| the 12 gastrointestinal pathogens spectrum of acute infectious diarrhea in a sentinel hospital, shenzhen, china. | acute infectious gastroenteritis is one of the most common diseases among all ages, particularly in developing countries. the pathogen spectrum may differ among different regions and seasons. to investigate the etiology of acute diarrhea in shenzhen, a prospective study was conducted from august 2014 to september 2015. stools from 412 patients with diarrhea (286 of whom were adults) including the general epidemiological information of the patients were collected. the 19 pathogens were detected b ... | 2016 | 27965649 |
| a novel phase variant of the cholera pathogen shows stress-adaptive cryptic transcriptomic signatures. | in a process known as phase variation, the marine bacterium and cholera pathogen vibrio cholerae alternately expresses smooth or rugose colonial phenotypes, the latter being associated with advanced biofilm architecture and greater resistance to ecological stress. to define phase variation at the transcriptomic level in pandemic v. cholerae o1 el tor strain n16961, we compared the rna-seq-derived transcriptomes among the smooth parent n16961, its rugose derivative (n16961r) and a smooth form obt ... | 2016 | 27842489 |
| rapid molecular approach for simultaneous detection of salmonella spp., shigella spp., and vibrio cholera. | gastrointestinal tract infection is still one of the serious public health problems in many geographic areas and is endemic in most countries including iran. early detection of the gastrointestinal tract pathogens can be extremely important. the aim of the current study was to apply a shortened time-multiplex polymerase chain reaction (pcr) for rapid and simultaneous detection of salmonella spp., shigella spp., and vibrio cholera. | 2016 | 28053842 |
| characteristics of bacterial pathogens associated with acute diarrhea in children under 5 years of age: a hospital-based cross-sectional study. | acute diarrhea is a leading cause of morbidity and mortality in children, particularly in those under the age of 5 years. rotavirus is recognized as the leading cause of acute diarrhea in children, however, the contribution of bacterial pathogens as causative agents varies throughout the world. here we report a hospital-based prospective study to analyze the characteristics of bacterial pathogens associated with acute diarrhea in children under 5 years of age. | 2016 | 27267601 |
| antibacterial, structural and optical characterization of mechano-chemically prepared zno nanoparticles. | structural investigations, optical properties and antibacterial performance of the pure zinc oxide (zno) nanoparticles (nps) synthesized by mechano-chemical method are presented. the morphology, dimensions and crystallinity of the zno nps were controlled by tweaking the mechanical agitation of the mixture and subsequent thermal treatment. zno nanoparticles in small (< 20 nm) dimensions with spherical morphology and narrow size distribution were successfully obtained after treating the mechano-ch ... | 2016 | 27183165 |
| cytotoxic and inflammatory responses induced by outer membrane vesicle-associated biologically active proteases from vibrio cholerae. | proteases in vibrio cholerae have been shown to play a role in its pathogenesis. v. cholerae secretes zn-dependent hemagglutinin protease (hap) and calcium-dependent trypsin-like serine protease (vesc) by using the type ii secretion system (tiiss). our present studies demonstrated that these proteases are also secreted in association with outer membrane vesicles (omvs) and transported to human intestinal epithelial cells in an active form. omv-associated hap induces dose-dependent apoptosis in i ... | 2016 | 26930702 |
| fluoroquinolone-resistant enteric bacteria in sub-saharan africa: clones, implications and research needs. | fluoroquinolones came into widespread use in african countries in the early 2000s, after patents for the first generation of these drugs expired. by that time, quinolone antibacterial agents had been used intensively worldwide and resistant lineages of many bacterial species had evolved. we sought to understand which gram negative enteric pandemic lineages have been reported from africa, as well as the nature and transmission of any indigenous resistant clones. a systematic review of articles in ... | 2016 | 27148238 |
| growth phase, oxygen, temperature, and starvation affect the development of viable but non-culturable state of vibrio cholerae. | vibrio cholerae can enter into a viable but non-culturable (vbnc) state in order to survive in unfavorable environments. in this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of vbnc of v. cholerae in artificial sea water (asw). different strains of the organism, the growth phase, and oxygen levels affected the progress of vbnc development. it was found t ... | 2016 | 27065970 |
| diversity and antibiograms of bacterial organisms isolated from samples of household drinking-water consumed by hiv-positive individuals in rural settings, south africa. | diarrhoea is a hallmark of hiv infections in developing countries, and many diarrhoea-causing agents are often transmitted through water. the objective of the study was to determine the diversity and antibiotic susceptibility profiles of bacterial organisms isolated from samples of household drinking-water consumed by hiv-infected and aids patients. in the present study, household water stored for use by hiv-positive patients was tested for microbial quality, and isolated bacterial organisms wer ... | 2012 | 23082625 |
| acquisition and evolution of sxt-r391 integrative conjugative elements in the seventh-pandemic vibrio cholerae lineage. | sxt-r391 integrative conjugative elements (ices) are self-transmissible mobile genetic elements able to confer multidrug resistance and other adaptive features to bacterial hosts, including vibrio cholerae, the causative agent of cholera. ices are arranged in a mosaic genetic structure composed of a conserved backbone interspersed with variable dna clusters located in conserved hot spots. in this study, we investigated ice acquisition and subsequent microevolution in pandemic v. cholerae. ninety ... | 2014 | 25139901 |
| the extended regulatory networks of sxt/r391 integrative and conjugative elements and inca/c conjugative plasmids. | nowadays, healthcare systems are challenged by a major worldwide drug resistance crisis caused by the massive and rapid dissemination of antibiotic resistance genes and associated emergence of multidrug resistant pathogenic bacteria, in both clinical and environmental settings. conjugation is the main driving force of gene transfer among microorganisms. this mechanism of horizontal gene transfer mediates the translocation of large dna fragments between two bacterial cells in direct contact. inte ... | 2015 | 26347724 |
| temperature affects c-di-gmp signalling and biofilm formation in vibrio cholerae. | biofilm formation is crucial to the environmental survival and transmission of vibrio cholerae, the facultative human pathogen responsible for the disease cholera. during its infectious cycle, v. cholerae experiences fluctuations in temperature within the aquatic environment and during the transition between human host and aquatic reservoirs. in this study, we report that biofilm formation is induced at low temperatures through increased levels of the signalling molecule, cyclic diguanylate (c-d ... | 2015 | 25684220 |
| inca/c conjugative plasmids mobilize a new family of multidrug resistance islands in clinical vibrio cholerae non-o1/non-o139 isolates from haiti. | mobile genetic elements play a pivotal role in the adaptation of bacterial populations, allowing them to rapidly cope with hostile conditions, including the presence of antimicrobial compounds. inca/c conjugative plasmids (acps) are efficient vehicles for dissemination of multidrug resistance genes in a broad range of pathogenic species of enterobacteriaceae acps have sporadically been reported in vibrio cholerae, the infectious agent of the diarrheal disease cholera. the regulatory network that ... | 2016 | 27435459 |
| structures of the nucleoid occlusion protein slma bound to dna and the c-terminal domain of the cytoskeletal protein ftsz. | cell division in most prokaryotes is mediated by ftsz, which polymerizes to create the cytokinetic z ring. multiple ftsz-binding proteins regulate ftsz polymerization to ensure the proper spatiotemporal formation of the z ring at the division site. the dna-binding protein slma binds to ftsz and prevents z-ring formation through the nucleoid in a process called "nucleoid occlusion" (no). as do most ftsz-accessory proteins, slma interacts with the conserved c-terminal domain (ctd) that is connecte ... | 2016 | 27091999 |
| variations in sxt elements in epidemic vibrio cholerae o1 el tor strains in china. | vibrio cholerae o1 el tor biotype strains are responsible for three multiyear epidemics of cholera in china during the seventh ongoing pandemic. the presence of the integrative conjugative element sxt is strongly correlated with resistance to nalidixic acid, tetracycline, and trimethoprim-sulfamethoxazole in these strains. here, we sequenced the conserved genes of the sxt element, including eex, setr, and int, from 59 v. cholerae o1 el tor strains and extracted and assembled the intact sxt seque ... | 2016 | 26956038 |
| a semi-quantitative approach to assess biofilm formation using wrinkled colony development. | biofilms, or surface-attached communities of cells encapsulated in an extracellular matrix, represent a common lifestyle for many bacteria. within a biofilm, bacterial cells often exhibit altered physiology, including enhanced resistance to antibiotics and other environmental stresses. additionally, biofilms can play important roles in host-microbe interactions. biofilms develop when bacteria transition from individual, planktonic cells to form complex, multi-cellular communities. in the laborat ... | 2012 | 22710417 |
| vibrio cholerae as a predator: lessons from evolutionary principles. | diarrheal diseases are the second-most common cause of death among children under the age of five worldwide. cholera alone, caused by the marine bacterium vibrio cholerae, is responsible for several million cases and over 120,000 deaths annually. when contaminated water is ingested, v. cholerae passes through the gastric acid barrier, penetrates the mucin layer of the small intestine, and adheres to the underlying epithelial lining. v. cholerae multiplies rapidly, secretes cholera toxin, and exi ... | 2013 | 24368907 |
| dna-uptake machinery of naturally competent vibrio cholerae. | natural competence for transformation is a mode of horizontal gene transfer that is commonly used by bacteria to take up dna from their environment. as part of this developmental program, so-called competence genes, which encode the components of a dna-uptake machinery, are expressed. several models have been proposed for the dna-uptake complexes of competent bacteria, and most include a type iv (pseudo)pilus as a core component. however, cell-biology-based approaches to visualizing competence p ... | 2013 | 24127573 |
| establishing polar identity in gram-negative rods. | in rod shaped bacteria, numerous cellular components are targeted to the cell poles, and such localization is often important for optimal function. in particular, recognition of poles is often linked to division site selection, chromosome segregation, chemotactic signaling, and motility. recent advances in understanding polarity include identification of a vibrio cholerae protein that mediates polar localization of a chromosome origin and chemotaxis clusters, as well as a downstream protein that ... | 2013 | 24029491 |
| secretion of tcpf by the vibrio cholerae toxin-coregulated pilus biogenesis apparatus requires an n-terminal determinant. | type iv pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. we and others have shown that type iv pili are important for protein secretion across the outer membrane, similar to type ii secretion systems. this study explored the relationship between protein secretion and pilus formation in vibrio cholerae. the toxin-coregulated pilus (tcp), a type iv pilus required for v. cholerae pathogenesis, is necessary for the secretion of the colonization fac ... | 2013 | 23564177 |
| characterization of the phd-doc and ccd toxin-antitoxin cassettes from vibrio superintegrons. | toxin-antitoxin (ta) systems have been reported in the genomes of most bacterial species, and their role when located on the chromosome is still debated. ta systems are particularly abundant in the massive cassette arrays associated with chromosomal superintegrons (si). here, we describe the characterization of two superintegron cassettes encoding putative ta systems. the first is the phd-doc(si) system identified in vibrio cholerae n16961. we determined its distribution in 36 v. cholerae strain ... | 2013 | 23475970 |
| tit-for-tat: type vi secretion system counterattack during bacterial cell-cell interactions. | the bacterial type vi secretion system (t6ss) is a dynamic organelle that bacteria use to target prey cells for inhibition via translocation of effector proteins. time-lapse fluorescence microscopy has documented striking dynamics of opposed t6ss organelles in adjacent sister cells of pseudomonas aeruginosa. such cell-cell interactions have been termed "t6ss dueling" and likely reflect a biological process that is driven by t6ss antibacterial attack. here, we show that t6ss dueling behavior stro ... | 2013 | 23415234 |
| association properties and unfolding of a βγ-crystallin domain of a vibrio-specific protein. | the βγ-crystallin superfamily possesses a large number of versatile members, of which only a few members other than lens βγ-crystallins have been studied. understanding the non-crystallin functions as well as origin of crystallin-like properties of such proteins is possible by exploring novel members from diverse sources. we describe a novel βγ-crystallin domain with s-type (spherulin 3a type) greek key motifs in protein vibrillin from a pathogenic bacterium vibrio cholerae. this domain is a par ... | 2013 | 23349723 |
| the two cis-acting sites, pars1 and oric1, contribute to the longitudinal organisation of vibrio cholerae chromosome i. | the segregation of bacterial chromosomes follows a precise choreography of spatial organisation. it is initiated by the bipolar migration of the sister copies of the replication origin (ori). most bacterial chromosomes contain a partition system (par) with pars sites in close proximity to ori that contribute to the active mobilisation of the ori region towards the old pole. this is thought to result in a longitudinal chromosomal arrangement within the cell. in this study, we followed the duplica ... | 2014 | 25010199 |
| composition of the dna-uptake complex of vibrio cholerae. | natural competence for transformation is a developmental program that allows certain bacteria to take up free extracellular dna from the environment and integrate this dna into their genome. thereby, natural transformation acts as mode of horizontal gene transfer and impacts bacterial evolution. the number of genes induced upon competence induction varies significantly between organisms. however, all of the naturally competent bacteria possess competence genes that encode so-called dna-uptake ma ... | 2014 | 24558639 |
| the vibrio cholerae diguanylate cyclase vca0965 has an agdef active site and synthesizes cyclic di-gmp. | diguanylate cyclases (dgcs) regulate biofilm formation and motility in bacteria by synthesizing the second messenger cyclic di-gmp (c-di-gmp) in response to environmental stimuli. dgc enzymatic activity is believed to be dependent on the presence of a gg(d/e)ef active site motif, however approximately 25% of known dgcs contain a degenerate active site. the vibrio cholerae protein vca0965 contains an agdef active site and is presumed to be an inactive dgc. | 2014 | 24490592 |
| giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes. | biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. the cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, edna and exopolysaccharides. this matrix fulfils a variety of functions for the community, from providing structural rigidity and protection f ... | 2015 | 25907113 |
| biofilm matrix proteins. | proteinaceous components of the biofilm matrix include secreted extracellular proteins, cell surface adhesins, and protein subunits of cell appendages such as flagella and pili. biofilm matrix proteins play diverse roles in biofilm formation and dissolution. they are involved in attaching cells to surfaces, stabilizing the biofilm matrix via interactions with exopolysaccharide and nucleic acid components, developing three-dimensional biofilm architectures, and dissolving biofilm matrix via enzym ... | 2015 | 26104709 |
| chromosome segregation in vibrio cholerae. | the study of chromosome segregation is currently one of the most exciting research frontiers in cell biology. in this review, we discuss our current knowledge of the chromosome segregation process in vibrio cholerae, based primarily on findings from fluorescence microscopy experiments. this bacterium is of special interest because of its eukaryotic feature of having a divided genome, a feature shared with 10% of known bacteria. we also discuss how the segregation mechanisms of v. cholerae compar ... | 2015 | 25732338 |
| the vibrio cholerae minor pilin tcpb initiates assembly and retraction of the toxin-coregulated pilus. | type iv pilus (t4p) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction atpases, respectively. a set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. the vibrio cholerae toxin-coregulated pilus (tcp) is among the simplest of the t4p systems, having a single minor pilin tcpb and ... | 2016 | 27992883 |
| nucleotide binding by the widespread high-affinity cyclic di-gmp receptor mshen domain. | c-di-gmp is a bacterial second messenger regulating various cellular functions. many bacteria contain c-di-gmp-metabolizing enzymes but lack known c-di-gmp receptors. recently, two mshe-type atpases associated with bacterial type ii secretion system and type iv pilus formation were shown to specifically bind c-di-gmp. here we report crystal structure of the mshe n-terminal domain (mshen1-145) from vibrio cholerae in complex with c-di-gmp at a 1.37 å resolution. this structure reveals a unique c- ... | 2016 | 27578558 |
| characterization of the vibrio cholerae vola surface-exposed lipoprotein lysophospholipase. | bacterial lipases play important roles in bacterial metabolism and environmental response. our laboratory recently discovered that a novel lipoprotein lysophospholipase, vola, localizes on the surface of the gram-negative aquatic pathogen vibrio cholerae. vola functions to cleave exogenous lysophosphatidylcholine, freeing the fatty acid moiety for use by v. cholerae. this fatty acid is transported into the cell and can be used as a nutrient and, more importantly, as a way to alter the membrane a ... | 2014 | 24532770 |
| identification and characterization of ribn, a novel family of riboflavin transporters from rhizobium leguminosarum and other proteobacteria. | rhizobia are symbiotic bacteria able to invade and colonize the roots of legume plants, inducing the formation of nodules, where bacteria reduce atmospheric nitrogen (n2) to ammonia (nh3). riboflavin availability influences the capacity of rhizobia to survive in the rhizosphere and to colonize roots. in this study, we identified the rl1692 gene of rhizobium leguminosarum downstream of a flavin mononucleotide (fmn) riboswitch. rl1692 encodes a putative transmembrane permease with two eama domains ... | 2013 | 23935051 |
| utility of serological tests in the era of molecular testing for diagnosis of human brucellosis in endemic area with limited resources. | the culture has always been the gold standard test for diagnosis of human brucellosis but the conventional brucella diagnostic tests viz. serology and culture are often beset with poor specificity & sensitivity respectively. the culture positivity rates for brucella vary from 92% for bone marrow to 10% for non-blood samples and also dependent on the type of sample. the primary immune-determinant for brucella species is the cell wall surface lipopolysaccharide, which is antigenically similar to o ... | 2016 | 27042465 |
| identification and characterization of the novel subunit ccom in the cbb3₃cytochrome c oxidase from pseudomonas stutzeri zobell. | cytochrome c oxidases (ccos), members of the heme-copper containing oxidase (hco) superfamily, are the terminal enzymes of aerobic respiratory chains. the cbb3-type cytochrome c oxidases (cbb3-cco) form the c-family and have only the central catalytic subunit in common with the a- and b-family hcos. in pseudomonas stutzeri, two cbb3 operons are organized in a tandem repeat. the atomic structure of the first cbb3 isoform (cbb3-1) was determined at 3.2 å resolution in 2010 (s. buschmann, e. warken ... | 2016 | 26814183 |
| structural characterization of cfa/iii and longus type ivb pili from enterotoxigenic escherichia coli. | the type iv pili are helical filaments found on many gram-negative pathogenic bacteria, with multiple diverse roles in pathogenesis, including microcolony formation, adhesion, and twitching motility. many pathogenic enterotoxigenic escherichia coli (etec) isolates express one of two type iv pili belonging to the type ivb subclass: cfa/iii or longus. here we show a direct correlation between cfa/iii expression and etec aggregation, suggesting that these pili, like the vibrio cholerae toxin-coregu ... | 2012 | 22447901 |
| novel genomic tools for specific and real-time detection of biothreat and frequently encountered foodborne pathogens. | the bacterial genera escherichia, salmonella, shigella, vibrio, yersinia, and francisella include important food safety and biothreat agents. by extensive mining of the whole genome and protein databases of diverse, closely and distantly related bacterial species and strains, we have identified novel genome regions, which we utilized to develop a rapid detection platform for these pathogens. the specific genomic targets we have identified to design the primers in francisella tularensis subsp. tu ... | 2012 | 22488053 |
| temperature depended role of shigella flexneri invasion plasmid on the interaction with acanthamoeba castellanii. | shigella flexneri is a gram-negative bacterium causing the diarrhoeal disease shigellosis in humans. the virulence genes required for invasion are clustered on a large 220 kb plasmid encoding type three secretion system (ttss) apparatus and virulence factors such as adhesions and invasion plasmid antigens (ipa). the bacterium is transmitted by contaminated food, water, or from person to person. acanthamoebae are free-living amoebae (fla) which are found in diverse environments and isolated from ... | 2012 | 22518151 |
| structure of the vibrio cholerae type ivb pilus and stability comparison with the neisseria gonorrhoeae type iva pilus. | type iv pili are multifunctional filaments displayed on many bacterial pathogens. members of the type iva pilus subclass are found on a diverse group of human pathogens, whereas type ivb pili are found almost exclusively on enteric bacteria. the type iva and ivb subclasses are distinguished by differences in the pilin subunits, including the fold of the globular domain. to understand the implications of the distinct pilin folds, we compared the stabilities of pilin subunits and pilus filaments f ... | 2012 | 22361030 |
| customizable pcr-microplate array for differential identification of multiple pathogens. | customizable pcr-microplate arrays were developed for the rapid identification of salmonella typhimurium, salmonella saintpaul, salmonella typhi, shigella dysenteriae, escherichia coli o157:h7, francisella tularensis subsp. tularensis, francisella tularensis subsp. novicida, vibrio cholerae, vibrio parahaemolyticus, yersinia pestis, and yersinia pseudotuberculosis. previously, we identified highly specific primers targeting each of these pathogens. here, we report the development of customizable ... | 2013 | 24215700 |
| a functional vipa-vipb interaction is required for the type vi secretion system activity of vibrio cholerae o1 strain a1552. | many gram-negative bacteria rely on a type vi secretion system (t6ss) to infect eukaryotic cells or to compete against other microbes. common to these systems is the presence of two conserved proteins, in vibrio cholerae denoted vipa and vipb, which have been shown to interact in many clinically relevant pathogens. in this study, mutagenesis of a defined region within the vipa protein was used to identify residues important for vipb binding in v. cholerae o1 strain a1552. | 2013 | 23642157 |
| effects of polyamines on vibrio cholerae virulence properties. | vibrio cholerae is the causative agent of the severe enteric disease cholera. to cause cholera the bacterium must be able to synthesize both cholera toxin (ct) and toxin-coregulated pilus (tcp) which mediates autoagglutination and is required for colonization of the small intestine. only a few environmental signals have been shown to regulate v. cholerae virulence gene expression. polyamines, which are ubiquitous in nature, and have been implicated in regulating virulence gene expression in othe ... | 2013 | 23593304 |
| the hsib1c1 (tssb-tssc) complex of the pseudomonas aeruginosa type vi secretion system forms a bacteriophage tail sheathlike structure. | protein secretion systems in gram-negative bacteria evolved into a variety of molecular nanomachines. they are related to cell envelope complexes, which are involved in assembly of surface appendages or transport of solutes. they are classified as types, the most recent addition being the type vi secretion system (t6ss). the t6ss displays similarities to bacteriophage tail, which drives dna injection into bacteria. the hcp protein is related to the t4 bacteriophage tail tube protein gp19, wherea ... | 2013 | 23341461 |
| circulating mucosal associated invariant t cells are activated in vibrio cholerae o1 infection and associated with lipopolysaccharide antibody responses. | mucosal associated invariant t (mait) cells are innate-like t cells found in abundance in the intestinal mucosa, and are thought to play a role in bridging the innate-adaptive interface. | 2014 | 25144724 |
| screening for inhibition of vibrio cholerae vipa-vipb interaction identifies small-molecule compounds active against type vi secretion. | the type vi secretion system (t6ss) is the most prevalent bacterial secretion system and an important virulence mechanism utilized by gram-negative bacteria, either to target eukaryotic cells or to combat other microbes. the components show much variability, but some appear essential for the function, and two homologues, denoted vipa and vipb in vibrio cholerae, have been identified in all t6sss described so far. secretion is dependent on binding of an α-helical region of vipa to vipb, and in th ... | 2014 | 24798289 |
| lack of outer membrane protein a enhances the release of outer membrane vesicles and survival of vibrio cholerae and suppresses viability of acanthamoeba castellanii. | vibrio cholerae, the causative agent of the diarrhoeal disease cholera, survives in aquatic environments. the bacterium has developed a survival strategy to grow and survive inside acanthamoeba castellanii. it has been shown that v. cholerae expresses outer membrane proteins as virulence factors playing a role in the adherence to interacted host cells. this study examined the role of outer membrane protein a (ompa) and outer membrane vesicles (omvs) in survival of v. cholerae alone and during it ... | 2014 | 24799908 |
| human pathogenic bacteria, fungi, and viruses in drosophila: disease modeling, lessons, and shortcomings. | drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. many drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. we discuss studies of human pathogens in flies revealing not only ... | 2014 | 24398387 |
| swedish isolates of vibrio cholerae enhance their survival when interacted intracellularly with acanthamoeba castellanii. | vibrio cholerae is a gram-negative bacterium that occurs naturally in aquatic environment. only v. cholerae o1 and v. cholerae o139 produce cholera toxin and cause cholera, other serogroups can cause gastroenteritis, open wounds infection, and septicaemia. v. cholerae o1 and v. cholerae o139 grow and survive inside acanthamoeba castellanii. the aim of this study is to investigate the interactions of the swedish clinical isolates v. cholerae o3, v. cholerae o4, v. cholerae o5, v. cholerae o11, an ... | 2016 | 27118300 |
| emergence of tetracycline resistant vibrio cholerae o1 biotype el tor serotype ogawa with classical ctxb gene from a cholera outbreak in odisha, eastern india. | in september 2010, a cholera outbreak was reported from odisha, eastern india. v. cholerae isolated from the clinical samples were biochemically and serologically confirmed as serogroup o1, biotype el tor, and serotype ogawa. multiplex pcr screening revealed the presence of various genes, namely, ompw, ctxb, zot, rfbo1, tcp, ace, hlya, ompu, rtx, and toxr, in all of the isolates. the isolates were resistant to co-trimoxazole, nalidixic acid, polymyxin b, spectinomycin, streptomycin, sulfamethoxa ... | 2016 | 26881083 |
| purification, crystallization and preliminary x-ray crystallographic analysis of tssl from vibrio cholerae. | the type vi secretion system (t6ss) is a macromolecular complex that is conserved in gram-negative bacteria. the t6ss secretes effector proteins into recipient cells in a contact-dependent manner in order to accomplish cooperative and competitive interactions with the cells. although the composition and mechanism of the t6ss have been intensively investigated across many gram-negative bacteria, to date structural information on t6ss components from the important pathogen vibrio cholerae has been ... | 2014 | 25195905 |
| functional importance of a pair of conserved glutamic acid residues and of ca(2+) binding in the cbb(3)-type oxygen reductases from rhodobacter sphaeroides and vibrio cholerae. | the cbb(3)-type cytochrome c oxidases are members of the family of heme-copper proton pumping respiratory oxygen reductases. the structure of the cbb(3)-type oxidase from pseudomonas stutzeri reveals that, in addition to the six redox-active metal centers (two b-type hemes, three c-type hemes, and cu(b)), the enzyme also contains at least one ca(2+). the calcium bridges two propionate carboxyls at the interface between the low-spin heme b and the active-site heme b(3) and, in addition, is ligate ... | 2012 | 22913716 |
| detection, isolation, and identification of vibrio cholerae from the environment. | recent molecular advances in microbiology have greatly improved the detection of bacterial pathogens in the environment. these improvements and a downward trend in the cost of molecular detection methods have contributed to increased frequency of detection of pathogenic microorganisms where traditional culture-based detection methods have failed. culture methods also have been greatly improved, and the confluence of the two suites of methods provides a powerful tool for detection, isolation, and ... | 2012 | 22875567 |
| asymmetric chromosome segregation in xanthomonas citri ssp. citri. | this study was intended to characterize the chromosome segregation process of xanthomonas citri ssp. citri (xac) by investigating the functionality of the parb factor encoded on its chromosome, and its requirement for cell viability and virulence. using tap tagging we show that parb is expressed in xac. disruption of parb increased the cell doubling time and precluded the ability of xac to colonize the host citrus. moreover, xac mutant cells expressing only truncated forms of parb exhibited the ... | 2013 | 24339434 |
| hexamers of the type ii secretion atpase gspe from vibrio cholerae with increased atpase activity. | the type ii secretion system (t2ss), a multiprotein machinery spanning two membranes in gram-negative bacteria, is responsible for the secretion of folded proteins from the periplasm across the outer membrane. the critical multidomain t2ss assembly atpase gspe(epse) had not been structurally characterized as a hexamer. here, four hexamers of vibrio cholerae gspe(epse) are obtained when fused to hcp1 as an assistant hexamer, as shown with native mass spectrometry. the enzymatic activity of the gs ... | 2013 | 23954505 |
| structure of vibrio cholerae ribosome hibernation promoting factor. | the x-ray crystal structure of ribosome hibernation promoting factor (hpf) from vibrio cholerae is presented at 2.0 å resolution. the crystal was phased by two-wavelength mad using cocrystallized cobalt. the asymmetric unit contained two molecules of hpf linked by four co atoms. the metal-binding sites observed in the crystal are probably not related to biological function. the structure of hpf has a typical β-α-β-β-β-α fold consistent with previous structures of yfia and hpf from escherichia co ... | 2013 | 23519794 |
| comea is essential for the transfer of external dna into the periplasm in naturally transformable vibrio cholerae cells. | the dna uptake of naturally competent bacteria has been attributed to the action of dna uptake machineries resembling type iv pilus complexes. however, the protein(s) for pulling the dna across the outer membrane of gram-negative bacteria remain speculative. here we show that the competence protein comea binds incoming dna in the periplasm of naturally competent vibrio cholerae cells thereby promoting dna uptake, possibly through ratcheting and entropic forces associated with comea binding. usin ... | 2014 | 24391524 |
| the vrra srna controls a stationary phase survival factor vrp of vibrio cholerae. | small non-coding rnas (srnas) are emerging regulatory elements in bacteria. the vibrio cholerae srna vrra has previously been shown to down-regulate outer membrane proteins (ompa and ompt) and biofilm matrix protein (rbmc) by base-pairing with the 5' region of the corresponding mrnas. in this study, we present an additional target of vrra in v. cholerae, the mrna coding for the ribosome binding protein vrp. vrp is homologous to ribosome-associated inhibitor a (raia) of escherichia coli which fac ... | 2015 | 25826569 |
| zinc coordination is essential for the function and activity of the type ii secretion atpase epse. | the type ii secretion system eps in vibrio cholerae promotes the extracellular transport of cholera toxin and several hydrolytic enzymes and is a major virulence system in many gram-negative pathogens which is structurally related to the type iv pilus system. the cytoplasmic atpase epse provides the energy for exoprotein secretion through atp hydrolysis. epse contains a unique metal-binding domain that coordinates zinc through a tetracysteine motif (cxxcx29 cxxc), which is also present in type i ... | 2016 | 27168165 |
| networking in microbes: conjugative elements and plasmids in the genus alteromonas. | to develop evolutionary models for the free living bacterium alteromonas the genome sequences of isolates of the genus have been extensively analyzed. however, the main genetic exchange drivers in these microbes, conjugative elements (ces), have not been considered in detail thus far. in this work, ces have been searched in several complete alteromonas genomes and their sequence studied to understand their role in the evolution of this genus. six genomes are reported here for the first time. | 2017 | 28056800 |
| vibrio campbellii hmga-mediated pyomelanization impairs quorum sensing, virulence, and cellular fitness. | melanization due to the inactivation of the homogentisate-1,2-dioxygenase gene (hmga) has been demonstrated to increase stress resistance, persistence, and virulence in some bacterial species but such pigmented mutants have not been observed in pathogenic members of the vibrio harveyi clade. in this study, we used vibrio campbellii atcc baa-1116 as model organism to understand how melanization affected cellular phenotype, metabolism, and virulence. an in-frame deletion of the hmga gene resulted ... | 2013 | 24376440 |
| identification of small molecules that antagonize diguanylate cyclase enzymes to inhibit biofilm formation. | bacterial biofilm formation is responsible for numerous chronic infections, causing a severe health burden. many of these infections cannot be resolved, as bacteria in biofilms are resistant to the host's immune defenses and antibiotic therapy. new strategies to treat biofilm-based infections are critically needed. cyclic di-gmp (c-di-gmp) is a widely conserved second-messenger signal essential for biofilm formation. as this signaling system is found only in bacteria, it is an attractive target ... | 2012 | 22850508 |
| bactericidal efficacy of elevated ph on fish pathogenic and environmental bacteria. | ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. there is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. the present study employed laboratory methods to evaluate the bactericidal efficacy of increased ph (ph 10.0-12.0) for exposure durations of up to 72 h to kill a variety of gram-negative and gram-positive bacteria including fish pathogens (aeromonas spp., yer ... | 2012 | 25685439 |
| high incidence of plasmids in marine vibrio species isolated from mai po nature reserve of hong kong. | mai po nature reserve is the largest mangrove ecosystem and the most polluted coastal water body in hong kong. plasmids screening of 100 vibrio isolates randomly showed 45 % of them contained 1-3 plasmids. these plasmid(s)-bearing isolates could be divided into 12 groups based on their plasmid profiles. phylogenetic analysis of the partial 16s rrna gene sequences confirmed that all plasmid(s)-bearing isolates belonged to vibrio cholerae. full dna sequences of the plasmids in groups i (pvcg1.1 an ... | 2012 | 22684730 |
| genome-wide characterization of vibrio phage φpp2 with unique arrangements of the mob-like genes. | vibrio parahaemolyticus is associated with gastroenteritis, wound infections, and septicemia in human and animals. phages can control the population of the pathogen. so far, the only one reported genome among giant vibriophages is kvp40: 244,835 bp with 26% coding regions that have t4 homologs. putative homing endonucleases (he) were found in vibrio phage kvp40 bearing one segd and vibrio cholerae phage icp1 carrying one mobc/e and one segg. | 2012 | 22676552 |
| cellular levels and binding of c-di-gmp control subcellular localization and activity of the vibrio cholerae transcriptional regulator vpst. | the second messenger, cyclic diguanylate (c-di-gmp), regulates diverse cellular processes in bacteria. c-di-gmp is produced by diguanylate cyclases (dgcs), degraded by phosphodiesterases (pdes), and receptors couple c-di-gmp production to cellular responses. in many bacteria, including vibrio cholerae, multiple dgcs and pdes contribute to c-di-gmp signaling, and it is currently unclear whether the compartmentalization of c-di-gmp signaling components is required to mediate c-di-gmp signal transd ... | 2012 | 22654664 |
| interplay between genetic regulation of phosphate homeostasis and bacterial virulence. | bacterial pathogens, including those of humans, animals, and plants, encounter phosphate (pi)-limiting or pi-rich environments in the host, depending on the site of infection. the environmental pi-concentration results in modulation of expression of the pho regulon that allows bacteria to regulate phosphate assimilation pathways accordingly. in many cases, modulation of pho regulon expression also results in concomitant changes in virulence phenotypes. under pi-limiting conditions, bacteria use ... | 2014 | 25483775 |
| a type vi secretion system is involved in pseudomonas fluorescens bacterial competition. | protein secretion systems are crucial mediators of bacterial interactions with other organisms. among them, the type vi secretion system (t6ss) is widespread in gram-negative bacteria and appears to inject toxins into competitor bacteria and/or eukaryotic cells. major human pathogens, such as vibrio cholerae, burkholderia and pseudomonas aeruginosa, express t6sss. bacteria prevent self-intoxication by their own t6ss toxins by producing immunity proteins, which interact with the cognate toxins. w ... | 2014 | 24551247 |
| identification of critical amino acids conferring lethality in vopk, a type iii effector protein of vibrio cholerae: lessons from yeast model system. | vopk, a type iii effector protein, has been implicated in the pathogenesis of vibrio cholerae strains belonging to diverse serogroups. ectopic expression of this protein exhibits strong toxicity in yeast model system. in order to map critical residues in vopk, we scanned the primary sequence guided by available data on various toxins and effector proteins. our in silico analysis of vopk indicated the presence of predicted mcf1-she (shxxxe) serine peptidase domain at the c-terminus region of the ... | 2015 | 26488395 |
| vibrio cholerae csra regulates toxr levels in response to amino acids and is essential for virulence. | toxr is a major virulence gene regulator in vibrio cholerae. although constitutively expressed under many laboratory conditions, our previous work demonstrated that the level of toxr increases significantly when cells are grown in the presence of the 4 amino acids asparagine, arginine, glutamate, and serine (nres). we show here that the increase in toxr production in response to nres requires the var/csr global regulatory circuit. the vars/vara two-component system controls the amount of active ... | 2015 | 26242626 |
| in situ proteolysis of the vibrio cholerae matrix protein rbma promotes biofilm recruitment. | the estuarine gram-negative rod and human diarrheal pathogen vibrio cholerae synthesizes a vps exopolysaccharide-dependent biofilm matrix that allows it to form a 3d structure on surfaces. proteins associated with the matrix include, rbma, rbmc, and bap1. rbma, a protein whose crystallographic structure suggests two binding surfaces, associates with cells by means of a vps-dependent mechanism and promotes biofilm cohesiveness and recruitment of cells to the biofilm. here, we show that rbma under ... | 2015 | 26240338 |
| quorum sensing-regulated chitin metabolism provides grazing resistance to vibrio cholerae biofilms. | association of vibrio cholerae with chitinous surfaces of zooplankton is important for its persistence in marine environments, as it provides accessibility to nutrients and resistance to stresses. predation by heterotrophic protists has a major impact on the survival of v. cholerae. v. cholerae forms biofilms as its main defensive strategy, and quorum sensing (qs) additionally regulates the production of antiprotozoal factors. the role of chitin and qs regulation in v. cholerae grazing resistanc ... | 2015 | 25615438 |
| functional characterization of the stringent response regulatory gene dksa of vibrio cholerae and its role in modulation of virulence phenotypes. | in bacteria, nutrient deprivation evokes the stringent response, which is mediated by the small intracellular signaling molecule ppgpp. in gram negatives, the rela enzyme synthesizes and spot hydrolyzes ppgpp, although the latter protein also has weak synthetase activity. dksa, a recently identified rna polymerase binding transcription factor, acts as a coregulator along with ppgpp for controlling the stringent response. recently, we have shown that three genes, rela, spot, and relv, govern cell ... | 2012 | 22904284 |
| predatory bacteriovorax communities ordered by various prey species. | the role of predation in altering microbial communities has been studied for decades but few examples are known for bacterial predators. bacteriovorax are halophilic prokaryotes that prey on susceptible gram-negative bacteria. we recently reported novel observations on the differential selection of bacteriovorax phylotypes by two different prey, vibrio parahaemolyticus and vibrio vulnificus. however, the conclusion is restricted by the limited number of prey tested. in this study, we have conduc ... | 2012 | 22461907 |
| bicarbonate increases binding affinity of vibrio cholerae toxt to virulence gene promoters. | the major vibrio cholerae virulence gene transcription activator, toxt, is responsible for the production of the diarrhea-inducing cholera toxin (ct) and the major colonization factor, toxin coregulated pilus (tcp). in addition to the two primary virulence factors mentioned, toxt is responsible for the activation of accessory virulence genes, such as alda, taga, acfa, acfd, tcpi, and tarab. toxt activity is negatively modulated by bile and unsaturated fatty acids found in the upper small intesti ... | 2014 | 25182489 |
| chromosome segregation proteins of vibrio cholerae as transcription regulators. | abstract bacterial para and parb proteins are best known for their contribution to plasmid and chromosome segregation, but they may also contribute to other cell functions. in segregation, para interacts with parb, which binds to pars centromere-analogous sites. in transcription, plasmid par proteins can serve as repressors by specifically binding to their own promoters and, additionally, in the case of parb, by spreading from a pars site to nearby promoters. here, we have asked whether chromoso ... | 2014 | 24803519 |
| c-di-gmp regulates motile to sessile transition by modulating msha pili biogenesis and near-surface motility behavior in vibrio cholerae. | in many bacteria, including vibrio cholerae, cyclic dimeric guanosine monophosphate (c-di-gmp) controls the motile to biofilm life style switch. yet, little is known about how this occurs. in this study, we report that changes in c-di-gmp concentration impact the biosynthesis of the msha pili, resulting in altered motility and biofilm phenotypes in v. cholerae. previously, we reported that cdgj encodes a c-di-gmp phosphodiesterase and a δcdgj mutant has reduced motility and enhanced biofilm form ... | 2015 | 26505896 |
| the lona protease regulates biofilm formation, motility, virulence, and the type vi secretion system in vibrio cholerae. | the presence of the lon protease in all three domains of life hints at its biological importance. the prokaryotic lon protease is responsible not only for degrading abnormal proteins but also for carrying out the proteolytic regulation of specific protein targets. posttranslational regulation by lon is known to affect a variety of physiological traits in many bacteria, including biofilm formation, motility, and virulence. here, we identify the regulatory roles of lona in the human pathogen vibri ... | 2016 | 26755629 |
| the entner-doudoroff pathway is obligatory for gluconate utilization and contributes to the pathogenicity of vibrio cholerae. | the entner-doudoroff (ed) pathway has recently been shown to play an important role in sugar catabolism for many organisms although very little information is available on the functionality of this pathway in vibrio cholerae, the causative agent of cholera. in this study, activation of the genes edd and eda, encoding 6-phosphogluconate dehydratase and 2-keto-3-deoxy-6-phosphogluconate aldolase, was used as a marker of a functional ed pathway in v. cholerae. transcriptional activation analyses an ... | 2012 | 22544275 |
| a factor converting viable but nonculturable vibrio cholerae to a culturable state in eukaryotic cells is a human catalase. | in our previous work, we demonstrated that viable but nonculturable (vbnc) vibrio cholerae o1 and o139 were converted to culturable by coculture with eukaryotic cells. furthermore, we isolated a factor converting vbnc v. cholerae to culturable (fcvc) from a eukaryotic cell line, ht-29. in this study, we purified fcvc by successive column chromatographies comprising uno q-6 anion exchange, bio-scale cht2-1 hydroxyapatite, and superdex 200 10/300 gl. homogeneity of the purified fcvc was demonstrat ... | 2015 | 25974870 |
| pf filamentous phage requires uvrd for replication in pseudomonas aeruginosa. | pf is a lysogenic filamentous phage that promotes biofilm development in pseudomonas aeruginosa. pf replicates by a rolling circle replication system which depends on a phage-encoded initiator protein and host factors usually involved in chromosome replication. rep, an accessory replicative dna helicase, is crucial for replication of filamentous phages in escherichia coli. in contrast, here we show that, instead of depending on rep, pf replication depends on uvrd, an accessory helicase implicate ... | 2016 | 27303696 |
| a novel peptidoglycan binding protein crucial for pbp1a-mediated cell wall biogenesis in vibrio cholerae. | the bacterial cell wall, which is comprised of a mesh of polysaccharide strands crosslinked via peptide bridges (peptidoglycan, pg), is critical for maintenance of cell shape and survival. pg assembly is mediated by a variety of penicillin binding proteins (pbp) whose fundamental activities have been characterized in great detail; however, there is limited knowledge of the factors that modulate their activities in different environments or growth phases. in vibrio cholerae, the cause of cholera, ... | 2014 | 24945690 |
| the dimerization domain in dape enzymes is required for catalysis. | the emergence of antibiotic-resistant bacterial strains underscores the importance of identifying new drug targets and developing new antimicrobial compounds. lysine and meso-diaminopimelic acid are essential for protein production and bacterial peptidoglycan cell wall remodeling and are synthesized in bacteria by enzymes encoded within dap operon. therefore dap enzymes may serve as excellent targets for developing a new class of antimicrobial agents. the dape-encoded n-succinyl-l,l-diaminopimel ... | 2014 | 24806882 |
| antibacterial properties of silver nanoparticles synthesized by marine ochrobactrum sp. | metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. in ... | 2014 | 25763025 |
| conformational coupling between the active site and residues within the k(c)-channel of the vibrio cholerae cbb3-type (c-family) oxygen reductase. | the respiratory chains of nearly all aerobic organisms are terminated by proton-pumping heme-copper oxygen reductases (hcos). previous studies have established that c-family hcos contain a single channel for uptake from the bacterial cytoplasm of all chemical and pumped protons, and that the entrance of the k(c)-channel is a conserved glutamate in subunit iii. however, the majority of the k(c)-channel is within subunit i, and the pathway from this conserved glutamate to subunit i is not evident. ... | 2014 | 25288772 |
| vibrio cholerae nsps, a homologue of abc-type periplasmic solute binding proteins, facilitates transduction of polyamine signals independent of their transport. | the polyamines norspermidine and spermidine are among the environmental signals that regulate vibrio cholerae biofilm formation. the effects of these polyamines are mediated by nsps, a member of the bacterial periplasmic solute binding protein superfamily. almost all members of this superfamily characterized to date are components of atp-binding cassette-type transporters involved in nutrient uptake. consequently, in the current annotation of the v. cholerae genome, nsps has been assigned a func ... | 2014 | 24530989 |
| pollution impacts on bacterioplankton diversity in a tropical urban coastal lagoon system. | despite a great number of published studies addressing estuarine, freshwater and marine bacterial diversity, few have examined urban coastal lagoons in tropical habitats. there is an increasing interest in monitoring opportunistic pathogens as well as indigenous microbial community members in these water bodies by current molecular and microbiological approaches. in this work, bacterial isolates were obtained through selective plate dilution methods to evaluate antibiotic resistances. in additio ... | 2012 | 23226484 |
| quorum sensing coordinates cooperative expression of pyruvate metabolism genes to maintain a sustainable environment for population stability. | quorum sensing (qs) is a microbial cell-cell communication system that regulates gene expression in response to population density to coordinate collective behaviors. yet, the role of qs in resolving the stresses caused by the accumulation of toxic metabolic by-products at high cell density is not well defined. in response to cell density, qs could be involved in reprogramming of the metabolic network to maintain population stability. using unbiased metabolomics, we discovered that vibrio choler ... | 2016 | 27923919 |
| quantification of high-specificity cyclic diguanylate signaling. | cyclic di-gmp (c-di-gmp) is a second messenger molecule that regulates the transition between sessile and motile lifestyles in bacteria. bacteria often encode multiple diguanylate cyclase (dgc) and phosphodiesterase (pde) enzymes that produce and degrade c-di-gmp, respectively. because of multiple inputs into the c-di-gmp-signaling network, it is unclear whether this system functions via high or low specificity. high-specificity signaling is characterized by individual dgcs or pdes that are spec ... | 2012 | 22802636 |
| the structure of mlc titration factor a (mtfa/yeei) reveals a prototypical zinc metallopeptidase related to anthrax lethal factor. | mtfa of escherichia coli (formerly yeei) was previously identified as a regulator of the phosphoenolpyruvate (pep)-dependent:glucose phosphotransferase system. mtfa homolog proteins are highly conserved, especially among beta- and gammaproteobacteria. we determined the crystal structures of the full-length mtfa apoenzyme from klebsiella pneumoniae and its complex with zinc (holoenzyme) at 2.2 and 1.95 å, respectively. mtfa contains a conserved h(149)e(150)xxh(153)+e(212)+y(205) metallopeptidase ... | 2012 | 22467785 |
| reduced virulence of the vibrio cholerae fadd mutant is due to induction of the extracytoplasmic stress response. | vibrio cholerae, an important human intestinal pathogen, is responsible for the diarrheal disease cholera. the pathogenesis of v. cholerae is a highly coordinated process that involves diverse regulatory factors. it has recently been demonstrated that disruption of the v. cholerae fadd gene, encoding a long-chain fatty acyl coenzyme a (acyl-coa) ligase, drastically reduces expression of the major virulence genes and in vivo lethality of this important human pathogen. this effect was due to reduc ... | 2013 | 23918781 |
| differential thiol-based switches jump-start vibrio cholerae pathogenesis. | bacterial pathogens utilize gene expression versatility to adapt to environmental changes. vibrio cholerae, the causative agent of cholera, encounters redox-potential changes when it transitions from oxygen-rich aquatic reservoirs to the oxygen-limiting human gastrointestinal tract. we previously showed that the virulence regulator aphb uses thiol-based switches to sense the anoxic host environment and transcriptionally activate the key virulence activator tcpp. here, by performing a high-throug ... | 2015 | 26748713 |
| systematic identification of cyclic-di-gmp binding proteins in vibrio cholerae reveals a novel class of cyclic-di-gmp-binding atpases associated with type ii secretion systems. | cyclic-di-gmp (c-di-gmp) is a ubiquitous bacterial signaling molecule that regulates a variety of complex processes through a diverse set of c-di-gmp receptor proteins. we have utilized a systematic approach to identify c-di-gmp receptors from the pathogen vibrio cholerae using the differential radial capillary action of ligand assay (dracala). the dracala screen identified a majority of known c-di-gmp binding proteins in v. cholerae and revealed a novel c-di-gmp binding protein, mshe (vc0405), ... | 2015 | 26506097 |
| two nucleotide second messengers regulate the production of the vibrio cholerae colonization factor gbpa. | the nucleotide second messengers camp and c-di-gmp allow many bacteria, including the human intestinal pathogen vibrio cholerae, to respond to environmental stimuli with appropriate physiological adaptations. in response to limitation of specific carbohydrates, camp and its receptor crp control the transcription of genes important for nutrient acquisition and utilization; c-di-gmp controls the transition between motile and sessile lifestyles often, but not exclusively, through transcriptional me ... | 2015 | 26286031 |
| effect of site-directed mutagenesis at the ggeef domain of the biofilm forming ggeef protein from vibrio cholerae. | vibrio cholerae, the cause of seven noted pandemics, leads a dual lifecycle-one in the human host in its virulent form, and the other as a sessile, non-virulent bacterium in aquatic bodies in surface biofilms. surface biofilms have been attributed to be associated with a ubiquitous protein domain present in all branches of bacteria, known as the ggd(/e)ef domain. while the diguanlyate cyclase activities of these proteins are universally established, the role of these proteins as diguanlyate-spec ... | 2016 | 26728467 |
| structure-function analysis of the transmembrane protein ampg from pseudomonas aeruginosa. | ampg is a transmembrane protein with permease activity that transports meuropeptide from the periplasm to the cytoplasm, which is essential for the induction of the ampc encoding β-lactamase. to obtain new insights into the relationship between ampg structure and function, comparative genomics analysis, secondary and tertiary structure modeling, site-directed mutational analyses and genetic complementation experiments were performed in this study. ampgs from different genera of bacteria (escheri ... | 2016 | 27959942 |
| microbial glycolipoprotein-capped silver nanoparticles as emerging antibacterial agents against cholera. | with the increased number of cholera outbreaks and emergence of multidrug resistance in vibrio cholerae strains it has become necessary for the scientific community to devise and develop novel therapeutic approaches against cholera. recent studies have indicated plausibility of therapeutic application of metal nano-materials. among these, silver nanoparticles (agnps) have emerged as a potential antimicrobial agent to combat infectious diseases. at present nanoparticles are mostly produced using ... | 2016 | 26829922 |
| manganese uptake in marine bacteria; the novel mntx transporter is widespread in roseobacters, vibrios, alteromonadales and the sar11 and sar116 clades. | we showed that two very different manganese transporters occur in various important genera of marine bacteria. the abc transporter encoded by sitabcd of the model roseobacter-clade bacterium ruegeria pomeroyi dss-3 is required for mn(2+) import and was repressed by the mur (manganese uptake regulator) transcriptional regulator in mn-replete media. most genome-sequenced roseobacter strains contain sitabcd, which are in at least two sub-groups, judged by their amino-acid sequences. however, a few ... | 2012 | 23190726 |
| chromosome dynamics in multichromosome bacteria. | on the basis of limited information, bacteria were once assumed to have no more than one chromosome. in the era of genomics, it has become clear that some, like eukaryotes, have more than one chromosome. multichromosome bacteria provide opportunities to investigate how split genomes emerged, whether the individual chromosomes communicate to coordinate their replication and segregation, and what selective advantages split genomes might provide. our current knowledge of these topics comes mostly f ... | 2012 | 22306663 |
| the vibrio cholerae cpx envelope stress response senses and mediates adaptation to low iron. | the cpx pathway, a two-component system that employs the sensor histidine kinase cpxa and the response regulator cpxr, regulates crucial envelope stress responses across bacterial species and affects antibiotic resistance. to characterize the cpxr regulon in vibrio cholerae, the transcriptional profile of the pandemic v. cholerae el tor c6706 strain was examined upon overexpression of cpxr. our data show that the cpx regulon of v. cholerae is enriched in genes encoding membrane-localized and tra ... | 2014 | 25368298 |
| the highly conserved bacterial rnase ybey is essential in vibrio cholerae, playing a critical role in virulence, stress regulation, and rna processing. | ybey, a highly conserved protein, is an rnase in e. coli and plays key roles in both processing of the critical 3' end of 16 s rrna and in 70 s ribosome quality control under stress. these central roles account for ybey's inclusion in the postulated minimal bacterial genome. however, ybey is not essential in e. coli although loss of ybey severely sensitizes it to multiple physiological stresses. here, we show that ybey is an essential endoribonuclease in vibrio cholerae and is crucial for virule ... | 2014 | 24901994 |