honokiol and ma ...	2015	25516242
inca/c plasmids harboured in serious multidrug-resistant vibrio cholerae serogroup o139 strains in china.	vibrio cholerae serogroup o139 emerged in 1992 and is one of two major serogroups to have caused cholera epidemics. after 1998, serious multidrug-resistant (mdr) o139 strains quickly became common in china, showing a multidrug resistance profile to eight antibiotics. it is a great threat to public health, and elucidation of its mechanisms of resistance will provide a helpful guide for the clinical treatment and prevention of cholera. in this study, mega-plasmids from mdr v. cholerae o139 strains ...	2015	25532743
monitoring water sources for environmental reservoirs of toxigenic vibrio cholerae o1, haiti.		2015	25531032
failure of the public health testing program for ballast water treatment systems.	since 2004, an international testing program has certified 53 shipboard treatment systems as meeting ballast water discharge standards, including limits on certain microbes to prevent the spread of human pathogens. we determined how frequently certification tests failed a minimum requirement for a meaningful evaluation, that the concentration of microbes in the untreated (control) discharge must exceed the regulatory limit for treated discharges. in 95% of cases where the result was accepted as ...	2015	25596892
a metalloprotease secreted by the type ii secretion system links vibrio cholerae with collagen.	vibrio cholerae is autochthonous to various aquatic niches and is the etiological agent of the life-threatening diarrheal disease cholera. the persistence of v. cholerae in natural habitats is a crucial factor in the epidemiology of cholera. in contrast to the well-studied v. cholerae-chitin connection, scarce information is available about the factors employed by the bacteria for the interaction with collagens. collagens might serve as biologically relevant substrates, because they are the most ...	2015	25561716