| steps in the development of a vibrio cholerae el tor biofilm. | we report that, in a simple, static culture system, wild-type vibrio cholerae el tor forms a three-dimensional biofilm with characteristic water channels and pillars of bacteria. furthermore, we have isolated and characterized transposon insertion mutants of v. cholerae that are defective in biofilm development. the transposons were localized to genes involved in (i) the biosynthesis and secretion of the mannose-sensitive haemagglutinin type iv pilus (msha); (ii) the synthesis of exopolysacchari ... | 1999 | 10564499 |
| a retroelement in vibrio cholerae. | | 1999 | 10564503 |
| the cada gene of vibrio cholerae is induced during infection and plays a role in acid tolerance. | vibrio cholerae is a facultative pathogen of humans that must survive exposure to inorganic and organic acids in the stomach and small intestine. to learn more about the mechanisms by which this pathogen colonizes the intestinal tract, we used a recombinase gene fusion reporter to identify transcripts induced during infection in an adult rabbit model of cholera. one of the genes identified was cada, which encodes an inducible lysine decarboxylase. cada was also induced during infections of the s ... | 1999 | 10564522 |
| intracellular replication of choleraphage straight phi92. | the broad host range choleraphage straight phi92 contains a linear double-stranded dna molecule of 68 kilobase (kb) pairs with 3' overhang cohesive ends. following infection with phage straight phi92, the host macromolecular synthesis is shut off within the first 5 min, and synthesis of phage-specific dna is detectable after 7 min of infection. at early times during infection, phage dna is replicated in circular form and the synthesis is membrane associated. the closed circular form serves as th ... | 1999 | 10567842 |
| randomized, double-blind, placebo-controlled, multicentered trial of the efficacy of a single dose of live oral cholera vaccine cvd 103-hgr in preventing cholera following challenge with vibrio cholerae o1 el tor inaba three months after vaccination. | cvd 103-hgr is a live oral cholera vaccine strain constructed by deleting 94% of the gene for the enzymatically active a subunit of cholera toxin from classical inaba vibrio cholerae o1 569b; the strain also contains a mercury resistance gene as an identifying marker. this vaccine was well tolerated and immunogenic in double-blind, controlled studies and was protective in open-label studies of volunteers challenged with v. cholerae o1. a randomized, double-blind, placebo-controlled, multicenter ... | 1999 | 10569747 |
| validation and characterization of a human volunteer challenge model for cholera by using frozen bacteria of the new vibrio cholerae epidemic serotype, o139. | until recently, all epidemic strains of vibrio cholerae were of the o1 serotype. current epidemics have also been caused by a new serotype, vibrio cholerae o139. although the pathogenesis and clinical features of o139 cholera are similar to those of o1 cholera, immunity to serotype o1 does not confer immunity to serotype o139. therefore, prior to beginning vaccine efficacy studies, we sought to validate the use of a large standardized frozen inoculum of virulent v. cholerae o139 4260b for use in ... | 1999 | 10569748 |
| the role of recombination and mutation in 16s-23s rdna spacer rearrangements. | the intragenomic heterogeneity of the bacterial intergenic (16s-23s rdna) spacer region (isr) was analysed from the following species in which sequences for the complete rrna operon (rrn) set have been determined (rrn number): enterococcus faecalis (6) and e. faecium (6), bacillus subtilis (10), staphylococcus aureus (9), vibrio cholerae (4), haemophilus influenzae (6) and escherichia coli (7). it was found that some spacer sequence blocks were highly conserved between operons of a genome, where ... | 1999 | 10571000 |
| microbiological quality and safety of ready-to-eat street-vended foods in johannesburg, south africa. | fifty-one ready-to-eat street foods, 18 dishwater, and 18 surface swab samples were collected from six vendors in johannesburg, south africa. food temperatures were recorded at the time of sampling. standard methods were used to determine aerobic plate counts (apcs), spore counts (scs), and enterobacteriaceae counts (ecs) for food samples as well as coliform counts (ccs) for water and swab samples. in addition, petrifilm escherichia coli count (pc) plates were used for the enumeration of colifor ... | 1999 | 10571317 |
| molecular characterization of vibrio cholerae o1 and non-o1 from human and environmental sources in malaysia. | a total of 31 strains of vibrio cholerae o1 (10 from outbreak cases and 7 from surface water) and non-o1 (4 from clinical and 10 from surface water sources) isolated between 1993 and 1997 were examined with respect to presence of cholera enterotoxin (ct) gene by pcr-based assays, resistance to antibiotics, plasmid profiles and random amplified polymorphic dna (rapd) analysis. all were resistant to 9 or more of the 17 antibiotics tested. identical antibiotic resistance patterns of the isolates ma ... | 1999 | 10579441 |
| expression of vibrio cholerae zonula occludens toxin and analysis of its subcellular localization. | vibrio cholerae elaborates zonula occludens toxin (zot), a protein that increases the permeability of small intestinal mucosa by opening intercellular tight junctions. the zot gene is located, together with the genes encoding ct and ace enterotoxins, within the genome of v. cholerae filamentous phage ctxsmall ef, cyrillic. interestingly, zot appears to be structurally and functionally related to the gene i product of other filamentous phages and it has been shown to be required for ctxsmall ef, ... | 1999 | 10588910 |
| survey on the distribution of vibrionaceae at the seaport areas in taiwan, 1991-1994. | a monthly survey on the distribution of human-pathogenic vibrionaceae of the seawater from five principal harbors in taiwan was conducted by national quarantine service from july, 1991 to february, 1994. of the total 1,167 vibrionaceae isolates, strains of vibrio alginolyticus (449 strains) were the most frequently isolated, followed by vibrio parahaemolyticus (262) , aeromonas hydrophila (153), vibrio cholerae non-o1 (86), and vibrio vulnificus (67). none of vibrio cholerae o1 was isolated. the ... | 1996 | 10592802 |
| a multifunctional atp-binding cassette transporter system from vibrio cholerae transports vibriobactin and enterobactin. | vibrio cholerae uses the catechol siderophore vibriobactin for iron transport under iron-limiting conditions. we have identified genes for vibriobactin transport and mapped them within the vibriobactin biosynthetic gene cluster. within this genetic region we have identified four genes, viup, viud, viug and viuc, whose protein products have homology to the periplasmic binding protein, the two integral cytoplasmic membrane proteins, and the atpase component, respectively, of other iron transport s ... | 1999 | 10601218 |
| characterization of adhesive epitopes with the omps display system. | omps is an outer membrane protein of vibrio cholerae where it forms trimeric pores that function in the uptake of maltose and maltodextrins. based on sequence similarity to lamb proteins, a model of omps folding in the outer membrane has been constructed. according to this model, omps contains 18 transmembrane beta-strands and nine surface-accessible loops. adhesive epitopes can, when inserted into surface-accessible loop 4 (l4) and expressed in escherichia coli, retain their functional characte ... | 2000 | 10601863 |
| development of a deltaglna balanced lethal plasmid system for expression of heterologous antigens by attenuated vaccine vector strains of vibrio cholerae. | we have previously shown that more prominent immune responses are induced to antigens expressed from multicopy plasmids in live attenuated vaccine vector strains of vibrio cholerae than to antigens expressed from single-copy genes on the v. cholerae chromosome. here, we report the construction of a deltaglna derivative of v. cholerae vaccine strain peru2. this mutant strain, peru2deltaglna, is unable to grow on medium that does not contain glutamine; this growth deficiency is complemented by pke ... | 2000 | 10603391 |
| molecular approaches for safer and stronger vaccines. | progress in molecular biology and biotechnology is making possible the development of new vaccines or the improvement of already existing ones. recombinant dna technology, genetic attenuation of bacterial and viral pathogens and their use as vectors for heterologous proteins, expression of microbial antigens in transgenic edible plants, and naked nucleic acid technology represent the most popular approaches hitherto adopted. a successful biotechnological approach to the development of new and im ... | 1999 | 10603647 |
| aeromonas-associated diarrhoea in bangladeshi children: clinical and epidemiological characteristics. | we studied the clinical and epidemiological features associated with aeromonas diarrhoea by a hospital survey of 7,398 children under 5 years of age presenting with diarrhoea. the data were actually based upon two cohorts from this survey, the majority of the data being identified from 405 (5.5%) in whom aeromonas was the sole enteric pathogen. aeromonas caviae was the most prevalent species, accounting for 32% (129/405) of all isolates. eighty-three per cent of children with aeromonas-associate ... | 1999 | 10605516 |
| n-terminus of mature heat-labile enterotoxin chain b is critical for its extracellular secretion in vibrio cholerae. | the effects of addition of a few amino acids to the amino- and carboxy-terminal regions of the mature portion of the heat-labile enterotoxin chain b (ltb) of escherichia coli on protein export, secretion and assembly were investigated. in e. coli, ltb (secretory protein) with or without the extension at the n- or c-terminus accumulated in the periplasmic fraction. for vibrio cholerae, ltb with the extension at the c-terminus was exported to the periplasm followed by secretion to the extracellula ... | 1999 | 10606749 |
| solution conformation and dynamics of the trisaccharide fragments of the o-antigen of vibrio cholerae o1, serotypes inaba and ogawa. | the conformational behavior of the trisaccharide fragments of the ogawa and inaba vibrio cholera serotypes has been studied using nmr and molecular dynamics (md). the obtained results indicate that there are no significant differences in the major conformation and in the extent of motion of the glycosidic torsions of these molecules. the differences in biological activity are probably not due to conformational effects but to van der waals and/or hydrogen bonding interactions between the antigens ... | 1999 | 10612004 |
| regulation and temporal expression patterns of vibrio cholerae virulence genes during infection. | the temporal expression patterns of the critical vibrio cholerae virulence genes, tcpa and ctxa, were determined during infection using a recombinase reporter. tcpa was induced biphasically in two temporally and spatially separable events in the small intestine, whereas ctxa was induced monophasically only after, and remarkably, dependent upon, tcpa expression; however, this dependence was not observed during in vitro growth. the requirements of the virulence regulators, toxr, tcpp, and toxt, fo ... | 1999 | 10612398 |
| diversity in the arrangement of the ctx prophages in classical strains of vibrio cholerae o1. | this study reports the results of a molecular analysis of the ctx prophages in classical biotype strains of vibrio cholerae o1 of clinical origin isolated between 1970 and 1979 in india. all strains were sensitive to group iv classical phage and polymyxin b but resistant to group 5 el tor phage. these phenotypic traits are consistent to that exhibited by the classical biotype. pcr studies reconfirmed their biotype assignment and showed the presence of intact ctx prophages and the presence of the ... | 2000 | 10612727 |
| inorganic polyphosphate is required for motility of bacterial pathogens. | the ppk gene encodes polyphosphate kinase (ppk), the principal enzyme in many bacteria responsible for the synthesis of inorganic polyphosphate (polyp) from atp. a null mutation in the ppk gene of six bacterial pathogens renders them greatly impaired in motility on semisolid agar plates; this defect can be corrected by the introduction of ppk gene in trans. in view of the fact that the motility of pathogens is essential to invade and establish systemic infections in host cells, this impairment i ... | 2000 | 10613886 |
| studies on vaccines against cholera. synthesis of neoglycoconjugates from the hexasaccharide determinant of vibrio cholerae o:1, serotype ogawa, by single-point attachment or by attachment of the hapten in the form of clusters. | the terminal hexasaccharide of the o-antigen of vibrio cholerae o:1, serotype ogawa, has been synthesized in the form of a glycoside whose aglycon (linker) allows conjugation to carrier proteins by reductive amination. the conjugate obtained from direct, single-point attachment of the linker-equipped hapten to chicken serum albumin (csa) contained seven hapten residues/csa. a neoglycoconjugate containing the carbohydrate antigen in the form of clusters was obtained using, as a hapten subcarrier, ... | 1999 | 10614066 |
| affinity purification and partial characterization of the zonulin/zonula occludens toxin (zot) receptor from human brain. | the intercellular tight junctions (tjs) of endothelial cells represent the limiting structure for the permeability of the blood-brain barrier (bbb). although the bbb has been recognized as being the interface between the bloodstream and the brain, little is known about its regulation. zonulin and its prokaryotic analogue, zonula occludens toxin (zot) elaborated by vibrio cholerae, both modulate intercellular tjs by binding to a specific surface receptor with subsequent activation of an intracell ... | 2000 | 10617135 |
| development and evaluation of a phage typing scheme for vibrio cholerae o139. | the scenario of cholera that existed previously changed in 1992 and 1993 with the emergence of toxigenic vibrio cholerae o139 in india. the genesis of the new serogroup formed the impetus to search for o139 phages in and around the country. a total of five newly isolated phages lytic to v. cholerae o139 strains were used for the development of this phage typing scheme. these phages differed from each other and also differed from the existing o1 phages in their lytic patterns, morphologies, restr ... | 2000 | 10618061 |
| pulsed-field gel electrophoresis-based molecular comparison of vibrio cholerae o1 isolates from domestic and imported cases of cholera in japan. | sixty-seven vibrio cholerae o1 el tor isolates (36 domestic and 31 imported) were classified into 19 subtypes by noti- and sfii-digested pulsed-field gel electrophoresis. twenty-five of 36 domestic and 4 imported isolates were assigned to a noti-a1-sfii-a1 subtype, suggesting that this pulse type is widely distributed in asia and japan. | 2000 | 10618132 |
| genetic diversity of vibrio cholerae in chesapeake bay determined by amplified fragment length polymorphism fingerprinting. | vibrio cholerae is indigenous to the aquatic environment, and serotype non-o1 strains are readily isolated from coastal waters. however, in comparison with intensive studies of the o1 group, relatively little effort has been made to analyze the population structure and molecular evolution of non-o1 v. cholerae. in this study, high-resolution genomic dna fingerprinting, amplified fragment length polymorphism (aflp), was used to characterize the temporal and spatial genetic diversity of 67 v. chol ... | 2000 | 10618215 |
| genetic diversity of clinical and environmental isolates of vibrio cholerae determined by amplified fragment length polymorphism fingerprinting. | vibrio cholerae, the causative agent of major epidemics of diarrheal disease in bangladesh, south america, southeastern asia, and africa, was isolated from clinical samples and from aquatic environments during and between epidemics over the past 20 years. to determine the evolutionary relationships and molecular diversity of these strains, in order to understand sources, origin, and epidemiology, a novel dna fingerprinting technique, amplified fragment length polymorphism (aflp), was employed. t ... | 2000 | 10618216 |
| [genetic control of vibrio cholerae pathogenicity: the temperate filamentous phage ctx, coding for cholera toxin and the "island of pathogenicity"]. | reviews modern data on the genetic control of the key factors of vibrio cholerae pathogenicity: cholera toxin and toxin-coregulated adhesion pili. pays special attention to the temperate filamentous ctx bacteriophage, whose genome contains structural genes of cholera toxin, and the "pathogenicity island" carrying tcp genes responsible for the most important factor of the human small intestine colonization with v. cholerae. discusses the mechanism of coordinated regulation of the activity of the ... | 1999 | 10621931 |
| the type 4 prepilin peptidases comprise a novel family of aspartic acid proteases. | type 4 prepilins or prepilin-like-proteins are secreted by a wide range of bacterial species and are required for a variety of functions including type 4 pilus formation, toxin and other enzyme secretion, gene transfer, and biofilm formation. a distinctive feature of these proteins is the presence of a specialized leader peptide that is cleaved off by a cognate membrane-bound type 4 prepilin peptidase (tfpp) during the process of secretion. in this report we show that the tfpps represent a novel ... | 2000 | 10625704 |
| a region of the transmembrane regulatory protein toxr that tethers the transcriptional activation domain to the cytoplasmic membrane displays wide divergence among vibrio species. | the virulence regulatory protein toxr of vibrio cholerae is unique in that it contains a cytoplasmic dna-binding-transcriptional activation domain, a transmembrane domain, and a periplasmic domain. although toxr and other transmembrane transcriptional activators have been discovered in other bacteria, little is known about their mechanism of activation. utilizing degenerate oligonucleotides and pcr, we have amplified internal toxr gene sequences from seven vibrio and photobacterium species and s ... | 2000 | 10629204 |
| molecular cloning and transcriptional regulation of ompt, a toxr-repressed gene in vibrio cholerae. | in pathogenic vibrio cholerae, at least 17 genes are co-ordinately regulated by toxr. most of these genes, including those that encode cholera toxin (ct), toxin co-regulated pilus (tcp), accessory colonization factor (acf) and ompu, are positively regulated. ompt is the only identified protein under negative regulation of toxr. to understand the molecular mechanism by which toxr represses ompt expression, we cloned ompt and characterized the ompt promoter and its interaction with toxr. sequence ... | 2000 | 10632889 |
| two regions of epsl involved in species-specific protein-protein interactions with epse and epsm of the general secretion pathway in vibrio cholerae. | extracellular secretion of proteins via the type ii or general secretion pathway in gram-negative bacteria requires the assistance of at least 12 gene products that are thought to form a complex apparatus through which secreted proteins are translocated. although this apparatus is specifically required only for the outer membrane translocation step during transport across the bacterial cell envelope, it is believed to span both membranes. the epse, epsl, and epsm proteins of the type ii apparatu ... | 2000 | 10633109 |
| an endogenous retrovirus and exogenous scrapie in a mouse model of aging. | as we enter the post-genomic era, there is an increasing need for accurate methods of identifying host and pathogen factors that contribute to bacterial, viral and fungal disease. in addition, there is a requirement for fast and precise techniques to evaluate potential therapies for the prevention of infectious diseases. the development of useful and cost-effective model systems will be crucial in advancing our knowledge of all aspects of microbial pathogenesis. in this series, we will learn of ... | 2000 | 10637643 |
| the synthesis and evaluation of novel sialic acid analogues bound to matrices for the purification of sialic acid-recognising proteins. | a novel n-acetylneuraminic acid analogue, 2-s-(5'-aminopentyl) 5-acetamido-3,5-dideoxy-2-thio-d-glycero-alpha-d-galacto-2- nonulopyranosidonic acid, as well as the thiosialoside 2-s-(2'-aminoethyl) 5-acetamido-3,5-dideoxy-2-thio-d-glycero-alpha-d-galacto-2- nonulopyranosidonic acid, have been synthesised and successfully coupled to cnbr-activated sepharose 4b through the terminal amino group. the resultant affinity resins have proved efficient in purifying a number of sialic acid-recognising pro ... | 1999 | 10637984 |
| cloning and characterization of vuua, a gene encoding the vibrio vulnificus ferric vulnibactin receptor. | the ability of vibrio vulnificus to acquire iron from the host has been shown to correlate with virulence. many iron transport genes are regulated by iron, and in v. vulnificus, transcriptional regulation by iron depends on the fur gene. the n-terminal amino acid sequence of a 72-kda iron-regulated outer membrane protein purified from a v. vulnificus fur mutant had 53% homology with the first 15 amino acids of the mature protein of the vibrio cholerae vibriobactin receptor, viua. in this report, ... | 2000 | 10639413 |
| molecular characterization of a new variant of toxin-coregulated pilus protein (tcpa) in a toxigenic non-o1/non-o139 strain of vibrio cholerae. | a toxigenic non-o1/non-o139 strain of vibrio cholerae (10259) was found to contain a new variant of the toxin-coregulated pilus (tcp) protein gene (tcpa) as determined by pcr and southern hybridization experiments. nucleotide sequence analysis data of the new tcpa gene in strain 10259 (o53) showed it to be about 74 and 72% identical to those of o1 classical and el tor biotype strains, respectively. the predicted amino acid sequence of the 10259 tcpa protein shared about 81 and 78% identity with ... | 2000 | 10639469 |
| optimizing the germfree mouse model for in vivo evaluation of oral vibrio cholerae vaccine and vector strains. | the germfree mouse model of vibrio cholerae infection can be used to judge immune responses to v. cholerae vaccine and vector strains. in the original model, a single oral inoculation was administered on day 0, a booster oral inoculation was administered on day 14, and immune responses were analyzed with samples collected on day 28. unfortunately, immune responses in this model frequently were low level, and interanimal variability occurred. in order to improve this model, we evaluated various p ... | 2000 | 10639476 |
| use of lambda phage s and r gene products in an inducible lysis system for vibrio cholerae- and salmonella enterica serovar typhimurium-based dna vaccine delivery systems. | novel methods for adapting dna vaccine technology to the prevention of mucosal diseases are greatly needed. here we show that regulated expression of phage lambda lysis genes s and r causes dramatic lysis of both vibrio cholerae and salmonella enterica serovar typhimurium cells with concomitant release of plasmid dna into the surrounding media. we also used single and double dnase mutant strains to show that secreted v. cholerae dnases can adversely affect the integrity of dna molecules released ... | 2000 | 10639478 |
| cholera vaccine inactivated oral. | | 1999 | 10641223 |
| outbreak of cholera in arid zone of bikaner. | bikaner being an arid zone was more or less unaffected by cholera until 1994 when an outbreak of clinical cholera occurred. we isolated 64 vibrio cholerae strains out of 475 stool samples received (isolation rate 13.47%). all the vibrio strains belonged to biotype el tor serotype ogawa. low isolation rate was probably related to the poor transportation and medical facilities available at remote areas and indiscriminate and irrational use of antibiotics. the antimicrobial susceptibility testing o ... | 1999 | 10645099 |
| emergence of nalidixic acid resistant vibrio cholerae o-1 in karachi. | | 1999 | 10647244 |
| lowering of the electric potential on the membrane as a possible signal modulating the expression of virulence factors in vibrio cholerae. | | 2000 | 10652109 |
| pandemic spread of an o3:k6 clone of vibrio parahaemolyticus and emergence of related strains evidenced by arbitrarily primed pcr and toxrs sequence analyses. | vibrio parahaemolyticus o3:k6 strains responsible for the increase in the number of cases of diarrhea in calcutta, india, beginning in february 1996 and those isolated from southeast asian travelers beginning in 1995 were shown to belong to a unique clone characterized by possession of the tdh gene but not the trh gene and by unique arbitrarily primed pcr (ap-pcr) profiles (j. okuda, m. ishibashi, e. hayakawa, t. nishino, y. takeda, a. k. mukhopadhyay, s. garg, s. k. bhattacharya, g. b. nair, an ... | 2000 | 10655349 |
| helicobacter pylori and epidemic vibrio cholerae o1 infection in peru. | in a cross-sectional study of the 1991 peruvian cholera epidemic, vibrio cholerae o1 infection was associated with helicobacter pylori infection, particularly in young children. these data support the hypothesis that hypochlorhydria induced by h. pylori is important in the pathogenesis of diarrhoeal disease. | 2000 | 10665561 |
| [isolation of vibrio cholerae non 01 from patients with acute gastroenteritis]. | it was assay by biochemical and immunological tests, strains of v. cholerae non-01 non-0139 isolated from two patients of the province of córdoba, argentina. they showed episodes of acute gastroenteritis. strains non-01 non-0139 were isolated from water samples ingested by patients. we conclude that strains identified from patients would have the source from contaminated environmental water by v. cholerae. | 1999 | 10668268 |
| super-integrons. | integrons represent the primary mechanism for antibiotic resistance gene capture and dissemination among gram-negative bacteria. the recent finding of super-integron (si) structures in the genomes of several bacterial species has expanded their role in genome evolution. the vibrio cholerae superintegron is gathered in a single chromosomal super-structure harbouring hundreds of gene cassettes. the encoded functions, when identifiable, are linked to adaptations extending beyond antibiotic resistan ... | 1999 | 10673003 |
| safety, immunogenicity, and lot stability of the whole cell/recombinant b subunit (wc/rctb) cholera vaccine in peruvian adults and children. | to assess the safety, immunogenicity, and lot stability of the whole cell/recombinant b subunit cholera vaccine, 2 lots manufactured in june 1991 and february 1992 were tested in january 1995. two oral doses of vaccine or placebo given 2 weeks apart were given with buffer to 216 peruvian adults and children. symptoms were elicited for 3 days after each dose. serum and plasma specimens obtained from each volunteer before vaccination and 10-14 days after the second dose were tested for vibriocidal ... | 1999 | 10674661 |
| climate and infectious disease: use of remote sensing for detection of vibrio cholerae by indirect measurement. | it has long been known that cholera outbreaks can be initiated when vibrio cholerae, the bacterium that causes cholera, is present in drinking water in sufficient numbers to constitute an infective dose, if ingested by humans. outbreaks associated with drinking or bathing in unpurified river or brackish water may directly or indirectly depend on such conditions as water temperature, nutrient concentration, and plankton production that may be favorable for growth and reproduction of the bacterium ... | 2000 | 10677480 |
| in vitro and in vivo analyses of constitutive and in vivo-induced promoters in attenuated vaccine and vector strains of vibrio cholerae. | the optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. we therefore introduced plasmids expressing the b subunit of cholera toxin (ctxb) under the control of a number of promoters into v. cholerae vaccine strain peru2. we evaluated the tac promoter, which is constitutively expressed in v. cholerae, as well as the ... | 2000 | 10678922 |
| iha: a novel escherichia coli o157:h7 adherence-conferring molecule encoded on a recently acquired chromosomal island of conserved structure. | the mechanisms used by shiga toxin (stx)-producing escherichia coli to adhere to epithelial cells are incompletely understood. two cosmids from an e. coli o157:h7 dna library contain an adherence-conferring chromosomal gene encoding a protein similar to iron-regulated gene a (irga) of vibrio cholerae (m. b. goldberg, s. a. boyko, j. r. butterton, j. a. stoebner, s. m. payne, and s. b. calderwood, mol. microbiol. 6:2407-2418, 1992). we have termed the product of this gene the irga homologue adhes ... | 2000 | 10678953 |
| the virulence regulatory protein toxr mediates enhanced bile resistance in vibrio cholerae and other pathogenic vibrio species. | the transmembrane regulatory protein toxr is required for expression of virulence factors in the human diarrheal pathogen vibrio cholerae, including cholera toxin (ct) and the toxin coregulated pilus (tcp). toxr is necessary for transcription of the gene encoding a second regulatory protein, toxt, which is the direct transcriptional activator of ct and tcp genes. however, toxr, independent of toxt, directly activates and represses transcription of the outer membrane porins ompu and ompt, respect ... | 2000 | 10678965 |
| infectious ctxphi and the vibrio pathogenicity island prophage in vibrio mimicus: evidence for recent horizontal transfer between v. mimicus and v. cholerae. | vibrio mimicus differs from vibrio cholerae in a number of genotypic and phenotypic traits but like v. cholerae can give rise to diarrheal disease. we examined clinical isolates of v. mimicus for the presence of ctxphi, the lysogenic filamentous bacteriophage that carries the cholera toxin genes in epidemic v. cholerae strains. four v. mimicus isolates were found to contain complete copies of ctxphi. southern blot analyses revealed that v. mimicus strain pt5 contains two ctx prophages integrated ... | 2000 | 10678967 |
| cytotoxic cell vacuolating activity from vibrio cholerae hemolysin. | a vibrio cholerae cytotoxin, designated vcvac, was found to cause vacuolation in vero cells. it was originally detected in the pathogenic o1 amazonia variant of v. cholerae and later shown to be produced in environmental strains and some el tor strains. comparison of vcvac production in various strains suggested that hemolysin was responsible for the vacuolating phenotype. genetic experiments established a firm correlation between vacuolation and hemolysin production. the mammalian cell vacuolat ... | 2000 | 10678992 |
| novel approaches to monitor bacterial gene expression in infected tissue and host. | elucidating the complex and dynamic host-microbe interactions during infection requires, among other things, detailed knowledge of microbial gene expression in vivo. recently, advances in fluorescence and bioluminescence detection techniques, as well as recombinase-based in vivo expression technology, have rendered monitoring virulence gene expression in vivo a feasible task. these techniques have been adapted by several laboratories to study the spatial and temporal patterns of virulence gene e ... | 2000 | 10679414 |
| cytotoxicity of non o1, non o139 vibrios isolated from fresh water bodies in vellore, south india. | the samples of plankton, soil sediment and water from a pond, a lake and a moat respectively in and around vellore were studied for environmental vibrios. vibrios were isolated from all these specimens after enrichment in alkaline peptone water and subculture on selective media. non o1, non o139 vibrio cholerae, aeromonas spp. and plesiomonas spp. were isolated. there were no isolates of v. cholerae serogroup o1 and o139. representative strains of non o1 and non o139 v. cholerae from environment ... | 1999 | 10680299 |
| acetyl-coa synthetase from the amitochondriate eukaryote giardia lamblia belongs to the newly recognized superfamily of acyl-coa synthetases (nucleoside diphosphate-forming). | the gene coding for the acetyl-coa synthetase (adp-forming) from the amitochondriate eukaryote giardia lamblia has been expressed in escherichia coli. the recombinant enzyme exhibited the same substrate specificity as the native enzyme, utilizing acetyl-coa and adenine nucleotides as preferred substrates and less efficiently, propionyl- and succinyl-coa. n- and c-terminal parts of the g. lamblia acetyl-coa synthetase sequence were found to be homologous to the alpha- and beta-subunits, respectiv ... | 2000 | 10681568 |
| vibrio cholerae in victoria. | | 2000 | 10682025 |
| gene replacement in gram-negative bacteria: the pmaksac vectors. | | 2000 | 10683723 |
| evaluation of antibacterial activity of asparagus racemosus willd. root. | different concentrations (50, 100, 150 microg/ml) of the methanol extract of the roots of asparagus racemosus willd. showed considerable in vitro antibacterial efficacy against escherichia coli, shigella dysenteriae, shigella sonnei, shigella flexneri, vibrio cholerae, salmonella typhi, salmonella typhimurium, pseudomonas putida, bacillus subtilis and staphylococcus aureus. the effects produced by the methanol extract were compared with chloramphenicol. | 2000 | 10685109 |
| epidemic cholera in guinea-bissau: the challenge of preventing deaths in rural west africa. | an epidemiologic investigation was conducted to identify factors associated with cholera mortality in a rural african setting and interventions likely to prevent deaths in future epidemics. | 2000 | 10689208 |
| double-blind, randomized, placebo controlled pilot study evaluating efficacy and reactogenicity of an oral etec b-subunit-inactivated whole cell vaccine against travelers' diarrhea (preliminary report). | diarrhea caused by enterotoxigenic e.coli (etec) is an important health problem in developing countries and in travelers to these areas. in previous trials formulations of etec vaccines containing the b-subunit of cholera toxin, which is antigenically similar to the heat labile enterotoxin of etec, and the most prevalent colonization factor antigens of etec, were shown to stimulate relevant mucosal immune responses in volunteers from sweden and egypt. | 2000 | 10689236 |
| phosphorylation of the flagellar regulatory protein flrc is necessary for vibrio cholerae motility and enhanced colonization. | the human pathogen vibrio cholerae specifically expresses virulence factors within the host, including cholera toxin (ct) and the toxin co-regulated pilus (tcp), which allow it to colonize the intestine and cause disease. v. cholerae is a highly motile organism by virtue of a polar flagellum, and motility has been inferred to be an important aspect of virulence, yet the exact role of motility in pathogenesis has remained undefined. the two-component regulatory system flrb/flrc is required for po ... | 2000 | 10692152 |
| delineation of pilin domains required for bacterial association into microcolonies and intestinal colonization by vibrio cholerae. | the toxin-co-regulated pilus (tcp), a type 4 pilus that is expressed by epidemic strains of vibrio cholerae o1 and o139, is required for colonization of the human intestine. the tcp structure is assembled as a polymer of repeating subunits of tcpa pilin that form long fibres, which laterally associate into bundles. previous passive immunization studies have suggested that the c-terminal region of tcpa is exposed on the surface of the pilus fibre and has a critical role in mediating the colonizat ... | 2000 | 10692166 |
| vibrio cholerae vibf is required for vibriobactin synthesis and is a member of the family of nonribosomal peptide synthetases. | a 7.5-kbp fragment of chromosomal dna downstream of the vibrio cholerae vibriobactin outer membrane receptor, viua, and the vibriobactin utilization gene, viub, was recovered from a sau3a lambda library of o395 chromosomal dna. by analogy with the genetic organization of the escherichia coli enterobactin gene cluster, in which the enterobactin biosynthetic and transport genes lie adjacent to the enterobactin outer membrane receptor, fepa, and the utilization gene, fes, the cloned dna was examine ... | 2000 | 10692380 |
| ctxphi infection of vibrio cholerae requires the tolqra gene products. | ctxphi is a lysogenic filamentous bacteriophage that encodes cholera toxin. filamentous phages that infect escherichia coli require both a pilus and the products of tolqra in order to enter host cells. we have previously shown that toxin-coregulated pilus (tcp), a type iv pilus that is an essential vibrio cholerae intestinal colonization factor, serves as a receptor for ctxphi. to test whether ctxphi also depends upon tol gene products to infect v. cholerae, we identified and inactivated the v. ... | 2000 | 10692381 |
| neonatal septicemia caused by vibrio cholerae o:139. | | 2000 | 10694008 |
| application of pcr for detection of toxigenic vibrio cholerae o1 in water samples during an outbreak of cholera. | | 1999 | 10696413 |
| [cholera in guinea: the 1994-1995 epidemic]. | since the first outbreak in 1970, cholera epidemics have occurred regularly in guinea. until 1994, epidemics recurred every 8 years and were confined to the capital and coastal areas. the first cases in every epidemic were observed in coastal lagoons near the sierra leone border. in 1994, the disease demonstrated its migratory ability as the first cases were reported in towns located in far eastern inland areas. spread of the disease from war-torn sierra leone and liberia where epidemics have al ... | 1999 | 10701212 |
| characterization of a putative virulence island in the chromosome of uropathogenic escherichia coli possessing a gene encoding a uropathogenic-specific protein. | this study was initiated to search for a homologue of the vibrio cholerae zot gene in uropathogenic escherichia coli (upec) using a specific dna probe. the faint signal obtained at low stringency with some upec strains associated with prostatitis cases prompted us to examine upec strains by pcr using primers designed from the conserved regions of the proteins of the zot group of putative ntpases containing the classical ntp binding motif. this led to the discovery of a dna fragment in upec strai ... | 2000 | 10702359 |
| distribution of is1358 and linkage to rfb-related genes in vibrio anguillarum. | the insertion sequence is1358 is linked to the rfb regions of both vibrio cholerae o1 and o139, and its location was suggestive of a role in generating new combinations of rfb genes. this provoked an examination of the distribution and localization of is1358 in vibrio anguillarum. s11358 was widely distributed in a number of v. anguillarum serogroups. in particular, when cosmid clones of v. anguillarum o1 were screened with is1358 and subsequently subcloned and sequenced, it was found that rfb-l ... | 2000 | 10708371 |
| [monitoring of life-threatening infection pathogens in relation to the problem of prediction of critical situations]. | the epidemic situation in the context of many infectious diseases caused by bacteria is presently assessed as being poor in russia and other countries. the spectrum of the pathogens that can deteriorate epidemic well-being is highly wide. the epidemic situation in terms of many infectious diseases, including those caused by such causative agents as bacillus anthracis, vibrio cholerae, yersinia pestis, francisella tularensis and others may deteriorate due to the emergence of their modified forms ... | 1999 | 10709458 |
| genomic diversity among vibrio cholerae o139 strains isolated in bangladesh and india between 1992 and 1998. | in order to assess the extent of genomic diversity among vibrio cholerae o139 strains, restriction fragment length polymorphisms in two genetic loci, rrn and ctx, were studied. analysis of 144 strains isolated from different regions of bangladesh and india between 1992 and 1998 revealed the presence of at least six distinct ribotypes (b-i through b-vi) of which three were new ribotypes, and one of these was represented by a nontoxigenic o139 strain. strains of ribotypes b-i through b-v shared 11 ... | 2000 | 10713434 |
| isolation and characterization of vich, encoding a new pleiotropic regulator in vibrio cholerae. | during the last decade, the hns gene and its product, the h-ns protein, have been extensively studied in escherichia coli. h-ns-like proteins seem to be widespread in gram-negative bacteria. however, unlike in e. coli and in salmonella enterica serovar typhimurium, little is known about their role in the physiology of those organisms. in this report, we describe the isolation of vich, an hns-like gene in vibrio cholerae, the etiological agent of cholera. this gene was isolated from a v. cholerae ... | 2000 | 10715012 |
| mobilization of plasmids and chromosomal dna mediated by the sxt element, a constin found in vibrio cholerae o139. | the vibrio cholerae sxt element encodes resistance to multiple antibiotics and is a conjugative, self-transmissible, and chromosomally integrating element (a constin). excision and self-transfer of the sxt element require an element-encoded integrase. we now report that the sxt element can also mobilize the plasmids rsf1010 and clodf13 in trans as well as chromosomal dna in an hfr-like manner. sxt element-mediated mobilization of plasmids and chromosomal dna, unlike its self-transfer, is not dep ... | 2000 | 10715015 |
| food handlers and foodborne diseases: knowledge, attitudes, and reported behavior in italy. | the purpose of this study was to evaluate knowledge, attitudes, and behavior concerning foodborne diseases and food safety issues among food handlers in italy. face-to-face interviews were conducted within a random sample using a structured questionnaire. of the 411 food handlers responding, 48.7% knew the main foodborne pathogens (salmonella spp., staphylococcus aureus, vibrio cholerae or other vibrio spp., clostridium botulinum, hepatitis a virus), and this knowledge was significantly greater ... | 2000 | 10716569 |
| the vellore vibrio watch 1996-98. | | 1999 | 10717740 |
| [bacteremia by vibrio cholera no 01, two cases]. | | 2000 | 10721567 |
| the role of probiotic cultures in the control of gastrointestinal health. | the use of probiotics to enhance intestinal health has been proposed for many years. probiotics are traditionally defined as viable microorganisms that have a beneficial effect in the prevention and treatment of specific pathologic conditions when they are ingested. there is a relatively large volume of literature that supports the use of probiotics to prevent or treat intestinal disorders. however, the scientific basis of probiotic use has been firmly established only recently, and sound clinic ... | 2000 | 10721914 |
| molecular evidence of clonality amongst vibrio cholerae o1 biotype el tor during an outbreak in malaysia. | forty-three clinical strains of v. cholerae o1 biotype e1 tor were isolated between 3 may and 10 june 1998 during an outbreak in the metropolitan area of kuala lumpur and its suburbs. with the exception of three inaba strains that were restricted to three members of a family, all the others belonged to the ogawa serotype. the strains were analysed for clonality using ribotyping and pulsed-field gel electrophoresis (pfge). two ribotypes, v/b21a and b27, were identified among 40 ogawa isolates usi ... | 2000 | 10722126 |
| cell vacuolation, a manifestation of the el tor hemolysin of vibrio cholerae. | culture supernatants of nontoxigenic nonepidemic clinical strains of vibrio cholerae belonging to diverse serogroups were found to induce vacuolation of nonconfluent hela cells. the vacuoles became prominent 18 h after introduction of culture supernatant, and vacuolated cells survived for 48 h and then died. only a fraction of the vacuolated cells took up neutral red dye, implying that there were differences in the vacuolar microenvironment. further tests showed that the factor responsible for v ... | 2000 | 10722584 |
| mutations in the extracellular protein secretion pathway genes (eps) interfere with rugose polysaccharide production in and motility of vibrio cholerae. | vibrio cholerae is the causal organism of the diarrheal disease cholera. the rugose variant of v. cholerae is associated with the secretion of an exopolysaccharide. the rugose polysaccharide has been shown to confer increased resistance to a variety of agents, such as chlorine, bioacids, and oxidative and osmotic stresses. it also promotes biofilm formation, thereby increasing the survival of the bacteria in the aquatic environments. here we show that the extracellular protein secretion system ( ... | 2000 | 10722590 |
| high-efficiency passive elution of bacterial lipopolysaccharides from polyacrylamide gels. | we recently described a method for recovering polyacrylamide-gel-separated bacterial lipopolysaccharides (lps) based on the sensitive on-gel lps detection (1-10 ng/band) with zinc-imidazole followed by passive elution from 32 microm average size gel microparticles into water. with this procedure, the recovery of rough- or semismooth-type lps after 3 h elution is about 70-80%, while that of smooth lps is only about 10%. here we evaluated whether a simple replacement of water with other eluents wo ... | 2000 | 10726753 |
| antibodies (igg) to lipopolysaccharide of vibrio cholerae o1 mediate protection through inhibition of intestinal adherence and colonisation in a mouse model. | an antiserum raised against purified lipopolysaccharide (lps) of a vibrio cholerae o1 strain (co366) induced passive protection against challenge with the parent as well as other o1 organisms but not against o139 or non-o1/non-o139 organisms. a considerable level of protection against o1 strains was also observed with the igg fraction of the antiserum which inhibited intestinal adherence and colonisation. the monovalent fab(igg) fragment, on the other hand, showed only a low level of protection. ... | 2000 | 10731603 |
| identification of an operon required for ferrichrome iron utilization in vibrio cholerae. | mutagenesis of vibrio cholerae with tnphoa, followed by screening for fusions that were activated under low-iron conditions, led to the identification of seven independent fusion strains, each of which was deficient in the ability to utilize ferrichrome as a sole iron source for growth in a plate bioassay and had an insertion in genes encoding products homologous to escherichia coli fhua or fhud. expression of the gene fusions was independent of irgb but regulated by fur. we report here a map of ... | 2000 | 10735886 |
| effect on systemic antibody concentrations of topical application of choleratoxin to skin of sheep. | to examine the ability of a vaccine formulation combining choleratoxin with an experimental antigen to induce a systemic antibody response when applied topically on unbroken skin of sheep. | 2000 | 10736674 |
| surveillance of bacterial pathogens associated with acute diarrhea in lima, peru. | a study was conducted in lima, peru, from january to april 1995, to determine the bacterial pathogens associated with acute diarrhea in adults, their susceptibility to common antimicrobials, the risk factors involved in cholera transmission, and the best clinical predictors of cholera. | 2000 | 10737846 |
| efficacy trial of single-dose live oral cholera vaccine cvd 103-hgr in north jakarta, indonesia, a cholera-endemic area. | a randomized, double-blind, placebo-controlled efficacy trial of one dose of cvd 103-hgr live oral cholera vaccine was performed in indonesia from 1993 to 1997. 67,508 persons aged 2-41 years ingested vaccine or placebo and were followed for four years, detecting cholera cases using hospital-based surveillance. a nested reactogenicity study (538 vaccinees, 535 controls) revealed no vaccine-attributable side effects. a nested immunogenicity study (n=657) showed vibriocidal seroresponses in 64-70% ... | 2000 | 10738097 |
| determination of biological toxins using capillary electrokinetic chromatography with multiphoton-excited fluorescence. | we report a highly sensitive and rapid strategy for characterizing biological toxins based on capillary electrokinetic chromatography with multiphoton-excited fluorescence. in this approach, aflatoxins b1, b2, and g1 and the cholera toxin a-subunit are fractionated in approximately 80 s in a narrow-bore electrophoretic channel using the negatively charged pseudostationary phase, carboxymethyl-beta-cyclodextrin. the aflatoxins--highly mutagenic multiple-ringed heterocycles produced by aspergillus ... | 2000 | 10740883 |
| [in vitro activities of levofloxacin and other antibiotics against fresh clinical isolates]. | in this study, the in vitro activity of levofloxacin (lvfx) against 1,020 fresh bacterial clinical isolates was compared with the activities of a range of ofloxacin, ciprofloxacin (cpfx), ampicillin (abpc), cefaclor, cefpodoxime, methicillin and benzylpenicillin. the clinical isolates except vibrio cholerae were collected in japan during 1998 from patients with infectious diseases. mics were determined using the agar dilution method according to the recommendations by the japan society of chemot ... | 1999 | 10746192 |
| evidence for specificity in type 4 pilus biogenesis by enteropathogenic escherichia coli. | type 4 fimbriae (pili) are surface appendages that are expressed by many species of gram-negative bacteria. previous studies have demonstrated that pseudomonas aeruginosa can express and assemble pilin subunits from several unrelated species, indicating a common mechanism for biogenesis of type 4 pili whereby structural subunits from one system may be interchanged with those of another. in this study, an isogenic mutant of enteropathogenic escherichia coli (epec) was constructed containing the e ... | 2000 | 10746776 |
| distribution of vibrio cholerae virulence genes among different vibrio species isolated in sardinia, italy. | the members of the genus vibrio include harmless aquatic strains as well as strains capable of causing epidemics of cholera. diarrhoea caused by vibrio cholerae is attributed to cholerae enterotoxin (ct) codified by the ctx operon and regulated by a number of virulence genes such as toxt, toxr and toxs. fifty-two vibrio strains were isolated from different aquatic environments in and around sardinia and searched by pcr for the presence of ctxa, zot, ace, toxr, toxs, toxt, tcpa and vpi virulence ... | 2000 | 10747228 |
| mucosal and systemic antibody responses after peroral or intranasal immunization: effects of conjugation to enterotoxin b subunits and/or of co-administration with free toxin as adjuvant. | the mucosa-binding molecules cholera toxin (ct) from vibrio cholerae and heat-labile enterotoxin (lt) from escherichia coli have previously been used as mucosal adjuvants and carriers for many types of antigen. however, since these molecules are toxic and cannot be used in human vaccines, it is important to study whether their non-toxic mucosa-binding b subunits, ctb and ltb, can be used as alternative safe mucosal adjuvants and/or carrier molecules. we have as a model protein antigen used human ... | 2000 | 10752686 |
| the suckling mouse model of cholera. | vibrio cholerae colonization of the suckling mouse intestine is a commonly used animal model for the human diarrheal disease cholera. this model has a number of advantages as well as disadvantages, and has been extremely useful in the identification and characterization of proven and putative virulence factors involved in human cholera. | 2000 | 10754579 |
| vibrio cholerae o139 in calcutta, 1992-1998: incidence, antibiograms, and genotypes. | we report results of surveillance for cholera caused by vibrio cholerae o139 from september 1992, when it was first identified, to december 1998. v. cholerae o139 dominated as the causative agent of cholera in calcutta during 1992-93 and 1996- 97, while the o1 strains dominated during the rest of the period. dramatic shifts in patterns of resistance to cotrimoxazole, neomycin, and streptomycin were observed. molecular epidemiologic studies showed clonal diversity among the o139 strains and conti ... | 2000 | 10756147 |
| vibrio cholerae o2 as a cause of a skin lesion in a tourist returning from tunisia. | isolates of vibrio cholerae other than o1 and o139 (non o1 vibrio cholerae) are associated with sporadic diarrheal disorders, and limited outbreaks of diarrhea, and have often been reported in association with extraintestinal infections. the majority of cases of non o1 vibrio cholerae infection involve immunocompromised patients with hematologic malignancies or cirrhosis. in italy, very few cases of gastrointestinal and extraintestinal infections due to non o1 vibrio cholerae have been described ... | 2000 | 10759577 |
| convergence of the secretory pathways for cholera toxin and the filamentous phage, ctxphi. | virulence of vibrio cholerae depends on secretion of cholera toxin (ct), which is encoded within the genome of a filamentous phage, ctxphi. release of ct is mediated by the extracellular protein secretion (eps) type ii secretion system. here, the outer membrane component of this system, epsd, was shown to be required for secretion of the phage as well. thus, epsd plays a role both in pathogenicity and in horizontal transfer of a key virulence gene. genomic analysis suggests that additional filam ... | 2000 | 10764646 |
| classical and el tor biotypes of vibrio cholerae differ in timing of transcription of tcpph during growth in inducing conditions. | two protein pairs in vibrio cholerae, toxrs and tcpph, are necessary for transcription from the toxt promoter and subsequent expression of cholera virulence genes. we have previously shown that transcription of tcpph in classical strains of v. cholerae is activated at mid-log-phase growth in toxr-inducing conditions, while transcription of tcpph in el tor strains is not. in this study, we showed that while transcription of tcpph differs at mid-log-phase growth in toxr-inducing conditions between ... | 2000 | 10769005 |
| [radiosensitivity of vibrio cholerae o1 incorporated in oysters, to (60)co]. | evaluate the effect of ionizing irradiation by 60co on vibrio cholerae o1, el-tor, ogawa, non-toxigenic, incorporated in live oysters crassostrea brasiliana. | 2000 | 10769357 |
| novel beta-lactamase genes from two environmental isolates of vibrio harveyi. | two ampicillin-resistant (amp(r)) isolates of vibrio harveyi, w3b and hb3, were obtained from the coastal waters of the indonesian island of java. strain w3b was isolated from marine water near a shrimp farm in north java while hb3 was from pristine seawater in south java. in this study, novel beta-lactamase genes from w3b (bla(vhw-1)) and hb3 (bla(vhh-1)) were cloned and their nucleotide sequences were determined. an open reading frame (orf) of 870 bp encoding a deduced protein of 290 amino aci ... | 2000 | 10770767 |
| distribution and content of class 1 integrons in different vibrio cholerae o-serotype strains isolated in thailand. | in this study, 176 clinical and environmental vibrio cholerae strains of different o serotypes isolated in thailand from 1982 to 1995 were selected and studied for the presence of class 1 integrons, a new group of genetic elements which carry antibiotic resistance genes. using pcr and dna sequencing, we found that 44 isolates contained class 1 integrons harboring the aadb, aada2, blap1, dfra1, and dfra15 gene cassettes, which encode resistance to gentamicin, kanamycin, and tobramycin; streptomyc ... | 2000 | 10770768 |