Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| molecular analyses of vibrio cholerae o1 clinical strains, including new nontoxigenic variants isolated in mexico during the cholera epidemic years between 1991 and 2000. | we studied the evolution of vibrio cholerae o1 during the 1991 to 2000 cholera epidemic in mexico by biochemical, serological, and molecular characterization of strains collected during this period. strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. as previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. bgli rrna analysis revealed that ... | 2009 | 19213700 |
| the impact of climate on the disease dynamics of cholera. | the size of infectious disease outbreaks frequently depends on climate influences as well as on the level of immunity in the host population. this is particularly the case with vectorborne and waterborne diseases, for which pathogen transmissibility critically depends on ecological conditions. here, a mathematical model that was applied to the bacterium vibrio cholerae to understand its disease dynamics in bangladesh is reviewed. when interfaced with empirical case data on cholera, the model sho ... | 2009 | 19220350 |
| surveillance of vibriophages reveals their role as biomonitoring agents in kolkata. | cholera is a public health threat in all developing countries. kolkata, a city in eastern india, is an endemic zone for cholera. during the course of a comprehensive investigation on the distribution of phages of vibrio cholerae o1 and o139 in freshwater bodies in kolkata, we were able to isolate the phages of v. cholerae o1 and o139. vibrio cholerae o1 phages were found at all the sites and exhibited a distinct seasonal cycle, with a primary peak (13.6-17.2 pfu ml(-1)) during monsoon (june to a ... | 2009 | 19220862 |
| experimental discovery of srnas in vibrio cholerae by direct cloning, 5s/trna depletion and parallel sequencing. | direct cloning and parallel sequencing, an extremely powerful method for microrna (mirna) discovery, has not yet been applied to bacterial transcriptomes. here we present srna-seq, an unbiased method that allows for interrogation of the entire small, non-coding rna (srna) repertoire in any prokaryotic or eukaryotic organism. this method includes a novel treatment that depletes total rna fractions of highly abundant trnas and small subunit rrna, thereby enriching the starting pool for srna transc ... | 2009 | 19223322 |
| glycogen contributes to the environmental persistence and transmission of vibrio cholerae. | pathogenic vibrio cholerae cycle between the nutrient-rich human intestinal tract and nutrient-poor aquatic environments and currently few bacterial factors are known that aid in the transition between these disparate environments. we hypothesized that the ability to store carbon as glycogen would facilitate both bacterial fitness in the aquatic environment and transmission of v. cholerae to new hosts. to investigate the role of glycogen in v. cholerae transmission, we constructed mutants that c ... | 2009 | 19226328 |
| single nanoparticle tracking-based detection of membrane receptor-ligand interactions. | we developed a single nanoparticle tracking-based detection method for membrane-associated molecules using a paucivalent gold nanoparticle (aunp)-modified supported lipid bilayer (slb) platform. here, the binding activity of membrane-associated molecules (cholera toxin binding to ganglioside gm(1) in this case) was determined by calculating the diffusion coefficients of membrane-tethered aunps. this nonbleaching nanoparticle-based method provides >100-fold improvement in sensitivity for the same ... | 2009 | 19228043 |
| molecular characterization of vibrio cholerae isolates from cholera outbreaks in north india. | vibrio cholerae isolates recovered from cholera outbreaks in bhind district of madhya pradesh and delhi, northern india were characterized. the o1 serogroup isolates from bhind outbreak were of inaba serotype whereas both ogawa and inaba serotypes were recovered from delhi. pcr analysis revealed that only o1 serogroup v. cholerae isolates carried the virulence-associated genes like ctxa, tcpa, ace, and zot. molecular typing by repetitive sequence based eric, vcr1, and vc1 pcr's revealed similar ... | 2009 | 19229498 |
| killing of enteric bacteria in drinking water by a copper device for use in the home: laboratory evidence. | water inoculated with 500-1000 colony forming units/ml of escherichia coli, salmonella typhi and vibrio cholerae was stored overnight at room temperature in copper pots or in glass bottles containing a copper coil devised by us. the organisms were no longer recoverable when cultured on conventional media, by contrast with water stored in control glass bottles under similar conditions. the amount of copper leached into the water after overnight storage in a copper pot or a glass bottle with a cop ... | 2009 | 19230946 |
| vibrio biofilms: so much the same yet so different. | vibrios are natural inhabitants of aquatic environments and form symbiotic or pathogenic relationships with eukaryotic hosts. recent studies reveal that the ability of vibrios to form biofilms (i.e. matrix-enclosed, surface-associated communities) depends upon specific structural genes (flagella, pili and exopolysaccharide biosynthesis) and regulatory processes (two-component regulators, quorum sensing and c-di-gmp signaling). here, we compare and contrast mechanisms and regulation of biofilm fo ... | 2009 | 19231189 |
| single-pass classification of all noncoding sequences in a bacterial genome using phylogenetic profiles. | identification and characterization of functional elements in the noncoding regions of genomes is an elusive and time-consuming activity whose output does not keep up with the pace of genome sequencing. hundreds of bacterial genomes lay unexploited in terms of noncoding sequence analysis, although they may conceal a wide diversity of novel rna genes, riboswitches, or other regulatory elements. we describe a strategy that exploits the entirety of available bacterial genomes to classify all noncod ... | 2009 | 19237465 |
| cholera caused by vibrio cholerae o1 induces t-cell responses in the circulation. | considerable effort is being made to understand the acute and memory antibody responses in natural cholera infection, while rather less is known about the roles of cellular immune responses involving t and b lymphocytes. we studied responses in adult patients hospitalized with cholera caused by vibrio cholerae o1. peripheral blood mononuclear cells from patients (n = 15) were analyzed by flow cytometry after stimulation with v. cholerae o1 membrane protein (mp) or toxin-coregulated pilus antigen ... | 2009 | 19237532 |
| the oligomeric assembly of the novel haem-degrading protein hbps is essential for interaction with its cognate two-component sensor kinase. | hbps, a novel protein of previously unknown function from streptomyces reticuli, is up-regulated in response to haemin- and peroxide-based oxidative stress and interacts with the sens/senr two-component signal transduction system. in this study, we report the high-resolution crystal structures (2.2 and 1.6 a) of octomeric hbps crystallized in the presence and in the absence of haem and demonstrate that iron binds to surface-exposed lysine residues of an octomeric assembly. based on an analysis o ... | 2009 | 19244623 |
| laboratory study of vibrio cholerae o1 survival on three types of boiled rice (oryza sativa l.) held at room temperature. | this study examined whether the survival of vibrio cholerae o1 on contaminated cooked rice was influenced by the type of rice. vibrios survived unchanged on clumps of glutinous white rice (wet, grains adhered) held at room temperature for 24 h. on nonglutinous white rice (slightly moist, grains separate), 30% viable vibrios remained at 24 h. on nonglutinous brown rice (moist, separate, covered with a mucus-like substance), the number of vibrios increased 2.7-fold at 24 h. survival rates of vibri ... | 2008 | 19244898 |
| assessment of safety, nutritional, and spoilage characteristics of different lagoon grey mullets (liza ramada, liza aurata, and liza saliens). | different lagoon grey mullets such as liza ramada (thinlip mullet), liza aurata (golden grey mullet), and liza saliens (leaping grey mullet) were analyzed for their nutritional, microbiological, and safety parameters. the microbiological values never exceeded the lower limits stipulated by the italian higher institute of health. the pathogenic species frequently associated with seafood (salmonella, listeria monocytogenes, vibrio cholerae, vibrio parahaemolyticus, and aeromonas hydrophila) were n ... | 2008 | 19244917 |
| genetic tools to study gene expression during bacterial pathogen infection. | the study of bacterial pathogenesis is in many ways the study of the regulatory mechanisms at work in the microbe during infection. the astonishing flexibility and adaptability of the bacterial cell has enabled many pathogenic species to freely transition between dramatically different environmental conditions. the transcriptional changes that underlie this ability can determine the success of the pathogen in the host. many techniques have been devised to examine the transcriptional repertoire o ... | 2009 | 19245943 |
| biotyping of vibrio cholerae o1: time to redefine the scheme. | considering the recent emergence of "hybrid biotype" and "el tor variant", we propose to redefine the biotyping scheme for vibrio cholerae o1 serogroup. the existing biotyping scheme has limitations and causes confusion as many of the hybrid biotype and el tor variant strains have phenotypic and genetic changes. a revised biotyping scheme will play a significant role to understand the ecology, epidemiology and nature of infection of v. cholerae o1 strains in future. | 2008 | 19246791 |
| docking and assembly of the type ii secretion complex of vibrio cholerae. | secretion of cholera toxin and other virulence factors from vibrio cholerae is mediated by the type ii secretion (t2s) apparatus, a multiprotein complex composed of both inner and outer membrane proteins. to better understand the mechanism by which the t2s complex coordinates translocation of its substrates, we are examining the protein-protein interactions of its components, encoded by the extracellular protein secretion (eps) genes. in this study, we took a cell biological approach, observing ... | 2009 | 19251862 |
| time course of bacterial diversity in stool samples of malnourished children with cholera receiving treatment. | recent nutritional interventions have targeted colonic functions in patients with infectious diarrhea during rehydration and during recovery from malnutrition, with the assumption that the effects will be influenced by metabolism of complex carbohydrates by colonic bacteria. however, the diversity of colonic bacteria in patients with cholera is not known. | 2009 | 19252449 |
| assessing clonality of vibrio cholerae strains isolated during four consecutive years (2004 - 2007) in iran. | genotypic and phenotypic characterizations of 50 clinical vibrio cholerae isolates obtained during 4 consecutive y from 2004 to 2007 in iran were studied. antimicrobial susceptibility test, biochemical fingerprinting with phene plate system (php-rv) and pulsed-field gel electrophoresis (pfge) were performed. antibiotic susceptibility test of all isolates showed 12 different profiles. the predominant antimicrobial resistance profile (62%) was simultaneous resistance to sxt, streptomycin, chloramp ... | 2009 | 19253091 |
| unusual codon usage bias in low expression genes of vibrio cholerae. | positive correlation between gene expression and synonymous codon usage bias is well documented in the literature. however, in the present study of vibrio cholerae genome, we have identified a group of genes having unusually high codon usage bias despite being low potential expressivity. our results suggest that codon usage in lowly expressed genes might also be selected on to preferably use non-optimal codons to maintain a low cellular concentration of the proteins that they encode. this would ... | 2008 | 19255636 |
| free-living acanthamoeba and naegleria spp. amebae in water sources of león, nicaragua. | free-living amebae (fla) are known to occur worldwide in water-related biotopes, but only limited information is available on these organisms in developing countries and so far no information on their presence is available from nicaragua. the aims of this study were to evaluate the prevalence of potentially pathogenic acanthamoeba spp. and naegleria spp. in different water sources to which the population of le6n municipality is exposed. since pathogenic amebae are thermotolerant, we were especia ... | 2008 | 19256418 |
| rapid detection of food-borne pathogens in clinical specimens, food and environmental samples. | 1. pcr and rt-pcr methods for 5-hour and 3-hour detection, respectively, of salmonellae and vibrio cholerae in stool, food and environmental water samples have been developed. 2. such methods can be used in routine laboratories for rapid detection of salmonellae and v cholerae and are essential for infection control purposes. | 2009 | 19258630 |
| application of lambda red recombination system to vibrio cholerae genetics: simple methods for inactivation and modification of chromosomal genes. | the lambda red-based recombination system is very useful for genetic manipulation of some gram-negative bacteria. here we report simple procedures for the inactivation and modification of genes of interest on vibrio cholerae chromosome using this recombination technique. for this purpose, a polymerase chain reaction (pcr) fragment carrying an antibiotic resistance cassette flanked by regions homologous to the target locus was electroporated into recipient v. cholerae strains expressing a highly ... | 2009 | 19268696 |
| transition state analogs of 5'-methylthioadenosine nucleosidase disrupt quorum sensing. | 5'-methylthioadenosine/s-adenosylhomocysteine nucleosidase (mtan) is a bacterial enzyme involved in s-adenosylmethionine-related quorum sensing pathways that induce bacterial pathogenesis factors. transition state analogs mt-dadme-immucillin-a, ett-dadme-immucillin-a and but-dadme-immucillin-a are slow-onset, tight-binding inhibitors of vibrio cholerae mtan (vcmtan), with equilibrium dissociation constants of 73, 70 and 208 pm, respectively. structural analysis of vcmtan with but-dadme-immucilli ... | 2009 | 19270684 |
| pore formation by vibrio cholerae cytolysin follows the same archetypical mode as beta-barrel toxins from gram-positive organisms. | vibrio cholerae cytolysin (vcc) forms sds-stable heptameric beta-barrel transmembrane pores in mammalian cell membranes. in contrast to structurally related pore formers of gram-positive organisms, no oligomeric prepore stage of assembly has been detected to date. in the present study, disulfide bonds were engineered to tie the pore-forming amino acid sequence to adjacent domains. in their nonreduced form, mutants were able to bind to rabbit erythrocytes and to native erythrocyte membranes suspe ... | 2009 | 19276173 |
| regulatory targets of quorum sensing in vibrio cholerae: evidence for two distinct hapr-binding motifs. | the quorum-sensing pathway in vibrio cholerae controls the expression of the master regulator hapr, which in turn regulates several important processes such as virulence factor production and biofilm formation. while hapr is known to control several important phenotypes, there are only a few target genes known to be transcriptionally regulated by hapr. in this work, we combine bioinformatic analysis with experimental validation to discover a set of novel direct targets of hapr. our results provi ... | 2009 | 19276207 |
| necrotizing soft-tissue infections and primary sepsis caused by vibrio vulnificus and vibrio cholerae non-o1. | vibrio species are a rare cause of necrotizing soft-tissue infections and primary septicemia, which are likely to occur in patients with hepatic disease, diabetes, adrenal insufficiency, and immunocompromised conditions. these organisms thrive in warm seawater and are often present in raw oysters, shellfish, and other seafood. this study examined fulminating clinical characteristics of vibrio vulnificus and vibrio cholerae non-o1 soft-tissue infections and identified outcome predictors. | 2009 | 19276771 |
| effect of vibrio cholerae on chemokine gene expression in ht29 cells and its modulation by lactobacillus gg. | epithelial cells participate in the innate immune response to pathogenic bacteria by elaborating chemokines. this study examined the effect of vibrio cholerae and lactobacillus rhamnosus gg on inflammatory chemokine gene expression in the ht29 human intestinal epithelial cell line. ht29 cells were exposed to v. cholerae 0139, lactobacillus or both for 2 h and cultured further thereafter for 4 h. rna was extracted from the cells and expression of genes for chemokines and related molecules was qua ... | 2009 | 19281529 |
| comparison of histopathological features of vibrio cholerae o1 el tor and o139 bengal infections in rabbit intestinal mucosa. | vibrio cholerae is the causative agent of the infectious disease, cholera. the bacteria adhere to the mucosal membrane and release cholera toxin, leading to watery diarrhea. there are >100 serovars of v. cholerae, but the o1 and o139 serovars are the main causative agents of cholera. the present study aimed to compare the severity of intestinal mucosal infection caused by o1 el tor and o139 v. cholerae in a rabbit ileal loop model. the results showed that although the fluid accumulation was simi ... | 2009 | 19283664 |
| bacterial martyrdom: phagocytes disabled by type vi secretion after engulfing bacteria. | to colonize during disease and prevent consumption by environmental unicellular eukaryotes, bacteria often disrupt phagocytosis. in this issue, ma et al. (2009) show that vibrio cholerae delivers the actin-crosslinking t6ss effector vgrg-1 following phagocytosis. the effector then causes irreversible cytoskeleton destruction, leading to bystander protection of the extracellular bacterial population. | 2009 | 19286128 |
| translocation of a vibrio cholerae type vi secretion effector requires bacterial endocytosis by host cells. | the type vi secretion system (t6ss) is a virulence mechanism common to several gram-negative pathogens. in vibrio cholerae, vgrg-1 is required for t6ss-dependent secretion. vgrg-1 is also secreted by t6ss and displays a c-terminal actin crosslinking domain (acd). using a heterologous reporter enzyme in place of the acd, we show that the effector and secretion functions of vgrg-1 are genetically dissociable with the acd being dispensable for secretion but required for t6ss-dependent phenotypes. f ... | 2009 | 19286133 |
| characterization of a new plasmid-like prophage in a pandemic vibrio parahaemolyticus o3:k6 strain. | vibrio parahaemolyticus is a common food-borne pathogen that is normally associated with seafood. in 1996, a pandemic o3:k6 strain abruptly appeared and caused the first pandemic of this pathogen to spread throughout many asian countries, america, europe, and africa. the role of temperate bacteriophages in the evolution of this pathogen is of great interest. in this work, a new temperate phage, vp882, from a pandemic o3:k6 strain of v. parahaemolyticus was purified and characterized after mitomy ... | 2009 | 19286788 |
| occurrence of virulent genes among environmental isolates of legionella pneumophila serogroup 1 strains from various parts of peninsular malaysia. | legionella pneumophila are intracellular pathogens, associated with human disease, attributed to the presence and absence of certain virulent genes. in this study, virulent gene loci (lvh and rtxa regions) associated with human disease were determined. thirty-three cooling tower water isolates, isolated between 2004 to 2006, were analyzed for the presence of these genes by pcr method. results showed that 19 of 33 (57.5%) of the l. pneumophila serogroup 1 isolates have both the genes. six (18.2%) ... | 2008 | 19287368 |
| galactooligosaccharides (gos) inhibit vibrio cholerae toxin binding to its gm1 receptor. | it is widely reported that cholera toxin (ctx) remains a significant cause of gastrointestinal disease globally, particularly in developing countries where access to clean drinking water is at a premium. vaccines are prohibitively expensive and have shown only short-term protection. consequently, there is scope for continued development of novel treatment strategies. one example is the use of galactooligosaccharides (gos) as functional mimics for the cell-surface toxin receptor (gm1). in this st ... | 2009 | 19290638 |
| nanotransportation system for cholera toxin in vibrio cholerae 01. | vibrio cholerae (v. cholerae) cholera toxin (ct), which causes a severe watery diarrheal illness, is secreted via the type ii secretion machinery; it remains unclear, however, how this toxin is transported toward the machinery. in this study, we determined that the ph-dependent intrabacterial transport system correlates with the priming of ct secretion by v. cholerae. the secretion and production of v. cholerae treated at different phs were examined by enzyme immunoassay. the localization of the ... | 2009 | 19294491 |
| cholera outbreaks caused by an altered vibrio cholerae o1 el tor biotype strain producing classical cholera toxin b in vietnam in 2007 to 2008. | vibrio cholerae o1 isolates collected during cholera outbreaks occurring from late 2007 to early 2008 in northern vietnam were revealed to represent an altered strain containing the rs1 element followed by a ctx prophage harboring el tor type rstr and classical ctxb on the large chromosome. | 2009 | 19297603 |
| stringent response in vibrio cholerae: genetic analysis of spot gene function and identification of a novel (p)ppgpp synthetase gene. | rela and spot of gram-negative organisms critically regulate cellular levels of (p)ppgpp. here, we have dissected the spot gene function of the cholera pathogen vibrio cholerae by extensive genetic analysis. unlike escherichia coli, v. choleraedeltareladeltaspot cells accumulated (p)ppgpp upon fatty acid or glucose starvation. the result strongly suggests rela-spot-independent (p)ppgpp synthesis in v. cholerae. by repeated subculturing of a v. choleraedeltareladeltaspot mutant, a suppressor stra ... | 2009 | 19298370 |
| genetic mapping of secretion and functional determinants of the vibrio cholerae tcpf colonization factor. | colonization of the human small intestine by vibrio cholerae requires the type iv toxin-coregulated pilus (tcp). tcpf, which is encoded within the tcp operon, is secreted from the bacterial cell by the tcp apparatus and is also essential for colonization. bacteria lacking tcpf are deficient in colonization, and anti-tcpf antibodies are protective in the infant mouse cholera model. in order to elucidate the regions of the protein that are required for secretion through the tcp apparatus and for i ... | 2009 | 19304855 |
| transmembrane cholesterol migration in planar lipid membranes measured with vibrio cholerae cytolysin as molecular tool. | the rate of transbilayer movement (flip-flop) of cholesterol was estimated using planar bilayers with defined initial asymmetry, formed by the opposing monolayers technique. vibrio cholerae cytolysin (vcc) was utilized as a molecular tool for measuring the cholesterol concentration in the cis leaflet of asymmetric bilayers. to quantify cholesterol flip-flop in planar lipid bilayers, a mathematical model was developed. it considers both the lateral diffusion rate of cholesterol within each monola ... | 2009 | 19306957 |
| [comparison of the transcriptional levels of mannitol pts operon between epidemic and non-epidemic strains of vibrio cholerae]. | to compare the transcription difference of the mannitol pts genes between epidemic and non-epidemic strains of vibrio cholerae el tor in mannitol ferment tests. | 2009 | 19317060 |
| hlyu acts as an h-ns antirepressor in the regulation of the rtx toxin gene essential for the virulence of the human pathogen vibrio vulnificus cmcp6. | in vibrio vulnificus, hlyu upregulates the expression of the large rtx toxin gene. in this work we identified the binding site of hlyu to -417 to -376 bp of the rtxa1 operon transcription start site. lacz fusions for a series of progressive deletions from the rtxa1 operon promoter showed that transcriptional activity increased independently of hlyu when its binding site was absent. thus hlyu must regulate the rtxa1 operon expression by antagonizing a negative regulator. concomitantly we found th ... | 2009 | 19320834 |
| the three-dimensional structure of the cytoplasmic domains of epsf from the type 2 secretion system of vibrio cholerae. | the type 2 secretion system (t2ss), a multi-protein machinery that spans both the inner and the outer membranes of gram-negative bacteria, is used for the secretion of several critically important proteins across the outer membrane. here we report the crystal structure of the n-terminal cytoplasmic domain of epsf, an inner membrane spanning t2ss protein from vibrio cholerae. this domain consists of a bundle of six anti-parallel helices and adopts a fold that has not been described before. the lo ... | 2009 | 19324092 |
| a toxin-antitoxin system promotes the maintenance of an integrative conjugative element. | sxt is an integrative and conjugative element (ice) that confers resistance to multiple antibiotics upon many clinical isolates of vibrio cholerae. in most cells, this approximately 100 kb element is integrated into the host genome in a site-specific fashion; however, sxt can excise to form an extrachromosomal circle that is thought to be the substrate for conjugative transfer. daughter cells lacking sxt can theoretically arise if cell division occurs prior to the element's reintegration. even t ... | 2009 | 19325886 |
| identification and characterization of oscr, a transcriptional regulator involved in osmolarity adaptation in vibrio cholerae. | vibrio cholerae is a facultative human pathogen. in its aquatic habitat and as it passes through the digestive tract, v. cholerae must cope with fluctuations in salinity. we analyzed the genome-wide transcriptional profile of v. cholerae grown at different nacl concentrations and determined that the expression of compatible solute biosynthesis and transporter genes, virulence genes, and genes involved in adhesion and biofilm formation is differentially regulated. we determined that salinity modu ... | 2009 | 19329635 |
| indole acts as an extracellular cue regulating gene expression in vibrio cholerae. | indole has been proposed to act as an extracellular signal molecule influencing biofilm formation in a range of bacteria. for this study, the role of indole in vibrio cholerae biofilm formation was examined. it was shown that indole activates genes involved in vibrio polysaccharide (vps) production, which is essential for v. cholerae biofilm formation. in addition to activating these genes, it was determined using microarrays that indole influences the expression of many other genes, including t ... | 2009 | 19329638 |
| high prevalence of spirochetosis in cholera patients, bangladesh. | the microbes that accompany the etiologic agent of cholera, vibrio cholerae, are only now being defined. in this study, spirochetes from the genus brachyspira were identified at high titers in more than one third of cholera patients in bangladesh. spirochetosis should now be tracked in the setting of cholera outbreaks. | 2009 | 19331734 |
| bystander protein protects potential vaccine-targeting ligands against intestinal proteolysis. | endowing mucosal vaccines with ligands that target antigen to mucosal lymphoid tissues may improve immunization efficacy provided that the ligands withstand the proteolytic environment of the gastro-intestinal tract until they reach their destination. our aim was to investigate whether and how three renowned ligands - ulex europaeus agglutinin i and the b subunits of cholera toxin and e. coli heat-labile enterotoxin - master this challenge. we assessed the digestive power of natural murine intes ... | 2009 | 19332091 |
| immunologic responses to vibrio cholerae in patients co-infected with intestinal parasites in bangladesh. | infection with intestinal helminths is common and may contribute to the decreased efficacy of vibrio cholerae vaccines in endemic compared to non-endemic areas. however, the immunomodulatory effects of concomitant intestinal parasitic infection in cholera patients have not been systematically evaluated. | 2009 | 19333369 |
| the vibrio cholerae cytolysin promotes chloride secretion from intact human intestinal mucosa. | the pathogenicity of the vibrio cholerae strains belonging to serogroup o1 and o139 is due to the production of virulence factors such as cholera toxin (ct) and the toxin-coregulated pilus (tcp). the remaining serogroups, which mostly lack ct and tcp, are more frequently isolated from aquatic environmental sources than from clinical samples; nevertheless, these strains have been reported to cause human disease, such as sporadic outbreaks of watery diarrhoea and inflammatory enterocolitis. this e ... | 2009 | 19333391 |
| comparison of automated ribotyping and pulsed-field gel electrophoresis for subtyping of vibrio cholerae. | to compare the discriminatory power of an automated ribotyping method for vibrio cholerae subtyping with the pulsed-field gel electrophoresis (pfge), to evaluate the possibility of automated ribotyping in use of outbreak investigations and surveillance of cholera. | 2009 | 19344358 |
| molecular diversification in the quorum-sensing system of vibrio cholerae: role of natural selection in the emergence of pandemic strains. | two haplotypes of the vibrio cholerae quorum-sensing system regulator hapr are described: hapr1, common among nonpandemic, non-o1, non-o139 strains, and hapr2, associated with pandemic o1 and o139 and epidemic o37 v. cholerae strains. the hapr2 has evolved under strong natural selection, implying that its fixation was influenced by conditions that led to cholera pandemics. | 2009 | 19346342 |
| cholera outbreak in kenyan refugee camp: risk factors for illness and importance of sanitation. | an outbreak of watery diarrhea struck within the kakuma refugee camp in kenya in april 2005; 418 people were treated, and 4 persons died. vibrio cholerae o1 was isolated from 33 patients. in june 2005, we conducted a retrospective matched case-control study to define risk factors associated with cholera among camp residents and identify interventions that could prevent further cases and future outbreaks. we identified cases of cholera through medical records at the main health facility in the ca ... | 2009 | 19346392 |
| expression of toll-like receptor 4 in uvea-resident tissue macrophages during endotoxin-induced uveitis. | to investigate the dynamics and distribution of toll-like receptor 4 (tlr4)-positive cells and resident tissue macrophages in the uvea during endotoxin-induced uveitis (eiu) in wistar rats. | 2009 | 19347047 |
| csra interacting small rnas in haemophilus spp genomes: a theoretical analysis. | the csra is a carbon storage regulator gene that encodes a protein with multiple rna interaction sites. bacterial non-coding small rnas like csrb, csrc and their counterparts in diverse bacterial genus are identified to control the regulatory activities of csra and its orthologs. an attempt has been made in this study to identify 'novel' non-coding small rnas that are involved in the regulatory activities of csra gene. all csra-interacting small rnas are computationally fingerprinted to have mul ... | 2009 | 19350225 |
| [vibrio species in the waters of southern sweden caused bath-wound fever. increased bacteria frequency according to studies on clams]. | 2009 | 19350770 | |
| psychrotrophic lactic acid bacteria used to improve the safety and quality of vacuum-packaged cooked and peeled tropical shrimp and cold-smoked salmon. | previously isolated lactic acid bacteria (lab) from seafood products have been investigated for their capacity to increase the sensory shelf life of vacuum-packaged shrimp and cold-smoked salmon and to inhibit the growth of three pathogenic bacteria. two different manufactured batches of cooked, peeled, and vacuum-packaged shrimp were inoculated with seven lab strains separately at an initial level of 5 log cfu g-t, and the spoilage was estimated by sensory analysis after 7 and 28 days of storag ... | 2009 | 19350982 |
| cholera outbreak--southern sudan, 2007. | vibrio cholerae causes cholera, an acute infectious diarrheal disease that can result in death without appropriate therapy, depending on the severity of the disease. war, poverty, inadequate sanitation, and large numbers of refugees and internally displaced persons (idps) are major precursors to cholera outbreaks. in 2005, southern sudan ended its 22-year civil war with north sudan; as a result, idps and refugees are returning to the south. during april--june 2007, investigators from the souther ... | 2009 | 19357634 |
| vibrio cholerae non-o1, non-o139 associated with seawater and plankton from coastal marine areas of the caribbean sea. | the aim of this study was to characterize the virulence properties and the antimicrobial resistance of vibrio cholerae isolates from a coastal area of the caribbean sea. three v. cholerae isolates were obtained from seawater and plankton using the hp selective medium for helicobacter pylori. these v. cholerae isolates belonged to the non-o1, non-o139 serogroups and they did not have cholera toxin genes. they were resistant to penicillins and some cephalosporins and were sensitive to netilmicin, ... | 2009 | 19358004 |
| inhibitory activity of myelin-associated glycoprotein on sensory neurons is largely independent of ngr1 and ngr2 and resides within ig-like domains 4 and 5. | myelin-associated glycoprotein (mag) is a sialic acid binding ig-like lectin (siglec) which has been characterized as potent myelin-derived inhibitor of neurite outgrowth. two members of the nogo-receptor (ngr) family, ngr1 and ngr2, have been identified as neuronal binding proteins of mag. in addition, gangliosides have been proposed to bind to and confer the inhibitory activity of mag on neurons. in this study, we investigated the individual contribution of ngrs and gangliosides to mag-mediate ... | 2009 | 19367338 |
| potent bactericidal action of a flavonoid fraction isolated from the stem bark of butea frondosa. | the flavonoid fraction isolated from the ethyl acetate fraction (bf-1) of butea frondosa (l.) stem bark exhibited distinct antimicrobial activity when tested against 129 bacterial strains belonging to 9 different genera of both gram-positive and gram-negative types. minimum inhibitory concentration (mic) of the fraction bf-1 was determined following nccls guidelines using the agar dilution method. twenty-four out of 36 strains of staphylococcus aureus were inhibited by 50-200 mg/l of the fractio ... | 2009 | 19368121 |
| polymer-based oral rehydration solution for treating acute watery diarrhoea. | acute diarrhoea is one of the principal causes of morbidity and mortality among children in low-income countries. glucose-based ors helps replace fluid and prevent further dehydration from acute diarrhoea. since 2004, the world health organization has recommended the osmolarity < 270 mosm/l (ors </= 270 ) over the > 310 mosm/l formulation (ors >/= 310). glucose polymer-based ors (eg prepared using rice or wheat) slowly releases glucose and may be superior. | 2009 | 19370638 |
| riboswitch conformations revealed by small-angle x-ray scattering. | riboswitches are functional rna molecules that control gene expression through conformational changes in response to small-molecule ligand binding. in addition, riboswitch 3d structure, like that of other rna molecules, is dependent on cation-rna interactions as the rna backbone is highly negatively charged. here, we show how small-angle x-ray scattering (saxs) can be used to probe rna conformations as a function of ligand and ion concentration. in a recent study of a glycine-binding tandem apta ... | 2009 | 19381558 |
| circulating phage type of vibrio cholerae in mysore. | 2009 | 19384046 | |
| prevalence and virulence properties of non-o1 non-o139 vibrio cholerae strains from seafood and clinical samples collected in italy. | seafood and clinical samples collected in italy during 2006 were analyzed to evaluate prevalence, serological and virulence properties of non-o1 non-o139 vibrio cholerae (ncv) isolates. biochemical and serological characterization of the strains was performed by standardized procedures while virulence properties of ncvs were assayed by molecular, in vivo and in vitro toxicological methods. of the 300 seafood samples examined, including mussel, cod, mackerel, anchovy, clam, prawn and cuttlefish, ... | 2009 | 19386376 |
| characterization of a novel protective monoclonal antibody that recognizes an epitope common to vibrio cholerae ogawa and inaba serotypes. | a novel protective monoclonal antibody (mab) that recognizes a lipopolysaccharide (lps) epitope common between serotypes ogawa and inaba of the o1 serogroup of vibrio cholerae was characterized and the potential to develop peptide mimics of this protective lps epitope was investigated. mab 72.1 recognizes both ogawa and inaba lps and it is vibriocidal and protective in passive immunization against infection by strains of both serotypes. the cdna-derived amino acid sequence of mab 72.1 is closely ... | 2009 | 19389772 |
| [characterization of vibrio cholerae non-o1 and non-o139 isolates associated with diarrhea]. | vibrio cholerae, etiologic agent of cholera, is transmitted to humans by ingestion of contaminated food or water. even though serogroups o1 and o139 are the ones usually associated to epidemic cholera, isolates from other serogroups also cause gastroenteritis and extraintestinal infections. during the period 2003-2005, presence of v. cholerae in stools was investigated in children with diarrhea that seaked assistance at the niño jesús hospital in tucumán. thirty four isolates of v. cholerae non- ... | 2009 | 19391519 |
| oscr, a new osmolarity-responsive regulator in vibrio cholerae. | 2009 | 19395495 | |
| identification of a calcium-controlled negative regulatory system affecting vibrio cholerae biofilm formation. | vibrio cholerae's capacity to cause outbreaks of cholera is linked to its survival and adaptability to changes in aquatic environments. one of the environmental conditions that can vary in v. cholerae's natural aquatic habitats is calcium (ca(+2)). in this study, we investigated the response of v. cholerae to changes in extracellular ca(2+) levels. whole-genome expression profiling revealed that ca(2+) decreased the expression of genes required for biofilm matrix production. luria-bertani (lb) m ... | 2009 | 19397680 |
| hurricanes, climate change and the cholera epidemic in puerto rico of 1855-1856. | hurricanes and global climate changes may affect the environmental factors of cholera dynamics in warm coastal areas, vulnerable to seasonal or sporadic outbreaks. the cholera epidemic of puerto rico in 1855-1856 had a profound effect on the puerto rican society; but it was not influenced by any climatic events, such as preceding hurricanes or storms based on past documentary sources. particularly, the environmental non-toxigenic strains of vibrio cholerae in puerto rican water sources can maint ... | 2008 | 19400536 |
| crystal structure of the vibrio cholerae ferric uptake regulator (fur) reveals insights into metal co-ordination. | the ferric uptake regulator (fur) is a metal-dependent dna-binding protein that acts as both a repressor and an activator of numerous genes involved in maintaining iron homeostasis in bacteria. it has also been demonstrated in vibrio cholerae that fur plays an additional role in pathogenesis, opening up the potential of fur as a drug target for cholera. here we present the crystal structure of v. cholerae fur that reveals a very different orientation of the dna-binding domains compared with that ... | 2009 | 19400801 |
| two site-directed mutations are required for the conversion of a sugar dehydratase into an aminotransferase. | l-colitose and d-perosamine are unusual sugars found in the o-antigens of some gram-negative bacteria such as escherichia coli, vibrio cholerae, and salmonella enterica, among others. the biosynthetic pathways for these two sugars begin with the formation of gdp-mannose from d-mannose 1-phosphate and gtp followed by the subsequent dehydration and oxidation of gdp-mannose to yield gdp-4-keto-6-deoxymannose. following the production of gdp-4-keto-6-deoxymannose, the two pathways diverge. in the ca ... | 2009 | 19402712 |
| lincomycin-induced over-expression of mature recombinant cholera toxin b subunit and the holotoxin in escherichia coli. | cholera toxin (ct) b subunit (ctb) was overproduced using a novel expression system in escherichia coli. an expression plasmid was constructed by inserting the gene encoding the full-length ctb and the shine-dalgarno (sd) sequence derived from ctb or from the heat-labile enterotoxin b subunit (ltb) of enterotoxigenic e. coli into the laczalpha gene fragment in the pbluescript sk(+) vector. the e. coli strain mv1184 was transformed with each plasmid and then cultured in caye broth containing linc ... | 2009 | 19410003 |
| a novel srna that modulates virulence and environmental fitness of vibrio cholerae. | we recently described the discovery and initial functional characterization of a new srna, vrra, in vibrio cholerae o1 strain a1552. the vrra homologs were found in all vibrio strains whose genome sequences were reported at present. in this article, we summarize the multi-functional features of vrra in v. cholerae pathogenesis and physiology, especially in relation to the regulation of outer membrane vesicle formation and its consequence in environmental adaptation of the bacterium. as the vrra ... | 2009 | 19411843 |
| comparison of traditional and molecular analytical methods for detecting biological agents in raw and drinking water following ultrafiltration. | to compare the performance of traditional methods to quantitative polymerase chain reaction (qpcr) for detecting five biological agents in large-volume drinking-water samples concentrated by ultrafiltration (uf). | 2009 | 19426268 |
| mechanism of drug resistance in a clinical isolate of vibrio fluvialis: involvement of multiple plasmids and integrons. | the role of mobile genetic elements in imparting multiple drug resistance to a clinical isolate of vibrio fluvialis (bd146) was investigated. this isolate showed complete or intermediate resistance to all of the 14 antibiotics tested. polymerase chain reaction (pcr) revealed the presence of a class 1 integron and the absence of the sxt element in this isolate. the strain harboured a 7.5 kb plasmid and a very low copy number plasmid of unknown molecular size. transformation of escherichia coli wi ... | 2009 | 19427174 |
| structural and unfolding features of hlyt, a tetrameric lysr type transcription regulator of vibrio cholerae. | hlyt from vibrio cholerae is a positive regulator of na(+)/h(+) antiporter, important for the survival of the organism in an aquatic environment and within the human host. here we report cloning, over-expression and purification of hlyt. analytical gel filtration and glutaraldehyde cross-linking indicate existence of tetrameric and dimeric forms of hlyt in solution. we propose an unfolding model of hlyt on the basis of guanidine hydrochloride-induced equilibrium unfolding, analyzed by cd and spe ... | 2009 | 19427417 |
| the rho gtpase inactivation domain in vibrio cholerae martx toxin has a circularly permuted papain-like thiol protease fold. | a rho gtpase inactivation domain (rid) has been discovered in the multifunctional, autoprocessing rtx toxin rtxa from vibrio cholerae. the rid domain causes actin depolymerization and rounding of host cells through inactivation of the small rho gtpases rho, rac, and cdc42. with only a few toxin proteins containing rid domains in the current sequence database, the structure and molecular mechanisms of this domain are unknown. using comparative sequence and structural analyses, we report homology ... | 2009 | 19434753 |
| intravenous immunoglobulin contains a broad repertoire of anticarbohydrate antibodies that is not restricted to the igg2 subclass. | specificities for carbohydrate igg antibodies, thought to be predominantly of the igg2 subclass, have never been broadly examined in healthy human subjects. | 2009 | 19443021 |
| intramuscular delivery of a cholera dna vaccine primes both systemic and mucosal protective antibody responses against cholera. | cholera is a potentially lethal diarrhea disease caused by the gram-negative bacterium vibrio cholerae. the need for an effective cholera vaccine is clearly indicated but the challenges of eliciting both systemic and mucosal immune responses remains a significant challenge. in the current report, we discovered that a dna vaccine expressing a protective cholera antigen, cholera toxin b subunit (ctb), delivered parenterally can elicit both systemic and mucosal anti-ctb antibody responses in mice. ... | 2009 | 19443090 |
| microbial oceanography in a sea of opportunity. | plankton use solar energy to drive the nutrient cycles that make the planet habitable for larger organisms. we can now explore the diversity and functions of plankton using genomics, revealing the gene repertoires associated with survival in the oceans. such studies will help us to appreciate the sensitivity of ocean systems and of the ocean's response to climate change, improving the predictive power of climate models. | 2009 | 19444203 |
| intranasal immunization with recombinant toxin-coregulated pilus and cholera toxin b subunit protects rabbits against vibrio cholerae o1 challenge. | intranasal immunization, a noninvasive method of vaccination, has been found to be effective in inducing systemic and mucosal immune responses. the present study was aimed at investigating the efficacy of intranasal immunization in inducing mucosal immunity in experimental cholera by subunit recombinant protein vaccines from vibrio cholerae o1. the structural genes encoding toxin-coregulated pilus a (tcpa) and b subunit of cholera toxin (ctxb) from v. cholerae o1 were cloned and expressed in esc ... | 2009 | 19453752 |
| non-o1 vibrio cholerae inguinal skin and soft tissue infection with bullous skin lesions in a patient with a penis squamous cell carcinoma. | vibrio spp. is a pathogen rarely isolated in cancer patients, and in most cases it is associated with haematological diseases. cutaneous manifestations of this organism are even rarer. we report a case of non-o1 vibrio cholerae inguinal skin and soft tissue infection presenting bullous skin lesions in a young type ii diabetic patient with a penis squamous cell carcinoma having a seawater exposure history. | 2009 | 19454006 |
| characterization of potentially virulent non-o1/non-o139 vibrio cholerae strains isolated from human patients. | traditional methods of typing vibrio cholerae define virulent strains according to their recognition by sera directed against the known epidemic serogroups o1 and o139, overlooking potentially virulent non-o1/non-o139 strains. here, we have undertaken the characterization of eight clinical isolates of non-o1/non-o139 v. cholerae, collected during cholera outbreaks in brazil. seven of these were typed as o26 and one, 17155, was defined as non-typable. a pcr-based approach has previously detected ... | 2010 | 19456828 |
| the sos response controls integron recombination. | integrons are found in the genome of hundreds of environmental bacteria but are mainly known for their role in the capture and spread of antibiotic resistance determinants among gram-negative pathogens. we report a direct link between this system and the ubiquitous sos response. we found that lexa controlled expression of most integron integrases and consequently regulated cassette recombination. this regulatory coupling enhanced the potential for cassette swapping and capture in cells under str ... | 2009 | 19460999 |
| zonulin is not increased in the cardiac and esophageal mucosa of patients with gastroesophageal reflux disease. | human zonulin, related to the zonula occludens toxin of vibrio cholerae, regulates intestinal permeability and is induced in inflammatory disorders of the lower gi tract. gastroesophageal reflux disease (gerd) is associated with an impairment of epithelial barrier function. here, we studied expression of zonulin in the gastroesophageal mucosa of 58 patients with typical reflux symptoms and 27 asymptomatic controls. during endoscopy, multiple biopsies from gastroesophageal mucosa were obtained fo ... | 2009 | 19463740 |
| mechanistic and structural insights into the proteolytic activation of vibrio cholerae martx toxin. | martx toxins modulate the virulence of a number of gram-negative vibrio species. this family of toxins is defined by the presence of a cysteine protease domain (cpd), which proteolytically activates the vibrio cholerae martx toxin. although recent structural studies of the cpd have uncovered a new allosteric activation mechanism, the mechanism of cpd substrate recognition or toxin processing is unknown. here we show that interdomain cleavage of martxvc enhances effector domain function. we also ... | 2009 | 19465933 |
| multiple antibiotic resistance profiles of vibrio cholerae non-o1 and non-o139. | in this study, the patterns of resistance to 10 antibiotics by 730 vibrio cholerae non-o1 and non-o139 species isolated from both environmental and seafood samples were investigated. susceptibility to different antimicrobial agents was assessed by the disc diffusion technique. the frequencies of resistance to 10 antimicrobial agents--ampicillin, chloramphenicol, bacitracin, erythromycin, gentamycin, streptomycin, oxytetracycline, vancomycin, penicillin, and neomycin--were 88, 46, 8, 64, 13, 85, ... | 2009 | 19468189 |
| rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method. | to develop a new, rapid and accurate reverse dot blot (rdb) method for the detection of intestinal pathogens in fecal samples. | 2009 | 19469006 |
| antibacterial activity of ciprofloxacin and trimethoprim, alone and in combinittion, against vibrio cholerae o1 biotype el tor serotype ogawa isolates. | in this communication, the ciprofloxacin-trimethoprim (cp-tm) combination showed synergistic (fractional inhibitory concentration, fic index 0.399) and additive (fic index 0.665-0.83) effects against vibrio cholerae o1 biotype el tor serotype ogawa isolates having cp mics 10 microg/ml and cp 0.66 microg/ml, respectively, following agar dilution checkerboard method. the time-kill study results demonstrated synergy between cp and tm against both groups of isolates providing 2.04 log10 (for strain ... | 2009 | 19469287 |
| insights into the evolution of sialic acid catabolism among bacteria. | sialic acids comprise a family of nine-carbon amino sugars that are prevalent in mucus rich environments. sialic acids from the human host are used by a number of pathogens as an energy source. here we explore the evolution of the genes involved in the catabolism of sialic acid. | 2009 | 19470179 |
| establishment of an adult mouse model for direct evaluation of the efficacy of vaccines against vibrio cholerae. | we describe here a new animal model that offers the prospect of using conventional adult mice for direct evaluation of the protective potential of new cholera vaccines. pretreatment of adult mice with oral streptomycin allowed intestinal colonization by streptomycin-resistant vibrio cholerae strains of either the o1 or the o139 serogroup. bacteria were recovered in greatest numbers from the cecum and large intestine, but recoveries from all regions of the gut correlated significantly with bacter ... | 2009 | 19470748 |
| differential modulation of nf-kappab-mediated pro-inflammatory response in human intestinal epithelial cells by chey homologues of vibrio cholerae. | vibrio cholerae, the etiological agent of cholera, colonizes the small intestine, produces an enterotoxin and causes acute inflammatory response at intestinal epithelial surface. chemotaxis and motility greatly influence the infectivity of v. cholerae although the role of chemotaxis genes in v. cholerae pathogenesis is less well understood. four chey genes are present in three clusters in the complete genome sequence of v. cholerae. a less motile and less adherent mutant was generated by inactiv ... | 2009 | 19474207 |
| overexpression, purification, crystallization and preliminary x-ray studies of vibrio cholerae epsg. | epsg is the major pseudopilin protein of the vibrio cholerae type ii secretion system. an expression plasmid that encodes an n-terminally truncated form of epsg with a c-terminal noncleavable his tag was constructed. recombinant epsg was expressed in escherichia coli; the truncated protein was purified and crystallized by hanging-drop vapor diffusion against a reservoir containing 6 mm zinc sulfate, 60 mm mes ph 6.5, 15% peg mme 550. the crystals diffracted x-rays to a resolution of 2.26 a and b ... | 2009 | 19478449 |
| pleiotropic effects of the twin-arginine translocation system on biofilm formation, colonization, and virulence in vibrio cholerae. | the twin-arginine translocation (tat) system serves to translocate folded proteins, including periplasmic enzymes that bind redox cofactors in bacteria. the tat system is also a determinant of virulence in some pathogenic bacteria, related to pleiotropic effects including growth, motility, and the secretion of some virulent factors. the contribution of the tat pathway to vibrio cholerae has not been explored. here we investigated the functionality of the tat system in v. cholerae, the etiologic ... | 2009 | 19480715 |
| vibriobactin antibodies: a vaccine strategy. | a new target strategy in the development of bacterial vaccines, the induction of antibodies to microbial outer membrane ferrisiderophore complexes, is explored. a vibriobactin (vib) analogue, with a thiol tether, 1-(2,3-dihydroxybenzoyl)-5,9-bis[[(4s,5r)-2-(2,3-dihydroxyphenyl)-4,5-dihydro-5-methyl-4-oxazolyl]carbonyl]-14-(3-mercaptopropanoyl)-1,5,9,14-tetraazatetradecane, was synthesized and linked to ovalbumin (ova) and bovine serum albumin (bsa). the antigenicity of the vib microbial iron che ... | 2009 | 19492834 |
| correlations between carbon metabolism and virulence in bacteria. | bacteria have developed several mechanisms which allow the preferred utilization of the most efficiently metabolizable carbohydrates when these organisms are exposed to a mixture of carbon sources. interestingly, the same or similar mechanisms are used by some pathogens to control various steps of their infection process. the efficient metabolism of a carbon source might serve as signal for proper fitness. alternatively, the presence of a specific carbon source might indicate to bacterial cells ... | 2009 | 19494580 |
| pore-forming toxins activate mapk p38 by causing loss of cellular potassium. | mitogen activated protein kinase (mapk) p38 has emerged as a survival protein in cells that are attacked by bacterial toxins forming small membrane pores. activation of p38 by pore forming toxins (pft) has been attributed to osmotic stress, but here we show that loss of k+ is likely to be the critical parameter. several lines of evidence support this conclusion: first, osmoprotection did not prevent p38-phosphorylation in alpha-toxin-loaded cells. second, treatment of cells with a k+ ionophore, ... | 2009 | 19497299 |
| recruitment of the earliest component of the bacterial flagellum to the old cell division pole by a membrane-associated signal recognition particle family gtp-binding protein. | the specialised signal recognition particle family guanosine 5c-triphosphate (gtp)-binding protein flhf is required for the correct localisation of flagella in several bacterial species. here, we characterise the regions of vibrio cholerae flhf that are required for its function and targeting to the old cell pole, and we present evidence for a mechanism by which flhf establishes flagellum polar localisation. substitution of residues in flhf nucleotide-binding motifs reduced gtp binding and the e ... | 2009 | 19497327 |
| functional role of a conserved aspartic acid residue in the motor of the na(+)-driven flagellum from vibrio cholerae. | the flagellar motor consists of a rotor and a stator and couples the flux of cations (h(+) or na(+)) to the generation of the torque necessary to drive flagellum rotation. the inner membrane proteins poma and pomb are stator components of the na(+)-driven flagellar motor from vibrio cholerae. affinity-tagged variants of poma and pomb were co-expressed in trans in the non-motile v. cholerae pomab deletion strain to study the role of the conserved d23 in the transmembrane helix of pomb. at ph 9, t ... | 2009 | 19501041 |
| sxy induces a crp-s regulon in escherichia coli. | escherichia coli is not considered naturally competent, yet it has homologues of the genes that most competent bacteria use for dna uptake and processing. in haemophilus influenzae and vibrio cholerae, these genes are regulated by the sxy and cyclic amp receptor (crp) proteins. we used microarrays to find out whether similar regulation occurs in e. coli. expression of sxy strongly induced 63 transcriptional units, 34 of which required crp for transcriptional activation and had promoter sites res ... | 2009 | 19502395 |