| molecular typing of epidemic and nonepidemic vibrio cholerae isolates and differentiation of v. cholerae and v. mimicus isolates by pcr-single-strand conformation polymorphism analysis. | to examine the utility of polymerase chain reaction (pcr)-single-strand conformation polymorphism (sscp) analysis to differentiate epidemic and nonepidemic vibrio cholerae isolates as well as to differentiate v. cholerae and vibrio mimicus isolates. | 2005 | 15715856 |
| comparative study of class 1 integron and vibrio cholerae superintegron integrase activities. | superintegrons (sis) and multiresistant integrons (mris) have two main structural differences: (i) the si platform is sedentary, while the mri platform is commonly associated with mobile dna elements and (ii) the recombination sites (attc) of si gene cassette clusters are highly homogeneous, while those of mri cassette arrays are highly variable in length and sequence. in order to determine if the latter difference was correlated with a dissimilarity in the recombination activities, we conducted ... | 2005 | 15716446 |
| toxin-antitoxin loci are highly abundant in free-living but lost from host-associated prokaryotes. | prokaryotic chromosomes code for toxin-antitoxin (ta) loci, often in multiple copies. in e.coli, experimental evidence indicates that ta loci are stress-response elements that help cells survive unfavorable growth conditions. the first gene in a ta operon codes for an antitoxin that combines with and neutralizes a regulatory 'toxin', encoded by the second gene. rele and mazf toxins are regulators of translation that cleave mrna and function, in interplay with tmrna, in quality control of gene ex ... | 2005 | 15718296 |
| genomic characterization of non-o1, non-o139 vibrio cholerae reveals genes for a type iii secretion system. | non-o1, non-o139 vibrio cholerae can cause gastroenteritis and extraintestinal infections, but, unlike o1 and o139 strains of v. cholerae, little is known about the virulence gene content of non-o1, non-o139 strains and their phylogenetic relationship to other pathogenic v. cholerae. comparative genomic microarray analysis of four pathogenic non-o1, non-o139 strains indicates that these strains are quite divergent from o1 and o139 strains. genomic sequence analysis of a non-o1, non-o139 strain ( ... | 2005 | 15728357 |
| effectiveness of mass oral cholera vaccination in beira, mozambique. | new-generation, orally administered cholera vaccines offer the promise of improved control of cholera in sub-saharan africa. however, the high prevalence of human immunodeficiency virus (hiv) infection in many cholera-affected african populations has raised doubts about the level of protection possible with vaccination. we evaluated a mass immunization program with recombinant cholera-toxin b subunit, killed whole-cell (rbs-wc) oral cholera vaccine in beira, mozambique, a city where the seroprev ... | 2005 | 15728808 |
| disaster, water, cholera, vaccines, and hope. | | 2005 | 15728816 |
| a six-year study on vibrio cholerae in southeastern iran. | cholera continues to be an important public health problem among many poorer communities. in order to determine the epidemiology of vibrio cholerae in southeastern iran, 3,594 patients with watery diarrhea, who were referred to the hospitals from zabol city and 45 neighboring rural populations of sistan-blouchestan province, were investigated over a period of 6 years (1997 - 2002). v. cholerae strains were isolated from 362 samples (10.07%). isolation of v. cholerae in this sample decreased from ... | 2005 | 15728982 |
| mucosal adjuvant properties of mutant lt-iia and lt-iib enterotoxins that exhibit altered ganglioside-binding activities. | lt-iia and lt-iib, the type ii heat-labile enterotoxins of escherichia coli, are closely related in structure and function to cholera toxin and lt-i, the type i heat-labile enterotoxins of vibrio cholerae and e. coli, respectively. recent studies from our group demonstrated that lt-iia and lt-iib are potent systemic and mucosal adjuvants. to determine whether binding of lt-iia and lt-iib to their specific ganglioside receptors is essential for adjuvant activity, lt-iia and lt-iib enterotoxins we ... | 2005 | 15731030 |
| a vibrio vulnificus type iv pilin contributes to biofilm formation, adherence to epithelial cells, and virulence. | vibrio vulnificus expresses a multitude of cell-associated and secreted factors that potentially contribute to pathogenicity, although the specific roles of most of these factors have been difficult to define. previously we have shown that a mutation in pild (originally designated vvpd), which encodes a type iv prepilin peptidase/n-methyltransferase, abolishes expression of surface pili, suggesting that they belong to the type iv class. in addition, a pild mutant exhibits reduced adherence to he ... | 2005 | 15731039 |
| structural basis for the function of stringent starvation protein a as a transcription factor. | stringent starvation protein a (sspa) of escherichia coli is an rna polymerase-associated transcriptional activator for the lytic development of phage p1 and is essential for stationary phase-induced acid tolerance of e. coli. we report the crystal structure of yersinia pestis sspa, which is 83% identical to e. coli sspa in amino acid sequence and is functionally complementary in supporting the lytic growth of phage p1 and acid resistance of an e. coli sspa mutant. the structure reveals that ssp ... | 2005 | 15735307 |
| genomic relatedness of the new matlab variants of vibrio cholerae o1 to the classical and el tor biotypes as determined by pulsed-field gel electrophoresis. | the genomes of the recently described matlab variants of vibrio cholerae o1 that are hybrids between classical and el tor biotypes were compared with those of el tor and classical biotypes by the use of pulsed-field gel electrophoresis. dendrograms constructed using the unweighted-pair group method using average linkages generated from noti restriction patterns of whole-chromosomal dna grouped these strains into two major clusters that were found to be similar but not identical to those of eithe ... | 2005 | 15750117 |
| sugars inhibit expression of the rugose phenotype of vibrio cholerae. | vibrio cholerae can shift to a rugose colony phenotype, reflecting expression of an exopolysaccharide that provides protection against a variety of environmental stresses. our data indicate that expression of the rugose phenotype is inhibited by a variety of sugars, including sucrose, dextrose, arabinose, fructose, and maltose. inhibition by sucrose may be one factor in explaining the failure of rugose strains to grow on thiosulfate citrate bile salts sucrose agar, the primary selective medium f ... | 2005 | 15750123 |
| resurgence of vibrio cholerae o139 in rohtak. | | 2005 | 15756047 |
| co-expression and immunity of legionella pneumophila mip gene and immunoadjuvant ctxb gene. | the mip gene of legionella pneumophila and the ctxb gene of vibrio cholerae were amplified by pcr respectively. the amplified cdna was ligated to the pcdna3.1(+) vector. the recombinant plasmids pcdna3.1-mip and pcdna3.1-ctxb were identified by restriction analysis and pcr, and further confirmed by sequencing analysis. nih3t3 cells were transfected with pcdna3.1-mip and pcdna3.1-ctxb according to the lipofection method. transient and stable products of the co-expression of the mip gene and ctxb ... | 2005 | 15756423 |
| vibrio cholerae sxt element, laos. | | 2005 | 15759340 |
| mixed diarrhoeal infection caused by vibrio cholerae and several other enteric pathogens in a 4-year-old child returning to germany from pakistan. | we report a mixed enteric infection in a 4-y-old child who returned from pakistan with fever, vomiting and profuse diarrhoea leading to severe dehydration. vibrio cholerae o1, salmonella paratyphi a and campylobacter coli were cultured from stool. furthermore, giardia lamblia antigen and hepatitis a rna were detected. this is the first paediatric cholera case seen in frankfurt/main. | 2005 | 15764195 |
| vibrio cholerae persistence in aquatic environments and colonization of intestinal cells: involvement of a common adhesion mechanism. | forty-one tnpho a mutants of vibrio cholerae o1 classical strain cd81 were analyzed for their ability to interact with chitin particles, tigriopus fulvus copepods and the intestine 407 cell line compared to the parent strain. thirteen mutants were less adhesive than cd81; in particular, t21, t33 and t87 were less adhesive towards all substrates and insensitive to inhibition by n-acetyl glucosamine (glcnac). by sds-page analysis of sarkosyl-insoluble membrane proteins (simps) isolated from mutant ... | 2005 | 15766778 |
| construction and characterization of a thya mutant derived from cholera vaccine candidate iem101. | a naturally cholera toxin gene negative vibrio cholerae (o1, el tor, ogawa) strain, named iem101, was isolated in china. the human volunteer tests showed that this strain was safe, able to colonize the intestinal mucosa, and able to induce a strong immune response. also other studies indicated that it was an efficient live vector to deliver heterologous antigens. in this article, a thymidylate synthase gene (thya)-defined mutant was constructed using homologous recombination. except for the morp ... | 2005 | 15767696 |
| [analysis of components of vibriophage vp4 receptor of vibrio cholerae ]. | | 2004 | 15769380 |
| [comparative genomic analysis of vibrio cholerae el tor preseventh and seventh pandemic strains isolated in various periods]. | genetic organization of 52 vibrio cholerae el tor biotype preseventh and seventh pandemic strains isolated in various periods was studied by pcr assay and dna-dna hybridization. it was established that the genome of most ancient of analyzed strains isolated from a diarrhea patient in 1910 was devoid of ctx and rs1 prophages, vibrio pathogenicity islands (vpi and vpi-2), and pandemic islands (vsp-1 and vsp-2) that contain key virulence genes. the appearance of pathogenic properties in cholera vib ... | 2005 | 15771251 |
| [comparative analysis of the major protective antigens production in vibrio cholerae recombinant and producer strains of the classical biovar]. | the comparative study of 4 constructed protective antigen producing strains of the classical biovar and v. cholerae strains 569 b inaba and m41 ogawa, used in manufacturing the cholera chemical vaccine "cholerogen-toxoid", was carried out. the study revealed that v. cholerae plasmid strains 2414 ogawa, 2415 inaba and nonplasmid strains 2416 ogawa, 2417 inaba had a higher level of production of the main protective antrigens in comparison with producer strains. they also synthesized much more (4-5 ... | 2005 | 15773401 |
| identification of a tcpc-tcpq outer membrane complex involved in the biogenesis of the toxin-coregulated pilus of vibrio cholerae. | the toxin-coregulated pilus (tcp) of vibrio cholerae and the soluble tcpf protein that is secreted via the tcp biogenesis apparatus are essential for intestinal colonization. the tcp biogenesis apparatus is composed of at least nine proteins but is largely uncharacterized. tcpc is an outer membrane lipoprotein required for tcp biogenesis that is a member of the secretin protein superfamily. in the present study, analysis of tcpc in a series of strains deficient in each of the tcp biogenesis prot ... | 2005 | 15774863 |
| virulence factors of non-o1 non-o139 vibrio cholerae isolated in córdoba, argentina. | v. cholerae non-o1 non-o139 serogroups isolated from clinical and environmental sources in córdoba, argentina, were analyzed for the presence and expression of virulence genes. most of the strains studied contained the genes toxr and hlya, but lacked ctxa, zot, ace, tcpa and stn. the culture supernatants were tested for hemolytic and cytotoxic activity. the enterotoxic potential of the strains was studied in a rabbit ileal loop assay and their genetic profiles were compared by pfge. the environm ... | 2004 | 15786867 |
| [toxins of vibrio cholerae]. | surveyed in the paper are published data on properties, biological activity, genetic determinants and action mechanisms of recently known toxins produced by different strains of vibrio cholerae irrespectively of their capacity for the synthesis of choleric toxin--the main virulence factor. their possible importance both for the general clinical pattern of cholera provoked by cholerogenic agents and as independent virulence factors causing diarrhea without cholera is elucidated. the sets and leve ... | 2005 | 15790027 |
| [cloning and expression of vibrio cholerae zonula occludens toxin (zot) gene in escherichia coli]. | two recombinant plasmids containing the cloned pcr-amplifled vibrio cholerae zonula occludens toxin (zot) gene was constructed in orientation providing its transcription from lac-promoter. one of them contained also its own zot promoter. the third plasmid was obtained by subcloning a vibrio cholerae dna fragment including intact zot and ace (accessory cholera enterotoxin) genes. the expression levels of the cloned genes in escherichia coli varied depending on a promoter type, host strain and cul ... | 2005 | 15790030 |
| the sodium cycle in vibrio cholerae: riddles in the dark. | twenty years ago, v. p. skulachev put forward the revolutionary concept of the chemiosmotic sodium cycle which is an integral of the paradigm of modern bioenergetics. this fundamental concept stimulated studies in many areas and yielded plenty of sometimes quite unexpected (and thus most valuable) discoveries. in particular, variations of the sodium cycle have been found in a surprisingly large number of pathogenic microorganisms, raising the question about the possible link of sodium energetics ... | 2005 | 15807652 |
| new drug targets for cholera therapy. | intestinal infection with vibrio cholerae results in secretory diarrhea with potentially massive fluid losses and volume depletion. morbidity and mortality associated with cholera remain a major problem in the developing world despite the success of oral rehydration therapy. new research aiming to inhibit cholera toxin binding to receptors in the intestine provides an attractive strategy for cholera therapy. together with anti-secretory agents, including inhibitors of enkephalinase and of the cy ... | 2005 | 15808339 |
| uptake of escherichia coli, vibrio cholerae non-o1 and enterococcus durans by, and depuration of mussels (mytilus galloprovincialis). | the uptakes of escherichia coli, vibrio cholerae non-o1 and enterococcus durans by mussels (mytilus galloprovincialis) and the times for depuration were investigated in order to determine the most useful indicator of vibrio contamination. the mussels were maintained in tanks of static seawater contaminated with bacteria at 5 log10 cfu/ml for bioaccumulation. depuration was carried out by circulating fresh seawater through the tanks. each organism was presented alone and with others to mussels, a ... | 2005 | 15808362 |
| antidiarrheal effects of l-histidine-supplemented rice-based oral rehydration solution in the treatment of male adults with severe cholera in bangladesh: a double-blind, randomized trial. | because of the antisecretory potential of l-histidine in the intestinal tract, its antidiarrheal effects were determined in cholera. | 2005 | 15809910 |
| adult non-biting midges: possible windborne carriers of vibrio cholerae non-o1 non-o139. | vibrio cholerae is a waterborne bacterium native to the aquatic environment. there are over 200 known serogroups yet only two cause cholera pandemics in humans. direct contact of human sewage with drinking water, sea-born currents and marine transportation, represent modes of dissemination of the bacteria and thus the disease. the simultaneous cholera outbreaks that occur sometimes in distant localities within continental landmasses are puzzling. here we present evidence that flying, non-biting ... | 2005 | 15816934 |
| physicochemical characterization of vibriophage n5. | phage n5 is one of the phages of vibrio cholerae serovar o1 biotype el tor (ghosh, a. n., ansari, m. q., and dutta, g. c. isolation and morphological characterization of el tor cholera phages. j. gen. virol. 70: 2241-2243, 1989). in the present communication the growth curve, molecular weight and confirmation of the genome, partial denaturation map and restriction endonuclease digestion pattern have been determined. partial denaturation map indicates that the genome has non-permuted / invariant ... | 2005 | 15823199 |
| new vibrio cholerae o1 biotype eltor bacteriophages. | we report the presence of three new o1 eltor vibriophages named as1, as2 and as3, isolated from the sewage and pond waters of the outskirts of kolkata. a few phages, named as4, with hexagonal heads and abnormally long tails with typical curly projections were also found in the water samples. | 2005 | 15823200 |
| a millennium update on pediatric diarrheal illness in the developing world. | more than one billion diarrhea episodes occur every year among children younger than 5 years of age in socioeconomically developing countries causing 2 to 2.5 million deaths. more than twenty viral, bacterial, and parasitic enteropathogens are currently associated with acute diarrhea. rotavirus and diarrheagenic escherichia coli are the most common pathogens responsible for acute diarrhea episodes in children; shigella spp., salmonella spp, campylobacter jejuni/coli, vibrio cholerae, aeromonas s ... | 2005 | 15825143 |
| self-limiting nature of seasonal cholera epidemics: role of host-mediated amplification of phage. | phage predation of vibrio cholerae has recently been reported to be a factor that influences seasonal epidemics of cholera in bangladesh. to understand more about this phenomenon, we studied the dynamics of the v. cholerae-phage interaction during a recent epidemic in dhaka. because the outbreak strain causing this epidemic was resistant to multiple antibiotics, including streptomycin, we used a selective medium containing streptomycin to monitor accurately the abundance of this strain in the en ... | 2005 | 15829587 |
| growth inhibition of enteric bacteria by vibrio cholerae in nutrient media containing lactate, acetate, or citrate. | in cross-streak tests on nutrient agar containing lactate, acetate, or citrate, the growth of certain enteric bacteria was inhibited by themselves or by vibrio cholerae, or by both. this mimicked the activity of bacteriocins, but the phenomenon was attributable to the accumulation of carbonate and increased alkalinity of the media. | 1974 | 15830491 |
| identification of dna markers for a transmissible pseudomonas aeruginosa cystic fibrosis strain. | a number of transmissible pseudomonas aeruginosa strains have been identified which potentially constitute an emerging threat to patients with cystic fibrosis (cf). we sought to identify dna markers that were specific to a transmissible p. aeruginosa cf clone and evaluate these probes on a large collection of genotypically distinct p. aeruginosa strains. using subtractive dna hybridization, in combination with analysis using the p. aeruginosa pao1 genome chip, dna markers specific for or absent ... | 2005 | 15834046 |
| considerations for development of whole cell bacterial vaccines to prevent diarrheal diseases in children in developing countries. | enteric pathogens constitute a major pediatric threat in the developing world through their impact on morbidity and mortality, physical and cognitive development and cause and effect relationship with malnutrition. although many bacterial pathogens can cause diarrheal diseases, a group of less than 10 including shigella spp., enterotoxigenic escherichia coli (etec), vibrio cholerae, and possibly, campylobacter jejuni account for a significant percentage of these diseases in developing countries. ... | 2005 | 15837361 |
| a glimpse into the expanded genome content of vibrio cholerae through identification of genes present in environmental strains. | vibrio cholerae has multiple survival strategies which are reflected both in its broad distribution in many aquatic environments and its high genotypic diversity. to obtain additional information regarding the content of the v. cholerae genome, suppression subtractive hybridization (ssh) was used to prepare libraries of dna sequences from two southern california coastal isolates which are divergent or absent in the clinical strain v. cholerae o1 el tor n16961. more than 1,400 subtracted clones w ... | 2005 | 15838025 |
| requirements for vibrio cholerae hapr binding and transcriptional repression at the hapr promoter are distinct from those at the apha promoter. | virulence gene expression in certain strains of vibrio cholerae is regulated in response to cell density by a quorum-sensing cascade that influences the levels of the luxr homolog hapr through small regulatory rnas that control the stability of its message. at high cell density, hapr represses the expression of the gene encoding the virulence gene activator apha by binding to a site between -85 and -58 in the apha promoter. we show here that a second binding site for hapr lies within the hapr pr ... | 2005 | 15838027 |
| characterization of enhancer binding by the vibrio cholerae flagellar regulatory protein flrc. | the human pathogen vibrio cholerae is a highly motile organism by virtue of a polar flagellum, and motility has been inferred to be an important aspect of virulence. it has previously been demonstrated that the sigma(54)-dependent activator flrc is necessary for both flagellar synthesis and for enhanced intestinal colonization. in order to characterize flrc binding, we analyzed two flrc-dependent promoters, the highly transcribed flaa promoter and the weakly transcribed flgk promoter, utilizing ... | 2005 | 15838043 |
| analysis of the pilu gene for the prepilin peptidase involved in the biogenesis of type iv pili encoded by plasmid r64. | in many type iv pili, the n-terminal amino acid of the pilin subunit is n-methylated phenylalanine. a prepilin peptidase removes the leader peptide from the precursor and methylates the amino group of the newly formed phenylalanine. pils, the precursor of the pilin encoded by plasmid r64, is processed by the prepilin peptidase pilu, but the n-terminal amino acid of the mature pilin is a non-methylated tryptophan that is otherwise modified. to study the relationship between the structure and func ... | 2005 | 15838638 |
| interactions between mytilus haemocytes and different strains of escherichia coli and vibrio cholerae o1 el tor: role of kinase-mediated signalling. | marine bivalves accumulate large amounts of bacteria from the environment (mainly vibrionaceae and coliforms). although persistence of different bacteria in bivalve tissues largely depends on their sensitivity to the bactericidal activity of circulating haemocytes and haemolymph soluble factors, the mechanisms involved in bacteria-host cell interactions in these invertebrates are largely unknown. in the mussel mytilus, differences in interactions between haemocytes and different escherichia coli ... | 2005 | 15839896 |
| the x-ray structure of the type ii secretion system complex formed by the n-terminal domain of epse and the cytoplasmic domain of epsl of vibrio cholerae. | gram-negative bacteria use type ii secretion systems for the transport of virulence factors and hydrolytic enzymes through the outer membrane. these sophisticated multi-protein complexes reach from the pore in the outer membrane via the pseudopilins in the periplasm and a multi-protein inner-membrane sub-complex, to an atpase in the cytoplasm. the human pathogen vibrio cholerae uses such a secretion machinery, called the eps-system, for the export of its major virulence factor cholera toxin into ... | 2005 | 15843017 |
| differential binding of escherichia coli enterotoxins lt-iia and lt-iib and of cholera toxin elicits differences in apoptosis, proliferation, and activation of lymphoid cells. | cholera toxin (ct), lt-iia, and lt-iib are potent adjuvants which induce distinct t-helper (th)-cell cytokine profiles and immunoglobulin g (igg) subclass and iga antibody responses. to determine if the distinct immune regulatory effects observed for lt-iia, lt-iib, and ct are elicited by binding of the enterotoxins to their cognate ganglioside receptors, the lineages of lymphoid cells that interact with the three enterotoxins and their effects on various lymphocyte responses in vitro were evalu ... | 2005 | 15845474 |
| differential induction of the toll-like receptor 4-myd88-dependent and -independent signaling pathways by endotoxins. | the biological response to endotoxin mediated through the toll-like receptor 4 (tlr4)-md-2 receptor complex is directly related to lipid a structure or configuration. endotoxin structure may also influence activation of the myd88-dependent and -independent signaling pathways of tlr4. to address this possibility, human macrophage-like cell lines (thp-1, u937, and mm6) or murine macrophage raw 264.7 cells were stimulated with picomolar concentrations of highly purified endotoxins. harvested supern ... | 2005 | 15845500 |
| the vaccine candidate vibrio cholerae 638 is protective against cholera in healthy volunteers. | vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the ctxphi prophage from c7258 (o1, el tor ogawa) and by insertion of the clostridium thermocellum endoglucanase a gene into the hemagglutinin/protease coding sequence. this vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. this article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subse ... | 2005 | 15845509 |
| activation of both acfa and acfd transcription by vibrio cholerae toxt requires binding to two centrally located dna sites in an inverted repeat conformation. | the gram-negative bacterium vibrio cholerae is the infectious agent responsible for the disease asiatic cholera. the genes required for v. cholerae virulence, such as those encoding the cholera toxin (ct) and toxin-coregulated pilus (tcp), are controlled by a cascade of transcriptional activators. ultimately, the direct transcriptional activator of the majority of v. cholerae virulence genes is the arac/xyls family member toxt protein, the expression of which is activated by the toxr and tcpp pr ... | 2005 | 15853890 |
| [the use of liposomes for detection of the surface lipopolysaccharide antigen, vibrio cholerae cells, and antibodies against them]. | a test system for determination of vibrio cholerae cells, surface o-antigen, and antibodies against them was developed on the basis of complement-dependent lysis of liposomes sensitized by the lipopolysaccharide-dependent antigen from vibrio cholerae 569b. the factors that affect the function of the liposomal reagent were studied, and the conditions for detecting antibodies and antigenic material were optimized. this system is highly specific and sensitive to be used for the determination of ant ... | 2005 | 15859469 |
| [research on detection of vibrio comma and vibro parahaemolyticus from foodstuffs using mpcr methods]. | to establish a set of multi-pcr (mpcr) methods to detect vibrio comma o1 serogroup (evc) and o139 serogroup, and vibrio parahaemolyticus rapidly and sensitively from foodstuffs. | 2005 | 15862042 |
| use of conformationally restricted pyridinium alpha-d-n-acetylneuraminides to probe specificity in bacterial and viral sialidases. | investigations into subtle changes in the catalytic activity of sialidases have been performed using enzymes from several different origins, and their results have been compared. this work highlights the potential pitfalls encountered when extending conclusions derived from mechanistic studies on a single enzyme even to those with high-sequence homology. specifically, a panel of 5 pyridinium n-acetylneuraminides were used as substrates in a study that revealed subtle differences in the catalytic ... | 2005 | 15864320 |
| virulence and the environment: a novel role for vibrio cholerae toxin-coregulated pili in biofilm formation on chitin. | the toxin-coregulated pilus (tcp) of vibrio cholerae is required for intestinal colonization and cholera toxin acquisition. here we report that tcp mediates bacterial interactions required for biofilm differentiation on chitinaceous surfaces. we also show that undifferentiated tcp- biofilms have reduced ecological fitness and, thus, that chitin colonization may represent an ecological setting outside the host in which selection for a host colonization factor may take place. | 2005 | 15866944 |
| a vertebrate-type ferredoxin domain in the na+-translocating nadh dehydrogenase from vibrio cholerae. | the na(+)-translocating nadh:quinone oxidoreductase from vibrio cholerae contains a single fe-s cluster localized in subunit nqrf. here we study the electronic properties of the fe-s center in a truncated version of the nqrf subunit comprising only its ferredoxin-like fe-s domain. mössbauer spectroscopy of the fe-s domain in the oxidized state is consistent with a binuclear fe-s cluster with tetrahedral sulfur coordination by the cysteine residues cys(70), cys(76), cys(79), and cys(111). importa ... | 2005 | 15870079 |
| sta and cgmp stimulate cftr translocation to the surface of villus enterocytes in rat jejunum and is regulated by protein kinase g. | the cystic fibrosis transmembrane conductance regulator (cftr) is critical to camp- and cgmp-activated intestinal anion secretion and the pathogenesis of secretory diarrhea. enterotoxins released by vibrio cholerae (cholera toxin) and escherichia coli (heat stable enterotoxin, or sta) activate intracellular camp and cgmp and signal cftr on the apical plasma membrane of small intestinal enterocytes to elicit chloride and fluid secretion. camp activates pka, whereas cgmp signals a cgmp-dependent p ... | 2005 | 15872007 |
| antibacterial potential from indian suregada angustifolia. | phytochemical analysis of the leaves from indian suregada angustifolia (baill. ex muell. arg.) airy shaw (euphorbiaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, n-octacosanol, alpha-amyrin, beta-sitosterol and beta-sitosterol-3-beta-d-glucopyranoside. aqueous (room temperature, boiled and autoclaved) and various solvent (methanol, chloroform and hexane) extracts of leaves were tested against 12 human pathogenic bacteria by the agar we ... | 2005 | 15878247 |
| divided genomes: negotiating the cell cycle in prokaryotes with multiple chromosomes. | historically, the prokaryotic genome was assumed to consist of a single circular replicon. however, as more microbial genome sequencing projects are completed, it is becoming clear that multipartite genomes comprised of more than one chromosome are not unusual among prokaryotes. chromosomes are distinguished from plasmids by the presence of essential genes as well as characteristic cell cycle-linked replication kinetics; unlike plasmids, chromosomes initiate replication once per cell cycle. the ... | 2005 | 15882408 |
| in vivo induced clpb1 gene of vibrio cholerae is involved in different stress responses and affects in vivo cholera toxin production. | previously in global transcription profile approach one of the cosmid clones of vibrio cholerae containing the genes pnuc, icmf, and a fragment of clpb2 showed higher expression in v. cholerae grown inside rabbit intestine. in the present report, both the stress responsive clpb genes of v. cholerae o395 were cloned, clpb1 from chromosome i and clpb2 present in chromosome ii. from the northern blot hybridization it was observed that the level of transcription of clpb2 was very low which could be ... | 2005 | 15883026 |
| diversity of vibrio cholerae strains isolated in delhi, india, during 1992-2000. | the national institute of communicable diseases (nicd), delhi, india, conducts a laboratory-based surveillance of cholera cases referred from the infectious disease hospital, delhi. the prevalence and antimicrobial susceptibilities of vibrio cholerae o1, o139, and others, isolated from cholera patients for nine years, were analyzed to determine the changing trends in their isolation and drug-resistance patterns. in total, 29,196 stool samples or rectal swabs, collected during april 1992-december ... | 2005 | 15884751 |
| vcer regulates the vcecab drug efflux pump operon of vibrio cholerae by alternating between mutually exclusive conformations that bind either drugs or promoter dna. | vcer, a member of the tetr family of transcriptional regulators, is a repressor of the vcecab operon, which encodes a multidrug efflux pump in vibrio cholerae. vcer binds to a 28 bp inverted-repeat within the vcer-vcec intergenic region and is dissociated from this site with cccp, a pump substrate. the rate of the cccp-induced conformational change in vcer was determined by stopped-flow fluorescence spectroscopy, revealing a highly co-operative process that occurs with a hill coefficient of appr ... | 2005 | 15890203 |
| persistence of vibrios in marine bivalves: the role of interactions with haemolymph components. | marine bivalves are widespread in coastal environments and, due to their filter-feeding habit, they can accumulate large numbers of bacteria thus acting as passive carriers of human pathogens. bivalves possess both humoral and cellular defence mechanisms that operate in a co-ordinated way to kill and eliminate infecting bacteria. vibrio species are very abundant in coastal waters and are commonly isolated from edible bivalves tissues where they can persist after depuration processes in controlle ... | 2005 | 15892695 |
| how to be moderately halophilic with broad salt tolerance: clues from the genome of chromohalobacter salexigens. | we analyzed the amino acid composition of different categories of proteins of the moderately halophilic bacterium chromohalobacter salexigens, as deduced from its genome sequence. comparison with non-halophilic representatives of the gamma-proteobacteria (escherichia coli, pseudomonas aeruginosa, vibrio cholerae) shows only a slight excess of acidic residues in the cytoplasmic proteins, and no significant differences were found in the acidity of membrane-bound proteins. in contrast, a very prono ... | 2005 | 15902510 |
| antidiarrhoeal activity of the methanol extract of the barks of xylocarpus moluccensis in castor oil- and magnesium sulphate-induced diarrhoea models in mice. | the methanol (meoh) extract of the barks of xylocarpus moluccensis, and different fractions of this extract were studied for antidiarrhoeal activity using castor oil- and magnesium sulphate-induced diarrhoea models in mice. at the doses of 250 and 500 mg/kg, the meoh extract showed significant antidiarrhoeal activity in both models. the etoac fraction (eaf) and the residual meoh fraction (rmf) exhibited similar activity using a dose of 250 mg/kg in both models. no antidiarrhoeal activity was obs ... | 2005 | 15905054 |
| bacterial cell-to-cell signaling in the gastrointestinal tract. | | 2005 | 15908344 |
| characterization of fluorescent chimeras of cholera toxin and escherichia coli heat-labile enterotoxins produced by use of the twin arginine translocation system. | cholera toxin (ct) is an ab(5) toxin responsible for the profuse secretory diarrhea resulting from vibrio cholerae infection. ct consists of a pentameric, receptor-binding b subunit (ctb) and a monomeric a subunit (cta) that has latent enzymatic activity. in addition to its enterotoxicity, ct has potent mucosal adjuvant activity and can also function as a carrier molecule with many potential applications in cell biology. in earlier studies, the toxic cta(1) domain was replaced by several other a ... | 2005 | 15908392 |
| molecular and functional characterization of o antigen transfer in vibrio cholerae. | the majority of gram-negative bacteria transfer o antigen polysaccharides onto the lipid a-core oligosaccharide via the action of surface polymer:lipid a-core ligases (waal). here, we characterize the waal proteins of vibrio cholerae with emphasis on structural and functional characterization of o antigen transfer and core oligosaccharide recognition. we demonstrate that the activity of two distantly related o antigen ligases is dependent on the presence of n-acetylglucosamine, and substitution ... | 2005 | 15908430 |
| cloning and expression of vibrio cholerae virulence gene, accessory cholera enterotoxin (ace). | the cholera enterotoxin (ct) has been considered a major virulence factor of vibrio cholerae. the accessory cholera enterotoxin (ace) gene is the third gene of v. cholerae virulence cassette. the gene coding for the ace toxin was amplified from v. cholerae isolates producing a single band of 314 bp. the presence of ace gene was confirmed by hybridization as well as by sequencing. the gene was successfully expressed in escherichia coli (lmg194) using expression, pbad/thio-topo vector. optimal con ... | 2004 | 15916081 |
| ultrafast dynamics of resonance energy transfer in cryptochrome. | in this communication, we report the ultrafast dynamics of resonance energy transfer in a blue-light photoreceptor, vibrio cholerae cryptochrome. the transfer was observed to occur in 60 ps. we also studied the local rigidity and solvation around the binding site of the photoantenna molecule. the results for the first time show energy transfer in cryptochrome suggesting some mechanistic similarities between photolyase that repairs damaged dna and cryptochrome that mediates blue-light signaling. | 2005 | 15926801 |
| all phaged out. | | 2005 | 15931726 |
| quantitative analyses of pollution-indicator and pathogenic bacteria in mumbai waters from ballast water exchange perspective. | as large numbers of ships either take in ballast from or discharge their ballast into the mumbai harbor region, it is pertinent to quantify microorganisms of health concerns and suggest on the suitability of water for ballasting purposes. to meet with this main aim, a selected set of general and pathogenic bacterial groups and their seasonal variations were studied from the mumbai harbor area. sampling was carried out during postmonsoon (november 2001), pre-monsoon (april 2002) and monsoon (octo ... | 2005 | 15931993 |
| determination of endotoxin by the measurement of the acetylated methyl glycoside derivative of kdo with gas-liquid chromatography-mass spectrometry. | a gas-liquid chromatographic-mass spectrometric (glc-ms) method was applied to the detection of 3-deoxy-d-manno-2-octulosonic acid (kdo), a constituent of bacterial lipopolysaccharide (lps, endotoxin). samples containing lps were dried, methanolyzed with 2 m hcl in methanol at 60 degrees c for 1 h and acetylated with acetic anhydride and pyridine (1:1, v/v) solution at 100 degrees c for 30 min, then the products were analyzed by glc-ms or glc-msms. four acetylated methylglycoside methyl ester de ... | 2006 | 15932775 |
| characterization of the small untranslated rna ryhb and its regulon in vibrio cholerae. | numerous small untranslated rnas (srnas) have been identified in escherichia coli in recent years, and their roles are gradually being defined. however, few of these srnas appear to be conserved in vibrio cholerae, and both identification and characterization of srnas in v. cholerae remain at a preliminary stage. we have characterized one of the few srnas conserved between e. coli and v. cholerae: ryhb. sequence conservation is limited to the central region of the gene, and ryhb in v. cholerae i ... | 2005 | 15937163 |
| genomic sequence and receptor for the vibrio cholerae phage ksf-1phi: evolutionary divergence among filamentous vibriophages mediating lateral gene transfer. | ksf-1phi, a novel filamentous phage of vibrio cholerae, supports morphogenesis of the rs1 satellite phage by heterologous dna packaging and facilitates horizontal gene transfer. we analyzed the genomic sequence, morphology, and receptor for ksf-1phi infection, as well as its phylogenetic relationships with other filamentous vibriophages. while strains carrying the msha gene encoding mannose-sensitive hemagglutinin (msha) type iv pilus were susceptible to ksf-1phi infection, naturally occurring m ... | 2005 | 15937172 |
| molecular tracking of the lineage of strains of vibrio cholerae o1 biotype el tor associated with a cholera outbreak in andaman and nicobar islands, india. | a large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigines occurred during october-november, 2002 in the nancowry group of andaman and nicobar islands in the indian ocean. twenty-one of the 67 stool samples from 67 patients were positive for toxigenic vibrio cholerae o1, serotype ogawa biotype el tor, which showed striking similarity in its antibiogram with some of the strains of v. cholerae o1 serotype ogawa biotype el tor isolated in kolkata. the nancowr ... | 2005 | 15941425 |
| [survival and growth of vibrio cholerae o139 inside acanthamoeba]. | to study the survival and growth of vibrio cholerae inside the acanthamoeba polyphage. | 2005 | 15941511 |
| regulatory roles of cell surface sialylation in susceptibility to sphingomyelinase in human diffuse large b cell lymphoma. | sphingolipid metabolites are important regulators of cell growth and apoptosis. to clarify the biological roles of cell surface sialylation in the effects of sphingomyelinase (sm) treatment on cell viability, the human diffuse large b cell lymphoma cell line, hbl-2 with or without treatment with vibrio cholerae neuraminidase, was incubated with exogenous bacterial sm which is a key enzyme of ceramide production from sphingolipids in cell membranes. sm treatment enhanced viability of hbl-2 cells ... | 2005 | 15942662 |
| [comparative evaluation of activity of antibacterial agents in vitro and their efficacy in experimental cholera due to strains of vibrio cholerae o1 and o139 serogroups in albino mice]. | activity of 16 antibacterial agents against human isolates of vibrio cholerae o1 and o139 serogroups (p-5879, 4990, 143/23, and mo-45, p- 16065 respectively) was studied in vitro. the efficacy of the agents was studied in a model of generalized cholera in albino mice. susceptibility of vibrio cholerae p-5879 (used as the control) in the in vitro experiments with respect to the antibacterial agents correlated with their in vivo efficacy. the strains of vibrio cholerae o1 and o139 serogroups isola ... | 2004 | 15945546 |
| intracellular survival and replication of vibrio cholerae o139 in aquatic free-living amoebae. | vibrio cholerae is a highly infectious bacterium responsible for large outbreaks of cholera among humans at regular intervals. a seasonal distribution of epidemics is known but the role of naturally occurring habitats are virtually unknown. plankton has been suggested to play a role, because bacteria can attach to such organisms forming a biofilm. acanthamoebea castellanii is an environmental amoeba that has been shown to be able to ingest and promote growth of several bacteria of different orig ... | 2005 | 15946296 |
| upregulation of human mitochondrial nadh dehydrogenase subunit 5 in intestinal epithelial cells is modulated by vibrio cholerae pathogenesis. | cholera still remains an important global predicament especially in india and other developing countries. vibrio cholerae, the etiologic agent of cholera, colonizes the small intestine and produces an enterotoxin that is largely responsible for the watery diarrheal symptoms of the disease. using rna arbitrarily primed pcr, nd5 a mitochondria encoded subunit of complex i of the mitochondrial respiratory chain was found to be upregulated in the human intestinal epithelial cell line int407 followin ... | 2005 | 15946665 |
| identification of the membrane penetrating domain of vibrio cholerae cytolysin as a beta-barrel structure. | vibrio cholerae cytolysin (vcc) is an oligomerizing pore-forming toxin that is related to cytolysins of many other gram-negative organisms. vcc contains six cysteine residues, of which two were found to be present in free sulphydryl form. the positions of two intramolecular disulphide bonds were mapped, and one was shown to be essential for correct folding of protoxin. mutations were created in which the two free cysteines were deleted, so that single cysteine substitution mutants could be gener ... | 2005 | 15948954 |
| mismatched hemagglutinin and neuraminidase specificities in recent human h3n2 influenza viruses. | the hemagglutinin (ha) of influenza viruses initiates infection by binding to sialic acid on the cell surface via alpha2,6 (human) or alpha2,3 (avian) linkage. the influenza neuraminidase (na) can cleave both alpha2,3- and alpha2,6-linked sialic acids, but all influenza nas have a marked preference for the non-human alpha2,3 linkage. recent h3n2 influenza viruses have lost the ability to agglutinate chicken red blood cells. to determine if changes in ha specificity or affinity correlate with na ... | 2005 | 15950996 |
| [cholera vaccine]. | | 2005 | 15954420 |
| virulence factors, pathogenesis and vaccine protection in cholera and etec diarrhea. | recent work has provided new insights into the pathogenesis of the potentially life-threatening diarrheas caused by vibrio cholerae and enterotoxigenic escherichia coli (etec): a new mechanism (post-translational degradation), which is involved in the control of cholera toxin expression, has been discovered. recent evidence also suggests that vibrios upregulate cholera toxin expression in response to intestinal fluid components, and enterotoxin-carrying bacterial outer membrane vesicles might ha ... | 2005 | 15963708 |
| the burden of cholera in the slums of kolkata, india: data from a prospective, community based study. | to conduct a prospective, community based study in an impoverished urban site in kolkata (formerly calcutta) in order to measure the burden of cholera, describe its epidemiology, and search for potential risk factors that could be addressed by public health strategies. | 2005 | 15964861 |
| [expression plasmid-host strain using chromosome-plasmid balanced lethal system based on the escherichia coli thya]. | to construct a vector for dna vaccine and protein expression by using chromosome-plasmid balanced lethal system which was based on the thya+ gene/deltathya escherichia coli. the thya genes from escherichia coli and vibrio cholerae were amplified by polymerase chain reaction and cloned into pcdna3 by replacing ampilicilin resistant gene. multiple cloning sites, the prokaryotic replicon, cmv promoter and the boving growth hormone polya signal were also included in the vectors. two new non-antibiot ... | 2003 | 15969077 |
| scis, an icmf homolog in salmonella enterica serovar typhimurium, limits intracellular replication and decreases virulence. | salmonella enterica serovar typhimurium utilizes macrophages to disseminate from the intestine to deeper tissues within the body. while s. enterica serovar typhimurium has been shown to kill its host macrophage, it can persist intracellularly beyond 18 h postinfection. to identify factors involved in late stages of infection, we screened a transposon library made in s. enterica serovar typhimurium for the ability to persist in j774 macrophages at 24 h postinfection. through this screen, we ident ... | 2005 | 15972528 |
| [comparison between biotype of vibrio cholerae o1 and genotype using polymerase chain reaction]. | to compare between biotype of vibrio cholerae o1 and genotype using polymerase chain reaction (pcr), 9 classical and 81 el tor biovar strains were investigated for hemolysis, agglutination of avian erythrocytes, vp test reactivity, sensitivity to both polymyxin b and classical phage iv, and genotype using pcr amplification of hlya, tcpa, rtxa and rtxc. one classical biovar strain showed atypical reaction upon agglutination of avian erythrocytes. eighteen el tor biovar strains showed atypical rea ... | 2005 | 15977570 |
| ctxphi and vibrio cholerae: exploring a newly recognized type of phage-host cell relationship. | the genes encoding cholera toxin, one of the principal virulence factors of the diarrhoeal pathogen vibrio cholerae, are part of the genome of ctxphi, a filamentous bacteriophage. thus, ctxphi has played a critical role in the evolution of the pathogenicity of v. cholerae. unlike the well-studied f pilus-specific filamentous coliphages, ctxphi integrates site-specifically into its host chromosome and forms stable lysogens. here we focus on the ctxphi life cycle and, in particular, on recent stud ... | 2005 | 15978069 |
| dual regulation of genes involved in acetoin biosynthesis and motility/biofilm formation by the virulence activator apha and the acetate-responsive lysr-type regulator alsr in vibrio cholerae. | apha is a quorum sensing-regulated activator that initiates the virulence cascade in vibrio cholerae by cooperating with the lysr-type regulator aphb at the tcpph promoter on the vibrio pathogenicity island (vpi). to identify the ancestral chromosomal genes in v. cholerae regulated by apha, we carried out a microarray analysis and show here that apha influences the expression of 15 genes not associated with the vpi. one set of genes strongly repressed by apha is involved in the biosynthesis of a ... | 2005 | 15978075 |
| crystal structure of the vibrio cholerae cytolysin (vcc) pro-toxin and its assembly into a heptameric transmembrane pore. | pathogenic vibrio cholerae secrete v. cholerae cytolysin (vcc), an 80 kda pro-toxin that assembles into an oligomeric pore on target cell membranes following proteolytic cleavage and interaction with cell surface receptors. to gain insight into the activation and targeting activities of vcc, we solved the crystal structure of the pro-toxin at 2.3a by x-ray diffraction. the core cytolytic domain of vcc shares a fold similar to the staphylococcal pore-forming toxins, but in vcc an amino-terminal p ... | 2005 | 15978620 |
| phage regulatory circuits and virulence gene expression. | in many pathogenic bacteria, genes that encode virulence factors are located in the genomes of prophages. clearly bacteriophages are important vectors for disseminating virulence genes, but, in addition, do phage regulatory circuits contribute to expression of these genes? phages of the lambda family that have genes encoding shiga toxin are found in certain pathogenic escherichia coli (known as shiga toxin producing e. coli) and the filamentous phage ctxphi, that carries genes encoding cholera t ... | 2005 | 15979389 |
| synthesis and pharmacological activities of some mononuclear ru(ii) complexes. | a series of mononuclear ru(ii) complexes of the type [ru(m)2(u)]2+, where m = 2,2'-bipyridine/1,10-phenanthroline and u = tpl (ru1), 4-cl-tpl (ru2), 4-ch3-tpl (ru3), 4-ch3o-tpl (ru4), and 4-no2-tpl (ru5), -pai (ru6), where tpl = thiopicolinanilide and pai = 2-phenyl-azo-imidazole, have been prepared and characterized by ir, uv-vis, 1h nmr, 13c-nmr, fab-mass spectrophotometer, and elemental analysis. the complexes display metal-ligand charge transfer (mlct) transitions in the visible region. the ... | 2005 | 15982893 |
| increased tolerance of vibrio cholerae o1 to temperature, ph, or drying associated with colonization of shrimp carapaces. | external surfaces of samples of shrimp carapace were inoculated with vibrio cholerae and stored at 22 degrees c for 1 h in a moist environment to facilitate their adhesion, or for 24 h to permit their colonization of the material. colonizing cells showed a higher resistance to the effects of high temperatures, low ph, and desiccation conditions than adherent cells. periods of 10, 5, and 3 min and 0 s were required to inactivate the pathogen when attached cells were exposed to 50, 60, 65, or 70 d ... | 2005 | 15992618 |
| fluorescent multiplex analysis of carrier protein post-translational modification. | | 2005 | 15997462 |
| development of a simple and rapid fluorogenic procedure for identification of vibrionaceae family members. | we describe a simple colony overlay procedure for peptidases (copp) for the rapid fluorogenic detection and quantification of vibrionaceae from seawater, shellfish, sewage, and clinical samples. the assay detects phosphoglucose isomerase with a lysyl aminopeptidase activity that is produced by vibrionaceae family members. overnight cultures are overlaid for 10 min with membranes containing a synthetic substrate, and the membranes are examined for fluorescent foci under uv illumination. fluoresce ... | 2005 | 16000757 |
| role for glycine betaine transport in vibrio cholerae osmoadaptation and biofilm formation within microbial communities. | vibrio cholerae is a halophilic facultative human pathogen found in marine and estuarine environments. accumulation of compatible solutes is important for growth of v. cholerae at nacl concentrations greater than 250 mm. we have identified and characterized two compatible solute transporters, opud and putp, that are involved in uptake of glycine betaine and proline by v. cholerae. v. cholerae does not, however, possess the bet genes, suggesting that it is unable to synthesize glycine betaine. in ... | 2005 | 16000796 |
| factors associated with virulence and survival in environmental and clinical isolates of vibrio cholerae o1 and non o1 in romania. | four hundred ninety seven strains of vibrio cholerae selected from isolates in romania in the last decade 1990-1999 were investigated for antibiotic resistance and for classical and putative virulence factors. v. cholerae o1 strains predominated in clinical cases and non o1 strains in the environment, excepting in 1992 when non o1 strains were frequent in clinical and environmental sources. v. cholerae o1 strains previously susceptible to tetracycline acquired clinically significant resistance t ... | 2003 | 16008141 |
| cholera in mozambique, variant of vibrio cholerae. | | 2004 | 16010751 |
| going against the grain: chemotaxis and infection in vibrio cholerae. | chemotaxis is the process by which motile cells move in a biased manner both towards favourable and away from unfavourable environments. the requirement of this process for infection has been examined in several bacterial pathogens, including vibrio cholerae. the single polar flagellum of vibrio species is powered by a sodium-motive force across the inner membrane, and can rotate to produce speeds of up to 60 cell-body lengths (approximately 60microm) per second. investigating the role of the ch ... | 2005 | 16012515 |
| cytotoxic and cell vacuolating activity of vibrio fluvialis isolated from paediatric patients with diarrhoea. | vibrio fluvialis is a halophilic vibrio species associated with acute diarrhoeal illness in humans. it has the potential to cause outbreaks and has an association with paediatric diarrhoea. in this study, 11 v. fluvialis strains isolated from hospitalized patients with acute diarrhoea at the infectious diseases hospital, kolkata were extensively characterized. all the strains showed growth in peptone broth containing 7% nacl. the strains showed variable results in voges-proskauer test and to a v ... | 2005 | 16014422 |
| enterotoxigenic escherichia coli and vibrio cholerae diarrhea, bangladesh, 2004. | flooding in dhaka in july 2004 caused epidemics of diarrhea. enterotoxigenic escherichia coli (etec) was almost as prevalent as vibrio cholerae o1 in diarrheal stools. etec that produced heat-stable enterotoxin alone was most prevalent, and 78% of strains had colonization factors. like v. cholerae o1, etec can cause epidemic diarrhea. | 2005 | 16022790 |
| pathogen adaptation to seasonal forcing and climate change. | many diverse infectious diseases exhibit seasonal dynamics. seasonality in disease incidence has been attributed to seasonal changes in pathogen transmission rates, resulting from fluctuations in extrinsic climate factors. multi-strain infectious diseases with strain-specific seasonal signatures, such as cholera, indicate that a range of seasonal patterns in transmission rates is possible in identical environments. we therefore consider pathogens capable of evolving their 'seasonal phenotype', a ... | 2005 | 16024354 |