| structural and functional characterization of is1358 from vibrio cholerae. | the new epidemic serovar o139 of vibrio cholerae has emerged from the pandemic serovar o1 biotype el tor through the replacement of a 22-kbp dna region by a 40-kbp o139-specific dna fragment. this o139-specific dna fragment contains an insertion sequence that was described previously (u. h. stroeher, k. e. jedani, b. k. dredge, r. morona, m. h. brown, l. e. karageorgos, j. m. albert, and p. a. manning, proc. natl. acad. sci. usa 92:10374-10378, 1995) and designated is1358o139. we studied the dis ... | 1998 | 9829917 |
| a family of stability determinants in pathogenic bacteria. | a novel segregational stability system was identified on plasmid r485, which originates from morganella morganii. the system is composed of two overlapping genes, stbd and stbe, which potentially encode proteins of 83 and 93 amino acids, respectively. homologs of the stbde genes were identified on the enterotoxigenic plasmid p307 from escherichia coli and on the chromosomes of vibrio cholerae and haemophilus influenzae biogroup aegyptius. the former two homologs also promote plasmid stability in ... | 1998 | 9829958 |
| evolutionary control of infectious disease: prospects for vectorborne and waterborne pathogens. | evolutionary theory may contribute to practical solutions for control of disease by identifying interventions that may cause pathogens to evolve to reduced virulence. theory predicts, for example, that pathogens transmitted by water or arthropod vectors should evolve to relatively high levels of virulence because such pathogens can gain the evolutionary benefits of relatively high levels of host exploitation while paying little price from host illness. the entrance of vibrio cholerae into south ... | 1998 | 9830519 |
| molecular basis of ribotype variation in the seventh pandemic clone and its o139 variant of vibrio cholerae. | ribotyping has been widely used to characterise the seventh pandemic clone including south american and o139 variants which appeared in 1991 and 1992 respectively. to reveal the molecular basis of ribotype variation we analysed the rrn operons and their flanking regions. all but one variation detected by bgli, the most discriminatory enzyme, was found to be due to changes within the rrn operons, resulting from recombination between operons. the recombinants are detected because of the presence o ... | 1998 | 9830524 |
| the amazonia variant of vibrio cholerae: molecular identification and study of virulence genes. | the pathogenic o1 amazonia variant of vibrio cholerae has been shown previously to have a cytotoxin acting on cultured vero and y-1 cells, and to lack important virulence factors such as the cholera toxin (coelho et al. 1995a). this study extends the molecular analysis of the amazonia strains, detecting the presence of the toxr gene, with a very similar sequence to that of the e1 tor and classical biotypes. the outer membrane proteins are analyzed, detecting a variation among the group of amazon ... | 1998 | 9830525 |
| membrane carbohydrate conjugates desialylation does not alter [3h]-dopamine uptake in rat striatal slices. | incubation of rat striatal slices induced a large decrease (about 50%) of da uptake and a slight desialylation of polysialogangliosides (gt1b, gd1b, gd1a) with an increase of monosialogangliosides (gm1). moreover, a pretreatment of slices by exogenous added neuraminidase of vibrio cholerae did not modify da uptake, although the pattern of gangliosides was modified and there was considerable loss (about 45%) of sialic acid in gangliosides and glycoproteins. it was verified that neuraminidase acti ... | 1998 | 9832192 |
| effect of canavanine from alfalfa seeds on the population biology of bacillus cereus | bacillus cereus uw85 suppresses diseases of alfalfa seedlings, although alfalfa seed exudate inhibits the growth of uw85 in culture (j. l. milner, s. j. raffel, b. j. lethbridge, and j. handelsman, appl. microbiol. biotechnol. 43:685-691, 1995). in this study, we determined the chemical basis for and biological role of the inhibitory activity. all of the alfalfa germ plasm tested included seeds that released inhibitory material. we purified the inhibitory material from one alfalfa cultivar and i ... | 1998 | 9835549 |
| epidemiology, genetics, and ecology of toxigenic vibrio cholerae. | cholera caused by toxigenic vibrio cholerae is a major public health problem confronting developing countries, where outbreaks occur in a regular seasonal pattern and are particularly associated with poverty and poor sanitation. the disease is characterized by a devastating watery diarrhea which leads to rapid dehydration, and death occurs in 50 to 70% of untreated patients. cholera is a waterborne disease, and the importance of water ecology is suggested by the close association of v. cholerae ... | 1998 | 9841673 |
| vibrio cholerae non-o1 on blood culture, saskatchewan. | | 1998 | 9844253 |
| james carroll: a biography. | james carroll was born in england in 1854; at the age of 15, he emigrated to canada where he worked at various odd jobs. at age 20, he crossed the border and volunteered for the us army, in which he remained for the rest of his life. appointed as hospital steward, he became interested in medicine. he was permitted to take basic courses at st paul university and later at bellevue hospital in new york. he received his md degree in 1891 from the university of maryland while still a sergeant. he the ... | 1998 | 9845758 |
| cholera toxin differentially regulates nitric oxide synthesis, tumor necrosis factor-alpha production and respiratory burst in murine macrophages. | the aim of this study was to determine if cholera toxin can modulate the expression of several macrophage effector functions. the effect of cholera toxin on the induction of no synthesis, production of tumor necrosis factor-alpha and induction of respiratory burst was examined in the j774.a2 macrophage cell line. pre-incubation of cell cultures with cholera toxin significantly down-regulated lipopolysaccharide-induced no synthesis and phorbol-12-myristate-13-acetate-induced respiratory burst. co ... | 1998 | 9848679 |
| a randomized clinical trial to compare the efficacy of erythromycin, ampicillin and tetracycline for the treatment of cholera in children. | to compare the clinical outcome of treatment of cholera in children with ampicillin, erythromycin or tetracycline, a double-'blind' randomized four-cell trial was carried out in bangladesh. ampicillin was chosen as additional therapy for acute respiratory tract infection, present in many subjects with diarrhoea. one hundred and eighty-four children aged 1-5 years who were not wasted, with diarrhoea of duration < 48 h, signs of some or severe dehydration, dark-field stool microscopy demonstrating ... | 1998 | 9850410 |
| competence for natural transformation in neisseria gonorrhoeae: a model system for studies of horizontal gene transfer. | a combined effort integrating studies of gonococcal tfp biogenesis, the data made available from the gonococcal genome sequence project and applied molecular genetics have been used to identify the fibrillar filaments themselves, the pilt protein and the comp protein as essential components for the dna uptake phase of competence for natural transformation. our ongoing studies are focused on identifying and understanding the complex interactions which exist between these essential constituents. t ... | 1998 | 9850683 |
| genetic organization of the regions associated with surface polysaccharide synthesis in vibrio cholerae o1, o139 and vibrio anguillarum o1 and o2: a review. | vibrio cholerae and v. anguillarum are recognized as aquatic-borne human and fish pathogens, respectively. based upon analyses of several genes and the presence of novel genetic elements it seems that these two species are very closely related. studies in this laboratory have identified an association of is1358 with rfb and capsule loci in these two species. the most recent findings suggest that is1358 is associated with the rfb region in v. cholerae o1 and o139 and in v. anguillarum o1 and o2. ... | 1998 | 9858748 |
| studies towards neoglycoconjugates from the monosaccharide determinant of vibrio cholerae o:1, serotype ogawa using the diethyl squarate reagent. | the effect of reaction time, concentration and molar excess of hapten upon the efficiency of the conjugation of carbohydrates to proteins using the diethyl squarate reagent has been studied using chicken serum albumin (csa) as the carrier protein and a linker-equipped d-glucose derivative as the hapten. a high degree of incorporation of the latter into csa was achieved with high efficiency, and the use of a large excess of the ligand was not necessary. conjugation of the immunodominant monosacch ... | 1998 | 9861698 |
| resurgent vibrio cholerae o139: rearrangement of cholera toxin genetic elements and amplification of rrn operon. | the unprecedented genesis of a novel non-o1 vibrio cholerae strain belonging to serogroup o139, which caused an epidemic in late 1992 in the indian subcontinent, and its subsequent displacement by el tor o1 vibrios after 18 months initiated a renewed investigation of the aspects of the organism that are related to pathogenesis. the reappearance of v. cholerae o139 with altered antibiotic sensitivity compared to o139 bengal (o139b) in late 1996 has complicated the epidemiological scenario of v. c ... | 1999 | 9864209 |
| [outcome of patients treated with intra-peritoneal immunochemotherapy for ovarian cancer]. | the aim of this study is to show that i.p. chemotherapy improves the evolution of the patients with an ovarian cancer, as the risk of a small number of complications due to this route of administration. | 1998 | 9864886 |
| study of proteases and other enzymes of vibrio cholerae 01 e2 tor and 0139 serotypes isolated in yavatmal (maharashtra). | v. cholerae 01 e1 tor isolated during cholera epidemic of 1994 and v cholerae 0139 serotype isolated during 1993 epidemic were subjected to the study of proteases and other enzymes. out of 26 strains of v. cholerae 01 studied, gelatinase and caseinase activity was seen in 100 and 69.23 percent strains respectively. all strains showed catalase and oxidase activity. of the other enzymes studied 19.23, 65.38 and 57.69 percent strains were positive for dnase, lipase and phosphatase respectively. non ... | 1998 | 9866901 |
| characterization of non-membrane-damaging cytotoxin of non-toxigenic vibrio cholerae o1 and its relevance to disease. | the non-membrane-damaging cytotoxin which causes dramatic cell rounding of cultured hela cells was purified to homogeneity from a clinical strain (wo5) of non-toxigenic vibrio cholerae o1 inaba belonging to the e1 tor biotype. the purified protein has a denatured molecular weight of 35 kda and a native molecular weight of approximately 37 kda indicating the monomeric nature of the protein. the 15 n-terminal amino acid sequence of non-membrane-damaging cytotoxin showed complete homology to the he ... | 1998 | 9868778 |
| a simple, nonenzymatic method for desialylating polysialylated ganglio-n-tetraose series gangliosides to produce gm1. | dowex-50w-h+ was used to catalyze the highly selective desialylation of polysialylated ganglio-n-tetraose series gangliosides to yield primarily gm1. high performance thin-layer chromatographic analysis of recovered lipid indicated that 60-70% of the recovered ganglioside was gm1. identification of the major product as gm1 was confirmed by proton nmr spectra and lack of sialic acid release by vibrio cholerae sialidase. | 1999 | 9869662 |
| note: characterization of vibrio cholerae o139 bengal isolated from water in malaysia. | four vibrio cholerae o139 bengal strains isolated from surface water were characterized by antibiotic resistance, plasmid profile, presence of cholera toxin gene and random amplification of polymorphic dna (rapd) analysis. all four strains exhibit multiple resistance towards the antibiotics tested with a multiple antibiotic resistance index of 0.5-0.66, and harboured a 2.0 mda non-conjugative plasmid. the vibrio cholerae o139 bengal were positive for the cholera toxin gene. antibiotyping and ran ... | 1998 | 9871327 |
| antisera to selected outer membrane proteins of vibrio cholerae protect against challenge with homologous and heterologous strains of v. cholerae. | each year cholera epidemics occur in various places around the world. though there is no effective vaccine against cholera, people who recover from an infection usually have prolonged immunity to the disease. sera from convalescent patients contain antibodies to a number of outer membrane proteins (omps) of v. cholerae. we isolated several omps (43, 42, 30, and 22 kda) from v. cholerae v86 e1 tor inaba, sequenced their amino-termini, and generated hyperimmune sera against them in rabbits. antise ... | 1998 | 9879921 |
| impact of medium-chain monoglycerides on intestinal colonisation by vibrio cholerae or enterotoxigenic escherichia coli. | although a number of studies have shown that various free fatty acids (ffas) and monoacylglycerides (mgs) have bactericidal properties in vitro, the role of these compounds in vivo has not been determined. this study evaluated the antibacterial properties of medium-chain mgs and ffas for different bacterial enteropathogens with an in-vitro bacterial killing assay and an in-vivo model of intestinal colonisation. incubation of test bacteria with medium-chain mgs for 4 h led to 100-10,000-fold redu ... | 1998 | 9879938 |
| oligomerization of vibrio cholerae cytolysin yields a pentameric pore and has a dual specificity for cholesterol and sphingolipids in the target membrane. | vibrio cholerae cytolysin permeabilizes animal cell membranes. upon binding to the target lipid bilayer, the protein assembles into homo-oligomeric pores of an as yet unknown stoichiometry. pore formation has been observed with model liposomes consisting of phosphatidylcholine and cholesterol, but the latter were much less susceptible to the cytolysin than were erythrocytes or intestinal epithelial cells. we here show that liposome permeabilization is strongly promoted if cholesterol is combined ... | 1999 | 9880509 |
| antibacterial activity of lactobacillus species against vibrio species. | forty-one lactobacillus strains were tested for antagonistic activity against nine strains of vibrio. l. plantarum and l. casei were the most effective, and l. brevis was the least effective in inhibiting the growth of vibrio species. l. gasseri and l. helveticus strains showed higher activity, while l. reuteri and l. fermentum showed lower inhibitory activity against vibrio species. l. acidophilus strains exhibited various degrees of antagonistic activities against vibrio species. however, none ... | 1998 | 9880930 |
| synthesis and evaluation of n-acetylneuraminic acid-based affinity matrices for the purification of sialic acid-recognizing proteins. | the synthesis of 2-s-(2-aminoethyl) 5-acetamido-3,5-dideoxy-2-thio-d-galacto-2-nonulopyranosidonic acid (1) has been successfully achieved from the precursors methyl 5-acetamido-4,7,8,9-tetra-o-acetyl-2-s-acetyl-3,5-dideoxy-2-thio-d-glyce ro-alpha-d-galacto-2-nonulopyranosonate (2) and 2-bromo-n-(tert-butoxycarbonyl)-ethylamine (5). compounds 1 and 2 were coupled, via amino and thioglycosidic linkages, respectively, to epoxy-activated sepharose 6b. the resultant affinity adsorbents have proved e ... | 1998 | 9881772 |
| structure-based discovery of a pore-binding ligand: towards assembly inhibitors for cholera and related ab5 toxins. | cholera toxin (ct) and escherichia coli heat-labile enterotoxin (lt) are two closely related multi-subunit ab5 proteins responsible for significant morbidity and mortality worldwide. an attractive strategy to prevent disease by these organisms is to interfere with the assembly process of these toxins, since prevention of toxin formation is better than preventing the effects of a toxin which is already formed. the b subunits form a ring with a central pore which surrounds the c-terminal residues ... | 1999 | 9887271 |
| two forms of vibrio cholerae o1 el tor hemolysin derived from identical precursor protein. | vibrio cholerae o1 grown in heart infusion broth produces two forms of el tor hemolysin (eth) monomers of 65 and 50 kda. these monomers form several different sizes of mixed oligomers ranging from 180 to 280 kda in the liposomal membranes. we found that the n-terminal amino acid sequences, nh2-trp-pro-ala-pro-ala-asn-ser-glu, of both the 65- and 50-kda toxins were identical. we assumed, therefore, that the 65- and 50-kda toxins were derivatives of the identical precursor protein and the 50-kda p ... | 1999 | 9889386 |
| microbial-host interactions at mucosal sites. host response to pathogenic bacteria at mucosal sites. | | 1999 | 9893360 |
| bacterial mucosal vaccines: vibrio cholerae as a live attenuated vaccine/vector paradigm. | | 1999 | 9893363 |
| preliminary assessment of the safety and immunogenicity of a new ctxphi-negative, hemagglutinin/protease-defective el tor strain as a cholera vaccine candidate. | vibrio cholerae 638 (el tor, ogawa), a new ctxphi-negative hemagglutinin/protease-defective strain that is a cholera vaccine candidate, was examined for safety and immunogenicity in healthy adult volunteers. in a double-blind placebo-controlled study, no significant adverse reactions were observed in volunteers ingesting strain 638. four volunteers of 42 who ingested strain 638 and 1 of 14 who received placebo experienced loose stools. the strain strongly colonized the human small bowel, as evid ... | 1999 | 9916056 |
| isolation and characterization of rugose form of vibrio cholerae o139 strain mo10. | an extracellular exopolysaccharide (slime) is produced by vibrio cholerae o139 mo10 in response to nutrient starvation. the presence of this slime layer on the cell surface and its subsequent release have been shown to be associated with biofilm formation and the change from a normal smooth colony morphology to a rugose one. an immunoelectron microscopic examination demonstrated that there is an epitope common to the exopolysaccharide antigen of v. cholerae o1 and that of o139 mo10. | 1999 | 9916115 |
| rfb mutations in vibrio cholerae do not affect surface production of toxin-coregulated pili but still inhibit intestinal colonization. | the toxin-coregulated pilus (tcp) of vibrio cholerae is essential for colonization. it was recently reported that rfb mutations in v. cholerae 569b cause the translocation arrest of the structural subunit of tcp, raising the possibility that the colonization defects of lipopolysaccharide mutants are due to effects on tcp biogenesis. however, an rfbb gene disruption in either v. cholerae o395 or 569b has no apparent effect on surface tcp production as assessed by immunoelectron microscopy and ctx ... | 1999 | 9916119 |
| quantification of bacterial lipopolysaccharides by the purpald assay: measuring formaldehyde generated from 2-keto-3-deoxyoctonate and heptose at the inner core by periodate oxidation. | we have adapted the purpald assay (m. s. quesenberry and y. c. lee, anal. biochem. 234, 50-55, 1996) to quantify lipopolysaccharide (lps) content in solution in 96-well microtiter plates at room temperature. this method employs the oxidation of unsubstituted terminal vicinal glycol groups in 2-keto-3-deoxyoctonate (kdo) and l-(or d-)glycero-d-manno-heptose of lps molecules by periodate to release formaldehyde. the formaldehyde is quantified at 550 nm (or 530-570 nm) by reacting with purpald reag ... | 1999 | 9918668 |
| purification and characterization of an aeromonas caviae metalloprotease that is related to the vibrio cholerae hemagglutinin/protease. | a zinc metalloprotease (ap34) from aeromonas caviae was purified by ammonium sulfate precipitation and subsequent gel filtration through sephadex g-100 and sephadex g-50 superfine. the molecular mass was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 34 kda. the protease showed maximum activity at ph 7.0 and was stable at 60 degrees c. ap34 was completely inactivated by edta and zincov. the n-terminal amino acid sequence of ap34 showed a high degree of homology with ... | 1999 | 9919673 |
| response of wild-type mutants of vibrio cholerae o1 possessing different combinations of virulence genes in the ligated rabbit ileal loop and in ussing chambers: evidence for the presence of additional secretogen. | five wild-type mutant strains of vibrio cholerae serogroup o1 that lacked the ctx virulence cassette, or contained a natural deletion of a virulence gene within the ctx virulence cassette, or possessed an additional virulence gene, along with a prototype toxigenic strain representing the el tor classical biotypes were examined by in-vivo and in-vitro methods to determine their enterotoxic potential. the ability of whole cells and culture supernates of the strains to cause fluid accumulation in t ... | 1999 | 9920125 |
| characterisation of cholera toxin by liquid chromatography--electrospray mass spectrometry. | cholera toxin, one of the toxins that may be generated by various strains of the bacterium vibrio cholerae, can be considered as a substance possibly used in biological warfare. the possibilities of characterising the toxin by liquid chromatography electrospray mass spectrometry (lc-es-ms) were investigated. the toxin can be detected by flow-injection (fia) es-ms of a dialysed solution and observation of the charge envelope signals of its a-unit and b-chain protein; sufficient information for id ... | 1999 | 9920483 |
| molecular characterization of vibrio cholerae o1 strains isolated in romania. | a collection of 89 vibrio cholerae o1 strains, isolated in romania between 1977 and 1994, and 6 strains from the republic of moldavia, was characterized by ribotyping, toxin gene restriction pattern (toxinogenotype) and distribution of cholera toxin gene (ctx), accessory toxin gene (ace) and zonula occludens toxin gene (zot). after bg/i endonuclease restriction of chromosomal dna, a total of 18 ribotypes and 21 toxinogenotypes were distinguished. deletions in the core region of the toxin gene ca ... | 1998 | 9921581 |
| the mutk gene of vibrio cholerae: a new gene involved in dna mismatch repair. | a new gene, mutk, of vibrio cholerae, encoding a 19-kda protein which is involved in repairing mismatches in dna via a presumably methyl-independent pathway, has been identified. the product of the mutk gene cloned in either high- or low-copy-number vectors can reduce the spontaneous mutation frequency of escherichia coli muts, mutl, mutu, and dam mutants. the spontaneous mutation frequency of a chromosomal mutk knockout mutant was almost identical to that of wild-type v. cholerae cells, indicat ... | 1999 | 9922251 |
| the spi-3 pathogenicity island of salmonella enterica. | pathogenicity islands are chromosomal clusters of pathogen-specific virulence genes often found at trna loci. we have determined the molecular genetic structure of spi-3, a 17-kb pathogenicity island located at the selc trna locus of salmonella enterica serovar typhimurium. the g+c content of spi-3 (47.5%) differs from that of the salmonella genome (52%), consistent with the notion that these sequences have been horizontally acquired. spi-3 harbors 10 open reading frames organized in six transcr ... | 1999 | 9922266 |
| [survival of vibrio cholerae 01 in freshwater surface and endemic cholera: a geological hypothesis]. | the danger that cholera is becoming endemic in latin america makes it imperative to know the geographic location of aquatic environments where ecological conditions favor long-term survival of the toxigenic vibrio cholerae o1 el tor biotype, and such aquatic environments should be sampled to determine if they harbor this microorganism. for efficient and effective sampling, it would be useful to know what kinds of waters are ecologically suitable for the survival of this pathogen during periods b ... | 1998 | 9924512 |
| characterization and nucleotide sequence of carb-6, a new carbenicillin-hydrolyzing beta-lactamase from vibrio cholerae. | a clinical strain of vibrio cholerae non-o1 non-o139 isolated in france produced a new beta-lactamase with a pi of 5.35. the purified enzyme, with a molecular mass of 33,000 da, was characterized. its kinetic constants show it to be a carbenicillin-hydrolyzing enzyme comparable to the five previously reported carb beta-lactamases and to sar-1, another carbenicillin-hydrolyzing beta-lactamase that has a pi of 4.9 and that is produced by a v. cholerae strain from tanzania. this beta-lactamase is d ... | 1999 | 9925522 |
| identification of a vibrio cholerae rtx toxin gene cluster that is tightly linked to the cholera toxin prophage. | we identify and characterize a gene cluster in el tor vibrio cholerae that encodes a cytotoxic activity for hep-2 cells in vitro. this gene cluster contains four genes and is physically linked to the cholera toxin (ctx) element in the v. cholerae genome. we demonstrate by using insertional mutagenesis that this gene cluster is required for the cytotoxic activity. the toxin, rtxa, resembles members of the rtx (repeats in toxin) toxin family in that it contains a gd-rich repeated motif. like other ... | 1999 | 9927695 |
| [resistance of respiratory and enteral bacteria to antibiotics]. | | 1998 | 9927887 |
| [vibrio cholerae non 01 sepsis in a healthy patient: review of reported cases in spain]. | | 1998 | 9930015 |
| [an update on cholera infection]. | | 1998 | 9932009 |
| [analysis of vibrio cholerae hemolysins using monolayer continuous cell cultures]. | the comparative study of the preparations of v.cholerae hemolysins of different serovars with the use of continuous cell lines cho-k1, vero, hela, l-929 was carried out. the preparations of hemolysins isolated from such strains as v.cholerae 569b, v.eltor 9949, v.cholerae o-mut 461/67-34 differed in their biological activity on experimental animal models and had different cytotoxic activity. the preparations exhibiting no activity when tested in vivo (v.cholerae and v.eltor hemolysins) were ceto ... | 1998 | 9949497 |
| comparison of survival of diarrhoeagenic agents in two local weaning foods (ogi and koko). | the ph values of both cooked and uncooked ogi and koko samples were determined and the survival rate of four diarrhoeagenic agents, enteroinvasive escherichia coli, salmonella typhi, shigella flexneri, and vibrio cholerae were studied after they were seeded into cooked ogi and koko. analysis of the ph of the cooked inoculated samples showed that there was a slight increase in ph (decrease in acidity) during storage for 48 h and 37 degrees c (from 3.5 to 3.7 for ogi and from 3.7 to 4.1 for koko). ... | 1998 | 9972074 |
| pseudomonas aeruginosa fur overlaps with a gene encoding a novel outer membrane lipoprotein, omla. | a novel outer membrane lipoprotein in pseudomonas aeruginosa is encoded by the omla gene, which was identified immediately upstream of the fur (ferric uptake regulator) gene. the omla and fur genes were divergently transcribed and had overlapping promoter regions. the proximal fur p2 promoter and the omla promoter shared a 5-bp dna motif for their -10 promoter elements. the distal fur p1 promoter was located within the omla coding sequence, and the omla and fur t1 mrnas overlapped by 154 nucleot ... | 1999 | 9973334 |
| genetic and transcriptional analyses of the vibrio cholerae mannose-sensitive hemagglutinin type 4 pilus gene locus. | the mannose-sensitive hemagglutinin (msha) of the vibrio cholerae o1 el tor biotype is a member of the family of type 4 pili. type 4 pili are found on the surface of a variety of gram-negative bacteria and have demonstrated importance as host colonization factors, bacteriophage receptors, and mediators of dna transfer. the gene locus required for the assembly and secretion of the msha pilus has been localized to a 16.7-kb region of the v. cholerae chromosome. sixteen genes required for hemagglut ... | 1999 | 9973335 |
| genetic diversity and population structure of vibrio cholerae. | multilocus enzyme electrophoresis (mlee) of 397 vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from mexico and guatemala, identified 279 electrophoretic types (ets) distributed in two major divisions (i and ii). linkage disequilibrium was demonstrated in both divisions and in subdivision ic of division i but not in subdivision ia, which includes 76% of the ets. despite this evidence of relatively frequent recombination, clonal lineages may persist for periods ... | 1999 | 9986816 |
| cholera in vietnam: changes in genotypes and emergence of class i integrons containing aminoglycoside resistance gene cassettes in vibrio cholerae o1 strains isolated from 1979 to 1996. | the number of cholera cases and the mortality rates reported from different regions of vietnam varied considerably in the period from 1979 to 1996, with between 2,500 and 6,000 cases reported annually from 1992 to 1995. annual mortality rates ranged from 2.0 to 9.6% from 1979 to 1983 to less than 1.8% after 1983. major cholera outbreaks were reported from the high plateau region for the first time in 1994 and 1995; this is an area with limited access to health services and safe drinking-water su ... | 1999 | 9986842 |
| toxr co-operative interactions are not modulated by environmental conditions or periplasmic domain conformation. | toxr is a transmembrane regulatory protein that controls virulence gene expression in vibrio cholerae. previous experiments using lambda repressor-toxr chimeric proteins and a lambda repressor-controlled reporter system (or1 pr-laczy) established that toxr sequences can effectively dimerize the amino-terminal domain of lambda repressor in escherichia coli. however, in e. coli, toxr does not respond to environmental signals that control virulence gene expression in v. cholerae. here, we report th ... | 1999 | 9987131 |
| the structural and functional organization of h-ns-like proteins is evolutionarily conserved in gram-negative bacteria. | the structural gene of the h-ns protein, a global regulator of bacterial metabolism, has been identified in the group of enterobacteria as well as in closely related bacteria, such as erwinia chrysanthemi and haemophilus influenzae. isolated outside these groups, the bph3 protein of bordetella pertussis exhibits a low amino acid conservation with h-ns, particularly in the n-terminal domain. to obtain information on the structure, function and/or evolution of h-ns, we searched for other h-ns-rela ... | 1999 | 9987132 |
| toxin-co-regulated pilus cluster in non-o1, non-toxigenic vibrio cholerae: evidence of a third allele of pilin gene. | polymerase chain reaction has been used to detect the presence of the virulence associated gene, tcpa and part of the promoter distal region of the toxin-co-regulated pilus cluster in non-o1, non-toxigenic, vibrio cholerae. the amplified regions were characterised by restriction fragment length polymorphism and heteroduplex motility assay. we describe the nucleotide sequence of the tcpa gene fragment from non-toxigenic vibrios from clinical and environmental sources. the present study shows that ... | 1999 | 9987841 |
| epidemiological study of an outbreak of cholera in delhi cantonment. | an epidemiological study was undertaken to investigate an outbreak of cholera in delhi cantonment during may 1991. the study design was a hybrid design using a retrospective case-control method superimposed on a population based cross-sectional approach. a total of 9 cases of cholera, confirmed in the laboratory as vibrio cholerae, 0-1, eltor, ogawa were identified using population based survey and compared with 33 controls from the same source population. the overall incidence rate was 0.71% an ... | 1997 | 9988980 |
| differentiation of microorganisms based on pyrolysis-ion trap mass spectrometry using chemical ionization. | the ability to differentiate microorganisms using pyrolysision trap mass spectrometry was demonstrated for five gram-negative disease-causing organisms: brucella melitensis, brucella suis, vibrio cholera, yersinia pestis, and francisella tularensis. bacterial profiles were generated for gamma-irradiated bacterial samples using pyrolytic methylation and compared for electron ionization and chemical ionization using several liquid reagents with increasing proton affinities. electron ionization com ... | 1999 | 9989380 |
| vibrio cholerae o1 serotype ogawa in a neonate. | in india, cholera is endemic and affects usually the 3 to 5-year-old age group. there have been occasional reports in the neonatal period with vibrio cholerae o139 bengal. we report here a case of vibrio cholerae o1 diarrhea in a 2-day-old, breastfed male, who had been delivered in the hospital and developed severe dehydration. | 1999 | 9990478 |
| cloning and characterisation of a novel ompb operon from vibrio cholerae 569b. | the ompb operon of vibrio cholerae 569b has been cloned and fully sequenced. the operon encodes two proteins, ompr and envz, which share sequence identity with the ompr and envz proteins of a variety of other bacteria. although the order of the ompr and envz genes of v. cholerae is similar to that of the ompb operon of e. coli, s. typhimurium and x. nematophilus, the vibrio operon exhibits a number of novel features. the structural organisation and features of the v. cholerae ompb operon are des ... | 1999 | 10023081 |
| role of dnak in in vitro and in vivo expression of virulence factors of vibrio cholerae. | the dnak gene of vibrio cholerae was cloned, sequenced, and used to construct a dnak insertion mutant which was then used to examine the role of dnak in expression of the major virulence factors of this important human pathogen. the central regulator of several virulence genes of v. cholerae is toxr, a transmembrane dna binding protein. the v. cholerae dnak mutant grown in standard laboratory medium exhibited phenotypes characteristic of cells deficient in toxr activity. using northern blot anal ... | 1999 | 10024539 |
| evolutionary relationships of pathogenic clones of vibrio cholerae by sequence analysis of four housekeeping genes. | studies of the vibrio cholerae population, using molecular typing techniques, have shown the existence of several pathogenic clones, mainly sixth-pandemic, seventh-pandemic, and u.s. gulf coast clones. however, the relationship of the pathogenic clones to environmental v. cholerae isolates remains unclear. a previous study to determine the phylogeny of v. cholerae by sequencing the asd (aspartate semialdehyde dehydrogenase) gene of v. cholerae showed that the sixth-pandemic, seventh-pandemic, an ... | 1999 | 10024551 |
| zonula occludens toxin is a powerful mucosal adjuvant for intranasally delivered antigens. | zonula occludens toxin (zot) is produced by toxigenic strains of vibrio cholerae and has the ability to reversibly alter intestinal epithelial tight junctions, allowing the passage of macromolecules through the mucosal barrier. in the present study, we investigated whether zot could be exploited to deliver soluble antigens through the nasal mucosa for the induction of antigen-specific systemic and mucosal immune responses. intranasal immunization of mice with ovalbumin (ova) and recombinant zot, ... | 1999 | 10024572 |
| genetic characterization of a new type iv-a pilus gene cluster found in both classical and el tor biotypes of vibrio cholerae. | the vibrio cholerae genome contains a 5.4-kb pil gene cluster that resembles the aeromonas hydrophila tap gene cluster and other type iv-a pilus assembly operons. the region consists of five complete open reading frames designated pilabcd and yace, based on the nomenclature of related genes from pseudomonas aeruginosa and escherichia coli k-12. this cluster is present in both classical and el tor biotypes, and the pila and pild genes are 100% conserved. the pila gene encodes a putative type iv p ... | 1999 | 10024587 |
| corpses and the spread of cholera. | | 1999 | 10030354 |
| ribotypes of clinical vibrio cholerae non-o1 non-o139 strains in relation to o-serotypes. | the emergence of vibrio cholerae o139 in 1992 and reports of an increasing number of other non-o1 serogroups being associated with diarrhoea, stimulated us to characterize v. cholerae non-o1 non-o139 strains received at the national institute of infectious diseases, japan for serotyping. ribotyping with the restriction enzyme bgli of 103 epidemiological unrelated mainly clinical strains representing 10 o-serotypes yielded 67 different typing patterns. ribotype similarity within each serotype was ... | 1998 | 10030702 |
| detection of genes encoding cholera toxin (ct), zonula occludens toxin (zot), accessory cholera enterotoxin (ace) and heat-stable enterotoxin (st) in vibrio mimicus clinical strains. | a total of 51 clinical strains of vibrio mimicus were searched for the presence of virulence-associated genes, like ctx, zot or ace genes which locate in "cholera virulence cassette," and the st gene by polymerase chain reaction. moreover, the pathological potential of each clinical strain was also examined by rabbit ileal loop (ril). three strains showed to have the ctx gene, of which only one strain was zot gene-positive. meanwhile, one other strain was zot+ but ctx-. all of these four strains ... | 1998 | 10037216 |
| a new level in the vibrio cholerae toxr virulence cascade: apha is required for transcriptional activation of the tcpph operon. | the expression of the toxr virulence regulon is dependent upon the regulatory proteins toxr/toxs, tcpp/tcph and toxt. we describe here a previously unidentified gene in vibrio cholerae, apha (activator of tcpp and tcph expression), which is required for the transcription of the tcpph operon. under conditions normally optimal for virulence gene expression, an in frame apha deletion decreased the expression of a cholera toxin promoter fusion (ctx-lacz) and prevented the production of the toxin co- ... | 1999 | 10048021 |
| antibiotic resistance conferred by a conjugative plasmid and a class i integron in vibrio cholerae o1 el tor strains isolated in albania and italy. | multidrug-resistant vibrio cholerae o1 el tor strains isolated during the 1994 outbreak of cholera in albania and italy were characterized for the molecular basis of antibiotic resistance. all strains were found to be resistant to tetracycline, streptomycin, spectinomycin, trimethoprim, sulfathiazole, and the vibriostatic compound o/129 (2,4-diamino-6,7-diisopropylteridine). resistance genes were self-transferable by a conjugative plasmid of about 60 mda, with the exception of spectinomycin resi ... | 1999 | 10049292 |
| environmental signals modulate toxt-dependent virulence factor expression in vibrio cholerae. | the regulatory protein toxt directly activates the transcription of virulence factors in vibrio cholerae, including cholera toxin (ct) and the toxin-coregulated pilus (tcp). specific environmental signals stimulate virulence factor expression by inducing the transcription of toxt. we demonstrate that transcriptional activation by the toxt protein is also modulated by environmental signals. toxt expressed from an inducible promoter activated high-level expression of ct and tcp in v. cholerae at 3 ... | 1999 | 10049382 |
| role of surface proteins in vibrio cholerae attachment to chitin. | the role of surface proteins in vibrio cholerae attachment to chitin particles in vitro was studied. treatment of v. cholerae o1 atcc 14034 and atcc 14035 with pronase e reduced the attachment of bacteria to chitin particles by 57 to 77%. a statistically significant reduction was also observed when the attachment to chitin was evaluated in the presence of homologous sarkosyl-insoluble membrane proteins (mps) (67 to 84%), n-acetylglucosamine (glcnac) (62%), the sugar that makes up chitin, and whe ... | 1999 | 10049907 |
| emergence of cholera in the central african republic. | | 1998 | 10052560 |
| optimization of preparative conditions for poly-dl-lactide- polyethylene glycol microspheres with entrapped vibrio cholera antigens. | poly-dl-lactide-polyethylene glycol (pela) with different contents of polyethylene glycol(peg) were synthesized and the peg content was estimated according to the integral height of hydrogen shown in 1h-nmr. pela microspheres containing v. cholera antigen, outer membrane protein (omp) were prepared by a water-in-oil-in-water (w/o/w) based on solvent evaporation procedure. antigen microspheres with smooth surface, suitable size for oral administration (0.5-5 microm), high loading efficiency (abou ... | 1999 | 10053185 |
| phagocytosis of vibrio cholerae o139 bengal by human polymorphonuclear leukocytes. | capsulated bacteria exhibit serum (complement) resistance and resistance to phagocytosis, which result in disseminated infections. vibrio cholerae o139 strains possess a thin capsule and have been found to be partially serum resistant in a previous study. in the present study, compared to a standard capsulated klebsiella pneumoniae strain, which showed total resistance to killing by phagocytosis, v. cholerae o139 strains were shown to be only partially resistant, with most strains showing <40% s ... | 1999 | 10066668 |
| diarrheagenicity evaluation of attenuated vibrio cholerae o1 and o139 strains in the human intestine ex vivo. | the recent spread of el tor cholera in latin america highlights the need for a safe and economical vaccine. the main approach for developing live recombinant vaccines has been to disarm known pathogenic strains of cholera toxin leaving intact antigens involved in protection. these recombinant vaccine candidates do not cause severe diarrhea, but they are too reactogenic for wide scale usage. we describe here a test capable of determining the diarrheagenic potential of attenuated v. cholerae strai ... | 1999 | 10067702 |
| transmission of epidemic vibrio cholerae o1 in rural western kenya associated with drinking water from lake victoria: an environmental reservoir for cholera? | sub-saharan africa has the highest reported cholera incidence and mortality rates in the world. in 1997, a cholera epidemic occurred in western kenya. between june 1997 and march 1998, 14,275 cholera admissions to hospitals in nyanza province in western kenya were reported. there were 547 deaths (case fatality rate = 4%). of 31 vibrio cholerae o1 isolates tested, all but one were sensitive to tetracycline. we performed a case-control study among 61 cholera patients and age-, sex-, and clinic-mat ... | 1999 | 10072150 |
| the polar flagellar motor of vibrio cholerae is driven by an na+ motive force. | vibrio cholerae is a highly motile bacterium which possesses a single polar flagellum as a locomotion organelle. motility is thought to be an important factor for the virulence of v. cholerae. the genome sequencing project of this organism is in progress, and the genes that are highly homologous to the essential genes of the na+-driven polar flagellar motor of vibrio alginolyticus were found in the genome database of v. cholerae. the energy source of its flagellar motor was investigated. we exam ... | 1999 | 10074090 |
| identification and characterization of is2404 and is2606: two distinct repeated sequences for detection of mycobacterium ulcerans by pcr. | molecular analysis of mycobacterium ulcerans has revealed two new insertion sequences (iss), is2404 and is2606. is2404 was identified by complete sequencing of a previously described repetitive dna segment from m. ulcerans. this element is 1,274 bp long, contains 12-bp inverted repeats and a single open reading frame (orf) potentially encoding a protein of 327 amino acids (aa), and apparently generates 7-bp direct repeats upon transposition. amino acid similarity was found between the putative t ... | 1999 | 10074520 |
| effects of changes in membrane sodium flux on virulence gene expression in vibrio cholerae. | the expression of several virulence factors of vibrio cholerae is coordinately regulated by the toxt molecule and the membrane proteins tcpp/h and toxr/s, which are required for toxt transcription. to identify proteins that negatively affect toxt transcription, we screened transposon mutants of v. cholerae carrying a chromosomally integrated toxt::lacz reporter construct for darker blue colonies on media containing 5-bromo-4-chlor-3-indolyl beta-d galactoside (x-gal). two mutants had transposon ... | 1999 | 10077658 |
| [cholera in africa and in latin america]. | | 1998 | 10078375 |
| [the current status of research on a cholera vaccine]. | cholera remains today a major health problem in most developing countries. the long-term control of cholera depends on the improvement of hygiene but this is a distant goal for many countries. the availability of an effective cholera vaccine is thus important for the prevention of cholera in such countries. more than a century after the first attempt to vaccinate against cholera by ferran in spain, there is still no truly effective cholera vaccine. a bacterial fraction vaccine, referred to as ch ... | 1998 | 10078377 |
| [traveller's diarrhea: which vaccines?]. | diarrheal diseases are a major cause of child morbidity and mortality, particularly in developing countries. it is estimated that diarrheal diseases and typhoid fever cause around 2.5 million deaths per year in the world. four bacteria and one virus share this responsibility: shigella spp, escherichia coli etec, vibrio cholerae, salmonella typhi and rotavirus. people travelling in countries with high endemicity of diarrhoeal diseases risk facing these four bacteria or the less common rotavirus, ... | 1998 | 10078386 |
| bacterial diarrheal pathogens. | | 1999 | 10079856 |
| in vivo expression and immunoadjuvancy of a mutant of heat-labile enterotoxin of escherichia coli in vaccine and vector strains of vibrio cholerae. | vibrio cholerae secretes cholera toxin (ct) and the closely related heat-labile enterotoxin (lt) of escherichia coli, the latter when expressed in v. cholerae. both toxins are also potent immunoadjuvants. mutant lt molecules that retain immunoadjuvant properties while possessing markedly diminished enterotoxic activities when expressed by e. coli have been developed. one such mutant lt molecule has the substitution of a glycine residue for arginine-192 [lt(r192g)]. live attenuated strains of v. ... | 1999 | 10085006 |
| expanded safety and immunogenicity of a bivalent, oral, attenuated cholera vaccine, cvd 103-hgr plus cvd 111, in united states military personnel stationed in panama. | to provide optimum protection against classical and el tor biotypes of vibrio cholerae o1, a single-dose, oral cholera vaccine was developed by combining two live, attenuated vaccine strains, cvd 103-hgr (classical, inaba) and cvd 111 (el tor, ogawa). the vaccines were formulated in a double-chamber sachet; one chamber contained lyophilized bacteria, and the other contained buffer. a total of 170 partially-immune american soldiers stationed in panama received one of the following five formulatio ... | 1999 | 10085055 |
| repair of bhk cell surface ganglioside gm3 after its degradation by extracellular sialidase. | treatment of bhk fibroblasts with v. cholerae sialidase for 20 min caused the breakdown of about 70% of total cellular ganglioside gm3 and the production of an approximately equivalent amount of lactosylceramide. on removal of the enzyme, a slow resynthesis of gm3 from lactosylceramide was observed, equivalent to about 5-6%/h of the degraded gm3. resynthesis of degraded surface ganglioside has not previously been observed, but its magnitude is similar to previous measurements of the rate of prot ... | 1998 | 10087510 |
| [vibrio cholerae o139 (bengal) infection]. | | 1999 | 10088330 |
| [cholera]. | | 1999 | 10088357 |
| intraduodenal inoculation of adult rabbits for evaluating the immunogenicity of genetically attenuated vibrio cholerae strains. | | 1998 | 10090073 |
| vibrio cholerae o1 el tor: identification of a gene cluster required for the rugose colony type, exopolysaccharide production, chlorine resistance, and biofilm formation. | the rugose colony variant of vibrio cholerae o1, biotype el tor, is shown to produce an exopolysaccharide, epsetr, that confers chlorine resistance and biofilm-forming capacity. epsetr production requires a chromosomal locus, vps, that contains sequences homologous to carbohydrate biosynthesis genes of other bacterial species. mutations within this locus yield chlorine-sensitive, smooth colony variants that are biofilm deficient. the biofilm-forming properties of epsetr may enable the survival o ... | 1999 | 10097157 |
| neonatal dietary gangliosides. | gangliosides are glycosphingolipids that are widely distributed in vertebrate tissues and body fluids and which are specially abundant in neural tissues. milk from different species has a particular ganglioside content and profile. human milk has a higher content of gangliosides than bovine milk. gd3 and gm3 are the predominant individual gangliosides in bovine milk. in human colostrum gd3 is also the main ganglioside whereas in human mature milk gm3 predominates over the other gangliosides. hum ... | 1998 | 10102661 |
| localization of dnak and groel in vibrio cholerae. | though the groel and dnak heat shock proteins are well characterized in prokaryotes, only scanty and controversial information exist about their cellular localization. in the present study, the localization of the heat shock proteins dnak and groel in normal and heat shocked cells of vibrio cholerae, was investigated both by immunogold labeling of ultrathin sections and biochemical methods. much of the dnak was found to be localized at the inner membrane in unstressed cells, most probably at the ... | 1999 | 10188245 |
| [vibrio cholerae temperate phage o139: characteristics and role in changing expression of chromosomal virulence genes]. | restriction analysis of temperate cholera phage 139 isolated from vibrio cholerae p16064, serogroup 0139, showed its dna to be double-stranded linear with cohesive terminals. dna-dna hybridization on nylon membranes revealed that many v. cholerae strains of serogroup 0139 isolated in different regions contained a temperate cholera phage 139 in their genomes. southern blot hybridization of chromosomal dna pst-fragments with phage probe showed that the temperate phage 139 was identical to the temp ... | 1999 | 10190102 |
| [comparative study of various methods for determining vibrio cholerae toxigenicity]. | testing of 138 vibrio cholerae strains for gene determinants responsible for the production of cholera enterotoxin by the polymerase chain reaction (pcr) and gene probing using molecular ct-probe showed good correlation of the results of different methods and correlation of these data with studies of v. cholerae strain virulence in vivo and in hemolytic activity test. the advantages of pcr in rapid assessment of the toxigenicity and epidemic significance of v. cholerae strains are demonstrated. | 1999 | 10190103 |
| analysis of an autoregulatory loop controlling toxt, cholera toxin, and toxin-coregulated pilus production in vibrio cholerae. | coordinate expression of many virulence genes in the human pathogen vibrio cholerae is controlled by the toxr, tcpp, and toxt proteins. these proteins function in a regulatory cascade in which toxr and tcpp, two inner membrane proteins, are required to activate toxt and toxt is the direct activator of virulence gene expression. toxt-activated genes include those whose products are required for the biogenesis of cholera toxin (ctx) and the toxin-coregulated pilus, the major subunit of which is tc ... | 1999 | 10198025 |
| molecular characterization of a new ribotype of vibrio cholerae o139 bengal associated with an outbreak of cholera in bangladesh. | vibrio cholerae o139 bengal initially appeared in the southern coastal region of bangladesh and spread northward, causing explosive epidemics during 1992 and 1993. the resurgence of v. cholerae o139 during 1995 after its transient displacement by a new clone of el tor vibrios demonstrated rapid changes in the epidemiology of cholera in bangladesh. a recent outbreak of cholera in two north-central districts of bangladesh caused by v. cholerae o139 led us to analyze strains collected from the outb ... | 1999 | 10203477 |
| gene capture in vibrio cholerae. | | 1999 | 10203830 |
| traditional ribotyping shows a higher discrimination than the automated riboprinter system in typing vibrio cholerae o1. | sixteen clinical vibrio cholerae o1 strains from four different countries were selected for comparison by traditional ribotyping and an automated riboprinter system for identification and discrimination purposes. automated ribotyping, which routinely uses the restriction enzyme ecori for typing all bacterial species, produced only five different ribotypes compared with 10 different ecori ribotypes obtained by the traditional method. traditional and automated ribotyping using the restriction enzy ... | 1999 | 10212447 |
| [bacteriological studies of traveller's diarrhoea (6). analysis of enteropathogenic bacteria at kansai airport quarantine station from september 4th, 1994 through december 1996]. | during the period of investigation from sept. 4, 1994 to dec, 1996, a total of 11,446,534 overseas travellers were quarantined at kansai airport quarantine station, and 22,187 voluntarily reported of episodes suffering from diarrhoea. bacteriological examination of the stools a total of 9,299 individuals' was performed, and the following results were obtained. 1) various enteropathogenic bacteria were isolated from 33.3% of the stools examined. bacterial species isolated were as follows: plesiom ... | 1999 | 10213987 |
| cloning and sequence analysis of the lipase and lipase chaperone-encoding genes from acinetobacter calcoaceticus rag-1, and redefinition of a proteobacterial lipase family and an analogous lipase chaperone family. | the genes encoding the lipase (lipa) and lipase chaperone (lipb) from acinetobacter calcoaceticus rag-1 were cloned and sequenced. the genes were isolated from a genomic dna library by complementation of a lipase-deficient transposon mutant of the same strain. transposon insertion in this mutant and three others was mapped to a single site in the chaperone gene. the deduced amino acid (aa) sequences for the lipase and its chaperone were found to encode mature proteins of 313 aa (32.5kda) and 347 ... | 1999 | 10216267 |
| site-specific integration of the conjugal vibrio cholerae sxt element into prfc. | vibrio cholerae o139, the first non-o1 serogroup of v. cholerae to give rise to epidemic cholera, is characteristically resistant to the antibiotics sulphamethoxazole, trimethoprim, chloramphenicol and streptomycin. resistances to these antibiotics are encoded by a 62 kb self-transmissible, conjugative, chromosomally integrating element designated the 'sxt element'. we found that the sxt element integrates site specifically into both v. cholerae and escherichia coli k-12 into the 5' end of prfc, ... | 1999 | 10216863 |