| acquisition of classical ctx prophage from vibrio cholerae o141 by el tor strains aided by lytic phages and chitin-induced competence. | the el tor biotype of vibrio cholerae o1, causing the current seventh pandemic of cholera, has replaced the classical biotype, which caused the sixth pandemic. the ctx prophages encoding cholera toxin in the two biotypes have distinct repressor (rstr) genes. recently, new variants of el tor strains that carry the classical type (ctx(class)) prophage have emerged. these "hybrid" strains apparently originate through lateral gene transfer and recombination events. to explore possible donors of the ... | 2008 | 18689675 |
| modulation of vibrio cholerae porin function by acidic ph. | the outer membrane of gram-negative bacteria contains porins, large pore-forming proteins which allow the traffic of hydrophilic compounds between the external medium and the periplasm. the oral mode of infection of vibrio cholerae, the agent of cholera, implies that the bacteria must adapt to severe changes in the environment, such as acidic ph and the presence of bile. because of their localization and the regulation of their expression in response to these external factors, the ompu and ompt ... | 2007 | 18690017 |
| contamination of community water sources by potentially pathogenic vibrios following sea water inundation. | potentially pathogenic members of the vibrionaceae family including vibrio cholerae and vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in southern india. phenotypic and genotypic studies were done to confirm the identity and detection of toxins. vibrio-gyr (gyrase b gene) was detected in all sixteen vibrio isolates. toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not de ... | 2007 | 18697592 |
| outbreak of cholera in a labour encampment in suburbs of a modern city in north india. | | 2007 | 18697595 |
| identification and functional characterization of gene components of type vi secretion system in bacterial genomes. | a new secretion system, called the type vi secretion system (t6ss), was recently reported in vibrio cholerae, pseudomonas aeruginosa and burkholderia mallei. a total of 18 genes have been identified to be belonging to this secretion system in v. cholerae. here we attempt to identify presence of t6ss in other bacterial genomes. this includes identification of orthologous sequences, conserved motifs, domains, families, 3d folds, genomic islands containing t6ss components, phylogenetic profiles and ... | 2008 | 18698408 |
| antibacterial properties of fish mucus from channa punctatus and cirrhinus mrigala. | extracts and preparations made from the animal origin were used extensively in folk and modern medicine for treating many human diseases. in the present study efforts have been made to find the antimicrobial effect of the mucus of two bottom dwelling fresh water fishes namely, channa punctatus and cirrhinus mrigala. fish mucus were tested against ten pathogenic bacteria such as escherichia coli, klebsiella oxytoca, klebsiella pneumoniae, lactobacillus vulgaris, proteus mirabilis, pseudomonas aer ... | 2008 | 18700685 |
| crystal structures of c4-dicarboxylate ligand complexes with sensor domains of histidine kinases dcus and dctb. | two-component signaling systems allow bacteria to adapt to changing environments. typically, a chemical or other stimulus is detected by the periplasmic sensor domain of a transmembrane histidine kinase sensor, which in turn relays a signal through a phosphotransfer cascade to the cognate cytoplasmic response regulator. such systems lead ultimately to changes in gene expression or cell motility. mechanisms of ligand binding and signal transduction through the cell membrane in histidine kinases a ... | 2008 | 18701447 |
| inapparent infections and cholera dynamics. | in many infectious diseases, an unknown fraction of infections produce symptoms mild enough to go unrecorded, a fact that can seriously compromise the interpretation of epidemiological records. this is true for cholera, a pandemic bacterial disease, where estimates of the ratio of asymptomatic to symptomatic infections have ranged from 3 to 100 (refs 1-5). in the absence of direct evidence, understanding of fundamental aspects of cholera transmission, immunology and control has been based on ass ... | 2008 | 18704085 |
| essential genes in salmonella enteritidis as identified by tnaraout mutagenesis. | tnaraout is a mariner-based transposon containing an arabinose-inducible promoter p(bad) facing outward. tnaraout mutagenesis previously used to identify essential genes in vibrio cholerae can also be used to identify in vitro essential genes in salmonella enteritidis. a mutant screen was conducted based on the assumption that a mutant-harboring tnaraout insertion in the promoter region of an essential gene should exhibit arabinose-dependent growth phenotype. among five isolated mutants with suc ... | 2008 | 18704577 |
| class 1 integrons and sxt elements conferring multidrug resistance in vibrio cholerae o1 strains associated with a recent large cholera outbreak in orissa, eastern india. | | 2008 | 18706789 |
| interplay between cyclic amp-cyclic amp receptor protein and cyclic di-gmp signaling in vibrio cholerae biofilm formation. | vibrio cholerae is a facultative human pathogen. the ability of v. cholerae to form biofilms is crucial for its survival in aquatic habitats between epidemics and is advantageous for host-to-host transmission during epidemics. formation of mature biofilms requires the production of extracellular matrix components, including vibrio polysaccharide (vps) and matrix proteins. biofilm formation is positively controlled by the transcriptional regulators vpsr and vpst and is negatively regulated by the ... | 2008 | 18708497 |
| vibrio cholerae o139 multiple-drug resistance mediated by yersinia pestis pip1202-like conjugative plasmids. | a conjugative plasmid, pmrv150, which mediated multiple-drug resistance (mdr) to at least six antibiotics, including ampicillin, streptomycin, gentamicin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole, was identified in a vibrio cholerae o139 isolate from hangzhou, eastern china, in 2004. according to partial pmrv150 dna sequences covering 15 backbone regions, the plasmid is most similar to pip1202, an inca/c plasmid in an mdr yersinia pestis isolate from a madagascar bubonic ... | 2008 | 18710912 |
| bacterial exotoxins downregulate cathelicidin (hcap-18/ll-37) and human beta-defensin 1 (hbd-1) expression in the intestinal epithelial cells. | cathelicidin (hcap-18/ll-37) and beta-defensin 1 (hbd-1) are human antimicrobial peptides (amps) with high basal expression levels, which form the first line of host defence against infections over the epithelial surfaces. the antimicrobial functions owe to their direct microbicidal effects as well as the immunomodulatory role. pathogenic microorganisms have developed multiple modalities including transcriptional repression to combat this arm of the host immune response. the precise mechanisms a ... | 2008 | 18717821 |
| increased isolation of vibrio cholerae o1 serotype inaba over serotype ogawa in pakistan. | although the predominant vibrio cholerae serotype in pakistan is ogawa and serotype inaba is rare, there has been a significant increase in the isolation of inaba in our referral laboratory in karachi. this paper reports this observation and further analysis of previous cholera data from 1993 to 2005 to assess the trend of occurrence and resistance pattern of v. cholerae strains. from january to september 2005, 245/3292 (7.4%) specimens yielded growth of v. cholerae. of these, 243 were serotype ... | 2008 | 18720620 |
| cholera toxin-specific memory b cell responses are induced in patients with dehydrating diarrhea caused by vibrio cholerae o1. | infection with vibrio cholerae induces durable immunity against subsequent disease, a process hypothesized to reflect anamnestic immune responses at the intestinal mucosa. the presence of antigen-specific memory b cells may therefore be a more direct measure of protection than serum antibody responses. | 2008 | 18729782 |
| vibrio cholerae o1 from accra, ghana carrying a class 2 integron and the sxt element. | vibrio cholerae o1 from a 2006 outbreak in accra were commonly resistant to multiple antimicrobials and, in particular, to trimethoprim/sulfamethoxazole, drugs commonly used in the treatment of cholera. we sought to determine the genetic basis for trimethoprim/sulfamethoxazole resistance in outbreak isolates. | 2008 | 18755696 |
| [characterization of the adhesive activity of cholera vibrions in mammalian red blood cells as an additional test for assessment of their epidemic significance]. | the in vitro study of the adhesive properties of v. cholerae eltor and v. cholerae o139 on a model of mammalian red blood cells revealed a correlation of their adhesive properties, the presence of the ctx ab, tcpa genes, and their hemolytic activity when blood group a (ii) red blood cells were used. in the latter case, the strains having the characteristics of ctx(+) tcp(+) hly(-) were ascertained to have a mean adhesive value (mav) of > 1.5, a red blood cell involvement coefficient (rbcic) of > ... | 2008 | 18756736 |
| [variation in the genome of ctxphi prophage of vibrio cholerae biovar el tor caused by tn5-mob transposon]. | a key pathogenicity factor of the cholera etiologic agent is cholera toxin (ct) whose synthesis is encoded by the ctxab operon forming apart of the ctxphi ptophage. alterations in the virulent properties of the cholera vibrios are based on the variability of the ctxphi prophage containing the genes for ctxab, zot, ace, cep, orfu, and psh in its core region. at the same time, the mechanism of the porophage genome reorganization needs further and more profound analysis. the goal of this work was t ... | 2008 | 18756818 |
| the extracellular nuclease dns and its role in natural transformation of vibrio cholerae. | free extracellular dna is abundant in many aquatic environments. while much of this dna will be degraded by nucleases secreted by the surrounding microbial community, some is available as transforming material that can be taken up by naturally competent bacteria. one such species is vibrio cholerae, an autochthonous member of estuarine, riverine, and marine habitats and the causative agent of cholera, whose competence program is induced after colonization of chitin surfaces. in this study, we in ... | 2008 | 18757542 |
| comparison of distribution of virulence determinants in clinical and environmental isolates of vibrio cholera. | the virulence of a pathogenic vibrio cholerae is dependent on a discrete set of genetic determinants. in this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of v. cholerae. | 2008 | 18762819 |
| construction of a trivalent candidate vaccine against shigella species with dna recombination. | in this work asd gene of shigella flexneri 2a strain t32 was replaced by vibrio cholerae toxin b subunit (ctxb) gene with dna recombination in vivo and in vitro. the resulting derivative of t32, designed as fwl01, could stably express ctxb, but its growth in lb medium depended on the presence of diaminopimelic acid (dap). then form i plasmid of shigella sonnei strain s7 was labeled with strain t32 asd gene and mobilized into fwl01. thus a trivalent candidate oral vaccine strain, designed as fsw0 ... | 2002 | 18763059 |
| a transient breach in the epithelial barrier leads to regulatory t-cell generation and resistance to experimental colitis. | previous studies have indicated that a defective epithelial barrier leads to inflammation of the underlying lamina propria. nevertheless, it is likely that physiologic breaks in the barrier must occur for homeostatic regulatory t cells to develop. we determined the effect of agents that disrupt epithelial tight junctions (ethanol and at1002, a vibrio cholerae zonula occludens toxin hexapeptide) on regulatory t-cell induction and resistance to induction of colitis by trinitrobenzene sulfonic acid ... | 2008 | 18765239 |
| intestinal adherence of vibrio cholerae involves a coordinated interaction between colonization factor gbpa and mucin. | the chitin-binding protein gbpa of vibrio cholerae has been recently described as a common adherence factor for chitin and intestinal surface. using an isogenic in-frame gbpa deletion mutant, we first show that v. cholerae o1 el tor interacts with mouse intestinal mucus quickly, using gbpa in a specific manner. the gbpa mutant strain showed a significant decrease in intestinal adherence, leading to less colonization and fluid accumulation in a mouse in vivo model. purified recombinant gbpa (rgbp ... | 2008 | 18765724 |
| preliminary x-ray diffraction analysis of yqjh from escherichia coli: a putative cytoplasmic ferri-siderophore reductase. | yqjh is a cytoplasmic fad-containing protein from escherichia coli; based on homology to viub of vibrio cholerae, it potentially acts as a ferri-siderophore reductase. this work describes its overexpression, purification, crystallization and structure solution at 3.0 a resolution. yqjh shares high sequence similarity with a number of known siderophore-interacting proteins and its structure was solved by molecular replacement using the siderophore-interacting protein from shewanella putrefaciens ... | 2008 | 18765906 |
| andrimid producers encode an acetyl-coa carboxyltransferase subunit resistant to the action of the antibiotic. | andrimid is a hybrid nonribosomal peptide-polyketide antibiotic that blocks the carboxyl-transfer reaction of bacterial acetyl-coa carboxylase (acc) and thereby inhibits fatty acid biosynthesis with submicromolar potency. the andrimid biosynthetic gene cluster from pantoea agglomerans encodes an admt gene with homology to the acetyl-coa carboxyltransferase (ct) beta-subunit gene accd. escherichia coli cells overexpressing admt showed resistance to andrimid. co-overproduction of admt with e. coli ... | 2008 | 18768797 |
| cholera toxin b accelerates disease progression in lupus-prone mice by promoting lipid raft aggregation. | infectious agents, including bacteria and viruses, are thought to provide triggers for the development or exacerbation of autoimmune diseases such as systemic lupus erythematosus in the genetically predisposed individual. molecular mimicry and engagement of tlrs have been assigned limited roles that link infection to autoimmunity, but additional mechanisms are suspected to be involved. in this study we show that t cells from lupus-prone mice display aggregated lipid rafts that harbor signaling, ... | 2008 | 18768857 |
| efficacy of partially hydrolyzed guar gum-added oral rehydration solution in the treatment of severe cholera in adults. | partially hydrolyzed guar gum (phgg) is a water-soluble fiber if added to oral rehydration solution (ors) and undergoes fermentation in the colon liberating short chain fatty acids (scfas). scfas potentiate the effect of ors, reducing the severity of diarrhea. | 2008 | 18769066 |
| detection, isolation, and identification of vibrio cholerae from the environment. | microbiological techniques for sampling the aquatic realm have become increasingly sophisticated, especially with advances in molecular biology. these techniques have been used to detect microorganisms that cannot be cultured by conventional bacteriological methods. this has resulted in a deeper and a clearer understanding of the ecology and epidemiology of microorganisms. important advances have been made in isolation, detection, and identification of vibrio cholerae over the past decade. the u ... | 2006 | 18770592 |
| clonal relationship among vibrio cholerae o1 el tor strains isolated in somalia. | one hundred and three vibrio cholerae o1 strains, selected to represent the cholera outbreaks which occurred in somalia in 1998-1999, were characterized by random amplified polymorphic dna patterns, ribotyping, and antimicrobial susceptibility. all strains showed a unique amplified dna pattern and 2 closely related ribotypes (b5a and b8a), among which b5a was the more frequently identified. ninety-one strains were resistant to ampicillin, chloramphenicol, spectinomycin, streptomycin, sulfamethox ... | 2009 | 18774337 |
| the bile response repressor brer regulates expression of the vibrio cholerae breab efflux system operon. | enteric pathogens have developed several resistance mechanisms to survive the antimicrobial action of bile. we investigated the transcriptional profile of vibrio cholerae o1 el tor strain c6706 under virulence gene-inducing conditions in the presence and absence of bile. microarray analysis revealed that the expression of 119 genes was affected by bile. the mrna levels of genes encoding proteins involved in transport were increased in the presence of bile, whereas the mrna levels of genes encodi ... | 2008 | 18776020 |
| transition state analogues in quorum sensing and sam recycling. | transition state structures can be derived from kinetic isotope effects and computational chemistry. molecular electrostatic potential maps of transition states serve as blueprints to guide synthesis of transition state analogue inhibitors of target enzymes. 5'- methylthioadenosine phosphorylase (mtap) functions in the polyamine pathway by recycling methylthioadenosine (mta) and maintaining cellular s-adenosylmethionine (sam). its transition state structure was used to guide synthesis of mt-dadm ... | 2008 | 18776260 |
| isolation, characterization and public health aspects of vibrio cholerae nag isolated from a danish duck farm. | the hygienic and pathogenic consequences of the isolation of vibrio cholerae nag from the conjunctiva of two ducklings, from brackish water samples in their surroundings, and from the intestinal contents of a duckling, are discussed in relation to present knowledge of the occurrence of vibrio cholerae nag in man and animals. | 1975 | 18777317 |
| severe diarrhea caused by cholera toxin-producing vibrio cholerae serogroup o75 infections acquired in the southeastern united states. | from 2003 through 2007, vibrio cholerae serogroup o75 strains possessing the cholera toxin gene were isolated from 6 patients with severe diarrhea, including 3 in georgia, 2 in alabama, and 1 in south carolina. these reports represent the first identification of v. cholerae o75 as a cause of illness in the united states. v. cholerae o75 was isolated from a water sample collected from a pond in louisiana in 2004. subsequently, 3 v. cholerae isolates from louisiana (2 from patients with diarrhea i ... | 2008 | 18781876 |
| role of the histone-like nucleoid structuring protein in the regulation of rpos and rpos-dependent genes in vibrio cholerae. | production of the zn-metalloprotease hemagglutinin (ha)/protease by vibrio cholerae has been reported to enhance enterotoxicity in rabbit ileal loops and the reactogenicity of live cholera vaccine candidates. expression of ha/protease requires the alternate sigma factor sigma(s) (rpos), encoded by rpos. the histone-like nucleoid structuring protein (h-ns) has been shown to repress rpos expression in escherichia coli. in v. cholerae strains of the classical biotype, h-ns has been reported to sile ... | 2008 | 18790865 |
| identification and characterization of cyclic diguanylate signaling systems controlling rugosity in vibrio cholerae. | vibrio cholerae, the causative agent of the disease cholera, can generate rugose variants that have an increased capacity to form biofilms. rugosity and biofilm formation are critical for the environmental survival and transmission of the pathogen, and these processes are controlled by cyclic diguanylate (c-di-gmp) signaling systems. c-di-gmp is produced by diguanylate cyclases (dgcs) and degraded by phosphodiesterases (pdes). proteins that contain ggdef domains act as dgcs, whereas proteins tha ... | 2008 | 18790873 |
| association of vibrio cholerae with plankton in coastal areas of mexico. | the el niño event of 1997/1998 provided an opportunity to carry out a field experiment in which the relationship of sea surface temperature and the association of vibrio cholerae with marine plankton could be assessed in mexican coastal and estuarine areas. plankton samples were collected from may 1997 through june 1999. sites included the mexican ports of veracruz, coatzacoalcos and frontera in the gulf of mexico and ensenada, guaymas, mazatlán, manzanillo, acapulco and oaxaca in the pacific oc ... | 2009 | 18793311 |
| effect of phage on the infectivity of vibrio cholerae and emergence of genetic variants. | seasonal epidemics of cholera in bangladesh are self-limited in nature, presumably due to phage predation of the causative vibrio cholerae during the late stage of an epidemic, when cholera patients excrete large quantities of phage in their stools. to further understand the mechanisms involved, we studied the effect of phage on the infectivity and survival of v. cholerae shed in stools. the 50% infectious dose of stool vibrios in infant mice was approximately 10-fold higher when the stools cont ... | 2008 | 18794293 |
| accommodation of gdp-linked sugars in the active site of gdp-perosamine synthase. | perosamine (4-amino-4,6-dideoxy- d-mannose), or its n-acetylated form, is one of several dideoxy sugars found in the o-antigens of such infamous gram-negative bacteria as vibrio cholerae o1 and escherichia coli o157:h7. it is added to the bacterial o-antigen via a nucleotide-linked version, namely gdp-perosamine. three enzymes are required for the biosynthesis of gdp-perosamine starting from mannose 1-phosphate. the focus of this investigation is gdp-perosamine synthase from caulobacter crescent ... | 2008 | 18795799 |
| influence of size, shape, and flexibility on bacterial passage through micropore membrane filters. | sterilization of fluids by means of microfiltration is commonly applied in research laboratories as well as in pharmaceutical and industrial processes. sterile micropore filters are subject to microbiological validation, where brevundimonas diminuta is used as a standard test organism. however, several recent reports on the ubiquitous presence of filterable bacteria in aquatic environments have cast doubt on the accuracy and validity of the standard filter-testing method. six different bacterial ... | 2008 | 18800559 |
| production of monoclonal antibodies specific to major outer membrane protein of edwardsiella tarda. | edwardsiella tarda is an important cause for hemorrhagic septicemia in fish and gastro and extra-intestinal infections in humans. monoclonal antibodies (mabs) were produced against outer membrane proteins (omps) of e. tarda et-7, isolated from diseased snakehead (ophiocephalus punctatus). two stable hybridoma clones, designated as 3f10 and 2c3 mabs were found to be potentially specific for e. tarda by indirect enzyme linked immunosorbent assay (elisa). these mabs recognized major immunogenic omp ... | 2010 | 18804863 |
| incidence of bacterial enteropathogens among hospitalized diarrhea patients from orissa, india. | bacteriological analysis of 1,551 stool/rectal swabs from all age groups of diarrhea patients of different hospitals of orissa from january 2004 to december 2006 was carried out using standard procedures. among all enteropathogens isolated in 886 culture-positive samples, escherichia coli constituted 75.5%, including 13.2% pathogenic e. coli; vibrio cholerae o1 constituted 17.3%; v. cholerae o139, 1%; shigella spp., 4.5% (shigella flexneri type 6, 2.9%, s. dysenteriae type i, 0.7%, s. sonnei, 0. ... | 2008 | 18806340 |
| vibrio cholerae flagellins induce toll-like receptor 5-mediated interleukin-8 production through mitogen-activated protein kinase and nf-kappab activation. | vaccine reactogenicity has complicated the development of safe and effective live, oral cholera vaccines. delta ctx vibrio cholerae mutants have been shown to induce inflammatory diarrhea in volunteers and interleukin-8 (il-8) production in cultured intestinal epithelial cells. bacterial flagellins are known to induce il-8 production through toll-like receptor 5 (tlr5). since the v. cholerae genome encodes five distinct flagellin proteins, flaa to flae, with homology to conserved tlr5 recognitio ... | 2008 | 18809662 |
| vibrio cholerae non-o1 infection in cirrhotics: case report and literature review. | vibrio species are ubiquitous in the marine environment and can cause severe infections in cirrhotic patients. patients with liver disease should be warned about the potential dangers of consuming raw or undercooked seafood, and avoiding exposure of wounds to seawater. we report a case of severe sepsis from vibrio cholerae non-o1 in a patient with cirrhosis awaiting orthotopic liver transplant. this case is aimed to advise clinicians about the importance of v. cholerae subtypes, and non-cholera ... | 2009 | 18811633 |
| epidemiological study of vibrio cholerae using variable number of tandem repeats. | by conventional genetic methods, including pulse-field gel electrophoresis and multilocus sequence typing, most pathogenic, cholera toxin-positive o1 and o139 isolates of vibrio cholerae cannot be distinguished. we evaluated relationships among 173 v. cholerae isolates collected between 1992 and 2007 from different geographic areas in india by analyzing five variable number of tandem repeat (vntr) loci. each vntr locus was highly variable, with between 5 and 19 alleles. eburst analysis revealed ... | 2008 | 18811655 |
| mechanisms of infectious diarrhea. | infectious diarrhea is an important public health problem worldwide. research has provided new insights into the mechanisms of diarrhea caused by various pathogens that are classified as noninflammatory, inflammatory or invasive. these three groups of organisms cause two diarrheal syndromes--noninflammatory diarrhea and inflammatory diarrhea. the noninflammatory diarrheas are caused by enterotoxin-producing organisms such as vibrio cholerae and enterotoxigenic escherichia coli, or by viruses tha ... | 2008 | 18813221 |
| secretory and gm1 receptor binding role of n-terminal region of ltb in vibrio cholerae. | heat labile enterotoxin from enterotoxigenic escherichia coli is similar to cholera toxin (ct) and is a leading cause of diarrhea in developing countries. it consists of an enzymatically active a subunit (lta) and a carrier pentameric b subunit (ltb). in the current study, we evaluated the importance of the n-terminal region of ltb by mutation analysis. deletion of the glutamine (deltaq3) residue and a substitution mutation e7g in the alpha1 helix region led to defects in ltb protein secretion. ... | 2008 | 18814842 |
| ftsk-dependent dimer resolution on multiple chromosomes in the pathogen vibrio cholerae. | unlike most bacteria, vibrio cholerae harbors two distinct, nonhomologous circular chromosomes (chromosome i and ii). many features of chromosome ii are plasmid-like, which raised questions concerning its chromosomal nature. plasmid replication and segregation are generally not coordinated with the bacterial cell cycle, further calling into question the mechanisms ensuring the synchronous management of chromosome i and ii. maintenance of circular replicons requires the resolution of dimers creat ... | 2008 | 18818731 |
| [prevalence of type iii secretion system genes in cholera vibrios from different serogroups]. | prevalence of vcs genes coding the type iii secretion system (t3ss) in cholera vibrios of different serogroups isolated in russia and neighboring countries was studied for the first time. virulent strains of o1 and o139 serogroups as well as toxigenic vibrio cholerae strains of other serogroups contained no t3ss genes. unlike mentioned strains, 29.2% of atoxigenic non o1/non o139 cholera vibrios isolated from patients in russia and neighboring countries contained the t3ss genes cluster, which mi ... | 2008 | 18819403 |
| [virulence of pre-ctxphi-carrying vibrio cholerae: genotypic and phenotypic characteristics]. | complex assessment of virulence of cholera vibrios carrying the truncated ctx element (pre-ctxphi prophage). | 2008 | 18819404 |
| controlled expression of cholera toxin b subunit from vibrio cholerae in escherichia coli. | the ctxb gene, the causative agent of cholera epidemic was successfully cloned from v. cholerae in e. coli. the insertion of the gene was confirmed by pcr as well as restriction digestion analyses. the sequencing results for the gene confirmed that the insert was in the correct orientation and in-frame with the p(bad) promoter and it showed that the gene was 99% homologous to the published ctxb sequence. the ctb protein was successfully expressed in e. coli using the pbad/his vector system. the ... | 2008 | 18819625 |
| covalent binding of flavins to rnfg and rnfd in the rnf complex from vibrio cholerae. | enzymes of the rnf family are believed to be bacterial redox-driven ion pumps, coupling an oxidoreduction process to the translocation of na+ across the cell membrane. here we show for the first time that rnf is a flavoprotein, with fmn covalently bound to threonine-175 in rnfg and a second flavin bound to threonine-187 in rnfd. rnf subunits d and g are homologous to subunits b and c of na+-nqr, respectively. each of these na+-nqr subunits includes a conserved s(t)gat motif, with fmn covalently ... | 2008 | 18831535 |
| mechanism of action of zot-derived peptide at-1002, a tight junction regulator and absorption enhancer. | tight junctions (tjs) are intercellular structures that control paracellular permeability and epithelial polarity. it is now accepted that tjs are highly dynamic structures that are regulated in response to exogenous and endogenous stimuli. here, we provide details on the mechanism of action of at-1002, the active domain of vibrio cholerae's second toxin, zonula occludens toxin (zot). at-1002, a hexamer peptide, caused the redistribution of zo-1 away from cell junctions as seen by fluorescence m ... | 2009 | 18832018 |
| riboflavin is an active redox cofactor in the na+-pumping nadh: quinone oxidoreductase (na+-nqr) from vibrio cholerae. | here we present new evidence that riboflavin is present as one of four flavins in na+-nqr. in particular, we present conclusive evidence that the source of the neutral radical is not one of the fmns and that riboflavin is the center that gives rise to the neutral flavosemiquinone. the riboflavin is a bona fide redox cofactor and is likely to be the last redox carrier of the enzyme, from which electrons are donated to quinone. we have constructed a double mutant that lacks both covalently bound f ... | 2008 | 18832377 |
| macrophage migration inhibitory factor plays a role in the regulation of microfold (m) cell-mediated transport in the gut. | it has been shown previously that certain bacteria rapidly (3 h) up-regulated in vivo microfold cell (m cell)-mediated transport of ag across the follicle-associated epithelium of intestinal peyer's patch. our aim was to determine whether soluble mediators secreted following host-bacteria interaction were involved in this event. a combination of proteomics and immunohistochemical analyses was used to identify molecules produced in the gut in response to bacterial challenge in vivo; their effects ... | 2008 | 18832726 |
| a comparison of clinical and immunologic features in children and older patients hospitalized with severe cholera in bangladesh. | : infection with vibrio cholerae induces protection from subsequent severe disease, suggesting that an effective vaccine could be an important preventive strategy. available vaccines provide less protection against cholera than natural infection, particularly in children. | 2008 | 18833030 |
| a novel dna microarray for rapid diagnosis of enteropathogenic bacteria in stool specimens of patients with diarrhea. | a microarray technique for the detection and identification of enteropathogenic bacteria at the species and subspecies levels was developed in this study, and the target bacteria included pathogenic escherichia coli, vibrio cholerae, vibrio parahaemolyticus, salmonella enterica, campylobacter jejuni, shigellae, yersinia enterocolitica, and listeria monocytogenes. the virulence gene of each pathogen was chosen as the amplification target, labeled with a fluorescence dye by multiplex polymerase ch ... | 2008 | 18834908 |
| bacterial enteropathogens of neonates admitted to an urban diarrhoeal hospital in bangladesh. | data on the aetiology of diarrhoea in neonates are scarce, especially from developing countries including bangladesh. a retrospective review of the electronic database of the microbiology laboratory of the international centre for diarrhoeal disease research, bangladesh (icddr,b), was carried out to examine enteropathogens associated with diarrhoea in neonates. stool specimens of the neonates on admission to the dhaka hospital of icddr,b were collected and sent to the laboratory for direct plati ... | 2009 | 18840632 |
| an outbreak of cholera among migrants living in a thai-myanmar border area. | to study epidemiologic characteristics of a cholera outbreak involving mainly myanmar migrants living in overcrowded conditions with poor sanitation in a thai-myanmar border district, in 2007. | 2008 | 18843875 |
| [clone and express ctb-stx2b fusion gene in enterohemrrhagic escherichia coli o157:h7 shigeal toxin 2b subunit and v cholera toxin b subunit and the detection of their immunogenicity]. | to clone and express the fusion gene encoding enterohemrrhagic escherichia coli o157 : h7 (ehec o157 : h7) shigela toxin 2b subunit (stx2b) and vibrio cholera toxin b subunit (ctb) as well as to detect the immunogenicity and gm1-binding ability of fusion protein. | 2008 | 18843998 |
| small molecule-induced allosteric activation of the vibrio cholerae rtx cysteine protease domain. | vibrio cholerae rtx (repeats in toxin) is an actin-disrupting toxin that is autoprocessed by an internal cysteine protease domain (cpd). the rtx cpd is efficiently activated by the eukaryote-specific small molecule inositol hexakisphosphate (insp6), and we present the 2.1 angstrom structure of the rtx cpd in complex with insp6. insp6 binds to a conserved basic cleft that is distant from the protease active site. biochemical and kinetic analyses of cpd mutants indicate that insp6 binding induces ... | 2008 | 18845756 |
| vibrio vulnificus rtx toxin plays an important role in the apoptotic death of human intestinal epithelial cells exposed to vibrio vulnificus. | during vibrio vulnificus infection, v. vulnificus reaches the intestine and then invades the bloodstream by crossing the intestinal mucosal barrier of the host, which results in systemic septicemia. previously, we reported that the rtxa toxin secreted through the rtxe transporter contributes to the cytotoxicity of v. vulnificus against intestinal epithelial cells. here, we used gene mutants of rtxe and rtxa to determine the role that v. vulnificus rtxa toxin plays in the apoptotic death of human ... | 2008 | 18849006 |
| genetic analysis of vibrio cholerae monolayer formation reveals a key role for deltapsi in the transition to permanent attachment. | a bacterial monolayer biofilm is a collection of cells attached to a surface but not to each other. monolayer formation is initiated when a bacterial cell forms a transient attachment to a surface. while some transient attachments are broken, others transition into the permanent attachments that define a monolayer biofilm. in this work, we describe the results of a large-scale, microscopy-based genetic screen for vibrio cholerae mutants that are defective in formation of a monolayer biofilm. thi ... | 2008 | 18849423 |
| flexibility of vibrio cholerae toxt in transcription activation of genes having altered promoter spacing. | cholera, a severe diarrheal disease, is caused by ingestion of the gram-negative bacterium vibrio cholerae. expression of v. cholerae virulence factors is highly regulated at the transcriptional and posttranscriptional levels by a complex network of proteins and small noncoding rnas. the direct activator of transcription of most v. cholerae virulence genes is the toxt protein. toxt binds to a 13-bp sequence, the toxbox, located upstream of genes in its regulon. however, the organization of toxbo ... | 2008 | 18849430 |
| emergence of asiatic vibrio diseases in south america in phase with el niño. | the seventh pandemic of vibrio cholerae unexpectedly reached the coast of peru in 1991, causing an explosive emergence of infections throughout the american continents. the origin and routes of dissemination are as yet unknown. a new vibrio epidemic arose in 1997 in south america (northern chile) when the pandemic clone of vibrio parahaemolyticus was for the fist time detected outside of asia. these 2 cases were concurrent with 2 episodes of el niño. | 2008 | 18854707 |
| the viability of pathogenic intestinal organisms in sea water with special reference to vibrio cholerae. | | 1948 | 18866176 |
| antigenic relationship of brucella and vibrio comma. | | 1948 | 18869808 |
| prevention of virus infection with enzyme of v. cholerae, studies with influenza virus in mice. | | 1948 | 18880594 |
| the mouse-protective test as a means of determining the inhibitory effect of chemicals on vibrio cholera. | | 1948 | 18886540 |
| antigenic relationship of salmonellae to inaba strains of vibrio comma isolated in egypt. | | 1948 | 18889792 |
| effect of copper sulphate on vibrio cholerae. | | 1947 | 18914662 |
| bacteriological examination of stools for vibrio cholerae. | | 1947 | 18917525 |
| aryl acid adenylating enzymes involved in siderophore biosynthesis: fluorescence polarization assay, ligand specificity, and discovery of non-nucleoside inhibitors via high-throughput screening. | the design and synthesis of a fluorescent probe fl-sal-ams 6 based on the tight-binding inhibitor 5'- o-[ n-(salicyl)sulfamoyl]adenosine (sal-ams) is described for the aryl acid adenylating enzymes (aaaes) known as mbta, ybte, ente, vibe, dhbe, and base involved in siderophore biosynthesis from mycobacterium tuberculosis, yersinia pestis, escherichia coli, vibrio cholerae, bacillus subtilis, and acinetobacter baumannii, respectively. the probe was successfully used to develop a fluorescence pola ... | 2008 | 18928302 |
| cyclic amp post-transcriptionally regulates the biosynthesis of a major bacterial autoinducer to modulate the cell density required to activate quorum sensing. | in vibrio cholerae, expression of the quorum sensing regulator hapr is induced by the accumulation of a major autoinducer synthesized by the activity of cqsa. here we show that the camp-camp receptor protein complex regulates cqsa expression at the post-transcriptional level. this conclusion is supported by the analysis of cqsa-lacz fusions, the ectopic expression of cqsa in deltacrp mutants and by northern blot analysis showing that cqsa mrna is unstable in deltacrp and deltacya (adenylate cycl ... | 2008 | 18930049 |
| influence of high pressure on the dimerization of toxr, a protein involved in bacterial signal transduction. | high hydrostatic pressure (hhp) is suggested to influence the structure and function of membranes and/or integrated proteins. we demonstrate for the first time hhp-induced dimer dissociation of membrane proteins in vivo with vibrio cholerae toxr variants in escherichia coli reporter strains carrying ctx::lacz fusions. dimerization ceased at 20 to 50 mpa depending on the nature of the transmembrane segments rather than on changes in the toxr lipid bilayer environment. | 2008 | 18931287 |
| simultaneous detection of enteric bacteria from surface waters by qpcr in comparison with conventional bacterial indicators. | a rapid quantitative polymerase chain reaction (qpcr) method was developed for simultaneous detection of enteric bacteria from surface waters by utilizing a pair of universal primers which targeted four bacteria strains, namely shigella dysenteriae, vibrio cholerae, salmonella typhimurium, and escherichia coli. it was estimated that the qpcr method had a 94% confidence, and a detection limit as 2.7 e. coli cells per sample in undiluted dna extracts. the qpcr method was applied for the bacteriolo ... | 2009 | 18931927 |
| transmission of vibrio cholerae is antagonized by lytic phage and entry into the aquatic environment. | cholera outbreaks are proposed to propagate in explosive cycles powered by hyperinfectious vibrio cholerae and quenched by lytic vibriophage. however, studies to elucidate how these factors affect transmission are lacking because the field experiments are almost intractable. one reason for this is that v. cholerae loses the ability to culture upon transfer to pond water. this phenotype is called the active but non-culturable state (abnc; an alternative term is viable but non-culturable) because ... | 2008 | 18949027 |
| altered pore properties and kinetic changes in mutants of the vibrio cholerae porin ompu. | the electrophysiological technique of patch-clamp was used to characterize the pore properties of site-directed mutants in the vibrio cholerae general diffusion porin ompu. changes in conductance and selectivity were observed, thus confirming the predicted pore location of these residues, based on homology with the escherichia coli porins ompf and ompc. some mutants acquire a weak selectivity for cations, which mirrors the properties of the homologous, deoxycholic acid sensitive, ompt porin of v ... | 2008 | 18949626 |
| murine antibody responses following systemic or mucosal immunization with viable or inactivated vibrio cholerae. | protocols are described for the induction of strong, consistent serum and mucosal antibody responses to vibrio cholerae o1 or o139 lipopolysaccharide (lps) following intranasal or oral immunization of adult mice with viable or formalin-killed bacteria. a simplified two-dose schedule for intranasal immunization has been identified, whereby viable bacteria elicit strong serum responses and, most importantly, also induce significant, sustained intestinal iga responses. using higher doses of bacteri ... | 2008 | 18951939 |
| distinct sensory pathways in vibrio cholerae el tor and classical biotypes modulate cyclic dimeric gmp levels to control biofilm formation. | quorum sensing (qs), or cell-cell communication in bacteria, is achieved through the production and subsequent response to the accumulation of extracellular signal molecules called autoinducers (ais). to identify ai-regulated target genes in vibrio cholerae el tor (v. cholerae(el)), the strain responsible for the current cholera pandemic, luciferase expression was assayed in an ai(-) strain carrying a random lux transcriptional reporter library in the presence and absence of exogenously added ai ... | 2009 | 18952786 |
| analysis of immune responses and serological cross reactivities among vibrio cholerae o1, shigella flexneri 2a and haemophilus influenzae b. | antigenic determinants expressed on the bacterial cell surface are of importance in the serological characterization and microbiological diagnosis. the bacterial strains carrying these identical or similar antigenic epitopes might react with antibodies produced against other strains. in this study, strong immunogenicity and antigenic cross reactivity were demonstrated among v. cholerae o1, s. flexnerii 2a and h. influenzae b surface components. the enzyme linked immunosorbent assay (elisa) resul ... | 2008 | 18954564 |
| repeatability and pattern recognition of bacterial fatty acid profiles generated by direct mass spectrometric analysis of in situ thermal hydrolysis/methylation of whole cells. | direct ci mass spectrometry profiling of fatty acid methyl esters (fames) from in situ thermal hydrolysis/methylation (thm) of whole bacterial cells with tetramethylammonium hydroxide (tmah) has been demonstrated as a potential method for real time and fieldable detection/identification of microorganisms. bacillus anthracis (ames), yersinia pestis (nair. kenya), vibrio cholerae (e1 tor), brucella melitensis (abortus wild) and francisella tularensis (lvs vaccine) were profiled by this method duri ... | 2003 | 18968943 |
| waterfowl: the missing link in epidemic and pandemic cholera dissemination? | | 2008 | 18974827 |
| pattern classification of phylogeny signals. | in this paper we propose the minimum entropy clustering (mec) method for clustering genes based on their phylogenetic signals. this entropy based method will cluster two genes together when their concatenation can decrease the entropy. an integral feature of mec is that it chooses the number of clusters automatically, which is a major advantage over the other methods. our simulation results show that this method is quite successful in clustering genes with a common phylogeny. | 2008 | 18976226 |
| reflected polarization guides chironomid females to oviposition sites. | chironomids (diptera: chironomidae; non-biting midges) are known to be carriers of the vibrio cholerae bacterium, responsible for the fatal cholera disease in humans. it was recently discovered that chironomid females choose their oviposition site by a visual cue. in this study, we test the hypothesis that this visual cue is the linear polarization of light reflected from the water surface. we conducted two multiple choice field experiments using egg traps with different light intensities and po ... | 2008 | 18978217 |
| vibrio cholerae: model organism to study bacterial pathogenesis--interview. | | 2007 | 18979011 |
| shifting prevalence of major diarrheal pathogens in patients seeking hospital care during floods in 1998, 2004, and 2007 in dhaka, bangladesh. | bangladesh experienced severe flooding and diarrheal epidemics in 2007. we compared flood data from 2007 with 2004 and 1998 for diarrheal patients attending the icddr,b hospital in dhaka. in 2007, vibrio cholerae o1 (33%), rotavirus (12%), and enterotoxigenic escherichia coli (etec) (12%) were most prevalent. more severe dehydration was seen in 2007 compared with 2004 and 1998 (p < 0.001). in 2007, v. cholerae o1 inaba (52%) and ogawa (48%) were seen, whereas in 2004 and 1998 it was primarily in ... | 2008 | 18981509 |
| prophylactic immunisation against traveller's diarrhoea caused by enterotoxin-forming strains of escherichia coli and against cholera: does it make sense and for whom? | traveller's diarrhoea (td) constitutes the most common disease relevant to travel medicine with etec as the leading causative pathogen. cholera is the most serious, but very rare form of td. etec and cholera share pathogenic mechanisms by producing a toxin that has an 80% amino acid homology. a consensus of german-speaking experts sees the indication to use the whole cell/b subunit oral cholera vaccine (wc--bs) if cholera is a risk for aid workers or travellers with an anticipated threat of chol ... | 2008 | 18984481 |
| detection of escherichia coli, salmonella spp., shigella spp., yersinia enterocolitica, vibrio cholerae, and campylobacter spp. enteropathogens by 3-reaction multiplex polymerase chain reaction. | the magnitude of bacterial diarrhea in developing countries is largely unknown because affordable detection methods are not available. we have developed a polymerase chain reaction (pcr)-based assay for use in areas with limited resources to screen for diarrheogenic strains from clinical isolates. to simplify the assay and minimize reagents, our method implemented the use of plasmids rather than bacteria as template controls and the use of bacterial suspensions or crude dna preparations rather t ... | 2009 | 18990527 |
| antimicrobial resistance and molecular characterization of vibrio cholerae o1 during the 2004 and 2005 outbreak of cholera in cameroon. | there was an outbreak of cholera in cameroon during 2004 and 2005; the epidemic began in douala in january 2004 and spread throughout the south of the country. the world health organization (who) reported 8005 cases in 2004 and 2847 cases in 2005. five hundred eighty-nine stool samples were received in the pasteur centre of cameroon and 352 were microbiologically confirmed to be positive for vibrio cholerae o1. isolated strains were tested for their antimicrobial susceptibilities. all the strain ... | 2009 | 18991540 |
| a proteoliposome based formulation administered by the nasal route produces vibriocidal antibodies against el tor ogawa vibrio cholerae o1 in balb/c mice. | a vaccine candidate against the enteric pathogen vibrio cholerae was developed based on a proteoliposome (pl) formulation using a wild type strain c7258, v. cholerae o1, el tor ogawa as part of strategy to develop a combined formulation against enteric diseases preventable by the stimulation of the mucosal immune system. a detergent extraction method was applied to obtain the pl. scanning electron microscopy and molecular exclusion chromatography showed the presence of two pl populations. photon ... | 2009 | 18996426 |
| characterization of vibrio cholerae outer membrane vesicles as a candidate vaccine for cholera. | outer membrane vesicles (omvs) offer a new approach for an effective cholera vaccine. we recently demonstrated that immunization of female mice with omvs induces a long-lasting immune response and results in protection of their neonatal offspring from vibrio cholerae intestinal colonization. this study investigates the induced protective immunity observed after immunization with omvs in more detail. analysis of the stomach contents and sera of the neonates revealed significant amounts of anti-om ... | 2009 | 19001078 |
| environmental signatures associated with cholera epidemics. | the causative agent of cholera, vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of v. cholerae, influencing the transmission of the disease in those regions of the world where the human population relies on untreated water as a source of drinking water. in this study, the ... | 2008 | 19001267 |
| development of isothermal taqman assays for detection of biothreat organisms. | taqman probe (dual-labeled dna probe)-based real-time detection, one of the most sensitive and specific fluorescent detection methods, has been widely utilized in conjunction with polymerase chain reaction (pcr). helicase-dependent amplification (hda) is an isothermal amplification technology that has a similar reaction scheme to pcr, but replaces thermocycling with a helicase capable of unwinding a dna duplex. here we describe a novel isothermal real-time detection method (hda-taqman) that comb ... | 2008 | 19007339 |
| complete sequence of plasmid pmp1 from the marine environmental vibrio vulnificus and location of its replication origin. | a novel cryptic plasmid, pmp1, from an environmental vibrio vulnificus mp-4 isolated from mai po nature reserve in hong kong, has been characterized. the 7.6-kb plasmid had guanine-cytosine content of 40.03% and encoded four open reading frames (orfs) with >100 amino acids. the predicted protein of orf1 contained 478 amino acids showing 29% identity and 50% similarity over 309 amino acids to the integrase of vibrio cholerae phage vp2. orf2 encoded a putative protein of 596 amino acids, which wer ... | 2009 | 19009320 |
| effect of the efflux inhibitors 1-(1-naphthylmethyl)-piperazine and phenyl-arginine-beta-naphthylamide on antimicrobial susceptibility and virulence factor production in vibrio cholerae. | the aim of the study was to test the hypothesis that the efflux pump inhibitors (epis) 1-(1-naphthylmethyl)-piperazine (nmp) and phenyl-arginine-beta-naphthylamide (pabetan) can inhibit the vibrio cholerae resistance-nodulation-division (rnd) family efflux systems, and thereby render v. cholerae susceptible to antimicrobial agents and inhibit the production of the virulence factors cholera toxin (ct) and the toxin coregulated pilus (tcp). | 2009 | 19010827 |
| diversity and seasonality of bioluminescent vibrio cholerae populations in chesapeake bay. | association of luminescence with phenotypic and genotypic traits and with environmental parameters was determined for 278 strains of vibrio cholerae isolated from the chesapeake bay during 1998 to 2000. three clusters of luminescent strains (a, b, and c) and two nonluminescent clusters (x and y) were identified among 180 clonal types. v. cholerae o1 strains isolated during pandemics and endemic cholera in the ganges delta were related to cluster y. heat-stable enterotoxin (encoded by stn) and th ... | 2009 | 19011071 |
| anaerobic growth promotes synthesis of colonization factors encoded at the vibrio pathogenicity island in vibrio cholerae el tor. | pathogenesis of the facultative anaerobe vibrio cholerae takes place at the gut under low oxygen concentrations. to identify proteins which change their expression level in response to oxygen availability, proteomes of v. cholerae el tor c7258 grown in aerobiosis, microaerobiosis and anaerobiosis were compared by two-dimensional electrophoresis. twenty-six differentially expressed proteins were identified which are involved in several processes including iron acquisition, alanine metabolism, pur ... | 2009 | 19015025 |
| connecting actin monomers by iso-peptide bond is a toxicity mechanism of the vibrio cholerae martx toxin. | the gram-negative bacterium vibrio cholerae is the causative agent of a severe diarrheal disease that afflicts three to five million persons annually, causing up to 200,000 deaths. nearly all v. cholerae strains produce a large multifunctional-autoprocessing rtx toxin (martx(vc)), which contributes significantly to the pathogenesis of cholera in model systems. the actin cross-linking domain (acd) of martx(vc) directly catalyzes a covalent cross-linking of monomeric g-actin into oligomeric chains ... | 2008 | 19015515 |
| the bicarbonate transporter is essential for bacillus anthracis lethality. | in the pathogenic bacterium bacillus anthracis, virulence requires induced expression of the anthrax toxin and capsule genes. elevated co2/bicarbonate levels, an indicator of the host environment, provide a signal ex vivo to increase expression of virulence factors, but the mechanism underlying induction and its relevance in vivo are unknown. we identified a previously uncharacterized abc transporter (bas2714-12) similar to bicarbonate transporters in photosynthetic cyanobacteria, which is essen ... | 2008 | 19023421 |
| 'gastro' of mirpur khas (sindh) is resolved. | diarrhoeal disease is a common cause of major public health concern in many parts of the world including pakistan. | 2008 | 19024176 |