Publications

molecular properties of bacterial multidrug transporters.	one of the mechanisms that bacteria utilize to evade the toxic effects of antibiotics is the active extrusion of structurally unrelated drugs from the cell. both intrinsic and acquired multidrug transporters play an important role in antibiotic resistance of several pathogens, including neisseria gonorrhoeae, mycobacterium tuberculosis, staphylococcus aureus, streptococcus pneumoniae, pseudomonas aeruginosa, and vibrio cholerae. detailed knowledge of the molecular basis of drug recognition and t ...	2000	11104814
[evaluation of cytotoxic activity of vibrio cholerae non-01 culture filtrate on established cell lines and human diploid cells].	the cell-destroying effect of cell free filtrates of 90 v. cholerae non-01 cultures was measured by titration method in 3 established cell lines: cho, hela and vero and in 3 human diploid cells cultures: mrc-5, wi-38 and pz. the vibrio strains differed in the titre of toxic effect. most sensitive was cho cell line, least sensitive were human diploid cell cultures. it was found that bacterial strains produced different substances toxic for various cell lines. among them nag-st toxin produced by 4 ...	2000	11107788
[toxigenic vibrio cholerae non-01].	the antimicrobial susceptibility and the presence of a heat-stable toxin were researched into 100 non-01 vibrio cholerae strains sent by 7 different health centers to the national reference laboratory of acute diarrheal diseases in "pedro kourí" tropical medicine institute. the presence of 20% toxigenic non-01 vibrio cholerae was detected, a figure substantially higher than that reported in other geographic areas, except for endemic areas. this result will make it possible to set epidemiological ...	2000	11107903
use of the omps-display--system to localize the receptor-binding region in the papg adhesin of uropathogenic escherichia coli.		2000	11109098
characterization of the multimeric eps complex required for cholera toxin secretion.	vibrio cholerae causes diarrheal disease through colonization of the small intestine. a critical aspect of v. cholerae pathogenesis is its ability to actively secrete cholera toxin to the extracellular environment. this occurs via the type ii secretion pathway, where the toxin subunits are first transported to the periplasm through the sec pathway. following folding and assembly the toxin is then translocated across the outer membrane by a specialized extracellular protein secretion (eps) machin ...	2000	11111909
vibriobactin biosynthesis in vibrio cholerae: vibh is an amide synthase homologous to nonribosomal peptide synthetase condensation domains.	the vibrio cholerae siderophore vibriobactin is biosynthesized from three molecules of 2,3-dihydroxybenzoate (dhb), two molecules of l-threonine, and one of norspermidine. of the four genes positively implicated in vibriobactin biosynthesis, we have here expressed, purified, and assayed the products of three: vibe, vibb, and vibh. all three are homologous to nonribosomal peptide synthetase (nrps) domains: vibe is a 2,3-dihydroxybenzoate-adenosyl monophosphate ligase, vibb is a bifunctional isoch ...	2000	11112537
reconstitution and characterization of the vibrio cholerae vibriobactin synthetase from vibb, vibe, vibf, and vibh.	vibriobactin [n(1)-(2,3-dihydroxybenzoyl)-n(5),n(9)-bis[2-(2, 3-dihydroxyphenyl)-5-methyloxazolinyl-4-carboxamido]norspermidine] , is an iron chelator from the cholera-causing bacterium vibrio cholerae. the six-domain, 270 kda nonribosomal peptide synthetase (nrps) vibf, a component of vibriobactin synthetase, has been heterologously expressed in escherichia coli and purified. vibf has an unusual nrps domain organization: cyclization-cyclization-adenylation-condensation-peptidyl carrier protein- ...	2000	11112538
chemoenzymatic synthesis of sialyl oligosaccharides with sialidases employing transglycosylation methodology.	a series of sialyloligosaccharides was synthesized using the transglycolytic activity of the sialidases from vibrio cholerae, clostridium perfringens, salmonella typhimurium, and newcastle disease virus. according to their hydrolytic activities the sialidases from v. cholerae and c. perfringens catalyze preferentially the formation of sialyl alpha(2-6)-linkages whereas the sialidases from s.typhimurium and newcastle disease virus show a distinct preference for alpha(2-3) directed sialylations. u ...	2000	11112571
analysis of hi0220 protein from haemophilus influenzae, a novel structural and functional analog of arcb protein from escherichia coli.	a haemophilus influenzae gene encoding a protein with high homology to arcb receptor protein from escherichia coli has been cloned. an error in the previously reported sequence of this gene has been found, thus increasing its open reading frame. the cloned gene comprising the entire open reading frame restores oxygen-dependent regulation of succinate dehydrogenase in an arcb-deficient e. coli strain. thus, this gene is a functional analog of arcb from e. coli. by screening partially sequenced ba ...	2000	11112851
cloning, sequencing and expression of the gene encoding the extracellular metalloprotease of aeromonas caviae.	a gene (apk) encoding the extracellular protease of aeromonas caviae ae6 has been cloned and sequenced. for cloning the gene, the dna genomic library was screened using skim milk lb agar. one clone harboring plasmid pkk3 was selected for sequencing. nucleotide sequencing of the 3.5 kb region of pkk3 revealed a single open reading frame (orf) of 1,785 bp encoding 595 amino acids. the deduced polypeptide contained a putative 16-amino acid signal peptide followed by a large propeptide. the n-termin ...	2000	10888351
tnaraout, a transposon-based approach to identify and characterize essential bacterial genes.	identification of genes that encode essential products provides a promising approach to validation of new antibacterial drug targets. we have developed a mariner-based transposon, tnaraout, that allows efficient identification and characterization of essential genes by transcriptionally fusing them to an outward-facing, arabinose-inducible promoter, pbad, located at one end of the transposon. in the absence of arabinose, such tnaraout fusion strains display pronounced growth defects. of a total ...	2000	10888841
endotoxin and antiendotoxin antibodies in patients with acute pancreatitis.	to elucidate the time course of endotoxaemia and antiendotoxin antibodies in patients with acute pancreatitis.	2000	10890542
conversion of vibrio eltor mak757 to classical biotype: role of phage ps166.	temperate phage ps166 infection of vibrio eltor mak757 resulted in complete changes in all biotype-specific determinants. about 10% of the ps166 lysogens of mak757 lost their eltor-specific determinants, namely, the ability to produce soluble hemolysin, cell-associated hemagglutinin for chicken erythrocytes, and resistance to polymyxin b, as well as resistance to mukherjee's group iv phage and sensitivity to eltor phage e4. these lysogens were found to have acquired the properties of classical s ...	2000	10891405
mechanism of phage ps166-mediated biotype conversion in vibrio cholerae: role of the hlya locus.	temperate phage ps166 lysogens of vibrio eltor mak757 biotype eltor belong to two major categories. seventy percent of the lysogens acquire auxotrophy for glycine and histidine and maintain their parental biotype. about 10% of the lysogens become cys(-) or cys(-) met(-) and are converted to the classical biotype with complete changes in all biotype-specific determinants. pcr and rflp analysis revealed that in the latter lysogens, the phage genome integrated at the hlya locus, whereas the same lo ...	2000	10891406
requirements for conversion of the na(+)-driven flagellar motor of vibrio cholerae to the h(+)-driven motor of escherichia coli.	bacterial flagella are powered by a motor that converts a transmembrane electrochemical potential of either h(+) or na(+) into mechanical work. in escherichia coli, the mota and motb proteins form the stator and function in proton translocation, whereas the flig protein is located on the rotor and is involved in flagellar assembly and torque generation. the sodium-driven polar flagella of vibrio species contain homologs of mota and motb, called poma and pomb, and also contain two other membrane ...	2000	10894732
vibrio cholerae h-ns silences virulence gene expression at multiple steps in the toxr regulatory cascade.	h-ns is an abundant nucleoid-associated protein involved in the maintenance of chromosomal architecture in bacteria. h-ns also has a role in silencing the expression of a variety of environmentally regulated genes during growth under nonpermissive conditions. in this study we demonstrate a role for h-ns in the negative modulation of expression of several genes within the toxr virulence regulon of vibrio cholerae. deletion of hns resulted in high, nearly constitutive levels of expression of the g ...	2000	10894740
sunlight-induced propagation of the lysogenic phage encoding cholera toxin.	in toxigenic vibrio cholerae, the cholera enterotoxin (ct) is encoded by ctxphi, a lysogenic bacteriophage. the propagation of this filamentous phage can result in the origination of new toxigenic strains. to understand the nature of possible environmental factors associated with the propagation of ctxphi, we examined the effects of temperature, ph, salinity, and exposure to direct sunlight on the induction of the ctx prophage and studied the transmission of the phage to potential recipient stra ...	2000	10899892
a new bacterial white spot syndrome (bwss) in cultured tiger shrimp penaeus monodon and its comparison with white spot syndrome (wss) caused by virus.	this paper describes a new bacterial white spot syndrome (bwss) in cultured tiger shrimp penaeus monodon. the affected shrimp showed white spots similar to those caused by white spot syndrome virus (wssv), but the shrimp remained active and grew normally without significant mortalities. the study revealed no evidence of wssv infection using electron microscopy, histopathology and nested polymerase chain reaction. electron microscopy indicated bacteria associated with white spot formation, and wi ...	2000	10907134
terminal glycosylation of bovine uroplakin iii, one of the major integral-membrane glycoproteins of mammalian bladder.	uroplakin iii (upiii) is one of the major transmembrane glycoproteins exposed at the luminal face of mammalian bladder. we investigated the terminal glycosylation of bovine upiii in order to ascertain whether it contains the alpha 2,3-sialylated sequence thus potentially serving as a receptor for uropathogenic escherichia coli expressing type s adhesins. we report the occurrence of sialic acid in alpha 2,3- and alpha 2,6-linkage to galactose in bovine upiii glycans as evidenced by the sensitivit ...	2000	10913821
iem101, a naturally attenuated vibrio cholerae strain as carrier for genetically detoxified derivatives of cholera toxin.	two mutants of cholera toxin (cts106 containing a pro106-->ser substitution and ctk63 containing a ser63-->lys substitution) with greatly reduced or no toxicity respectively, were expressed in the naturally attenuated iem101 vibrio cholerae strain (el tor, ogawa) which does not express cholera toxin (ct). expression was driven by the natural promoter of ct, or by a promoter known to induce strong in vivo expression such as nirb. in the rabbit ileal loop assay, where 10(4) wild type bacteria were ...	2000	10924789
[vibrio cholerae o139 isolated from humans and the water from open reservoirs: a comparative genotyping].	the comparative study of the genomes of v. cholerae o139 isolated from humans and from water of surface reservoirs was carried out with the use of single- and double-primer polymerase chain reaction (pcr). the profiles of polymorphic dna fragments obtained in this study made it possible to find out differences between groups of strains, as well as the individual features of some of them. the comparison of strains isolated from humans and from water in single-primer pcr revealed that they, in spi ...	2000	10925861
[the expression of the pathogenic properties of the vibrio cholerae o139 serogroup in vitro].	cholera toxin, hemolysin, dermonecrotic and proteolytic factors have been detected and identified in v. cholerae o139. the production of these substances has been found to depend on the conditions of the cultivation of vibrios, and the types of proteases have been determined.	2000	10925862
[the apud-system function of the intestines and the morphological changes in the internal organs of adult rabbits infected with toxigenic vibrio cholerae].	v. cholerae infection with clearly pronounced diarrhea was reproduced in adult rabbits with the use of the ritard system. the state of the apud system of the intestine of the animals and morphological changes in internal organs in experimental cholera were described. as noted in this study, the manifestation of changes in the intestine and other organs, as well as the reaction of apudocytes to v. cholerae infection, were linked with the intensity of diarrhea and the time of the death of the anim ...	2000	10925863
[strains of vibrio cholerae serogroups o1 and o139 that produce the basic protective antigens].	to find out stable and effective producers of major protective antigens intended for use as components of cholera chemical vaccine against v. cholerae strains of serogroups o and o139, the comparative analysis of the production of cholera toxin, toxin-coregulated pili (tcp), antigens o1 and o139, polysaccharide capsule and outer membrane protein ompu in different v. cholerae strains groups o1 and o139 has been made. v. cholerae strain km68, serogroup o1, has been found capable of the production ...	2000	10925874
prediction of transcription terminators in bacterial genomes.	this study describes an algorithm that finds rho-independent transcription terminators in bacterial genomes and evaluates the accuracy of its predictions. the algorithm identifies terminators by searching for a common mrna motif: a hairpin structure followed by a short uracil-rich region. for each terminator, an energy-scoring function that reflects hairpin stability, and a tail-scoring function based on the number of u nucleotides and their proximity to the stem, are computed. a confidence valu ...	2000	10926490
a putative heat-labile enterotoxin expressed by strains of aeromonas media.	fifteen isolates of aeromonas media (seven from diarrhoeal stools, four from water and four from superficial skin ulcers of catfish) were examined for enterotoxin production. ten of these isolates (six diarrhoeal, one from water and three from fish) caused accumulation of fluid in the initial rabbit ileal loop (ril) tests. isolates from diarrhoeal stools and fish caused relatively more fluid accumulation than those from water. those strains that caused little or no fluid accumulation in the init ...	2000	10933251
vaccines for the future: problems and potential solutions from the countries that need them.		2000	10934500
effect of iron on the survival of vibrio cholerae in water.	effect of iron in the form of ferric oxide (fe2o3) on the survival of v. cholerae o1 was studied. v. cholerae o1 survived for 8 days in plain water whereas in presence of fe2o3 it survived up to 15 days. presence of organic material in the water further promoted the bacterial survival by at least 4 days. there was no difference between the behaviour of el tor and classical biotype. these results indicate that the presence of iron in water could promote the survival of v. cholerae o1 in water and ...	2000	10935316
entry into and release of solvents by escherichia coli in an organic-aqueous two-liquid-phase system and substrate specificity of the acrab-tolc solvent-extruding pump.	growth of escherichia coli is inhibited upon exposure to a large volume of a harmful solvent, and there is an inverse correlation between the degree of inhibition and the log p(ow) of the solvent, where p(ow) is the partition coefficient measured for the partition equilibrium established between the n-octanol and water phases. the acrab-tolc efflux pump system is involved in maintaining intrinsic solvent resistance. we inspected the solvent resistance of delta acrab and/or delta tolc mutants in ...	2000	10940021
development of hyperfimbriated strains of vibrio cholerae o1.	the vibrio cholerae o1 and o139 fimbrillin genes (fima or msha) were amplified by polymerase chain reaction and cloned into an escherichia coli pcr vector. these clones were sequenced. the fima sequences were found to be identical between v cholerae o1 and o139. one of the plasmids was digested with ecor i and inserted into the ecor i site of pgex-3x. the plasmid pvpp thus obtained was transferred into strains of wild-type v cholerae o1 bgd17 (classical in biotype) and its fimbriated strain by e ...	2000	10941926
vibrio cholerae ace stimulates ca(2+)-dependent cl(-)/hco(3)(-) secretion in t84 cells in vitro.	ace, accessory cholera enterotoxin, the third enterotoxin in vibrio cholerae, has been reported to increase short-circuit current (i(sc)) in rabbit ileum and to cause fluid secretion in ligated rabbit ileal loops. we studied the ace-induced change in i(sc) and potential difference (pd) in t84 monolayers mounted in modified ussing chambers, an in vitro model of a cl(-) secretory cell. ace added to the apical surface alone stimulated a rapid increase in i(sc) and pd that was concentration dependen ...	2000	10942706
evaluation of oral hypo-osmolar glucose-based and rice-based oral rehydration solutions in the treatment of cholera in children.	in a randomized controlled clinical trial, the efficacy of a low-sodium low-glucose oral rehydration solution (ors) and a low-sodium rice-based ors was compared with standard who glucose ors in the treatment of severe cholera in children aged 2-10y. in total, 120 children were evaluated for the study, of whom 58 patients were positive for vibrio cholerae and were included in the study. of these 58 cases, 19 received rice-based hypo-osmolar ors, 20 received who-ors and 19 received glucose-based h ...	2000	10943958
altered expression of the toxr-regulated porins ompu and ompt diminishes vibrio cholerae bile resistance, virulence factor expression, and intestinal colonization.	the transmembrane transcriptional activators toxr and tcpp modulate expression of vibrio cholerae virulence factors by exerting control over toxt, which encodes the cytoplasmic transcriptional activator of the ctx, tcp, and acf virulence genes. however, toxr, independently of tcpp and toxt, activates and represses transcription of the genes encoding two outer-membrane porins, ompu and ompt. to determine the role of toxr-dependent porin regulation in v. cholerae pathogenesis, the toxr-activated o ...	2000	10944196
prevalence and virulence properties of vibrio cholerae non-o1, aeromonas spp. and plesiomonas shigelloides isolated from cambé stream (state of paraná, brazil).	the incidence of vibrio cholerae, aeromonas spp. and plesiomonas shigelloides was determined in water samples from cambé stream. the samples were collected from seven different sites. the serogroups, virulence markers and drug resistance profiles were also evaluated. twelve aer. hydrophila, 12aer. caviae, eight aer. sobria, seven ple. shigelloides and two v. cholerae non-o1 were isolated. they belonged to different serogroups and all produced haemolysis in different assays. five of the aeromonas ...	2000	10945781
nontoxigenic vibrio cholerae o1 bacteremia: case report and review.		2000	10947231
phagocytic cell killing mediated by secreted cytotoxic factors of vibrio cholerae.	vibrio cholerae strain vb1 secretes a number of enzymes into the outside medium that utilize atp as a substrate. such enzymes are found in the outside medium during the mid-log phase of growth, when the optical density at 650 nm is about 0.4, and they demonstrate nucleoside diphosphate kinase (ndk), 5' nucleotidase, and adenylate kinase (ak) activities. we report that the filtered growth medium of v. cholerae, as well as the flowthrough fraction of a green sepharose column during fractionation o ...	2000	10948107
vibrio cholerae o139 conjugate vaccines: synthesis and immunogenicity of v. cholerae o139 capsular polysaccharide conjugates with recombinant diphtheria toxin mutant in mice.	epidemiologic and experimental data provide evidence that a critical level of serum immunoglobulin g (igg) antibodies to the surface polysaccharide of vibrio cholerae o1 (lipopolysaccharide) and of vibrio cholerae o139 (capsular polysaccharide [cps]) is associated with immunity to the homologous pathogen. the immunogenicity of polysaccharides, especially in infants, may be enhanced by their covalent attachment to proteins (conjugates). two synthetic schemes, involving 1-ethyl-3-(3-dimethylaminop ...	2000	10948122
treasure trove for cholera research.		2000	10952295
dna sequence of both chromosomes of the cholera pathogen vibrio cholerae.	here we determine the complete genomic sequence of the gram negative, gamma-proteobacterium vibrio cholerae el tor n16961 to be 4,033,460 base pairs (bp). the genome consists of two circular chromosomes of 2,961,146 bp and 1,072,314 bp that together encode 3,885 open reading frames. the vast majority of recognizable genes for essential cell functions (such as dna replication, transcription, translation and cell-wall biosynthesis) and pathogenicity (for example, toxins, surface antigens and adhes ...	2000	10952301
characterization of vibrio cholerae o1 antigen as the bacteriophage k139 receptor and identification of is1004 insertions aborting o1 antigen biosynthesis.	bacteriophage k139 was recently characterized as a temperate phage of o1 vibrio cholerae. in this study we have determined the phage adsorption site on the bacterial cell surface. phage-binding studies with purified lipopolysaccharide (lps) of different o1 serotypes and biotypes revealed that the o1 antigen serves as the phage receptor. in addition, phage-resistant o1 el tor strains were screened by using a virulent isolate of phage k139. analysis of the lps of such spontaneous phage-resistant m ...	2000	10960093
predicted highly expressed genes of diverse prokaryotic genomes.	our approach in predicting gene expression levels relates to codon usage differences among gene classes. in prokaryotic genomes, genes that deviate strongly in codon usage from the average gene but are sufficiently similar in codon usage to ribosomal protein genes, to translation and transcription processing factors, and to chaperone-degradation proteins are predicted highly expressed (phx). by these criteria, phx genes in most prokaryotic genomes include those encoding ribosomal proteins, trans ...	2000	10960111
ramón y cajal, microbiologist.		2000	10963336
development and validation of a detection system for wild-type vibrio cholerae in genetically modified cholera vaccine.	orochol, a live oral cholera vaccine licensed in switzerland and in other countries, is based on the genetically modified vibrio cholerae strain cvd103-hgr. this strain is derived from the wild-type o1 strain inaba 569b by deletion of a fragment internal to the ctxa gene encoding the a1 subunit of cholera toxin and by replacement of an internal fragment of the hlya gene with a fragment carrying the mer operon mediating mercury resistance. in this study we describe a polymerase chain reaction (pc ...	2000	10964441
virulence genes in environmental strains of vibrio cholerae.	the virulence of a pathogen is dependent on a discrete set of genetic determinants and their well-regulated expression. the ctxab and tcpa genes are known to play a cardinal role in maintaining virulence in vibrio cholerae, and these genes are believed to be exclusively associated with clinical strains of o1 and o139 serogroups. in this study, we examined the presence of five virulence genes, including ctxab and tcpa, as well as toxr and toxt, which are involved in the regulation of virulence, i ...	2000	10966424
molecular studies of the intestinal mucosal barrier physiopathology using cocultures of epithelial and immune cells: a technical update.	peyer's patch lymphocytes cocultured with caco-2 cells trigger the phenotypic conversion of enterocytes into cells that express morphological and functional m-cell properties. we report a technical update for setting up this model, which will enable the study of m-cell biology, the identification by biochemical approaches of molecules involved in the interaction of microorganisms with m cells, and the development of vectors that would efficiently target the mucosal immune system.	2000	10967292
a cytotoxin-producing strain of vibrio cholerae non-o1, non-o139 as a cause of cholera and bacteremia after consumption of raw clams.	we report a case of a cholera-like gastroenteritis subsequent with bacteremia in a healthy man following consumption of raw clams. although we failed to recover the organism from the patient's stool culture, his blood culture was positive for a non-cholera toxin-producing yet cytotoxin-producing non-o1 and non-o139 vibrio cholerae.	2000	10970422
lipid peroxidation during experimental cholera intoxication.	cholera intoxication in albino mice was induced by intraperitoneal injection of endotoxin in doses of ld(16), ld(25), and ld(50) and combination of endo- and enterotoxin in doses equivalent to ld(25). dose-dependent activation of superoxide dismutase, phasic changes in the contents of mda and conjugated trienes and dienes, and modulatory influence of enterotoxin on catalase activity in the blood were observed during intoxication.	2000	10977911
the o139 serogroup of vibrio cholerae comprises diverse clones of epidemic and nonepidemic strains derived from multiple v. cholerae o1 or non-o1 progenitors.	sixty-four representative strains of vibrio cholerae o139 were analyzed, to re-examine the origin of this serogroup. ribotyping differentiated the strains into 3 hindiii and 7 bgli ribotypes. one hindiii and 5 bgli ribotypes were shared by all toxigenic o139 strains. of 6 nontoxigenic o139 strains, 3 shared ribotypes with the toxigenic strains, carried genes encoding toxin coregulated pilus, and were susceptible to the cholera toxin-converting bacteriophage ctxphi. the remaining 3 strains belong ...	2000	10979913
role and behaviour of the hydrophobic conditions in bacterial adhesion to incurrent siphon in a bivalve mollusc.	surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens playing an important role in microbes retention by the incurrent siphon of a marine bivalve. feeding retention experiments with the bivalve mesodesma donacium was done with hydrophobic strains alone (staphylococcus aureus, salmonella paratyphi, vibrio cholerae) or with mixed cultures using a hydrophilic strain (aeromonas hydrophila). results showed that hydrophobic bacteria are retained in greater numbe ...	2000	10997493
delivery of protein antigens and dna by virulence-attenuated strains of salmonella typhimurium and listeria monocytogenes.	two different plasmid-vector systems were developed which allow the efficient production and presentation of protein antigens in antigen-presenting cells (apc) by means of virulence-attenuated bacteria. the first antigen-delivery system is based on the secretion machinery of the escherichia coli hemolysin (hlya-type i secretion system), which transports proteins, possessing the specific hlya secretion signal (hlya(s)) at the c-terminus, across both membranes of gram-negative bacteria. this syste ...	2000	11000455
activation, stimulation and uptake of bacterial ghosts in antigen presenting cells.	bacterial ghosts have been shown to be an innovative system to prepare vaccines of various bacteria with all features of the intact bacterial cell envelopes, especially all antigenic epitopes, but also to target recombinant proteins inserted in the cell envelopes of the ghost preparations to specific antigen presenting cells. to investigate the activation of the antigen presenting cell by bacterial ghosts in more detail we studied the uptake of bacterial ghosts in dendritic porcine cells and raw ...	2000	11000461
characterization and immunogenicity of vibrio cholerae ghosts expressing toxin-coregulated pili.	bacterial ghosts are attractive for use as non-living vaccines and as carriers of heterologous antigens of vaccine relevance. ghosts were prepared from vibrio cholerae strains of o1 or o139 serogroup after growth under culture conditions, which favor or repress the production of toxin-coregulated pili (tcp). immunoblotting confirmed the tcp status of these v. cholerae ghosts (vcg), which retained the cellular morphology and envelope sub-component profile of viable bacteria. rabbits were immunize ...	2000	11000467
detection of faecal leucocytes & erythrocytes from stools of cholera patients suggesting an evidence of an inflammatory response in cholera.	detection of faecal leucocytes and rbcs in stool samples of cholera patients has been reported in a small number of studies. this study extends these observations by examining stool samples of cholera patients in calcutta.	2000	11006654
vibrio cholerae o139 bengal: a descriptive study.	a prospective study was conducted to determine the clinical and laboratory characteristics and the clinical course of cholera due to vibrio cholerae o139 bengal. the study subjects included 22 adult males with stool culture-proven v. cholerae o139. on enrollment, mean +/- sd concentrations (mmol/l) of serum sodium, potassium, chloride, and bicarbonate were 134 +/- 3, 4 +/- 1, 102 +/- 4, and 13 +/- 4 respectively, and stool sodium, potassium, chloride, and bicarbonate concentrations were 120 +/- ...	2000	11014767
production of heat-labile enterotoxin by strains of aeromonas veronii bv veronii.	three isolates of aeromonas veronii bv veronii (2 environmental, one blood infection) were examined to see if they produce any enterotoxin and, if so, to determine its characteristics. two isolates caused fluid accumulation in the initial rabbit ileal loop tests. the other strain did so after a single passage through the rabbit ileal loop. all the isolates showed gradual enhancement of fluid secretion after each subsequent passage. inocula of 1 x 10(4) viable cells and 0.25 ml of culture filtrat ...	2000	11014770
class 1 integron-borne, multiple-antibiotic resistance encoded by a 150-kilobase conjugative plasmid in epidemic vibrio cholerae o1 strains isolated in guinea-bissau.	in the 1996-1997 cholera epidemic in guinea-bissau, surveillance for antimicrobial resistance showed the emergence of a multidrug-resistant strain of vibrio cholerae o1 during the course of the epidemic. the strain was resistant to ampicillin, erythromycin, tetracycline, furazolidone, aminoglycosides, trimethoprim, and sulfamethoxazole. concomitant with the emergence of this strain, we observed a resurgence in the number of registered cholera cases as well as an increase in the case fatality rat ...	2000	11015401
bacterial virulence gene regulation: an evolutionary perspective.	coevolution between bacteria and their plant or animal hosts determines characteristics of the interaction, the bacterial virulence genes involved, and the regulatory systems controlling expression of virulence genes. the long-standing association between salmonellae and their animal hosts has resulted in the acquisition by salmonella subspecies of a variety of virulence genes and the evolution of complex regulatory networks. the particular repertoire of virulence genes acquired by different sal ...	2000	11018137
detection of toxigenic vibrio cholerae from environmental water samples by an enrichment broth cultivation-pit-stop semi-nested pcr procedure.	a pit-stop semi-nested pcr assay for the detection of toxigenic vibrio cholerae in environmental water samples was developed and its performance evaluated. the pcr technique amplifies sequences within the cholera toxin operon specific for toxigenic v. cholerae. the pcr procedure coupled with an enrichment culture detected as few as four v. cholerae organisms in pure culture. treated sewage, surface, ground and drinking water samples were seeded with v. cholerae and following enrichment, a detect ...	2000	11021588
the vibrio cholerae o1 chromosomal integron.	until the discovery of the vibrio cholerae repeat (vcr), the gene capture and expression systems termed integrons had been typically associated with antibiotic-resistance gene cassettes with usually less than five genes in an array. a method is described for the cloning of the ends of large cassette arrays. conserved restriction sites within vcrs facilitated the mapping by southern hybridization and cloning of the 5' end of the vcr array, and using appropriate fragments it was possible to develo ...	2000	11021935
genetic relationships between clinical and environmental vibrio cholerae isolates based on multilocus enzyme electrophoresis.	a total of 107 isolates of vibrio cholerae, including 29 strains belonging to serogroup o139, were studied using multilocus enzyme electrophoresis (mlee) to determine allelic variation in 15 housekeeping enzyme loci. all loci were polymorphic and 99 electrophoretic types (ets) were identified from the total sample. no significant clustering of isolates was detected in the dendrogram generated from a matrix of coefficients of distances with respect to serogroup, biotype or country of isolation. t ...	2000	11021936
antisense pna effects in escherichia coli are limited by the outer-membrane lps layer.	antisense peptide nucleic acids (pnas) can inhibit escherichia coli gene expression and cell growth through sequence-specific rna binding, and this opens possibilities for novel anti-infective agents and tools for microbial functional genomics. however, the cellular effects of pnas are limited relative to effects in cell extracts, presumably because of cell barrier components such as the outer-membrane lipopolysaccharide (lps) layer or drug efflux pumps, both of which function to exclude antibio ...	2000	11021941
the vibrio cholerae toxr/tcpp/toxt virulence cascade: distinct roles for two membrane-localized transcriptional activators on a single promoter.	toxr is required in vibrio cholerae for transcriptional activation of the toxt gene, the protein product of which activates numerous genes involved in virulence. although toxr cannot activate the toxt promoter in escherichia coli, the products of the tcpph operon are shown here to activate the toxt promoter, and co-expression with toxrs enhances activation. an identical pattern was seen in a deltatcppdeltatoxr strain of v. cholerae when tcpph or toxrs was expressed from plasmids. although overex ...	2000	11029691
[molecular epidemiology of large bacterial endemics in sub-saharan africa].	over the past decades, the differentiation of bacterial strains for epidemiological purposes had been based on conventional phenotypic characters. more recently, methods studying the directly coded molecules or semantides (nucleic acids or proteins) have allowed, concomitantly with the technical progresses of electrophoresis, the description of stable, discriminant, reproducible markers, which were applicable to large series of isolates. initially applied to study nosocomial infections in indust ...	2000	11030062
in vivo covalent cross-linking of cellular actin by the vibrio cholerae rtx toxin.	enteric pathogens often export toxins that elicit diarrhea as a part of the etiology of disease, including toxins that affect cytoskeletal structure. recently, we discovered that the intestinal pathogen vibrio cholerae elicits rounding of epithelial cells that is dependent upon a gene we designated rtxa. here we investigate the association of rtxa with the cell-rounding effect. we find that v. cholerae exports a large toxin, rtx (repeats-in-toxin) toxin, to culture supernatant fluids and that th ...	2000	11032799
construction of a vibrio cholerae vaccine candidate using transposon delivery and flp recombinase-mediated excision.	recent efforts to develop a vaccine against the diarrheal disease cholera have focused on the use of live attenuated strains of the causative organism, vibrio cholerae. the ogawa lipopolysaccharide phenotype is expressed by many epidemic strains, and motility defects reduce the risk of reactive diarrhea in vaccine recipients. we therefore converted a motile inaba(+) vaccine candidate, peru-2, to a nonmotile ogawa(+) phenotype using a mariner-based transposon carrying rfbt, the gene required for ...	2000	11035750
construction and characterization of a nonproliferative el tor cholera vaccine candidate derived from strain 638.	in recent clinical assays, our cholera vaccine candidate strain, vibrio cholerae 638 el tor ogawa, was well tolerated and immunogenic in cuban volunteers. in this work we describe the construction of 638t, a thymidine auxotrophic version of improved environmental biosafety. in so doing, the thya gene from v. cholerae was cloned, sequenced, mutated in vitro, and used to replace the wild-type allele. except for its dependence on thymidine for growth in minimal medium, 638t is essentially indisting ...	2000	11035753
association of protease activity in vibrio cholerae vaccine strains with decreases in transcellular epithelial resistance of polarized t84 intestinal epithelial cells.	culture supernatants prepared from reactogenic strains of vibrio cholerae cause a decrease in the transcellular epithelial resistance of t84 intestinal cells. this decrease correlates with the presence of hemagglutinin/protease but not with the presence of other potential accessory toxins or proteases. these data suggest a possible role for hemagglutinin/protease in reactogenicity, although other factors may also contribute.	2000	11035765
a novel action of the proton pump inhibitor rabeprazole and its thioether derivative against the motility of helicobacter pylori.	the motility of helicobacter pylori was maximum at 37 degrees c and at ph 6. a newly developed proton pump inhibitor, rabeprazole (rpz), and its thioether derivative (rpz-th) markedly inhibited the motility of h. pylori. the concentrations of the drug necessary to inhibit 50% of the motility were 0.25, 16, 16, and >64 microgram/ml for rpz-th, rpz, lansoprazole, and omeprazole, respectively. no such inhibitory effects were observed with h(2) blockers or anti-h. pylori agents. the motilities of ca ...	2000	11036024
bactericidal activity of lemon juice and lemon derivatives against vibrio cholerae.	food products can be possible vectors of the agent responsible for cholera epidemics, because some of these products allow vibrio cholerae o1 to develop to concentrations above the dangerous level. this study deals with the behaviour of essential oils, natural and concentrated lemon juice and fresh and dehydrated lemon peel against v. cholerae o1 biotype eltor serotype inaba tox+. our aim was to evaluate whether these products, used at different dilutions, exhibit bactericidal or bacteriostatic ...	2000	11041258
active intestinal chloride secretion in human carriers of cystic fibrosis mutations: an evaluation of the hypothesis that heterozygotes have subnormal active intestinal chloride secretion.	to explain the very high frequency of cystic fibrosis (cf) mutations in most populations of european descent, it has been proposed that cf heterozygotes have a survival advantage when infected with vibrio cholerae or escherichia coli, the toxins of which induce diarrhea by stimulation of active intestinal chloride secretion. two assumptions underlie this hypothesis: (1) chloride conductance by the cf transmembrane conductance regulator (cftr) is the rate-limiting step for active intestinal chlor ...	2000	11055897
[experimental resistance of vibrio cholerae el tor to nalidixic acid and fluoroquinolones].	it was shown that sensitivity of vibrio cholerae eltor p-5879 to tetracycline, levomycetin, furazolidone, trimethoprim/sulfamethoxazole, aminoglycosides, beta-lactams, rifampicin, quinolones in vitro correlated with drugs efficacy in the treatment of experimental cholera of albino mice. mutants of v. cholerae eltor p-5879 nalr resistant to nalidixic acid (mic 160-200 mg/l) formed with frequency 10(-9)-110(-8) had no cross resistance to fluoroquinolones. but the efficacy of ofloxacin, lomefloxaci ...	2000	11057367
detection of virulence associated genes, haemolysin and protease amongst vibrio cholerae isolated in malaysia.	eighty-four strains of vibrio cholerae o1, o139 and non-o1/non-o139 from clinical and environmental sources were investigated for the presence of the toxin co-regulated pilus gene, tcpa, the virulence cassette genes ctxa, zot, ace and cep and also for their ability to elaborate haemolysin and protease. the ctxa and zot genes were detected using dna-dna hybridization while the ace, cep and tcpa genes were detected using pcr. production of haemolysin and protease was detected using mammalian eryth ...	2000	11057956
rapid method for species-specific identification of vibrio cholerae using primers targeted to the gene of outer membrane protein ompw.	the distribution of genes for an outer membrane protein (ompw) and a regulatory protein (toxr) in vibrio cholerae and other organisms was studied using respective primers and probes. pcr amplification results showed that all (100%) of the 254 v. cholerae strains tested were positive for ompw and 229 ( approximately 98%) of 233 were positive for toxr. none of the 40 strains belonging to other vibrio species produced amplicons with either ompw- or toxr-specific primers, while 80 bacterial strains ...	2000	11060082
emergence of vibrio cholerae o1 biotype el tor serotype inaba from the prevailing o1 ogawa serotype strains in india.	the toxigenic inaba serotype of vibrio cholerae o1 biotype el tor reappeared in india in 1998 and 1999, almost 10 years after its last dominance in calcutta in 1989. extensive molecular characterization by ribotyping, restriction fragment length polymorphism, and pulsed-field gel electrophoresis indicated that recent inaba strains are remarkably different from the earlier inaba strains but are very similar to the prevailing v. cholerae o1 ogawa el tor biotype strains. the antibiograms of the ina ...	2000	11060101
tetracycline resistant cholera in kelantan.	sensitivity testing on vibrio cholerae isolates during an epidemic in 1998 in kelantan identified strains resistant to tetracycline. this prompted a change in the usual management of cholera in kelantan. the antibiotic of choice was changed from tetracycline to erythromycin.	2000	11072502
inorganic polyphosphate in vibrio cholerae: genetic, biochemical, and physiologic features.	vibrio cholerae o1, biotype el tor, accumulates inorganic polyphosphate (poly p) principally as large clusters of granules. poly p kinase (ppk), the enzyme that synthesizes poly p from atp, is encoded by the ppk gene, which has been cloned from v. cholerae, overexpressed, and knocked out by insertion-deletion mutagenesis. the predicted amino acid sequence of ppk is 701 residues (81.6 kda), with 64% identity to that of escherichia coli, which it resembles biochemically. as in e. coli, ppk is part ...	2000	11073913
global spread of microorganisms by ships.		2000	11081499
human zonulin, a potential modulator of intestinal tight junctions.	intercellular tight junctions are dynamic structures involved in vectorial transport of water and electrolytes across the intestinal epithelium. zonula occludens toxin derived from vibrio cholerae interacts with a specific intestinal epithelial surface receptor, with subsequent activation of a complex intracellular cascade of events that regulate tight junction permeability. we postulated that this toxin may mimic the effect of a functionally and immunologically related endogenous modulator of i ...	2000	11082037
vibrio cholerae requires rpos for efficient intestinal colonization.	vibrio cholerae is a facultative intestinal pathogen that lives in aquatic environments, often in association with planktonic species. in the suckling mouse, oral inoculation with v. cholerae leads to intestinal colonization and symptoms of diarrheal disease. results reported here indicate a role for the alternative sigma factor, rpos, in intestinal colonization in this model of cholera. we constructed within rpos multiple independent mutations which consistently resulted in a fivefold decrease ...	2000	11083783
sequence analysis of tnphoa insertion sites in vibrio cholerae mutants defective in rugose polysaccharide production.	vibrio cholerae can switch from a smooth to a wrinkled or rugose colony phenotype characterized by the secretion of a polysaccharide that enables the bacteria to survive harsh environmental conditions. in order to understand the genetic basis of rugosity, we isolated tnphoa-induced stable, smooth mutants of two o1 el tor rugose strains and mapped the insertion sites in several of the mutants using a modified y-adapter pcr technique. one of the tnphoa insertions was mapped to the first gene of th ...	2000	11083805
phylogeny of vibrio cholerae based on reca sequence.	we sequenced a 705-bp fragment of the reca gene from 113 vibrio cholerae strains and closely related species. one hundred eighty-seven nucleotides were phylogenetically informative, 55 were phylogenetically uninformative, and 463 were invariant. not unexpectedly, vibrio parahaemolyticus and vibrio vulnificus strains formed out-groups; we also identified isolates which resembled v. cholerae biochemically but which did not cluster with v. cholerae. in many instances, v. cholerae serogroup designat ...	2000	11083852
ctx prophages in classical biotype vibrio cholerae: functional phage genes but dysfunctional phage genomes.	ctxphi is a filamentous, lysogenic bacteriophage whose genome encodes cholera toxin, the primary virulence factor produced by vibrio cholerae. ctx prophages in o1 el tor and o139 strains of v. cholerae are found within arrays of genetically related elements integrated at a single locus within the v. cholerae large chromosome. the prophages of o1 el tor and o139 strains generally yield infectious ctxphi. in contrast, o1 classical strains of v. cholerae do not produce ctxphi, although they produce ...	2000	11092860
monoclonal antibody ds6 detects a tumor-associated sialoglycotope expressed on human serous ovarian carcinomas.	a newly developed murine monoclonal antibody, ds6, immunohistochemically reacts with an antigen, ca6, that is expressed by human serous ovarian carcinomas but not by normal ovarian surface epithelium or mesothelium. ca6 has a limited distribution in normal adult tissues and is most characteristically detected in fallopian tube epithelium, inner urothelium and type 2 pneumocytes. pre-treatment of tissue sections with either periodic acid or neuraminidase from vibrio cholerae abolishes immunoreact ...	2000	11093807
cluster-analysis & patterns of dissemination of multidrug resistance among clinical strains of vibrio cholerae in calcutta, india.	antimicrobial resistance among vibrio cholerae has been monitored for several years in calcutta. to investigate the changing trends in multidrug resistance (mdr) among different serogroups of v. cholerae and to perform software assisted cluster analysis the current study was undertaken.	2000	11094852
[simultaneous detection and differentiation of o1 classical e1 tor, o139 and nono1 nono139 strains of vibrio cholerae by using multiplex pcr].	to explore the rapid and sensitive procedures for detection and differentiation of o1 classical(cvc), el tor(evc), o139 and nono1 nono139 strains of vibrio cholerae.	2000	11372395
environmental cues and gene expression in porphyromonas gingivalis and actinobacillus actinomycetemcomitans.	microorganisms typically adapt to environmental cues by turning on and off the expression of virulence genes which, in turn, allows for optimal growth and survival within different environmental niches. this adaptation strategy includes sensing and responding to changes in nutrients, ph, temperature, oxygen tension, redox potential, microbial flora, and osmolarity. for a bacterium to adhere to, penetrate, replicate in, and colonize host cells, it is critical that virulence genes are expressed du ...	2000	11355267
year's comments for 2000.		2000	11334302
reappearance of vibrio cholerae serogroup 0139 in yavatmal during june-august-1998.		2000	11271727
clinical profile of non-o1 strain-o139 of vibrio cholerae in the region of ambajogai, maharashtra.	to study clinical profile of the newly emerged novel strain non-o1, o139 of vibrio cholerae, in the region of ambajogai, district beed of maharashtra.	2000	11273144
evaluation of synthetic schemes to prepare immunogenic conjugates of vibrio cholerae o139 capsular polysaccharide with chicken serum albumin.	vibrio cholerae serotype o139 is a new etiologic agent of epidemic cholera. there is no vaccine available against cholera caused by this serotype. v. cholerae o139 is an encapsulated bacterium, and its polysaccharide capsule is an essential virulent factor and likely protective antigen. this study evaluated several synthetic schemes for preparation of conjugates of v. cholerae o139 capsular polysaccharide (cps) with chicken serum albumin as the carrier protein (csa) using 1-ethyl-3(3-dimethylami ...	2000	11294508
improvements for multipurpose bacteriological identification tables to suit the diagnosis of vibrio cholerae.	the aim of the study was to reduce to key tests the 4 extensive polyvalent diagnostic biochemical tables most widely used in croatia and to adapt them for the demonstration of vibrio cholerae and its differentiation from the 3 vibrios (v. alvinolyticus, v. mentschikovii, v. fluvialis) important in differential diagnosis. the fourth table has now been adapted to differentiate among all 12 vibrio species known to be human pathogens (v. mimicus, v. cincinatiensis, v. holisae, v. damsela, v. furnisi ...	2000	11268787
live bacterial delivery systems for development of mucosal vaccines.	by expression of foreign antigens in attenuated strains derived from bacterial pathogens and in non-pathogenic commensal bacteria, recombinant vaccines are being developed that aim to stimulate mucosal immunity. recent advances in the pathogenesis and molecular biology of these bacteria have allowed rational development of new and improved bacterial carriers and more effective gene expression systems. these advances have improved the performance and versatility of these delivery systems to induc ...	2000	11249657
an outbreak of eltor cholera in aizwal town of mizoram, india.	during the months of may, june and through early part of july 1994, an unusual occurrence of severe dehydrating watery diarrhoea cases and deaths were reported from aizwal town, the capital of mizoram, a north-eastern state of india. vibrio cholerae 01 biotype eltor, the causative agent responsible for this outbreak, was isolated from 50.0% of hospitalised cases. the disease affected older children and adults more (52.9%) than younger children below five years of age. vibrio cholerae 01 strains ...	2000	11407007
mechanical carrier of bacterial enteric pathogens by chrysomya megacephala (diptera: calliphoridae) in chiang mai, thailand.	chrysomya megacephala was studied regarding its mechanically bacterial carrier in urban areas of chiang mai, northern thailand. fifty-six adult flies were randomly collected using sweep insect net during april-may, 1999 from 3 fresh food markets and examined for bacteriological isolation. among them, 49 flies (87.5%) were bacterial carriers. the total 22 bacterial species and 8 groups were isolated. three species previously reported as the bacterial enteric pathogens causing diarrheal disease we ...	2000	11414447
[cholera 1].		2000	11385767
[cholera 2].		2000	11385820
modulation of intestinal permeability: a novel and innovative approach for the oral delivery of drugs, macromolecules and antigens.		2000	11255677
serotypes and phage types of vibrio cholerae in mysore.	a total of 565 samples of acute diarrhoeal stools from children received over a period of twelve months from november 1996 to october 1997, yielded 289 (51.15%) isolates of v. cholerae. out of these, 277 (95.85%) were v. cholerae 01 serotype ogawa, 7 (2.42%) were v. cholerae 0139 and 5 (1.73%) were v. cholerae non-o1 non-0139. phage typing of the isolates was carried out by niced calcutta. out of 78 isolates, 69 (88.46%) belong to phage type t27. of the remaining, 3 (3.85%), 3(3.85%), 2(2.56%) a ...	2000	11668944
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