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construction of a vibrio splendidus mutant lacking the metalloprotease gene vsm by use of a novel counterselectable suicide vector.vibrio splendidus is a dominant culturable vibrio in seawater, and strains related to this species are also associated with mortality in a variety of marine animals. the determinants encoding the pathogenic properties of these strains are still poorly understood; however, the recent sequencing of the genome of v. splendidus lgp32, an oyster pathogen, provides an opportunity to decipher the basis of the virulence properties by disruption of candidate genes. we developed a novel suicide vector bas ...200717122399
a microbial diagnostic microarray technique for the sensitive detection and identification of pathogenic bacteria in a background of nonpathogens.a major challenge in microbial diagnostics is the parallel detection and identification of low-bundance pathogens within a complex microbial community. in addition, a high specificity providing robust, reliable identification at least at the species level is required. a microbial diagnostic microarray approach, using single nucleotide extension labeling with gyrb as the marker gene, was developed. we present a novel concept applying competitive oligonucleotide probes to improve the specificity o ...200717123456
phenotypic and molecular typing of vibrio cholerae o1 and o139 isolates from india.to determine whether vibrio cholerae strains with similar phage types are also genetically homogeneous or heterogeneous by molecular typing methods like pfge and rapd-pcr employed in this study.200717087996
identification of vibrio isolates by a multiplex pcr assay and rpob sequence determination.vibrio, a diverse genus of aquatic bacteria, currently includes 72 species, 12 of which occur in human clinical samples. of these 12, three species--vibrio cholerae, vibrio parahaemolyticus, and vibrio vulnificus-account for the majority of vibrio infections in humans. rapid and accurate identification of vibrio species has been problematic because phenotypic characteristics are variable within species and biochemical identification requires 2 or more days to complete. to facilitate the identifi ...200717093013
a recombinant multivalent combination vaccine protects against chlamydia and genital herpes.chlamydia trachomatis and herpes simplex virus type 2 (hsv-2) genital infections pose a considerable public health challenge worldwide. considering the high incidence of coinfections by the two pathogens, a combination vaccine that can be administered as a single regimen would be highly desirable. recombinant vibrio cholerae ghosts (rvcg) offer an attractive approach for the induction of humoral and cellular immune responses against human and animal pathogens. in this study, we evaluated a bival ...200717094789
nmr structure and binding studies confirm that pa4608 from pseudomonas aeruginosa is a pilz domain and a c-di-gmp binding protein.pa4608 is a 125 residue protein from pseudomonas aeruginosa with a recent identification as a pilz domain and putative bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-gmp) adaptor protein that plays a role in bacterial second-messenger regulated processes. the nuclear magnetic resonance (nmr) structure of pa4608 has been determined and c-di-gmp binding has been confirmed by nmr titration studies. the monomeric core structure of pa4608 contains a six-stranded anti-parallel beta barrel fl ...200717096419
structural transitions and thermodynamics of a glycine-dependent riboswitch from vibrio cholerae.riboswitches are complex folded rna domains found in noncoding regions of mrna that regulate gene expression upon small molecule binding. recently, breaker and coworkers reported a tandem aptamer riboswitch (vci-ii) that binds glycine cooperatively. here, we use hydroxyl radical footprinting and small-angle x-ray scattering (saxs) to study the conformations of this tandem aptamer as a function of mg(2+) and glycine concentration. we fit a simple three-state thermodynamic model that describes the ...200717118400
mutants of type ii heat-labile enterotoxin lt-iia with altered ganglioside-binding activities and diminished toxicity are potent mucosal adjuvants.the structure and function lt-iia, a type ii heat-labile enterotoxin of escherichia coli, are closely related to the structures and functions of cholera toxin and lt-i, the type i heat-labile enterotoxins of vibrio cholerae and enterotoxigenic escherichia coli, respectively. while lt-iia is a potent systemic and mucosal adjuvant, recent studies demonstrated that mutant lt-iia(t34i), which exhibits no detectable binding activity as determined by an enzyme-linked immunosorbent assay, with ganglios ...200717118982
questionable merits of the field trial of an oral killed whole cell cholera vaccine in vietnam during 1998-2003. 200717049687
bacteriocin-like inhibitor substances produced by mexican strains of bacillus thuringiensis.bacteriocins are antimicrobial peptides synthesized and secreted by bacteria and could potentially be used as natural food preservatives. here, we report the production of bacteriocin-like inhibitor substances (bt-blis) by five mexican strains of bacillus thuringiensis. bacillus thuringiensis subsp. morrisoni (lbit 269), b. thuringiensis subsp. kurstaki (lbit 287), b. thuringiensis subsp kenyae (lbit 404), b. thuringiensis subsp. entomocidus (lbit 420) and b. thuringiensis subsp. tolworthi (lbit ...200717031616
use of a real time pcr assay for detection of the ctxa gene of vibrio cholerae in an environmental survey of mobile bay.toxigenic vibrio cholerae, the etiological agent of cholera, is a natural inhabitant of the marine environment and causes severe diarrheal disease affecting thousands of people each year in developing countries. it is the subject of extensive testing of shrimp produced and exported from these countries. we report the development of a real time pcr (qpcr) assay to detect the gene encoding cholera toxin, ctxa, found in toxigenic v. cholerae strains. this assay was tested against dna isolated from ...200717034889
safety and immunogenicity of a reformulated vietnamese bivalent killed, whole-cell, oral cholera vaccine in adults.vietnam currently produces an orally administered, bivalent (o1 and o139) killed whole-cell vaccine and is the only country in the world with endemic cholera to use an oral cholera vaccine in public health practice. in order to allow international use, the vaccine had to be reformulated to meet world health organization (who) requirements. we performed a randomized, placebo controlled, safety and immunogenicity studies of this reformulated vaccine among vietnamese adults. one hundred and forty-f ...200717055622
rapid separation and concentration of food-borne pathogens in food samples prior to quantification by viable-cell counting and real-time pcr.buoyant density gradient centrifugation has been used to separate bacteria from complex food matrices, as well as to remove compounds that inhibit rapid detection methods, such as pcr, and to prevent false-positive results due to dna originating from dead cells. applying a principle of buoyant density gradient centrifugation, we developed a method for rapid separation and concentration following filtration and low- and high-speed centrifugation, as well as flotation and sedimentation buoyant den ...200717056684
global gene expression and phenotypic analysis of a vibrio cholerae rpoh deletion mutant.vibrio cholerae, the cause of cholera, can grow in a variety of environments outside of human hosts. during infection, this pathogen must adapt to significant environmental alterations, including the elevated temperature of the human gastrointestinal tract. sigma(32), an alternative sigma factor encoded by rpoh, activates transcription of genes involved in the heat shock response in several bacterial species. here, we assessed the role of sigma(32) in v. cholerae physiology. in aggregate, our fi ...200717085549
characterization of a higba toxin-antitoxin locus in vibrio cholerae.toxin-antitoxin (ta) loci, which were initially characterized as plasmid stabilization agents, have in recent years been detected on the chromosomes of numerous free-living bacteria. vibrio cholerae, the causative agent of cholera, contains 13 putative ta loci, all of which are clustered within the superintegron on chromosome ii. here we report the characterization of the v. cholerae higba locus, also known as vca0391/2. deletion of higa alone was not possible, consistent with predictions that i ...200717085558
regulation of rugosity and biofilm formation in vibrio cholerae: comparison of vpst and vpsr regulons and epistasis analysis of vpst, vpsr, and hapr.vibrio cholerae undergoes phenotypic variation that generates two morphologically different variants, termed smooth and rugose. the transcriptional profiles of the two variants differ greatly, and many of the differentially regulated genes are controlled by a complex regulatory circuitry that includes the transcriptional regulators vpsr, vpst, and hapr. in this study, we identified the vpst regulon and compared the vpst and vpsr regulons to elucidate the contribution of each positive regulator t ...200717071756
temporal quorum-sensing induction regulates vibrio cholerae biofilm architecture.vibrio cholerae, the pathogen that causes cholera, also survives in aqueous reservoirs, probably in the form of biofilms. quorum sensing negatively regulates v. cholerae biofilm formation through hapr, whose expression is induced at a high cell density. in this study, we show that the concentration of the quorum-sensing signal molecule cai-1 is higher in biofilms than in planktonic cultures. by measuring hapr expression and activity, we found that the induction of quorum sensing in biofilm-assoc ...200717074850
comparative expression study to increase the solubility of cold adapted vibrio proteins in escherichia coli.functional and structural studies require gene overexpression and purification of soluble proteins. we wanted to express proteins from the psychrophilic bacterium vibrio salmonicida in escherichia coli, but encountered solubility problems. to improve the solubility of the proteins, we compared the effects of six n-terminal fusion proteins (gb1, z, thioredoxin, gst, mbp and nusa) and an n-terminal his6-tag. the selected test set included five proteins from the fish pathogen v. salmonicida and two ...200717064934
peru-15, a live attenuated oral cholera vaccine, is safe and immunogenic in bangladeshi toddlers and infants.a live oral vibrio cholerae o1 el tor vaccine, peru-15 was tested in a double-blind, randomized placebo controlled study for safety and immunogenicity in phase i and phase ii studies in 240 bangladeshi children aged 9 months-5 years of age. two different doses (2x10(7) and 2x10(8)cfu) were tested. vaccination did not elicit adverse events and the strain was genetically stable. vibriocidal antibody responses developed in 42/50 (84%) toddlers (2-5 years) and 35/50 (70%) of younger children (9-23 m ...200716996172
the role of a heat shock protein from v. cholerae 0139 in the gut immune response.an immunodominant heat shock protein (hsp 24) was purified from vibrio cholerae o139 at 42 degrees c and used as an immunomodulator for studying the gut immune response. t cell clone and t cell line specific for the hsp 24 were generated from the lymphocytes of lamina propria and intra-epithelial lymphocytes of mice orally infected with v. cholerae o139, respectively. the t cell clone was tcr alphabeta(+), cd4(+) and appeared to play an important role in the functioning of gut b-lymphocytes. the ...200717006619
purification and characterization of a lectin from the banana shrimp fenneropenaeus merguiensis hemolymph.a lectin from the hemolymph of the banana shrimp fenneropenaeus merguiensis was purified by affinity chromatography on a fetuin-agarose column following by gel filtration on a superose-12 column. the native molecular mass of purified f. merguiensis lectin (fml) determined by gel filtration was 316.2 kda and its carbohydrate content was estimated to be 4.4%. by sds-page analysis, purified fml consisted of 32.3 kda and 30.9 kda subunits. these data suggest that this lectin is an oligomer. two-dime ...200716934939
generation and characterization of murine monoclonal antibodies to genus-specific 31-kilodalton recombinant cell surface protein of brucella abortus.in the present study hybridomas were produced from fusion with splenocytes of balb/c mice immunized with the recombinant 31-kda cell surface protein (r31csp) specific for brucella species. a set of eight stabilized hybridoma cell lines was generated against r31csp. monoclonal antibodies (mabs) produced by all these clones exhibited reactivity for r31csp as well as with the protein of 31-kda, derived from whole-cell lysate of 31-kda brucella abortus 544. four of eight mabs were igg1, two igg2b, a ...200717725382
the cyclic amp receptor protein modulates quorum sensing, motility and multiple genes that affect intestinal colonization in vibrio cholerae.vibrio cholerae is the causative agent of cholera, which continues to be a major public health concern in asia, africa and latin america. the bacterium can persist outside the human host and alternates between planktonic and biofilm community lifestyles. transition between the different lifestyles is mediated by multiple signal transduction pathways including quorum sensing. expression of the zn-metalloprotease haemagglutinin (ha)/protease is subject to a dual regulation which involves the quoru ...200717768239
vibrio cholerae: cholera toxin.the bacterial protein toxin of vibrio cholerae, cholera toxin, is a major agent involved in severe diarrhoeal disease. cholera toxin is a member of the ab toxin family and is composed of a catalytically active heterodimeric a-subunit linked with a homopentameric b-subunit. upon binding to its receptor, gm0(1), cholera toxin is internalized and transported in a retrograde manner through the golgi to the er, where it is retrotranslocated to the cytosol. here, cholera toxin reaches its intracellula ...200717716938
gene expression of commensal lactobacillus johnsonii strain ncc533 during in vitro growth and in the murine gut.work with pathogens like vibrio cholerae has shown major differences between genes expressed in bacteria grown in vitro and in vivo. to explore this subject for commensals, we investigated the transcription of the lactobacillus johnsonii ncc533 genome during in vitro and in vivo growth using the microarray technology. during broth growth, 537, 626, and 277 of the 1,756 tested genes were expressed during exponential phase, "adaptation" (early stationary phase), and stationary phase, respectively. ...200717827285
orthologous transcription factors in bacteria have different functions and regulate different genes.transcription factors (tfs) form large paralogous gene families and have complex evolutionary histories. here, we ask whether putative orthologs of tfs, from bidirectional best blast hits (bbhs), are evolutionary orthologs with conserved functions. we show that bbhs of tfs from distantly related bacteria are usually not evolutionary orthologs. furthermore, the false orthologs usually respond to different signals and regulate distinct pathways, while the few bbhs that are evolutionary orthologs d ...200717845071
molecular characterization of recent vibrio cholerae o1, el tor, inaba strains isolated from hospitalized patients in kolkata, india.to study the phenotypic and genotypic characterization of newly emerged v. cholerae o1, inaba strains isolated from patients with diarrhoea.200717854903
vibrio cholerae o1 strains with decreased susceptibility to fluoroquinolones in travellers returning from india (rajasthan) to france, april 2007. 200717868606
[cholera and pregnancy: epidemiological, clinical, and evolutionary aspects].this descriptive study had for objective to describe the epidemiological, clinical, therapeutic, and evolutionary aspects of the association cholera and pregnancy during the cholera epidemic in senegal in 2004 and 2005.200717870270
type vi secretion system translocates a phage tail spike-like protein into target cells where it cross-links actin.genes encoding type vi secretion systems (t6ss) are widely distributed in pathogenic gram-negative bacterial species. in vibrio cholerae, t6ss have been found to secrete three related proteins extracellularly, vgrg-1, vgrg-2, and vgrg-3. vgrg-1 can covalently cross-link actin in vitro, and this activity was used to demonstrate that v. cholerae can translocate vgrg-1 into macrophages by a t6ss-dependent mechanism. protein structure search algorithms predict that vgrg-related proteins likely assem ...200717873062
vibrio cholerae o1 el tor cluster in sydney linked to imported whitebait.three cases of cholera in women aged 71, 72 and 84 years were notified in november 2006 in sydney, new south wales. this is the first reported cluster of cholera in australia for over 30 years, and was an unusual outbreak in patients with no history of recent travel to cholera-endemic areas. a food trace-back investigation found that the only exposure common to all cases was consumption of raw whitebait imported from indonesia. this outbreak demonstrates that the practice of eating raw whitebait ...200717874982
regulatory networks controlling vibrio cholerae virulence gene expression. 200717875629
detection of viable and viable nonculturable vibrio cholerae o1 through cultures and immunofluorescence in the tucumán rivers, argentina.vibrio cholerae has been sporadically isolated from rivers in tucumán, argentina, since the outbreak in 1991. the aim of this study was to determine the environmental reservoir of the bacterium in these rivers, assessing the presence of vibrio cholerae non-o1 and o1 (the latter both in its viable culturable and non culturable state) and its relationship to environmental physicochemical variables. 18 water samplings were collected in the salí river (in canal norte and banda) and the lules river b ...200717876456
[molecular subtyping of vibrio cholerae isolates by pulsed-field gel electrophoresis in shenzhen from 1993].to determine the genetic relationships between different vibrio cholerae isolates in shenzhen from 1993 to 2002.200717877182
application of duplex-pcr in rapid and reliable detection of toxigenic vibrio cholerae in water samples in thailand.toxigenic vibrio cholerae, the cause of cholera, is a native flora of the aquatic environment which is transmitted through drinking water and still remains the leading cause of morbidity and mortality in many developing countries including thailand. the culture method (cm), which is routinely used for assessing water quality, has not proven as efficient as molecular methods because the notorious pathogen survives in water mostly in a non-culturable state. we employed duplex-polymerase chain reac ...200717878662
virulence genes of clinical vibrio cholerae o1 isolates in thailand and their ribotypes.to determine virulence associated-genes and ribotypes of vibrio cholerae epidemic strains isolated from cholera patients in thailand.200717881059
development of peptide mimics of a protective epitope of vibrio cholerae ogawa o-antigen and investigation of the structural basis of peptide mimicry.as an alternative approach toward the development of a cholera vaccine, the potential of peptide mimics of vibrio cholerae lipopolysaccharide (lps) to elicit cross-reactive immune responses against lps was investigated. two closely related protective monoclonal antibodies, s-20-4 and a-20-6, which are specific for ogawa o-antigen (o-specific polysaccharide; o-sp) of v. cholerae o1, were used as the target antibodies (abs) to pan phage display libraries under different elution conditions. six pha ...200717881351
comparison of different electrophoretic parameters of pulse-field gel electrophoresis for vibrio cholerae subtyping.molecular subtyping is used to distinguish pathogenic bacterial strains during epidemiological surveys of infectious diseases and the discovery of novel pathogens. there is a need to standardize protocols involving pulse-field gel electrophoresis (pfge), a crucial method in molecular subtyping, to make inter-laboratory results comparable and information exchange possible. the pfge pattern varies with electrophoretic parameters (eps), so it is important to select the parameter that can distinguis ...200717689765
vpsa- and luxo-independent biofilms of vibrio cholerae.the natural life cycle of vibrio cholerae involves the transitioning of cells between different environmental surfaces such as the chitinous shell of crustaceae and the epithelial layer of the human intestine. previous studies using static biofilm systems showed a strict dependence of biofilm formation on the vps and lux genes, which are essential for exopolysaccharide formation and cell-cell signaling, respectively. the authors' report here that in biofilms grown under hydrodynamic conditions, ...200717697110
transcriptional upregulation of inflammatory cytokines in human intestinal epithelial cells following vibrio cholerae infection.coordinated expression and upregulation of interleukin-1alpha, interleukin-1beta, tumor necrosis factor-alpha, interleukin-6, granulocyte-macrophage colony-stimulating factor, interleukin-8, monocyte chemotactic protein-1 (mcp-1) and epithelial cell derived neutrophil activator-78, with chemoattractant and proinflammatory properties of various cytokine families, were obtained in the intestinal epithelial cell line int407 upon vibrio cholerae infection. these proinflammatory cytokines also showed ...200717697117
the safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of at-1001 in coeliac disease subjects: a proof of concept study.lifelong adherence to a strict gluten-free diet is the cornerstone of coeliac disease treatment. elucidation of disease pathogenesis has created opportunities for novel therapeutic approaches to coeliac disease. at-1001 is an inhibitor of paracellular permeability whose structure is derived from a protein secreted by vibrio cholerae.200717697209
prolonged colonization of mice by vibrio cholerae el tor o1 depends on accessory toxins.cholera epidemics caused by vibrio cholerae el tor o1 strains are typified by a large number of asymptomatic carriers who excrete vibrios but do not develop diarrhea. this carriage state was important for the spread of the seventh cholera pandemic as the bacterium was mobilized geographically, allowing the global dispersion of this less virulent strain. virulence factors associated with the development of the carriage state have not been previously identified. we have developed an animal model o ...200717698571
hemolysin and the multifunctional autoprocessing rtx toxin are virulence factors during intestinal infection of mice with vibrio cholerae el tor o1 strains.the seventh cholera pandemic that started in 1961 was caused by vibrio cholerae o1 strains of the el tor biotype. these strains produce the pore-forming toxin hemolysin, a characteristic used clinically to distinguish classical and el tor biotypes. even though extensive in vitro data on the cytolytic activities of hemolysin exist, the connection of hemolysin to virulence in vivo is not well characterized. to study the contribution of hemolysin and other accessory toxins to pathogenesis, we utili ...200717698573
changes in nucleoid morphology and origin localization upon inhibition or alteration of the actin homolog, mreb, of vibrio cholerae.mreb is an actin homolog required for the morphogenesis of most rod-shaped bacteria and for other functions, including chromosome segregation. in caulobacter crescentus and escherichia coli, the protein seems to play a role in the segregation of sister origins, but its role in bacillus subtilis chromosome segregation is less clear. to help clarify its role in segregation, we have here studied the protein in vibrio cholerae, whose chromosome i segregates like the one in c. crescentus and whose ch ...200717704222
occurrence, significance & molecular epidemiology of cholera outbreaks in west bengal.diarrhoeal disease outbreaks are causes of major public health emergencies in india. we carried out investigation of two cholera outbreaks, for identification, antimicrobial susceptibility testing, phage typing and molecular characterization of isolated vibrio cholerae o1, and to suggest prevention and control measures.200717704555
[investigation on status of pollution of vibrio cholera in seafood and aquatic products in 12 provinces of china in 2005].to understand the pollution rates of vibrio cholera (v. cholera) in different seafood, aquatic products and their circulatory processes, so as to help making measures for cholera control and prevention.200717708875
martx, multifunctional autoprocessing repeats-in-toxin toxins. 200717646359
genetic variation of capsule/lps biogenesis in two serogroup o31 vibrio cholerae isolates.both nrt36s and a5 are nag-st-producing, serogroup o31 vibrio cholerae. nrt36s is encapsulated and causes diarrhea when administered to volunteers; a5 is unencapsulated and does not colonize or cause illness in humans. the capsule/lps (cps/lps) biogenesis regions in these two isolates were similar except that a 6.5-kb fragment in a5 has replaced a 10-kb fragment in nrt36s in the middle of the cps/lps gene cluster. although the genes of the replaced region were homologous to genes from other cps/ ...200717651134
use of hp selective medium to detect helicobacter pylori associated with other enteric bacteria in seawater and marine molluscs.this project investigated the utility of hp selective medium to isolate h. pylori cells from seawater and from marine molluscs.200717651221
[pathogenic vibrios in oysters (crassostrea rhizophorae) served at restaurants in rio de janeiro: a public health warning].forty oyster samples (crassostrea rhizophorae) served raw in 15 restaurants in the city of rio de janeiro were evaluated in order to investigate the presence of vibrio spp. the oyster samples were analyzed and subjected to enrichment in alkaline peptone water with the addition of 1 and 3% nacl and incubated at 37 degrees c for 24 hours. following this, the cultures were seeded onto thiosulfate citrate bile sucrose agar (tcbs) and the suspected colonies were subjected to biochemical characterizat ...200717653465
regulation of virulence in vibrio cholerae: the toxr regulon.vibrio cholerae is a gram-negative bacterium that is the causative agent of cholera. this disease consists of enormous fluid loss through stools, which can be fatal. cholera epidemics appear in explosive outbreaks that have occurred repeatedly throughout history. the virulence factors toxin coregulated pilus (tcp) and cholera toxin (ct) are essential for colonization of the host and enterotoxicity, respectively. these virulence factors are under the control of toxt, an arac/xyls family protein t ...200717661707
[transcriptional repressor gene--mtlr of mannitol pts operon in vibrio cholerae].the fermentation rates of mannitol in toxigenic and non-toxigenic el tor strains of vibrio cholerae are obviously different, which is a valuable indicator in the rapid identification of toxigenic strain. to determine the regulating role of mtlr in transcription of mannitol pts operon in v. cholerae, and whether it plays a role in the ferment difference of the toxigenic and non-toxigenic strains, the mtlr deletion mutants from the mannitol rapid-ferment strain (non-toxigenic strain) and slow-ferm ...200717672318
comparative genomics and site-directed mutagenesis support the existence of only one input channel for protons in the c-family (cbb3 oxidase) of heme-copper oxygen reductases.oxygen reductase members of the heme-copper superfamily are terminal respiratory oxidases in mitochondria and many aerobic bacteria and archaea, coupling the reduction of molecular oxygen to water to the translocation of protons across the plasma membrane. the protons required for catalysis and pumping in the oxygen reductases are derived from the cytoplasmic side of the membrane, transferred via proton-conducting channels comprised of hydrogen bond chains containing internal water molecules alo ...200717676874
simultaneous direct detection of toxigenic and non-toxigenic vibrio cholerae from rectal swabs and environmental samples by sandwich elisa.a mab-based simple, specific and rapid two-tip dipstick elisa was developed for simultaneous detection of toxin- and non-toxin-producing strains of vibrio cholerae, and for direct detection of v. cholerae from rectal swabs of patients and from environmental water samples. rabbit polyclonal antibodies and murine mabs were raised against recombinant protein (r-protein) antigens of cholera toxin b (ctxb) and outer membrane protein w (ompw). rabbit polyclonal antibodies to both r-proteins were coate ...200717893171
a novel multiplex pcr for the identification of vibrio parahaemolyticus, vibrio cholerae and vibrio vulnificus.to establish a simple multiplex polymerase chain reaction (pcr) that will identify vibrio parahaemolyticus, vibrio cholerae and vibrio vulnificus.200717897378
vcer negatively regulates the vcecab mdr efflux operon and positively regulates its own synthesis in vibrio cholerae 569b.the vcecab (vce) operon encodes the multidrug resistance pump vcecab (vce), which contributes to resistance of vibrio cholerae to carbonyl cyanide m-chlorophenylhydrazine (cccp), deoxycholate, and pentachlorophenol by several-fold. vcer, which encodes the tetr-type repressor vcer and is divergently transcribed from vce, has been characterized in escherichia coli. detailed characterization of vcer in v. cholerae 569b confirmed the repressive effect of vcer on vce function and indicated several no ...200717898844
differential regulation of interchromosomal copies of toxr-induced genes.in vibrio cholerae, toxr transcriptionally activates a number of virulence genes in response to various environmental signals. in the present study, transcription profiling by macroarray was carried out with 13 pairs of genes, one copy of which is present in each chromosome under toxr-inducing (ph 6.5, osmolarity 66 mmol/l, 30 degrees c) and toxr-repressing (ph 8.5, osmolarity 300 mmol/l, 37 degrees c) conditions followed by high ph (8.5) and low ph (6.5) conditions to eliminate ph effect. the g ...200717898856
putative virulence genes of vibrio cholerae from seafoods and the coastal environment of southwest india.shrimp, clam and oysters were obtained at two fish markets and at a fish landing dock, and plankton, water and sediment samples were obtained from four river estuaries, in southern india. the samples were analyzed for vibrio cholerae by conventional isolation techniques and by polymerase chain reaction (pcr) procedures. v. cholerae was isolated from 2 of 5 shrimp, 2 of 5 clam and 5 of 20 water samples. all biochemically confirmed isolates of v. cholerae were positive for toxr. for direct detecti ...200717900729
phenotypic characterization of pore mutants of the vibrio cholerae porin ompu.general-diffusion porins form large beta-barrel channels that control the permeability of the outer membrane of gram-negative bacteria to nutrients, some antibiotics, and external signals. here, we have analyzed the effects of mutations in the ompu porin of vibrio cholerae at conserved residues that are known to affect pore properties in the escherichia coli porins ompf and ompc. various phenotypes were investigated, including sensitivity to beta-lactam antibiotics, growth on large sugars, and s ...200717905973
pathogenicity, antibiotic susceptibility and genetic similarity of environmental and clinical isolates of vibrio cholerae.isolates of vibrio cholerae were obtained from clinical and environmental samples and the pathogenicity of these isolates was confirmed by hemolytic assay. the clinical isolates were more pathogenic than environmental isolates. antibiotic susceptibility of v. cholerae to a set of antibiotics showed a marked variation. the environmental isolates exhibited more resistance to the antibiotics than clinical isolates. the plasmid curing technique was used to check the encoding of antibiotic resistance ...200717907749
pulsenet usa standardized pulsed-field gel electrophoresis protocol for subtyping of vibrio parahaemolyticus.pulsenet is a national molecular subtyping network for foodborne disease surveillance composed of public health and food regulatory agencies. participants employ molecular subtyping of foodborne pathogens using a standardized method of pulsed-field gel electrophoresis (pfge) for conducting laboratory-based surveillance of foodborne pathogens. the pulsenet standardized pfge protocols are developed through a comprehensive testing process. the reproducibility of the protocol undergoes an internal e ...200717883312
the chitin catabolic cascade in the marine bacterium vibrio cholerae: characterization of a unique chitin oligosaccharide deacetylase.chitin, one of the most abundant organic substances in nature, is consumed by marine bacteria, such as vibrio cholerae, via a multitude of tightly regulated genes (li and roseman 2004, proc natl acad sci usa. 101:627-631). one such gene, cod, is reported here. it encodes a chitin oligosaccharide deacetylase (cod), when cells are induced by chitobiose, (glcnh(2))(2), or crude crab shells. cod was molecularly cloned (cod-6his), overproduced, and purified to apparent homogeneity. cod is secreted at ...200717884842
[vibrio cholerae hemolytic activity].mechanisms of realization of vibrio cholerae hemolytic activitywere analyzed using summarized own results and data from the literature. it has been shown that lectin receptor, which coded by hlya gene, participates in lysis of sheep erythrocytes, but not of rabbit erythrocytes, as well as interact with d-galactose with selectivity to 3 anomers. lectin nature of hlya can determine formation of its complexes with lypopolysaccharides (lps) and enzymes, which promote realization of hemolysis (by lip ...200717886381
a semi-automated vibriocidal assay for improved measurement of cholera vaccine-induced immune responses.vibriocidal antibody assay has been a surrogate standard assay in the evaluation of cholera vaccine efficacy because it has a good correlation with protection. although the optical density-based vibriocidal assay in a 96-well microtiter-plate format is widely used in clinical trials, it has limitations as vibriocidal titers are altered by incubation time and samples with the same end-point titers could have potentially different vibriocidal kinetics. in the present study, we developed an improve ...200717888533
pathogenicity of environmental isolates of v. cholerae in mice.environmental v. cholerae (vc) have the potential for virulence in people and they may also be a reservoir of accessory virulence genes. we infected mice with two non-o1, non-o139 vc (tp and sio) that were isolated in san diego county and compared them to vc o1 el tor n16961 using a model of pneumonia in adult mice. live but not heat killed vc el tor and tp caused fatal hemorrhagic pneumonia despite a >90% decrease in cfu in 24h suggesting the disease was toxin mediated. sio did not cause pneumo ...200717890125
structural studies on vibrio cholerae toxr periplasmic and cytoplasmic domains.the transcription activator toxr controls the expression of cholera toxin, pilus colonization factor and outer membrane protein in vibrio cholerae. it binds to the 5'-ttttgat-3' tandemly repeated dna sequence in the cholera toxin promoter region. toxr is a membrane protein having distinct periplasmic and cytoplasmic domains. the two domains have been cloned, over-expressed and purified for structural studies. the cytoplasmic domain is more compact than the periplasmic domain. the periplasmic dom ...200717890167
compromised outer membrane integrity in vibrio cholerae type ii secretion mutants.the type ii secretion (t2s) system of vibrio cholerae is a multiprotein complex that spans the cell envelope and secretes proteins important for pathogenesis as well as survival in different environments. here we report that, in addition to the loss of extracellular secretion, removal or inhibition of expression of the t2s genes, epsc-n, results in growth defects and a broad range of alterations in the outer membrane that interfere with its barrier function. specifically, the sensitivity to memb ...200717890307
the cyclic amp receptor protein modulates colonial morphology in vibrio cholerae.inactivation of the quorum-sensing regulator hapr causes vibrio cholerae el tor biotype strain c7258 to adopt a rugose colonial morphology that correlates with enhanced biofilm formation. v. cholerae mutants lacking the cyclic amp (camp) receptor protein (crp) produce very little hapr, which results in elevated expression of vibrio exopolysaccharide (vps) genes and biofilm compared to the wild type. however, deltacrp mutants still exhibited smooth colonial morphology and expressed reduced levels ...200717921282
mapping critical interactive sites within the periplasmic domain of the vibrio cholerae type ii secretion protein epsm.the type ii secretion (t2s) system is present in many gram-negative species, both pathogenic and nonpathogenic, where it supports the delivery of a variety of toxins, proteases, and lipases into the extracellular environment. in vibrio cholerae, the t2s apparatus is composed of 12 eps proteins that assemble into a multiprotein complex that spans the entire cell envelope. two of these proteins, epsm and epsl, are key components of the secretion machinery present in the inner membrane. in addition ...200717921296
cholera toxin, lt-i, lt-iia and lt-iib: the critical role of ganglioside binding in immunomodulation by type i and type ii heat-labile enterotoxins.the heat-labile enterotoxins expressed by vibrio cholerae (cholera toxin) and escherichia coli (lt-i, lt-iia and lt-iib) are potent systemic and mucosal adjuvants. coadministration of the enterotoxins with a foreign antigen produces an augmented immune response to that antigen. although each enterotoxin has potent adjuvant properties, the means by which the enterotoxins induce various immune responses are distinctive for each adjuvant. various mutants have been engineered to dissect the function ...200717931161
[viable but non-culturable form of bacteria].viable but non-culturable (vbnc) bacteria concept has been defined in 1982 when it has been shown that there exists bacteria whose metabolic activity continue and which can have the ability to reproduce in suitable conditions although they have lost their capability to reproduce in culture. recent studies have shown that most of the human pathogens (campylobacter spp., escherichia coli, francisella tularensis, helicobacter pylori, legionella pneumophila, listeria monocytogenes, mycobacterium tub ...200717933263
[establishment of fluorescent amplified fragment length polymorphism in vibrio cholerae and evaluation in molecular typing].to develop fluorescent amplified fragment length polymorphism (aflp) method and to evaluate the its typing capability with pulsed-field gel electrophoresis (pfge) in molecular typing of vibrio cholerae.200717939389
selective chromosome amplification in vibrio cholerae.most bacteria have one chromosome but some have more than one, as is common in eukaryotes. how multiple chromosomes are maintained in bacteria remains largely obscure. here we have examined the behaviour of the two vibrio cholerae chromosomes as a function of growth rate. at slow growth rates, both chromosomes were maintained at copy numbers of one to two per cell. increasing the growth rate by nutritional shift-up amplified the origin-proximal dna of the larger chromosome (chri) to four copies ...200717944831
association of vibrio cholerae o1 el tor and o139 bengal with the copepods acartia tonsa and eurytemora affinis.the association of vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (v. cholerae o1 el tor and o139) in the aquatic environment. to date, interactions between specific serogroups and species of plankton remain poorly understood. laboratory microcosm experiments were carried out to compare q ...200717951440
rapid detection of the vibrio cholerae ctx gene in food enrichments using real-time polymerase chain reaction.a real-time polymerase chain reaction (qpcr) assay for the detection of the ctxa gene of toxigenic vibrio cholerae (vc) was validated against standard culture techniques. the first experimental phase determined optimal enrichment conditions for detection by culture and qpcr of vc in shrimp, bottled water, milk, and potato salad. the conditions tested included temperature (35 and 42 degrees c), time (6 and 18 h), and effect of shaking (0 and 100 rpm). no definitive trends were found with enrichme ...200717955973
characterization of vibrio cholerae aerotaxis.the ability to move toward favorable environmental conditions, called chemotaxis, is common among motile bacteria. in particular, aerotaxis has been extensively studied in escherichia coli and was shown to be dependent on the aer and tsr genes. three putative aer gene homologs were identified in the vibrio cholerae genome, designated aer-1 (vc0512), aer-2 (vca0658), and aer-3 (vca0988). deletion analyses indicated that only one of them, aer-2, actively mediates an aerotaxis response, as assayed ...200717956426
[identification and molecular study on vibrio cholerae in sea products].to investigate the serologic type, phage-biotype and toxic factor of vibrio cholerae isolated from different sea products, analyze the relation between the vibrio cholerae in sea products and cholera epidemiology, and provide references for forecasting cholera epidemic situation and drawing out a preventing plan.200717959056
phylogenetic analysis of vibrios and related species by means of atpa gene sequences.we investigated the use of atpa gene sequences as alternative phylogenetic and identification markers for vibrios. a fragment of 1322 bp (corresponding to approximately 88% of the coding region) was analysed in 151 strains of vibrios. the relationships observed were in agreement with the phylogeny inferred from 16s rrna gene sequence analysis. for instance, the vibrio cholerae, vibrio halioticoli, vibrio harveyi and vibrio splendidus species groups appeared in the atpa gene phylogenetic analyses ...200717978204
generation and characterization of murine monoclonal antibodies to recombinant 26-kda periplasmic protein of brucella abortus.in the present study, hybridomas were developed for the production of monoclonal antibodies (mab) against recombinant 26-kda periplasmic protein (rbp26) of brucella abortus. a set of six stabilized hybridoma cell lines were generated. monoclonal antibodies secreted by all of these clones exhibited reaction for rbp26, as well as with the protein of 26-kda, derived from whole cell lysate of b. abortus 544. three out of six mabs were igg1, two were igm, and one was igg2b in nature. these mabs did n ...200717979549
effectiveness in prevention of travellers' diarrhoea by an oral cholera vaccine wc/rbs.to investigate the effectiveness of an oral cholera vaccine (dukoral((r))) in preventing travellers' diarrhoea.200717983977
emergence of multidrug-resistant strain of vibrio cholerae o1 in bangladesh and reversal of their susceptibility to tetracycline after two years. 200717985827
molecular mechanisms of virstatin resistance by non-o1/non-o139 strains of vibrio cholerae.virstatin is a previously described small molecule inhibitor of vibrio cholerae virulence. we have demonstrated that the molecule inhibits the activity of the transcriptional activator toxt, thereby preventing elaboration of the toxin co-regulated pilus (tcp) and cholera toxin in vitro and in vivo in o1 strains of v. cholerae. while strains of the o1 and o139 serogroups are the cause of most epidemic and endemic cholera currently seen globally, sporadic disease caused by strains of non-o1/non-o1 ...200717986190
an in vivo expression technology screen for vibrio cholerae genes expressed in human volunteers.in vivo expression technology (ivet) has been widely used to study gene expression of human bacterial pathogens in animal models, but has heretofore not been used in humans to our knowledge. as part of ongoing efforts to understand vibrio cholerae pathogenesis and develop improved v. cholerae vaccines, we have performed an ivet screen in humans for genes that are preferentially expressed by v. cholerae during infection. a library of 8,734 nontoxigenic v. cholerae strains carrying transcriptional ...200717986616
vibrio infections in louisiana: twenty-five years of surveillance 1980-2005.a total of 1,007 vibrio infections were reported to the infectious disease epidemiology department at the louisiana office of public heath, between 1980 and 2005. the most common were vibrio vulnificus (257 infections), vibrio parahemolyticus (249 infections), and vibrio cholerae non o1 (200 cases). other species were much less common. vibrio vulnificus infections, which are associated with consumption of raw seafood (particularly oysters) or contact with sea water, and severe immuno-suppression ...200717987958
viable but nonculturable vibrio cholerae o1 in biofilms in the aquatic environment and their role in cholera transmission.vibrio cholerae persists in aquatic environments predominantly in a nonculturable state. in this study coccoid, nonculturable v. cholerae o1 in biofilms maintained for 495 days in mathbaria, bangladesh, pond water became culturable upon animal passage. culturability, biofilm formation, and the wbe, ctxa, and rstr2 genes were monitored by culture, direct fluorescent antibody (dfa), and multiplex pcr. dfa counts were not possible after formation of biofilm. furthermore, wbe, but not ctxa, were amp ...200717968017
[the centenary of the discovery of the vibrio el tor (1905) or dubious beginnings of the seventh pandemic of cholera].as a direct result of the 1865 cholera epidemic, health authorities have realized that the mecca pilgrimage represented a permanent risk for the global diffusion of this scourge. it was decided to open five quarantine stations along the red sea, among them the el tor station. there, felix gotschlich, in 1905, isolated for the first time the el tor vibrio from pilgrims deceased when coming back from mecca. this vibrio had atypical biologic properties. although agglutinated by specific antisera, i ...200717992832
a clarion call for greater investment in global sanitation. 200717993346
a structural study of gdp-4-keto-6-deoxy-d-mannose-3-dehydratase: caught in the act of geminal diamine formation.di- and trideoxysugars are an important class of carbohydrates synthesized by certain plants, fungi, and bacteria. colitose, for example, is a 3,6-dideoxysugar found in the o-antigens of gram-negative bacteria such as escherichia coli, salmonella enterica, yersinia pseudotuberculosis, and vibrio cholerae, among others. these types of dideoxysugars are thought to serve as antigenic determinants and to play key roles in bacterial defense and survival. four enzymes are required for the biochemical ...200717997582
the major vibrio cholerae autoinducer and its role in virulence factor production.vibrio cholerae, the causative agent of the human disease cholera, uses cell-to-cell communication to control pathogenicity and biofilm formation. this process, known as quorum sensing, relies on the secretion and detection of signalling molecules called autoinducers. at low cell density v. cholerae activates the expression of virulence factors and forms biofilms. at high cell density the accumulation of two quorum-sensing autoinducers represses these traits. these two autoinducers, cholerae aut ...200718004304
flexibility in the abc transporter msba: alternating access with a twist.atp-binding cassette (abc) transporters are integral membrane proteins that translocate a wide variety of substrates across cellular membranes and are conserved from bacteria to humans. here we compare four x-ray structures of the bacterial abc lipid flippase, msba, trapped in different conformations, two nucleotide-bound structures and two in the absence of nucleotide. comparison of the nucleotide-free conformations of msba reveals a flexible hinge formed by extracellular loops 2 and 3. this hi ...200718024585
complexity of rice-water stool from patients with vibrio cholerae plays a role in the transmission of infectious diarrhea.at the international centre for diarrhoeal disease research, bangladesh, one-half of the rice-water stool samples that were culture-positive for vibrio cholerae did not contain motile v. cholerae by standard darkfield microscopy and were defined as darkfield-negative (df(-)). we evaluated the host and microbial factors associated with df status, as well as the impact of df status on transmission. viable counts of v. cholerae in df(-) stools were three logs lower than in df(+) stools, although df ...200718024592
a type iii secretion system in vibrio cholerae translocates a formin/spire hybrid-like actin nucleator to promote intestinal colonization.we have previously characterized a non-o1, non-o139 vibrio cholerae strain, am-19226, that lacks the known virulence factors but contains components of a type iii secretion system (t3ss). in this study, we demonstrated that the t3ss is functional and is required for intestinal colonization in the infant mouse model. we also identified vopf, which is conserved among t3ss-positive v. cholerae strains, as an effector containing both formin homology 1-like (fh1-like) and wasp homology 2 (wh2) domain ...200718005688
genes induced late in infection increase fitness of vibrio cholerae after release into the environment.the facultative pathogen vibrio cholerae can exist in both the human small bowel and in aquatic environments. while investigation of the infection process has revealed many factors important for pathogenesis, little is known regarding transmission of this or other water-borne pathogens. using a temporally controlled reporter of transcription, we focus on bacterial gene expression during the late stage of infection and identify a unique class of v. cholerae genes specific to this stage. mutationa ...200718005744
studies on the antimicrobial potential of the cardiovascular drug lacidipine.the cardiovascular drug lacidipine was screened in vitro for possible antibacterial activity with respect to 389 gram-positive and gram-negative bacterial strains. it was noticed that most bacteria (233) failed to grow at 50-200 microg/ml concentrations of the drug. some strains were inhibited at even lower concentrations. the bacteria could be arranged according to their decreasing order of sensitivity as follows: staphylococcus aureus, vibrio cholerae, salmonella spp., shigellae, escherichia c ...200718019422
[global warming: trailblazer for tropical infections in germany?].since 1850, the co (2) content of the atmosphere has increased from 280 to 360 ppm, and the average surface temperature has risen from 14.6 to 15.3 c . a further increase between 1.8 and 4.0 c is expected for the 21st century. temperate and cold climate zones are affected predominantly, but tropical regions are not spared. at the same time, the world wide climate effects of the "el niño southern oscillation" are amplified. global warming enhances the growth of tropical pathogens (malarial plasmo ...200718033654
dissemination of a single vibrio cholerae clone in cholera outbreaks during 2005 in iran.in this study, 50 vibrio cholerae o1 serotype inaba isolates were collected during several cholera outbreaks throughout iran during the summer of 2005. the results of antibiotic susceptibility testing showed that 86, 84, 84 and 82 % of the isolates were resistant to streptomycin, chloramphenicol, co-trimoxazole and tetracycline, respectively. the strains were genotyped using randomly amplified polymorphic dna (rapd), pfge and ribotyping techniques. pcr showed that 100, 98 and 98 % carried the ct ...200718033829
evidence for a clonally different origin of the two cholera epidemics of 2001-2002 and 1980-1987 in south africa.vibrio cholerae o1 serotype ogawa and serotype inaba isolates from the cholera epidemic that occurred in 2001 and 2002 in south africa were compared with isolates of v. cholerae o1 serotype inaba from the epidemic that occurred between 1980 and 1987. pfge using noti digestion was used to compare stored isolates received during the 1980s epidemic with those received during the epidemic in 2001/2002. a selected number of these isolates were then sequenced to compare the sequence of the wbet gene i ...200718033834
the structural basis of cyclic diguanylate signal transduction by pilz domains.the second messenger cyclic diguanylate (c-di-gmp) controls the transition between motile and sessile growth in eubacteria, but little is known about the proteins that sense its concentration. bioinformatics analyses suggested that pilz domains bind c-di-gmp and allosterically modulate effector pathways. we have determined a 1.9 a crystal structure of c-di-gmp bound to vca0042/plzd, a pilz domain-containing protein from vibrio cholerae. either this protein or another specific pilz domain-contain ...200718034161
antibacterial activity directed isolation of compounds from punica granatum.chemical investigation of the methanolic extract of pomegranate fruit following antibacterial activity directed isolation led to the isolation of pelargonidin-3-galactose, cyanidin-3-glucose, gallic acid, quercetin, and myricetin. all these compounds exhibited substantial activity against species of corynebacteria, staphylococci, streptococci, bacillus subtilis, shigella, salmonella, vibrio cholera, and escherichia coli. however, all these compounds were more active against gram-positive species ...200718034726
molecular cloning and characterization of all rnd-type efflux transporters in vibrio cholerae non-o1.resistance nodulation cell division (rnd) efflux transporters are thought to be involved in mediating multidrug resistance in gram-negative bacteria, including vibrio cholerae non-o1. there are six operons for putative rnd-type efflux transporters present in the chromosome of v. cholerae o1 including two operons, vexab and vexcd, which had already been identified. all of the six operons were cloned from v. cholerae non-o1, nctc4716 by the pcr method, introduced, and expressed in cells of drug hy ...200718037783
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