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in-silico structural and functional characterization of a v. cholerae o395 hypothetical protein containing a pdz1 and an uncommon protease domain.vibrio cholerae, the causative agent of epidemic cholera, has been a constant source of concern for decades. it has constantly evolved itself in order to survive the changing environment. acquisition of new genetic elements through genomic islands has played a major role in its evolutionary process. in this present study a hypothetical protein was identified which was present in one of the predicted genomic island regions of the large chromosome of v. cholerae o395 showing a strong homology with ...201323441214
a quorum sensing-mediated switch contributes to natural transformation of vibrio cholerae.there is a fundamental gap in our understanding of how horizontal gene transfer contributes to the enormous range of genetic variations that are observed among bacteria. the objective of our study was to better understand how the acquisition of genetic material by natural transformation is regulated within a population of vibrio cholerae cells. v. cholerae is an aquatic bacterium and a facultative human pathogen. it acquires natural competence for transformation in response to changing environme ...201223446800
fatal non-o1, non-o139 vibrio cholerae septicaemia in a patient with chronic liver disease.a 49-year-old male with underlying liver disease presented with fever and signs of sepsis. non-o1/non-o139 vibrio cholerae was isolated from his blood culture, which was positive for the hlya and toxr genes. we report this fatal case of non-o1/non-o139 v. cholera sepsis and review the literature on non-o1/non-o139 v. cholerae sepsis in patients with chronic liver disease.201323449872
immune adjuvant effect of v. cholerae o1 derived proteoliposome coadministered by intranasal route with vi polysaccharide from salmonella typhi.the proteoliposome derived from vibrio cholerae o1 (plc) is a nanoscaled structure obtained by a detergent extraction process. intranasal (i.n) administration of plc was immunogenic at mucosal and systemic level vs. v. cholerae; however the adjuvant potential of this structure for non-cholera antigens has not been proven yet. the aim of this work was to evaluate the effect of coadministering plc with the vi polysaccharide antigen (poli vi) of s. typhi by the i.n route. the results showed that po ...201323458379
cholera outbreaks in nigeria are associated with multidrug resistant atypical el tor and non-o1/non-o139 vibrio cholerae.the current millennium has seen a steep rise in the number, size and case-fatalities of cholera outbreaks in many african countries. over 40,000 cases of cholera were reported from nigeria in 2010. variants of vibrio cholerae o1 el tor biotype have emerged but very little is known about strains causing cholera outbreaks in west africa, which is crucial for the implementation of interventions to control epidemic cholera.201323459673
bacterial community composition associated with chironomid egg masses.chironomids (diptera: chironomidae) are the most widely distributed and often the most abundant insect in freshwater. they undergo a complete metamorphosis of four life stages, of which the egg, larva, and pupae are aquatic and the adult is terrestrial. chironomid egg masses were found to be natural reservoirs of vibrio cholerae and aeromonas species. to expand the knowledge of the endogenous bacterial community associated with chironomid egg masses, denaturing gradient gel electrophoresis and c ...201223461272
development of quinoline-based disruptors of biofilm formation against vibrio cholerae.biofilm formation is a major cause of bacterial persistence in nosocomial infections, leading to extended treatment times and increased rates of morbidity and mortality. despite this, there are currently no biofilm inhibitors approved for clinical use. the synthesis and biological evaluation of a library of amino alcohol quinolines as lead compounds for the disruption of biofilm formation in vibrio cholerae is now reported. application of selective metal-halogen exchange chemistry installed both ...201323461487
role of a teha homolog in vibrio cholerae c6706 antibiotic resistance and intestinal colonization.vibrio cholerae is the causative agent of the devastating diarrheal disease cholera. a number of regulatory pathways are involved in v. cholerae pathogenesis and antibiotic resistance. for example, there are over 40 lysr-family proteins in the v. cholerae genome, but most of their functions are unknown. in this study, we examine the role of vc2323 (tehavc) and its divergently transcribed lysr-family regulator vc2324 (tehrvc) in v. cholerae pathogenesis. we found that in v. cholerae c6706, the ex ...201323461522
large outbreak of cholera caused by el tor variant vibrio cholerae o1 in the eastern coast of odisha, india during 2009.a large outbreak of cholera reported during april-july 2009 in the kendrapada district of odisha, india was investigated. forty-one rectal swabs and 41 water samples, collected from diarrhoeal patients and from different villages were bacteriologically analysed for the isolation of bacterial enteriopathogens, antibiogram profile and detection of various toxic genes. the bacteriological analysis of rectal swabs and environmental water samples revealed the presence of v. cholerae o1 ogawa biotype ...201323461927
delivery of immunogens to mucosal immune system using an oral inactivated cholera vaccine: a new approach for development of oral vaccines.oral vaccines have several attractive features; however, due to several challenges, to date, only a limited number of oral vaccines are licensed. over the past two decades, several oral vehicle delivery systems have been developed to address these challenges and deliver antigens to the target cells in the mucosal immune system. while the size of vehicle delivery systems, the quantity of components in the vehicle formulation, the dose of administration, and even the type of animals species, are i ...201323466688
immunization with cholera toxin b subunit induces high-level protection in the suckling mouse model of cholera.cholera toxin (ct) is the primary virulence factor responsible for severe cholera. vibrio cholerae strains unable to produce ct show severe attenuation of virulence in animals and humans. the pentameric b subunit of ct (ctb) contains the immunodominant epitopes recognized by antibodies that neutralize ct. although ctb is a potent immunogen and a promising protective vaccine antigen in animal models, immunization of humans with detoxified ct failed to protect against cholera. we recently demonstr ...201323468950
characterization of the phd-doc and ccd toxin-antitoxin cassettes from vibrio superintegrons.toxin-antitoxin (ta) systems have been reported in the genomes of most bacterial species, and their role when located on the chromosome is still debated. ta systems are particularly abundant in the massive cassette arrays associated with chromosomal superintegrons (si). here, we describe the characterization of two superintegron cassettes encoding putative ta systems. the first is the phd-doc(si) system identified in vibrio cholerae n16961. we determined its distribution in 36 v. cholerae strain ...201323475970
prevalence and molecular characterization of vibrio cholerae o1, non-o1 and non-o139 in tropical seafood in cochin, india.the objective of this study was to determine the prevalence of o1, o139, and non-o1 and non-o139 vibrio cholerae, which were associated with fresh and raw seafood samples harvested from cochin, india waters during 2009-2011. results from v. cholerae-specific biochemical, molecular, and serological assays identified five el tor v. cholerae o1 ogawa strains and 377 non-o1, non-o139 v. cholerae strains from 265 seafood samples. v. cholerae o139 strains were not isolated. polymerase chain reaction a ...201323489050
evaluation of enteric-coated tablets as a whole cell inactivated vaccine candidate against vibrio cholerae.a vaccine candidate against cholera was developed in the form of oral tablets to avoid difficulties during application exhibited by current whole cell inactivated cholera vaccines. in this study, enteric-coated tablets were used to improve the protection of the active compound from gastric acidity. tablets containing heat-killed whole cells of vibrio cholerae strain c7258 as the active pharmaceutical compound was enteric-coated with the polymer kollicoat(®) mae-100p, which protected them efficie ...201323492079
simultaneous detection of integrase and antibiotic resistance genes within sxt constin in vibrio cholerae o1 el tor strains isolated from iran using multiplex-pcr.amongst the various antibiotic resistant elements in vibrio. cholerae, sxt constin (sxt-c) is important. we were going to design a quick method for determination of antibiotic resistance gene pattern in sxt-c.201223493053
abundance and distribution of vibrio cholerae, v. parahaemolyticus, and v. vulnificus following a major freshwater intrusion into the mississippi sound.in response to a major influx of freshwater to the mississippi sound following the opening of the bonnet carre spillway, water samples were collected from three sites along the mississippi shoreline to assess the impact of altered salinity on three pathogenic vibrio species. salinity readings across the affected area during the 2011 sample period ranged from 1.4 to 12.9 ppt (mean = 7.0) and for the 2012 sample period from 14.1 to 23.6 ppt (mean = 19.8). analyses of the data collected in 2011 sho ...201323494573
molecular analysis of non-o1/non-o139 vibrio cholerae isolated from hospitalised patients in china.cholera is still a significant public health issue in developing countries. the aetiological agent is vibrio cholerae and only two serogroups, o1 and o139, are known to cause pandemic or epidemic cholera. in contrast, non-o1/non-o139 v. cholerae has only been reported to cause sporadic cholera-like illness and localised outbreaks. the aim of this study was to determine the genetic diversity of non-o1/non-o139 v. cholerae isolates from hospitalised diarrhoeal patients in zhejiang province, china.201323497008
synthesis and concentration dependent antibacterial activities of cuo nanoflakes.we report, synthesis and antibacterial activities of cuo nanoflakes. cuo nanoparticles are prepared at room temperature through sol-gel method. x-ray diffraction studies show the particles are monoclinic (crystalline) in nature. scanning electron microscopy (sem) images clearly show that the prepared particles are flake like in structure. fourier transform infrared (ftir) spectra exhibits three different bands that correspond to the au and bu modes. antibacterial studies were performed on shigel ...201323498227
biocompatible nanostructured magnesium oxide-chitosan platform for genosensing application.a novel organic-inorganic platform comprising of chitosan (ch) modified nanostructured magnesium oxide (nanomgo) has been electrophoretically deposited on the indium-tin-oxide (ito) substrate. the single stranded probe dna (ssdna) sequence of vibrio cholerae has been covalently functionalized onto ch-nanomgo/ito surface. the cytotoxicity assay of nanomgo particles, examined using human intestinal cell line (int 407), reveals no significant cytotoxicity at the given doses in the range of 50-350 μ ...201323500361
characterization of undermethylated sites in vibrio cholerae.the activities of dna methyltransferases are important for a variety of cellular functions in bacteria. in this study, we developed a modified high-throughput technique called methyl homopolymer tail mediated sequencing (methyl htm-seq) to identify the undermethylated sites in the vibrio cholerae genome for the two dna methyltransferases, dam, an adenine methyltransferase, and vchm, a cytosine methyltransferase, during growth in rich medium in vitro. many of the undermethylated sites occurred in ...201323504020
biological activity of recombinant accessory cholerae enterotoxin (ace) on rabbit ileal loops and antibacterial assay.vibrio cholerae (v. cholerae) causes a potentially lethal disease named cholera. the cholera enterotoxin (ct) is a major virulence factor of v. cholerae. in addition to ct, v. cholerae produces other putative toxins, such as the zonula occludens toxin (zot) and accessory cholera enterotoxin (ace). the ace gene is the third gene of the v. cholerae virulence cassette. the ace toxin alters ion transport, causes fluid accumulation in ligated rabbit ileal loops, and is a cause of mild diarrhea. the a ...201223507621
comparison of two recombinant systems for expression of cholera toxin b subunit from vibrio cholerae.the aim of this study was to assess the production of recombinant cholera toxin b subunit (rctb) protein in two different expression systems (pae_ctxb and pqe_ctxb constructs) in escherichia coli bl21 (de3).201323508422
β-lactam antibiotics promote bacterial mutagenesis via an rpos-mediated reduction in replication fidelity.regardless of their targets and modes of action, subinhibitory concentrations of antibiotics can have an impact on cell physiology and trigger a large variety of cellular responses in different bacterial species. subinhibitory concentrations of β-lactam antibiotics cause reactive oxygen species production and induce poliv-dependent mutagenesis in escherichia coli. here we show that subinhibitory concentrations of β-lactam antibiotics induce the rpos regulon. rpos-regulon induction is required fo ...201323511474
immune responses to the o-specific polysaccharide antigen in children who received a killed oral cholera vaccine compared to responses following natural cholera infection in bangladesh.current oral cholera vaccines induce lower levels of protective efficacy and shorter durations of protection in young children than in adults. immunity against cholera is serogroup specific, and immune responses to vibrio cholerae lipopolysaccharide (lps), the antigen that mediates serogroup-specific responses, are associated with protection against disease. despite this, responses against v. cholerae o-specific polysaccharide (osp), a key component of the lps responsible for specificity, have n ...201323515016
rapid spread of vibrio cholerae o1 el tor variant in odisha, eastern india, in 2008 and 2009.the emergence and spread of vibrio cholerae o1 el tor variant strains causing severe diarrhea has been witnessed worldwide in recent years. in the state of odisha, india, the spread of the v. cholerae o1 el tor variant strains was studied during outbreaks in 2008 and 2009. analysis of 194 v. cholerae o1 ogawa strains revealed that v. cholerae o1 el tor variant strains are spreading gradually throughout the state, causing outbreaks replacing typical v. cholerae o1 el tor biotype strains.201323515546
genome sequence of vibrio cholerae g4222, a south african clinical isolate.vibrio cholerae, a gram-negative pathogen autochthonous to the aquatic environment, is the causative agent of cholera. here, we report the complete genome sequence of v. cholerae g4222, a clinical isolate from south africa.201323516184
an approach to a cold chain free oral cholera vaccine: in vitro and in vivo characterization of vibrio cholerae gastro-resistant microparticles.the present work describes the formulation of eudragit(®) l30 d-55 microparticles (mp) alone or with mucoadhesive agents, alginate or carbopol(®), as an approach for the development of an oral cholera vaccine. in the first part, a spray drying technique was optimized for microparticle elaboration, obtaining a microparticle size ranging from 7 to 9 μm with high encapsulation efficiencies. moreover, gastro resistant properties and vibrio cholerae (vc) antigenicity were maintained, but for eudragit ...201323518363
structure of the cytoplasmic domain of tcpe, the inner membrane core protein required for assembly of the vibrio cholerae toxin-coregulated pilus.type iv pili are long thin surface-displayed polymers of the pilin subunit that are present in a diverse group of bacteria. these multifunctional filaments are critical to virulence for pathogens such as vibrio cholerae, which use them to form microcolonies and to secrete the colonization factor tcpf. the type iv pili are assembled from pilin subunits by a complex inner membrane machinery. the core component of the type iv pilus-assembly platform is an integral inner membrane protein belonging t ...201323519659
structure of vibrio cholerae ribosome hibernation promoting factor.the x-ray crystal structure of ribosome hibernation promoting factor (hpf) from vibrio cholerae is presented at 2.0 å resolution. the crystal was phased by two-wavelength mad using cocrystallized cobalt. the asymmetric unit contained two molecules of hpf linked by four co atoms. the metal-binding sites observed in the crystal are probably not related to biological function. the structure of hpf has a typical β-α-β-β-β-α fold consistent with previous structures of yfia and hpf from escherichia co ...201323519794
vibrio cholerae vttr(a) and vttr(b) regulatory influences extend beyond the type 3 secretion system genomic island.a subset of non-o1/non-o139 serogroup strains of vibrio cholerae cause disease using type 3 secretion system (t3ss)-mediated mechanisms. an ∼50-kb genomic island carries genes encoding the t3ss structural apparatus, effector proteins, and two transmembrane transcriptional regulators, vttr(a) and vttr(b), which are toxr homologues. previous experiments demonstrated that vttr(a) and vttr(b) are necessary for colonization in vivo and promote bile-dependent t3ss gene expression in vitro. to better u ...201323524608
the aquatic environment as a reservoir of vibrio cholerae o1 in hydrographic basins of the state of pernambuco, brazil.after the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in pernambuco, brazil, where cholera is endemic. after a quiescent period, 4 rfbn (serogroup o1) positive water samples that were culture negative were detected by multiplex single-tube nested pcr (mstnpcr); 2 of these were also ctxa (cholera toxin) positive. from may to june 2012, 30 v. cholerae o1 isolates were obtained by culturing samples. these isolates were analyzed for t ...201323533357
α-cyclodextrin decreases cholera toxin binding to gm1-gangliosides.cholera toxin (ct), the principal virulence factor secreted by vibrio cholerae, is an a-b5 type exotoxin that binds to host cell gm1-gangliosides and is responsible for cholera diarrhoea. we tested the hypothesis that the cyclic hexasaccharide α-cyclodextrin (α-cd), but not the cyclic heptasaccharides methyl-β-cyclodextrin (md-β-cd) and hydroxypropyl-β-cyclodextrin (hp-β-cd) inhibit binding of ct to gm1-gangliosides. we report that α-cd decreases ct binding to gm1-ganglioside-coated microtitre p ...201323538564
a visual assay to monitor t6ss-mediated bacterial competition.type vi secretion systems (t6sss) are molecular nanomachines allowing gram-negative bacteria to transport and inject proteins into a wide variety of target cells(1,2). the t6ss is composed of 13 core components and displays structural similarities with the tail-tube of bacteriophages(3). the phage uses a tube and a puncturing device to penetrate the cell envelope of target bacteria and inject dna. it is proposed that the t6ss is an inverted bacteriophage device creating a specific path in the ba ...201323542679
the genome of vp3, a t7-like phage used for the typing of vibrio cholerae.the bacteriophage vp3 is used in a phage-biotyping scheme as one of the typing phages of vibrio cholerae o1 biotype el tor strains. here, we have sequenced and analyzed its genome. the genome consists of 39,481 bp with an overall g + c content of 42.6 %. fifty-two open reading frames (orfs) were predicted. within the genome, 17 highly conserved phage promoters and 6 rho-independent terminators were predicted. when assessed with rluc as a reporter gene, 12 of 16 cloned vp3 promoters showed activi ...201323543142
a thermostabilized magnetogenosensing assay for dna sequence-specific detection and quantification of vibrio cholerae.vibrio cholerae is a human pathogen that causes mild to severe diarrheal illnesses and has major public health significance. herein, we present a thermostabilized electrochemical genosensing assay combining the use of magnetic beads as a biorecognition platform and gold nanoparticles as a hybridization tag for the detection and quantification of v. cholerae lolb gene single-stranded asymmetric pcr amplicons as an alternative to the time-consuming classical isolation method. this thermostabilized ...201323545172
distribution and pathogenic relationship of virulence associated genes among vibrio alginolyticus from the mariculture systems.vibrio alginolyticus has been confirmed as an important pathogen for aquatic animals. however, the pathogenic mechanism of v. alginolyticus is not completely understood. a total of 31 isolates of v. alginolyticus from sea water, fish and shrimp on the mariculture systems were fingerprinted by pulsed-field gel electrophoresis. the pathogenicity of these isolates was tested by challenge and the 21 genes associated with the virulence of vibrio cholerae or vibrio parahaemolyticus were examined in v. ...201323562411
temporal and spatial distribution patterns of potentially pathogenic vibrio spp. at recreational beaches of the german north sea.the number of reported vibrio-related wound infections associated with recreational bathing in northern europe has increased within the last decades. in order to study the health risk from potentially pathogenic vibrio spp. in the central wadden sea, the seasonal and spatial distribution of vibrio vulnificus, vibrio parahaemolyticus, vibrio alginolyticus and vibrio cholerae were investigated at ten recreational beaches in this area over a 2-year period. v. alginolyticus and v. parahaemolyticus w ...201323563708
secretion of tcpf by the vibrio cholerae toxin-coregulated pilus biogenesis apparatus requires an n-terminal determinant.type iv pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. we and others have shown that type iv pili are important for protein secretion across the outer membrane, similar to type ii secretion systems. this study explored the relationship between protein secretion and pilus formation in vibrio cholerae. the toxin-coregulated pilus (tcp), a type iv pilus required for v. cholerae pathogenesis, is necessary for the secretion of the colonization fac ...201323564177
infrared spectroscopic evidence of a redox-dependent conformational change involving ion binding residue nqrb-d397 in the na(+)-pumping nadh:quinone oxidoreductase from vibrio cholerae.the na(+)-pumping nadh:quinone oxidoreductase (na(+)-nqr) is a unique respiratory enzyme that conserves energy by translocating na(+) through the plasma membrane. found only in prokaryotes, the enzyme serves as the point of entry of electrons into the respiratory chain in many pathogens, including vibrio cholerae and yersinia pestis. in this study, a combined electrochemical and fourier transform infrared (ftir) spectroscopic approach revealed that na(+)-nqr undergoes significant conformational ...201323566241
a novel marker for the species-specific detection and quantitation of vibrio cholerae by targeting an outer membrane lipoprotein lolb gene.vibrio cholerae o1 and o139 are the major serotypes associated with illness, and some v. cholera non-o1 and non-o139 isolates produce cholera toxin. the present study describes a quantitative polymerase chain reaction (qpcr) assay for the species-specific detection and quantitation of v. cholera using a primer pair based on an outer membrane lipoprotein lolb gene for the amplification of a 195 bp dna fragment. the qpcr primer set for the accurate diagnosis of v. cholera was developed from public ...201323568211
studies on bioprospecting potential of a gastropod mollusc cantharus tranquebaricus (gmelin, 1791).to study the biological activities of the tissue extract of cantharus tranquebaricus (c. tranquebaricus).201223569843
production of chitosan from endolichenic fungi isolated from mangrove environment and its antagonistic activity.to screen the chitosan producing ability of endolichenic fungi and its antibacterial activity.201223569884
outbreak of cholera in tilathi vdc saptari nepal.background on 2011, cluster of cholera cases was reported in the tilathi vdc of saptari, nepal. objective the outbreak was investigated to identify the etiological agent and possible source of infection and guiding the prevention and control measures. methods demographic and clinical details were collected from the suspected case-patients, and the outbreak was described by time, place, and person. focus group discussion and key informant interview were conducted to assess the practice of sanitat ...201223575050
the papain inhibitor (spi) of streptomyces mobaraensis inhibits bacterial cysteine proteases and is an antagonist of bacterial growth.a novel papain inhibitory protein (spi) from streptomyces mobaraensis was studied to measure its inhibitory effect on bacterial cysteine protease activity (staphylococcus aureus sspb) and culture supernatants (porphyromonas gingivalis, bacillus anthracis). further, growth of bacillus anthracis, staphylococcus aureus, pseudomonas aeruginosa, and vibrio cholerae was completely inhibited by 10 μm spi. at this concentration of spi, no cytotoxicity was observed. we conclude that spi inhibits bacteria ...201323587952
analysis of vibrio cholerae genome sequences reveals unique rtxa variants in environmental strains and an rtxa-null mutation in recent altered el tor isolates.vibrio cholerae genome sequences were analyzed for variation in the rtxa gene that encodes the multifunctional autoprocessing rtx (martx) toxin. to accommodate genomic analysis, a discrepancy in the annotated rtxa start site was resolved experimentally. the correct start site is an atg downstream from rtxc resulting in a gene of 13,638 bp and deduced protein of 4,545 amino acids. among the el tor o1 and closely related o139 and o37 genomes, rtxa was highly conserved, with nine alleles differing ...201323592265
effects of polyamines on vibrio cholerae virulence properties.vibrio cholerae is the causative agent of the severe enteric disease cholera. to cause cholera the bacterium must be able to synthesize both cholera toxin (ct) and toxin-coregulated pilus (tcp) which mediates autoagglutination and is required for colonization of the small intestine. only a few environmental signals have been shown to regulate v. cholerae virulence gene expression. polyamines, which are ubiquitous in nature, and have been implicated in regulating virulence gene expression in othe ...201323593304
in vitro anti-biofilm and anti-bacterial activity of junceella juncea for its biomedical application.to investigate the anti-biofilm and anti-bacterial activity of junceella juncea (j. juncea) against biofilm forming pathogenic strains.201223593571
in vitro and in vivo bactericidal activity of vitex negundo leaf extract against diverse multidrug resistant enteric bacterial pathogens.to investigate in vitro and in vivo antibacterial potentials of vitex negundo (v. negundo) leaf extracts against diverse enteric pathogens.201323608373
review of the inhibition of biological activities of food-related selected toxins by natural compounds.there is a need to develop food-compatible conditions to alter the structures of fungal, bacterial, and plant toxins, thus transforming toxins to nontoxic molecules. the term 'chemical genetics' has been used to describe this approach. this overview attempts to survey and consolidate the widely scattered literature on the inhibition by natural compounds and plant extracts of the biological (toxicological) activity of the following food-related toxins: aflatoxin b1, fumonisins, and ochratoxin a p ...201323612750
rpos plays a central role in the sos induction by sub-lethal aminoglycoside concentrations in vibrio cholerae.bacteria encounter sub-inhibitory concentrations of antibiotics in various niches, where these low doses play a key role for antibiotic resistance selection. however, the physiological effects of these sub-lethal concentrations and their observed connection to the cellular mechanisms generating genetic diversification are still poorly understood. it is known that, unlike for the model bacterium escherichia coli, sub-minimal inhibitory concentrations (sub-mic) of aminoglycosides (ags) induce the ...201323613664
time series analysis of cholera in matlab, bangladesh, during 1988-2001.the study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of bangladesh and developed a forecasting model for understanding the magnitude of incidence. diarrhoea surveillance data collected between 1988 and 2001 were obtained from a field research site in matlab, bangladesh. cholera cases were defined as vibrio cholerae o1 isolated from faecal specimens of patients who sought care at treatment centres serving the matlab populat ...201323617200
acid-detoxified inaba lipopolysaccharide (pmlps) is a superior cholera conjugate vaccine immunogen than hydrazine-detoxified lipopolysaccharide and induces vibriocidal and protective antibodies.worldwide, in endemic areas of cholera, the group most burdened with cholera is children. this is especially vexing as young children (2-5 years of age) do not respond as well, or for as long as adults do, to the current killed oral cholera vaccines (ocv). conjugate vaccines based on the hapten-carrier paradigm have been developed for several bacterial pathogens that cause widespread and severe diseases in young children. we and others have studied different formulations of vibrio cholerae (vc) ...201323620159
antioxidant, antibacterial and cytotoxic effects of the phytochemicals of whole leucas aspera extract.to investigate the antioxidant, antibacterial and cytotoxic activity of whole leucas aspera (labiatae) (l. aspera) alcoholic extract.023620850
vibrio cholerae non-o1, non-o139 serogroups and cholera-like diarrhea, kolkata, india.we identified 281 vibrio cholerae non-o1, non-o139 strains from patients with diarrhea in kolkata, india. cholera-like diarrhea was the major symptom (66.0%); some patients (20.3%) had severe dehydration. these strains lacked the ctxa gene but many had hlya, rtxa, and rtxc genes. pulsed-field gel electrophoresis showed no genetic link among strains.201323622872
lipopolysaccharide modifications of a cholera vaccine candidate based on outer membrane vesicles reduce endotoxicity and reveal the major protective antigen.the causative agent of the life-threatening gastrointestinal infectious disease cholera is the gram-negative, facultative human pathogen vibrio cholerae. we recently started to investigate the potential of outer membrane vesicles (omvs) derived from v. cholerae as an alternative approach for a vaccine candidate against cholera and successfully demonstrated the induction of a long-lasting, high-titer, protective immune response upon immunization with omvs using the mouse model. in this study, we ...201323630951
cholera outbreak in districts around lake chilwa, malawi: lessons learned.cholera is endemic in malawi with seasonal outbreaks during the wet season. people living around lake chilwa rely on the lake for their water supply. from may 2009 to may 2010, a cholera outbreak occurred in fishing communities around lake chilwa. this paper describes the outbreak response and lessons learned for prevention and management of future outbreaks.201223638267
a quantitative polymerase chain reaction assay for rapid detection of 9 pathogens directly from stools of travelers with diarrhea.every year, 80 million tourists traveling to tropical and subtropical areas contract traveler's diarrhea (td). forty percent to 80% of cases are caused by bacteria, yet clinical diagnostic tests are available to identify only a few of the strains that cause td. we aimed to develop a quantitative polymerase chain reaction (qpcr) assay to identify all major pathogens in stool samples.201323639597
a functional vipa-vipb interaction is required for the type vi secretion system activity of vibrio cholerae o1 strain a1552.many gram-negative bacteria rely on a type vi secretion system (t6ss) to infect eukaryotic cells or to compete against other microbes. common to these systems is the presence of two conserved proteins, in vibrio cholerae denoted vipa and vipb, which have been shown to interact in many clinically relevant pathogens. in this study, mutagenesis of a defined region within the vipa protein was used to identify residues important for vipb binding in v. cholerae o1 strain a1552.201323642157
accumulation of mutations in dna gyrase and topoisomerase iv genes contributes to fluoroquinolone resistance in vibrio cholerae o139 strains.high resistance rates to nalidixic acid (nal) in vibrio cholerae serogroup o139 strains have been found, and ciprofloxacin (cip) resistance is also observed. in this study, mutations within the quinolone-resistance determining regions (qrdrs) of dna gyrase and topoisomerase iv from nal-resistant o139 strains were analysed. the predominant mutation profile was s83i in gyra in combination with s85l in parc. in addition, the combination substitutions of d87n in gyra and d420n in pare in combination ...201323643392
cholera: pathophysiology and emerging therapeutic targets.cholera is a diarrheal disease that remains an important global health problem with several hundreds of thousands of reported cases each year. this disease is caused by intestinal infection with vibrio cholerae, which is a highly motile gram-negative bacterium with a single-sheathed flagellum. in the course of cholera pathogenesis, v. cholerae expresses a transcriptional activator toxt, which subsequently transactivates expressions of two crucial virulence factors: toxin-coregulated pilus and ch ...201323651092
outbreak of cholera in the east akim municipality of ghana following unhygienic practices by small-scale gold miners, november 2010.in october 2010 an outbreak of cholera began among a group of small-scale gold miners in the east-akim municipality (eam), eastern region. we investigated to verify the diagnosis, identify risk factors and recommend control measures.201223661823
a comparative proteomic analysis of vibrio cholerae o1 wild-type cells versus a phob mutant showed that the phob/phor system is required for full growth and rpos expression under inorganic phosphate abundance.phob/phor is a two-component system originally described as involved in inorganic phosphate (pi) transport and metabolism under pi limitation. in order to disclose other roles of this system, a proteomic analysis of vibrio cholerae 569bsr and its phob/phor mutant under high pi levels was performed. most of the proteins downregulated by the mutant have roles in energy production and conversion and in amino acid transport and metabolism. in contrast, the phob/phor mutant upregulated genes mainly i ...201323665147
horizontal gene transfer of a genetic island encoding a type iii secretion system distributed in vibrio cholerae.twelve vibrio cholerae isolates with genes for a type iii secretion system (t3ss) were detected among 110 environmental and 14 clinical isolates. t3ss-related genes were distributed among the various serogroups and pulsed-field gel electrophoresis of noti-digested genomes showed genetic diversity in these strains. however, the restriction fragment length polymorphism profiles of the t3ss-related genes had similar patterns. additionally, naturally competent t3ss-negative v. cholerae incorporated ...201323668604
decoupled roles for the atypical, bifurcated binding pocket of the ybff hydrolase.serine hydrolases have diverse intracellular substrates, biological functions, and structural plasticity, and are thus important for biocatalyst design. amongst serine hydrolases, the recently described ybff enzyme family are promising novel biocatalysts with an unusual bifurcated substrate-binding cleft and the ability to recognize commercially relevant substrates. we characterized in detail the substrate selectivity of a novel ybff enzyme from vibrio cholerae (vc-ybff) by using a 21-member lib ...201323670977
the outer surface lipoprotein vola mediates utilization of exogenous lipids by vibrio cholerae.previous work from our laboratory showed that the gram-negative aquatic pathogen vibrio cholerae can take up a much wider repertoire of fatty acids than other gram-negative organisms. the current work elaborated on the ability of v. cholerae to exploit an even more diverse pool of lipid nutrients from its environment. we have demonstrated that the bacterium can use lysophosphatidylcholine as a metabolite for growth. using a combination of thin-layer chromatography and mass spectrometry, we also ...201323674613
malonate inhibits virulence gene expression in vibrio cholerae.we previously found that inhibition of the tca cycle, either through mutations or chemical inhibition, increased toxt transcription in vibrio cholerae. in this study, we found that the addition of malonate, an inhibitor of succinate dehydrogenase (sdh), decreased toxt transcription in v. cholerae, an observation inconsistent with the previous pattern observed. unlike another sdh inhibitor, 2-thenoyltrifluoroacetone (ttfa), which increased toxt transcription and slightly inhibited v. cholerae gro ...201323675480
burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the global enteric multicenter study, gems): a prospective, case-control study.diarrhoeal diseases cause illness and death among children younger than 5 years in low-income countries. we designed the global enteric multicenter study (gems) to identify the aetiology and population-based burden of paediatric diarrhoeal disease in sub-saharan africa and south asia.201323680352
alanine-scanning mutagenesis of wh2 domains of vopf reveals residues important for conferring lethality in a saccharomyces cerevisiae model.vopf, the type iii effector molecule, has been implicated in the pathogenesis of non-o1, non-o139 strains of vibrio cholerae. it is a protein of 530 amino acids, comprises of one formin homology 1-like (fh1-like) domain and three wasp homology 2 (wh2) domains. previous works have demonstrated that wh2 domains are crucial for vopf function as a modulator of cellular actin homeostasis. furthermore, domain deletion analysis also suggests that vopf variant constituted with only wh2 domain 3 is more ...201323680644
structural representative of the protein family pf14466 has a new fold and establishes links with the c2 and plat domains from the widely distant pfams pf00168 and pf01477.the domain of unknown function (duf) yp_001302112.1, a protein secreted by the human intestinal microbita, has been determined by nmr and represents the first structure for the pfam pf14466. its nmr structure is classified as a new fold, which, nonetheless, shows limited similarities with representatives of the plat/lh2 domains from pf01477 and the c2 domains from pf00168, both of which bind ca(2+) for their physiological functions. further experiments revealed affinity of yp_001302112.1 for ca( ...201323681886
structural basis for biofilm formation via the vibrio cholerae matrix protein rbma.during the transition from a free-swimming, single-cell lifestyle to a sessile, multicellular state called a biofilm, bacteria produce and secrete an extracellular matrix comprised of nucleic acids, exopolysaccharides, and adhesion proteins. the vibrio cholerae biofilm matrix contains three major protein components, rbma, bap1, and rbmc, which are unique to vibrio cholerae and appear to support biofilm formation at particular steps in the process. here, we focus on rbma, a structural protein wit ...201323687270
application of tetraplex pcr for detection of vibrio cholerae, v. parahaemolyticus, v. vulnificus and v. mimicus in cockle.a tetraplex pcr method was developed for simultaneous detection of vibrio cholerae, v. parahaemolyticus, v. vulnificus and v. mimicus in cockle samples in comparison with conventional culture method. specific primers targeting ompw of v. cholerae, tl of v. parahaemolyticus, hsp60 of v. vulnificus and sodb of v. mimicus were employed in the same pcr. detection limit of the tetraplex pcr assay was 104 cfu/ml (400 cfu/pcr reaction) for pure cultures of all four species of vibrio. in vibrio spiked c ...201323691635
the cholera outbreak in haiti: where and how did it begin?in october 2010, cholera appeared in haiti for the first time in nearly a century. the secretary-general of the united nations formed an independent panel to "investigate and seek to determine the source of the 2010 cholera outbreak in haiti". to fulfill this mandate, the panel conducted concurrent epidemiological, water and sanitation, and molecular analysis investigations. our may 2011 findings indicated that the 2010 haiti cholera outbreak was caused by bacteria introduced into haiti as a res ...201423695726
detection of vibrio cholerae using the intrinsic catalytic activity of a magnetic polymeric nanoparticle.a novel and sensitive magnetic polymeric nanoparticle (mpnp)-polymerase chain reaction-colorimetry (magneto-pcr-colorimetry) technique was developed for detection of vibrio cholerae ( v. cholerae ). the technique involved an amplification of v. cholerae dna on the surface of an mpnp and then employed the intrinsic catalytic activity of the mpnp to detect the target gene by colorimetry. an amino-modified forward primer was covalently labeled onto the mpnp surface which would bind to pcr product d ...201323697890
triplex pcr assay for the rapid identification of 3 major vibrio species, vibrio cholerae, vibrio parahaemolyticus, and vibrio fluvialis.a triplex pcr assay was developed for the identification of 3 major vibrio spp., vibrio cholerae, vibrio parahaemolyticus, and vibrio fluvialis by targeting their haemolysin, haem-utilizing, and central regulatory genes, respectively. this simple, rapid, sensitive, and specific assay using cell lysates from 227 samples established its usefulness in research and epidemiology.201323706502
microalgae associated brevundimonas sp. msk 4 as the nano particle synthesizing unit to produce antimicrobial silver nanoparticles.the biosynthesis of silver nanoparticles and its antimicrobial property was studied using bacteria isolated from spirulina products. isolated bacteria were identified as bacillus sp. msk 1 (jx495945), staphylococcus sp. msk 2 (jx495946), bacillus sp. msk 3 (jx495947) and brevundimonas sp. msk 4 (jx495948). silver nanoparticles (agnps) were synthesized using bacterial culture filtrate with agno3. the initial syntheses of ag nanoparticles were characterized by uv-vis spectrophotometer (by measurin ...201323711394
whole genome sequencing and comparative genomic analyses of two vibrio cholerae o139 bengal-specific podoviruses to other n4-like phages reveal extensive genetic diversity.vibrio cholerae o139 bengal is the only serogroup other than o1 implicated in cholera epidemics. we describe the isolation and characterization of an o139 serogroup-specific phage, vb_vchp_vcho139-i (ϕvcho139-i) that has similar host range and virion morphology as phage vb_vchp_ja1 (ϕja1) described previously. we aimed at a complete molecular characterization of both phages and elucidation of their genetic and structural differences and assessment of their genetic relatedness to the n4-like phag ...201323714204
escherichia coli heat-stable toxin b impairs intestinal epithelial barrier function by altering tight junction proteins.escherichia coli heat-stable toxin b (stb) causes diarrhea in animals. stb binds to sulfatide, its receptor, and is then internalized. in the cytoplasm, through a cascade of events, stb triggers the opening of ion channels, allowing ion secretion and water loss and leading to diarrhea. tight junctions (tjs) are well known for controlling paracellular traffic of ions and water by forming a physical intercellular barrier in epithelial cells, and some bacterial toxins are known to affect adversely ...201323716609
quorum-sensing autoinducers resuscitate dormant vibrio cholerae in environmental water samples.cholera epidemics have long been known to spread through water contaminated with human fecal material containing the toxigenic bacterium vibrio cholerae. however, detection of v. cholerae in water is complicated by the existence of a dormant state in which the organism remains viable, but resists cultivation on routine bacteriological media. growth in the mammalian intestine has been reported to trigger "resuscitation" of such dormant cells, and these studies have prompted the search for resusci ...201323716683
transport of nucleosides in the vccnt facilitated by sodium gradients from molecular dynamics simulations.nucleosides are required for dna and rna synthesis, and the nucleoside adenosine has a function in a variety of signaling processes. nucleosides require a specialized class of integral membrane proteins, known as nucleoside transporters (nts), for specific transport across cell membranes. nts are also important determinants for the transport of nucleoside-derived drugs across cell membranes. recently, the crystal structure of the vccnt (vibrio cholerae concentrative nucleoside transporter) was r ...201323722168
non-toxigenic vibrio cholerae bacteraemia: case report and review of the literature.vibrio cholerae is a serious public health problem worldwide, but in the uk, v. cholerae infections are rare. here, we report a case of v. cholerae bacteraemia in an elderly patient. to our knowledge, this is the first non-travel-related v cholerae bacteraemia in the uk.201323722436
expression and secretion of cholera toxin b subunit in lactobacilli.lactic acid bacteria (lab) are used in various fields, including in food and medical supplies. there has been a great deal of research into vaccine development using lab as carriers due to their "generally recognized as safe" status. cholera is an infectious disease that causes diarrhea due to cholera toxin (ct) produced by vibrio cholerae. the pentameric cholera toxin b (ctb) subunit has no toxicity, and is used as an antigen in cholera vaccines and as a delivery molecule in vaccines to various ...201323727916
mannitol and the mannitol-specific enzyme iib subunit activate vibrio cholerae biofilm formation.vibrio cholerae is a halophilic, gram-negative rod found in marine environments. strains that produce cholera toxin cause the diarrheal disease cholera. v. cholerae use a highly conserved, multicomponent signal transduction cascade known as the phosphoenolpyruvate phosphotransferase system (pts) to regulate carbohydrate uptake and biofilm formation. regulation of biofilm formation by the pts is complex, involving many different regulatory pathways that incorporate distinct pts components. the pt ...201323728818
a quinazoline-2,4-diamino analog suppresses vibrio cholerae flagellar motility by interacting with motor protein pomb and induces envelope stress.vibrio cholerae strains of serogroups o1 and o139, the causative agents of the diarrheal illness cholera, express a single polar flagellum powered by sodium motive force and require motility to colonize and spread along the small intestine. in a previous study, we described a high-throughput assay for screening for small molecules that selectively inhibit bacterial motility and identified a family of quinazoline-2,4-diamino analogs (q24das) that (i) paralyzed the sodium-driven polar flagellum of ...201323733460
vibrio cholerae o1 isolate with novel genetic background, thailand-myanmar. 201323735934
acanthamoeba castellanii of the t4 genotype is a potential environmental host for enterobacter aerogenes and aeromonas hydrophila.acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including legionella pneumophila, pseudomonas aeruginosa, vibrio cholerae, helicobacter pylori, listeria monocytogenes, mycobacterium spp., and escherichia coli. in this capacity, acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts.201323742105
detection of escherichia coli, salmonella species, and vibrio cholerae in tap water and bottled drinking water in isfahan, iran.the quality of drinking water has an important role in human infection and disease. this study was aimed at comparing polymerase chain reaction and culture in detecting escherichia coli, salmonella species and vibrio cholera in tape water and bottled drinking water in various seasons in isfahan province, iran.201323742181
a three-loci variable number of tandem repeats analysis for molecular subtyping of vibrio cholerae o1 and o139.rapid and easy-to-use molecular subtyping methods are being explored and used for the surveillance of bacterial diseases, including multiple-loci variable number of tandem repeats (vntr) analysis (mlva). in this study, we assessed different vntr combinations for the subtyping of vibrio cholerae serogroups o1 and o139 with strain panels selected from a long-term nationwide cholera survey. by only using three highly variable loci (vc0147, vca0171, and vca0283), we acquired a high discriminatory po ...201323746357
determination of tolerable fatty acids and cholera toxin concentrations using human intestinal epithelial cells and balb/c mouse macrophages.the positive role of fatty acids in the prevention and alleviation of non-human and human diseases have been and continue to be extensively documented. these roles include influences on infectious and non-infectious diseases including prevention of inflammation as well as mucosal immunity to infectious diseases. cholera is an acute intestinal illness caused by the bacterium vibrio cholerae. it occurs in developing nations and if left untreated, can result in death. while vaccines for cholera exi ...201323748896
[the formation of toxigenic vibrio cholerae]. 201323751482
tin oxide quantum dot based dna sensor for pathogen detection.we report the application of nano crystalline tin oxide quantum dots (sno2-qds) for electrochemical detection of vibrio cholerae based on dna hybridization technique. sno2-qds (- 1-5 nm) have been synthesized by laser ablation technique in liquid (lal) and electrophoretically deposited onto hydrolyzed surface of indium tin oxide (ito) coated glass electrode. a single stranded oligonucleotide probe (23 bases) have been designed form the virulent gene sequence of v. cholerae and has been immobiliz ...201323755572
siderocalin outwits the coordination chemistry of vibriobactin, a siderophore of vibrio cholerae.the human protein siderocalin (scn) inhibits bacterial iron acquisition by binding catechol siderophores. several pathogenic bacteria respond by making stealth siderophores that are not recognized by scn. fluvibactin and vibriobactin, respectively of vibrio fluvialis and vibrio cholerae , include an oxazoline adjacent to a catechol. this chelating unit binds iron either in a catecholate or a phenolate-oxazoline coordination mode. the latter has been suggested to make vibriobactin a stealth sider ...201323755875
detection of vibrio cholerae in environmental waters including drinking water reservoirs of azerbaijan.cholera, a globally prevalent gastrointestinal disease, remains a persistent problem in many countries including the former soviet republics of the caucasus region where sporadic outbreaks occurred recently. historically, this region has experienced cholera during every pandemic since 1816; however, no known comprehensive evaluation of the presence of vibrio cholerae in surface waters using molecular methods has been done. here we present the first report of the presence of v. cholerae in surfac ...201223757128
role of gbpa protein, an important virulence-related colonization factor, for vibrio cholerae's survival in the aquatic environment.vibrio cholerae n-acetyl glucosamine-binding protein a (gbpa) is a chitin binding protein and a virulence factor involved in the colonization of human intestine. we investigated the distribution and genetic variations of gbpa in 488 v. cholerae strains of environmental and clinical origin, belonging to different serogroups and biotypes. we found that the gene is consistently present and highly conserved including an environmental v. cholerae-related strain of ancestral origin. the gene was also ...201223760830
re-identification of aeromonas isolates from chironomid egg masses as the potential pathogenic bacteria aeromonas aquariorum.egg masses of the non-biting midge chironomous sp. have recently been found to serve as a reservoir for vibrio cholerae and aeromonas species. these insects are widely distributed in freshwater and evidence suggests that they may disseminate pathogenic bacteria species into drinking water systems. in the current study the taxonomy of 26 aeromonas isolates, previously recovered from chironomid egg masses, was re-evaluated. it was found that 23 isolates, which had previously been identified as aer ...201123761256
vibrio cholerae o1 biotype el tor strains isolated in 1992 from varanasi, india harboured el tor ctxφ and classical ctxb on the chromosome-i and classical ctxφ and classical ctxb on the chromosome-ii.in this study, we report the presence of the el tor ctxφ and classical ctxφ in vibrio cholerae o1 strains isolated from varanasi, india. polymerase chain reaction, dna sequencing and restriction fragment length polymorphism revealed that, although ctx-positive strains isolated after 1990 contain ctxφ harbouring el tor type of rstr and classical ctxb, strains isolated before 1990 contain el tor type of rstr and el tor ctxb. two v. cholerae o1 strains (vc104 and vc106) represent an altered/hybrid ...201123761370
clinical and epidemiologic features of diarrheal disease due to aeromonas hydrophila and plesiomonas shigelloides infections compared with those due to vibrio cholerae non-o1 and vibrio parahaemolyticus in bangladesh.using data from the international centre for diarrhoeal disease research, bangladesh (icddr,b) from 1996 to 2001, we compared the clinical features of diarrhea in patients with stool specimens yielding only a. hydrophila (189 patients; 1.4% of 13,970 patients screened) or p. shigelloides (253 patients) compared to patients with sole v. cholerae non-o1 infection (99 patients) or v. parahaemolyticus infection (126 patients). patients exhibited similar frequencies of fever (temperature >37.8°c), st ...201223762755
detection of toxigenic vibrio cholerae o1 in freshwater lakes of the former soviet republic of georgia.three freshwater lakes, lisi lake, kumisi lake and tbilisi sea, near tbilisi, georgia, were studied from january 2006 to december 2007 to determine the presence of vibrio cholerae employing both bacteriological culture method and direct detection methods, namely pcr and direct fluorescent antibody (dfa). for pcr, dna extracted from water samples was tested for presence of v. cholerae and genes coding for selected virulence factors. vibrio cholerae non-o1/non-o139 was routinely isolated by cultur ...201023765992
environmental reservoirs of vibrio cholerae and their role in cholera.in the aquatic environment, vibrio cholerae has been reported to be associated with a variety of living organisms, including animals with an exoskeleton of chitin, aquatic plants, protozoa, bivalves, waterbirds, as well as abiotic substrates (e.g. sediments). most of these are well-known or putative environmental reservoirs for the bacterium, defined as places where the pathogen lives over time, with the potential to be released and to cause human infection. environmental reservoirs also serve a ...201023765995
analysis of clonally related environmental vibrio cholerae o1 el tor isolated before 1992 from varanasi, india reveals origin of sxt-ices belonging to o139 and o1 serogroups.in this study, we report the presence of sxt in environmental vibrio cholerae o1 el tor strains isolated before 1992 from varanasi, india. all isolates, except one, were resistant to tm, and/or sul, sm, fr, na and am. none contained plasmids. pcr and dna sequencing revealed the presence of sxt containing dfra1 and/or sulii, strab in six isolates and dfr18, sulii and strab in five isolates. three clinical v. cholerae o1 isolated during 1992 contained the antibiotic resistance gene cassette aada1 ...201023765998
sequence analysis of vibrio cholerae orfu and zot from pre-ctxφ and ctxφ reveals multiple origin of pre-ctxφ and ctxφ.a multiplex pcr was developed to detect pre-ctxφ and ctxφ in vibrio cholerae. a total of 115 v. cholerae were tested, of which 42 v. cholerae o1 and 18 v. cholerae o139 contained ctxφ. six v. cholerae o139 contained only pre-ctxφ and three v. cholerae o1 and 23 v. cholerae o139 contained both pre-ctxφ and ctxφ. none of the v. cholerae non-o1 and non-o139 that were tested had pre-ctxφ or ctxφ. results of restriction fragment length polymorphism (rflp) analysis revealed the v. cholerae isolates po ...201023766000
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