| identification of the target dna sequence and characterization of dna binding features of hlyu, and suggestion of a redox switch for hlya expression in the human pathogen vibrio cholerae from in silico studies. | hlyu, a transcriptional regulator common in many vibrio species, activates the hemolysin gene hlya in vibrio cholerae, the rtxa1 operon in vibrio vulnificus and the genes of plp-vah1 and rtxachbde gene clusters in vibrio anguillarum. the protein is also proposed to be a potential global virulence regulator for v. cholerae and v. vulnificus. mechanisms of gene control by hlyu in v. vulnificus and v. anguillarum are reported. however, detailed elucidation of the interaction of hlyu in v. cholerae ... | 2015 | 25605793 |
| orderly replication and segregation of the four replicons of burkholderia cenocepacia j2315. | bacterial genomes typically consist of a single chromosome and, optionally, one or more plasmids. but whole-genome sequencing reveals about ten per-cent of them to be multipartite, with additional replicons which by size and indispensability are considered secondary chromosomes. this raises the questions of how their replication and partition is managed without compromising genome stability and of how such genomes arose. vibrio cholerae, with a 1 mb replicon in addition to its 3 mb chromosome, i ... | 2016 | 27428258 |
| malonate inhibits virulence gene expression in vibrio cholerae. | we previously found that inhibition of the tca cycle, either through mutations or chemical inhibition, increased toxt transcription in vibrio cholerae. in this study, we found that the addition of malonate, an inhibitor of succinate dehydrogenase (sdh), decreased toxt transcription in v. cholerae, an observation inconsistent with the previous pattern observed. unlike another sdh inhibitor, 2-thenoyltrifluoroacetone (ttfa), which increased toxt transcription and slightly inhibited v. cholerae gro ... | 2013 | 23675480 |
| enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases. | chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. these properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (pa) that cannot be controlled when the oligomers are produced by chemical hydrolysis. to determine the influence of the pa on the biological activities, defined chitosan oligomers in sufficient amounts are need ... | 2015 | 25732514 |
| role of the cai-1 fatty acid tail in the vibrio cholerae quorum sensing response. | quorum sensing is a mechanism of chemical communication among bacteria that enables collective behaviors. in v. cholerae, the etiological agent of the disease cholera, quorum sensing controls group behaviors including virulence factor production and biofilm formation. the major v. cholerae quorum-sensing system consists of the extracellular signal molecule called cai-1 and its cognate membrane bound receptor called cqss. here, the ligand binding activity of cqss is probed with structural analogu ... | 2012 | 23092313 |
| rapid and sensitive quantification of vibrio cholerae and vibrio mimicus cells in water samples by use of catalyzed reporter deposition fluorescence in situ hybridization combined with solid-phase cytometry. | a new protocol for rapid, specific, and sensitive cell-based quantification of vibrio cholerae/vibrio mimicus in water samples was developed. the protocol is based on catalyzed reporter deposition fluorescence in situ hybridization (card-fish) in combination with solid-phase cytometry. for pure cultures, we were able to quantify down to 6 v. cholerae cells on one membrane with a relative precision of 39% and down to 12 cells with a relative precision of 17% after hybridization with the horseradi ... | 2012 | 22885749 |
| microbial diversity and potential pathogens in ornamental fish aquarium water. | ornamental fishes are among the most popular and fastest growing categories of pets in the united states (u.s.). the global scope and scale of the ornamental fish trade and growing popularity of pet fish in the u.s. are strong indicators of the myriad economic and social benefits the pet industry provides. relatively little is known about the microbial communities associated with these ornamental fishes or the aquarium water in which they are transported and housed. using conventional molecular ... | 2012 | 22970112 |
| genomic analysis of icevchban8: an atypical genetic element in vibrio cholerae. | genomic islands (gis) and integrative conjugative elements (ices) are major players in bacterial evolution since they encode genes involved in adaptive functions of medical or environmental importance. here we performed the genomic analysis of icevchban8, an unusual ice found in the genome of a clinical non-toxigenic vibrio cholerae o37 isolate. icevchban8 shares most of its genetic structure with sxt/r391 ices. however, this ice codes for a different integration/excision module is located at a ... | 2012 | 22673571 |
| α-hydroxyketone synthesis and sensing by legionella and vibrio. | bacteria synthesize and sense low molecular weight signaling molecules, termed autoinducers, to measure their population density and community complexity. one class of autoinducers, the α-hydroxyketones (ahks), is produced and detected by the water-borne opportunistic pathogens legionella pneumophila and vibrio cholerae, which cause legionnaires' disease and cholera, respectively. the "legionella quorum sensing" (lqs) or "cholera quorum sensing" (cqs) genes encode enzymes that produce and sense ... | 2012 | 22736983 |
| cholera: environmental reservoirs and impact on disease transmission. | vibrio cholerae is widely known to be the etiological agent of the life-threatening diarrheal disease cholera. cholera remains a major scourge in many developing countries, infecting hundreds of thousands every year. remarkably, v. cholerae is a natural inhabitant of brackish riverine, estuarine, and coastal waters, and only a subset of strains are known to be pathogenic to humans. recent studies have begun to uncover a very complex network of relationships between v. cholerae and other sea dwel ... | 2013 | 25674360 |
| acanthamoeba castellanii of the t4 genotype is a potential environmental host for enterobacter aerogenes and aeromonas hydrophila. | acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including legionella pneumophila, pseudomonas aeruginosa, vibrio cholerae, helicobacter pylori, listeria monocytogenes, mycobacterium spp., and escherichia coli. in this capacity, acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts. | 2013 | 23742105 |
| a transcriptional regulator linking quorum sensing and chitin induction to render vibrio cholerae naturally transformable. | the human pathogen vibrio cholerae is an aquatic bacterium associated with zooplankton and their chitinous exoskeletons. on chitinous surfaces, v. cholerae initiates a developmental programme, known as natural competence, to mediate transformation, which is a mode of horizontal gene transfer. competence facilitates the uptake of free dna and recombination into the bacterial genome. recent studies have indicated that chitin surfaces are required, but not sufficient to induce competence. two addit ... | 2013 | 23382174 |
| the vibrio cholerae extracellular chitinase chia2 is important for survival and pathogenesis in the host intestine. | in aquatic environments, vibrio cholerae colonizes mainly on the chitinous surface of copepods and utilizes chitin as the sole carbon and nitrogen source. of the two extracellular chitinases essential for chitin utilization, the expression of chia2 is maximally up-regulated in host intestine. recent studies indicate that several bacterial chitinases may be involved in host pathogenesis. however, the role of v. cholerae chitinases in host infection is not yet known. in this study, we provide evid ... | 2014 | 25244128 |
| the type ii secretion pathway in vibrio cholerae is characterized by growth phase-dependent expression of exoprotein genes and is positively regulated by σe. | vibrio cholerae, an etiological agent of cholera, circulates between aquatic reservoirs and the human gastrointestinal tract. the type ii secretion (t2s) system plays a pivotal role in both stages of the lifestyle by exporting multiple proteins, including cholera toxin. here, we studied the kinetics of expression of genes encoding the t2s system and its cargo proteins. we have found that under laboratory growth conditions, the t2s complex was continuously expressed throughout v. cholerae growth, ... | 2014 | 24733097 |
| sulfonamides with potent inhibitory action and selectivity against the α-carbonic anhydrase from vibrio cholerae. | by using n-α-acetyl-l-lysine or gaba scaffolds and the conversion of the terminal amino group to the guanidine one, benzenesulfonamides incorporating water solubilizing moieties were synthesized. the new compounds were medium potency inhibitors of the cytosolic carbonic anhydrase (ca, ec 4.2.1.1) isoforms i and ii, and highly effective, nanomolar inhibitors of the pathogenic bacterial α-ca from vibrio cholerae. these sulfonamides possess good selectivity for inhibiting the bacterial over the mam ... | 2014 | 25050173 |
| autophagy and endosomal trafficking inhibition by vibrio cholerae martx toxin phosphatidylinositol-3-phosphate-specific phospholipase a1 activity. | vibrio cholerae, responsible for acute gastroenteritis secretes a large multifunctional-autoprocessing repeat-in-toxin (martx) toxin linked to evasion of host immune system, facilitating colonization of small intestine. unlike other effector domains of the multifunctional toxin that target cytoskeleton, the function of alpha-beta hydrolase (abh) remained elusive. this study demonstrates that abh is an esterase/lipase with catalytic ser-his-asp triad. abh binds with high affinity to phosphatidyli ... | 2015 | 26498860 |
| an intracellular replication niche for vibrio cholerae in the amoeba acanthamoeba castellanii. | vibrio cholerae is a human pathogen and the causative agent of cholera. the persistence of this bacterium in aquatic environments is a key epidemiological concern, as cholera is transmitted through contaminated water. predatory protists, such as amoebae, are major regulators of bacterial populations in such environments. therefore, we investigated the interaction between v. cholerae and the amoeba acanthamoeba castellanii at the single-cell level. we observed that v. cholerae can resist intracel ... | 2015 | 26394005 |
| the cpx system regulates virulence gene expression in vibrio cholerae. | bacteria possess signal transduction pathways capable of sensing and responding to a wide variety of signals. the cpx envelope stress response, composed of the sensor histidine kinase cpxa and the response regulator cpxr, senses and mediates adaptation to insults to the bacterial envelope. the cpx response has been implicated in the regulation of a number of envelope-localized virulence determinants across bacterial species. here, we show that activation of the cpx pathway in vibrio cholerae el ... | 2015 | 25824837 |
| vibrio cholerae feoa, feob, and feoc interact to form a complex. | feo is the major ferrous iron transport system in prokaryotes. despite having been discovered over 25 years ago and found to be widely distributed among bacteria, feo is poorly understood, as its structure and mechanism of iron transport have not been determined. the feo operon in vibrio cholerae is made up of three genes, encoding the feoa, feob, and feoc proteins, which are all required for feo system function. feoa and feoc are both small cytoplasmic proteins, and their function remains uncle ... | 2016 | 26833408 |
| rpos plays a central role in the sos induction by sub-lethal aminoglycoside concentrations in vibrio cholerae. | bacteria encounter sub-inhibitory concentrations of antibiotics in various niches, where these low doses play a key role for antibiotic resistance selection. however, the physiological effects of these sub-lethal concentrations and their observed connection to the cellular mechanisms generating genetic diversification are still poorly understood. it is known that, unlike for the model bacterium escherichia coli, sub-minimal inhibitory concentrations (sub-mic) of aminoglycosides (ags) induce the ... | 2013 | 23613664 |
| a novel mechanism for the biogenesis of outer membrane vesicles in gram-negative bacteria. | bacterial outer membrane vesicles (omvs) have important biological roles in pathogenesis and intercellular interactions, but a general mechanism of omv formation is lacking. here we show that the vacj/yrb abc (atp-binding cassette) transport system, a proposed phospholipid transporter, is involved in omv formation. deletion or repression of vacj/yrb increases omv production in two distantly related gram-negative bacteria, haemophilus influenzae and vibrio cholerae. lipidome analyses demonstrate ... | 2016 | 26806181 |
| increasing antimicrobial resistance of vibrio cholerae oi biotype e1 tor strains isolated in a tertiary-care centre in india. | the antimicrobial susceptibility patterns are on constant change with the recent emergence of multidrug-resistant strains of most bacteria. results of recent studies in india showed that most isolates of vibrio cholerae o1 were resistant to the commonly-used antibiotics. the study was conducted to determine the antibiotic susceptibility patterns of v. cholerae o1 isolated during 2008-2010 at the hospital of the jawaharlal nehru institute of post graduate medical education and research, puducherr ... | 2012 | 22524114 |
| sequencing of bacterial genomes: principles and insights into pathogenesis and development of antibiotics. | the impact of bacterial diseases on public health has become enormous, and is partly due to the increasing trend of antibiotic resistance displayed by bacterial pathogens. sequencing of bacterial genomes has significantly improved our understanding about the biology of many bacterial pathogens as well as identification of novel antibiotic targets. since the advent of genome sequencing two decades ago, about 1,800 bacterial genomes have been fully sequenced and these include important aetiologica ... | 2013 | 24705262 |
| competence and natural transformation in vibrios. | natural transformation is a major mechanism of horizontal gene transfer in bacteria. by incorporating exogenous dna elements into chromosomes, bacteria are able to acquire new traits that can enhance their fitness in different environments. within the past decade, numerous studies have revealed that natural transformation is prevalent among members of the vibrionaceae, including the pathogen vibrio cholerae. four environmental factors: (i) nutrient limitation, (ii) availability of extracellular ... | 2013 | 23803158 |
| mutagenesis and modeling to predict structural and functional characteristics of the staphylococcus aureus mepa multidrug efflux pump. | mepa is a multidrug and toxin extrusion (mate) family protein and the only mate protein encoded within the staphylococcus aureus genome. structural data for mate proteins are limited to a single high-resolution example, norm of vibrio cholerae. substitution mutations were created in mepa using gradient plates containing both a substrate and reserpine as an efflux pump inhibitor. site-directed mutagenesis of plasmid-based mepa was used to reproduce these mutations, as well as unique or low-freque ... | 2013 | 23175649 |
| overexpression of the tcp gene cluster using the t7 rna polymerase/promoter system and natural transformation-mediated genetic engineering of vibrio cholerae. | the human pathogen and aquatic bacterium vibrio cholerae belongs to the group of naturally competent bacteria. this developmental program allows the bacterium to take up free dna from its surrounding followed by a homologous recombination event, which allows integration of the transforming dna into the chromosome. taking advantage of this phenomenon we genetically engineered v. cholerae using natural transformation and flp recombination. more precisely, we adapted the t7 rna polymerase/promoter ... | 2013 | 23308292 |
| multidrug transport protein norm from vibrio cholerae simultaneously couples to sodium- and proton-motive force. | membrane transporters belonging to the multidrug and toxic compound extrusion family mediate the efflux of unrelated pharmaceuticals from the interior of the cell in organisms ranging from bacteria to human. these proteins are thought to fall into two classes that couple substrate efflux to the influx of either na(+) or h(+). we studied the energetics of drug extrusion by norm from vibrio cholerae in proteoliposomes in which purified norm protein was functionally reconstituted in an inside-out o ... | 2014 | 24711447 |
| the challenges and successes of implementing a sustainable antimicrobial resistance surveillance programme in nepal. | antimicrobial resistance (amr) is a major global public health concern and its surveillance is a fundamental tool for monitoring the development of amr. in 1998, the nepalese ministry of health (moh) launched an infectious disease (id) programme. the key components of the programme were to establish a surveillance programme for amr and to develop awareness among physicians regarding amr and rational drug usage in nepal. | 2014 | 24650008 |
| a cell wall damage response mediated by a sensor kinase/response regulator pair enables beta-lactam tolerance. | the bacterial cell wall is critical for maintenance of cell shape and survival. following exposure to antibiotics that target enzymes required for cell wall synthesis, bacteria typically lyse. although several cell envelope stress response systems have been well described, there is little knowledge of systems that modulate cell wall synthesis in response to cell wall damage, particularly in gram-negative bacteria. here we describe wigk/wigr, a histidine kinase/response regulator pair that enable ... | 2015 | 26712007 |
| vibrio cholerae porin ompu induces caspase-independent programmed cell death upon translocation to the host cell mitochondria. | porins, a major class of outer membrane proteins in gram-negative bacteria, primarily act as transport channels. ompu is one of the major porins of human pathogen, vibrio cholerae. in the present study, we show that v. cholerae ompu has the ability to induce target cell death. although ompu-mediated cell death shows some characteristics of apoptosis, such as flipping of phosphatidylserine in the membrane as well as cell size shrinkage and increased cell granularity, it does not show the caspase- ... | 2015 | 26559970 |
| family resemblances: a common fold for some dimeric ion-coupled secondary transporters. | membrane transporter proteins catalyze the passage of a broad range of solutes across cell membranes, allowing the uptake and efflux of crucial compounds. because of the difficulty of expressing, purifying, and crystallizing integral membrane proteins, relatively few transporter structures have been elucidated to date. although every membrane transporter has unique characteristics, structural and mechanistic similarities between evolutionarily diverse transporters have been identified. here, we ... | 2015 | 26503722 |
| crystal structure of the minor pilin cofb, the initiator of cfa/iii pilus assembly in enterotoxigenic escherichia coli. | type iv pili are extracellular polymers of the major pilin subunit. these subunits are held together in the pilus filament by hydrophobic interactions among their n-terminal α-helices, which also anchor the pilin subunits in the inner membrane prior to pilus assembly. type iv pilus assembly involves a conserved group of proteins that span the envelope of gram-negative bacteria. among these is a set of minor pilins, so named because they share their hydrophobic n-terminal polymerization/membrane ... | 2015 | 26324721 |
| predicting homogeneous pilus structure from monomeric data and sparse constraints. | type iv pili (t4p) and t2ss (type ii secretion system) pseudopili are filaments extending beyond microbial surfaces, comprising homologous subunits called "pilins." in this paper, we presented a new approach to predict pseudo atomic models of pili combining ambiguous symmetric constraints with sparse distance information obtained from experiments and based neither on electronic microscope (em) maps nor on accurate a priori symmetric details. the approach was validated by the reconstruction of th ... | 2015 | 26064954 |
| nqrm (duf539) protein is required for maturation of bacterial na+-translocating nadh:quinone oxidoreductase. | na(+)-translocating nadh:quinone oxidoreductase (na(+)-nqr) catalyzes electron transfer from nadh to ubiquinone in the bacterial respiratory chain, coupled with na(+) translocation across the membrane. na(+)-nqr maturation involves covalent attachment of flavin mononucleotide (fmn) residues, catalyzed by flavin transferase encoded by the nqr-associated apbe gene. analysis of complete bacterial genomes has revealed another putative gene (duf539, here renamed nqrm) that usually follows the apbe ge ... | 2016 | 26644436 |
| cochleates derived from vibrio cholerae o1 proteoliposomes: the impact of structure transformation on mucosal immunisation. | cochleates are phospholipid-calcium precipitates derived from the interaction of anionic lipid vesicles with divalent cations. proteoliposomes from bacteria may also be used as a source of negatively charged components, to induce calcium-cochleate formation. in this study, proteoliposomes from v. cholerae o1 (plc) (sized 160.7±1.6 nm) were transformed into larger (16.3±4.6 µm) cochleate-like structures (named adjuvant finlay cochleate 2, afco2) and evaluated by electron microscopy (em). measurem ... | 2012 | 23077508 |
| arginine-specific mono adp-ribosylation in vitro of antimicrobial peptides by adp-ribosylating toxins. | among the several toxins used by pathogenic bacteria to target eukaryotic host cells, proteins that exert adp-ribosylation activity represent a large and studied family of dangerous and potentially lethal toxins. these proteins alter cell physiology catalyzing the transfer of the adp-ribose unit from nad to cellular proteins involved in key metabolic pathways. in the present study, we tested the capability of four of these toxins, to adp-ribosylate α- and β- defensins. cholera toxin (ct) from vi ... | 2012 | 22879887 |
| lipopolysaccharide modifications of a cholera vaccine candidate based on outer membrane vesicles reduce endotoxicity and reveal the major protective antigen. | the causative agent of the life-threatening gastrointestinal infectious disease cholera is the gram-negative, facultative human pathogen vibrio cholerae. we recently started to investigate the potential of outer membrane vesicles (omvs) derived from v. cholerae as an alternative approach for a vaccine candidate against cholera and successfully demonstrated the induction of a long-lasting, high-titer, protective immune response upon immunization with omvs using the mouse model. in this study, we ... | 2013 | 23630951 |
| population structure and evolution of non-o1/non-o139 vibrio cholerae by multilocus sequence typing. | pathogenic non-o1/non-o139 vibrio cholerae strains can cause sporadic outbreaks of cholera worldwide. in this study, multilocus sequence typing (mlst) of seven housekeeping genes was applied to 55 non-o1/non-o139 isolates from clinical and environmental sources. data from five published o1 isolates and 17 genomes were also included, giving a total of 77 isolates available for analysis. there were 66 sequence types (sts), with the majority being unique, and only three clonal complexes. the v. cho ... | 2013 | 23776471 |
| host cell contact induces expression of virulence factors and viea, a cyclic di-gmp phosphodiesterase, in vibrio cholerae. | vibrio cholerae, a noninvasive bacterium, colonizes the intestinal epithelium and secretes cholera toxin (ct), a potent enterotoxin that causes the severe fluid loss characteristic of the disease cholera. in this study, we demonstrate that adherence of v. cholerae to the intestinal epithelial cell line int 407 strongly induces the expression of the major virulence genes ctxab and tcpa and the virulence regulatory gene toxt. no induction of toxr and tcpp, which encode transcriptional activators o ... | 2013 | 23435982 |
| immune adjuvant effect of v. cholerae o1 derived proteoliposome coadministered by intranasal route with vi polysaccharide from salmonella typhi. | the proteoliposome derived from vibrio cholerae o1 (plc) is a nanoscaled structure obtained by a detergent extraction process. intranasal (i.n) administration of plc was immunogenic at mucosal and systemic level vs. v. cholerae; however the adjuvant potential of this structure for non-cholera antigens has not been proven yet. the aim of this work was to evaluate the effect of coadministering plc with the vi polysaccharide antigen (poli vi) of s. typhi by the i.n route. the results showed that po ... | 2013 | 23458379 |
| adp-ribosylargininyl reaction of cholix toxin is mediated through diffusible intermediates. | cholix toxin is an adp-ribosyltransferase found in non-o1/non-o139 strains of vibrio cholera. the catalytic fragment of cholix toxin was characterized as a diphthamide dependent adp-ribosyltransferase. | 2014 | 25494717 |
| rna thermometer controls temperature-dependent virulence factor expression in vibrio cholerae. | vibrio cholerae is the bacterium that causes the diarrheal disease cholera. the bacteria experience a temperature shift as v. cholerae transition from contaminated water at lower temperatures into the 37 °c human intestine. within the intestine, v. cholerae express cholera toxin (ct) and toxin-coregulated pilus (tcp), two main virulence factors required for disease. ct and tcp expression is controlled by the transcriptional activator protein toxt. we identified an rna thermometer motif in the 5' ... | 2014 | 25228776 |
| evaluation of anticoagulants for serologic assays of cholera vaccination. | blood collected with an anticoagulant is beneficial for simultaneous evaluation of immune cells and humoral components such as antibodies. however, it is critical that the anticoagulant does not affect quantitative and qualitative analyses of antibodies. in the present study, we examined the potential interference of the widely used anticoagulants heparin, edta, and acid citrate dextrose (acd) on vibriocidal antibody activities and vibrio cholerae lipopolysaccharide (lps)-specific igg, igm, and ... | 2014 | 24717970 |
| bacterial outer membrane vesicles and vaccine applications. | vaccines based on outer membrane vesicles (omv) were developed more than 20 years ago against neisseria meningitidis serogroup b. these nano-sized structures exhibit remarkable potential for immunomodulation of immune responses and delivery of meningococcal antigens or unrelated antigens incorporated into the vesicle structure. this paper reviews different applications in omv research and development (r&d) and provides examples of omv developed and evaluated at the finlay institute in cuba. a go ... | 2014 | 24715891 |
| comparative sequence- and structure-inspired drug design for pilf protein of neisseria meningitidis. | serogroup a of neisseria meningitidis is the organism responsible for causing epidemic diseases in developing countries by a pilus-mediated adhesion to human brain endothelial cells. type iv pilus assembly protein (pilf) associated with bacterial adhesion, aggregation, invasion, host cell signaling, surface motility, and natural transformation can be considered as a candidate for effective anti-meningococcal drug development. since the crystal structure of pilf was not available, in the present ... | 2015 | 25928839 |
| the role of china in the global spread of the current cholera pandemic. | epidemics and pandemics of cholera, a severe diarrheal disease, have occurred since the early 19th century and waves of epidemic disease continue today. cholera epidemics are caused by individual, genetically monomorphic lineages of vibrio cholerae: the ongoing seventh pandemic, which has spread globally since 1961, is associated with lineage l2 of biotype el tor. previous genomic studies of the epidemiology of the seventh pandemic identified three successive sub-lineages within l2, designated w ... | 2015 | 25768799 |
| serum bactericidal assay for the evaluation of typhoid vaccine using a semi-automated colony-counting method. | typhoid fever, mainly caused by salmonella enterica serovar typhi (s. typhi), is a life-threatening disease, mostly in developing countries. enzyme-linked immunosorbent assay (elisa) is widely used to quantify antibodies against s. typhi in serum but does not provide information about functional antibody titers. although the serum bactericidal assay (sba) using an agar plate is often used to measure functional antibody titers against various bacterial pathogens in clinical specimens, it has rare ... | 2016 | 27216239 |
| type vi secretion system sheaths as nanoparticles for antigen display. | the bacterial type 6 secretion system (t6ss) is a dynamic apparatus that translocates proteins between cells by a mechanism analogous to phage tail contraction. t6ss sheaths are cytoplasmic tubular structures composed of stable vipa-vipb (named for clpv-interacting protein a and b) heterodimers. here, the structure of the vipa/b sheath was exploited to generate immunogenic multivalent particles for vaccine delivery. sheaths composed of vipb and vipa fused to an antigen of interest were purified ... | 2016 | 26929342 |
| actin cross-linking domain of aeromonas hydrophila repeat in toxin a (rtxa) induces host cell rounding and apoptosis. | the repeat in toxin (rtx) of an environmental isolate atcc 7966 of aeromonas hydrophila consists of six genes (rtxachbde) organized in an operon similar to the gene organization found for the rtx of the vibrio species. the first gene in this operon (rtxa) encodes an exotoxin in vibrios, while other genes code for proteins needed for proper activation of rtxa and in secretion of this toxin from vibrio cholerae. however, the rtxa of atcc 7966, as well as from the clinical isolate ssu of a. hydroph ... | 2012 | 22814176 |
| phage morphology recapitulates phylogeny: the comparative genomics of a new group of myoviruses. | among dsdna tailed bacteriophages (caudovirales), members of the myoviridae family have the most sophisticated virion design that includes a complex contractile tail structure. the myoviridae generally have larger genomes than the other phage families. relatively few "dwarf" myoviruses, those with a genome size of less than 50 kb such as those of the mu group, have been analyzed in extenso. here we report on the genome sequencing and morphological characterization of a new group of such phages t ... | 2012 | 22792219 |
| pharmacophore selection and redesign of non-nucleotide inhibitors of anthrax edema factor. | antibiotic treatment may fail to protect individuals, if not started early enough, after infection with bacillus anthracis, due to the continuing activity of toxins that the bacterium produces. stable and easily stored inhibitors of the edema factor toxin (ef), an adenylyl cyclase, could save lives in the event of an outbreak, due to natural causes or a bioweapon attack. the toxin's basic activity is to convert atp to camp, and it is thus in principle a simple phosphatase, which means that many ... | 2012 | 23202316 |
| screening helicobacter pylori genes induced during infection of mouse stomachs. | to investigate the effect of in vivo environment on gene expression in helicobacter pylori (h. pylori) as it relates to its survival in the host. | 2012 | 22969195 |
| feoa and feoc are essential components of the vibrio cholerae ferrous iron uptake system, and feoc interacts with feob. | the ferrous iron transport system feo is widely distributed among bacterial species, yet its physical structure and mechanism of iron transport are poorly understood. in vibrio cholerae, the feo operon consists of three genes, feoabc. feob encodes an 83-kda protein with an amino-terminal gtpase domain and a carboxy-terminal domain predicted to be embedded in the inner membrane. while feob is believed to form the pore for iron transport, the roles of feoa and feoc are unknown. in this work, we sh ... | 2013 | 23955009 |
| bile salt-induced intermolecular disulfide bond formation activates vibrio cholerae virulence. | to be successful pathogens, bacteria must often restrict the expression of virulence genes to host environments. this requires a physical or chemical marker of the host environment as well as a cognate bacterial system for sensing the presence of a host to appropriately time the activation of virulence. however, there have been remarkably few such signal-sensor pairs identified, and the molecular mechanisms for host-sensing are virtually unknown. by directly applying a reporter strain of vibrio ... | 2013 | 23341592 |
| enhanced interaction of vibrio cholerae virulence regulators tcpp and toxr under oxygen-limiting conditions. | vibrio cholerae is the causative agent of the diarrheal disease cholera. the ability of v. cholerae to colonize and cause disease requires the intricately regulated expression of a number of virulence factors during infection. one of the signals sensed by v. cholerae is the presence of oxygen-limiting conditions in the gut. it has been shown that the virulence activator aphb plays a key role in sensing low oxygen concentrations and inducing the transcription of another key virulence activator, t ... | 2014 | 24491579 |
| proteomic analysis of vibrio cholerae outer membrane vesicles. | outer membrane vesicles (omvs) produced by gram-negative bacteria provide an interesting research material for defining cell-envelope proteins without experimental cell disruption. omvs are also promising immunogenic platforms and may play important roles in bacterial survival and pathogenesis. we used in-solution trypsin digestion coupled to mass spectrometry to identify 90 proteins present in omvs of vibrio cholerae when grown under conditions that activate the tcp pilus virulence regulatory p ... | 2014 | 24706774 |
| a large family of anti-activators accompanying xyls/arac family regulatory proteins. | arac negative regulators (anr) suppress virulence genes by directly down-regulating arac/xyls members in gram-negative bacteria. in this study, we sought to investigate the distribution and molecular mechanisms of regulatory function for anrs among different bacterial pathogens. we identified more than 200 anrs distributed in diverse clinically important gram negative pathogens, including vibrio spp., salmonella spp., shigella spp., yersinia spp., citrobacter spp., enterotoxigenic (etec) and ent ... | 2016 | 27038276 |
| nonredundant roles of iron acquisition systems in vibrio cholerae. | vibrio cholerae, the causative agent of the severe diarrheal disease cholera, thrives in both marine environments and the human host. to do so, it must encode the tools necessary to acquire essential nutrients, including iron, under these vastly different conditions. a number of v. cholerae iron acquisition systems have been identified; however, the precise role of each system is not fully understood. to test the roles of individual systems, we generated a series of mutants in which only one of ... | 2016 | 26644383 |
| bacterial quorum sensing: its role in virulence and possibilities for its control. | quorum sensing is a process of cell-cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly. this process enables bacteria to express energetically expensive processes as a collective only when the impact of those processes on the environment or on a host will be maximized. among the many traits controlled by quorum sensing is the expression of virulence factors by pathogenic bacteria. here we review the quorum-sensing circuits of st ... | 2012 | 23125205 |
| mlp24 (mcpx) of vibrio cholerae implicated in pathogenicity functions as a chemoreceptor for multiple amino acids. | the chemotaxis of vibrio cholerae, the causative agent of cholera, has been implicated in pathogenicity. the bacterium has more than 40 genes for methyl-accepting chemotaxis protein (mcp)-like proteins (mlps). in this study, we found that glycine and at least 18 l-amino acids, including serine, arginine, asparagine, and proline, serve as attractants to the classical biotype strain o395n1. based on the sequence comparison with vibrio parahaemolyticus, we speculated that at least 17 mlps of v. cho ... | 2012 | 22753378 |
| relative contributions of vibrio polysaccharide and quorum sensing to the resistance of vibrio cholerae to predation by heterotrophic protists. | protozoan grazing is a major mortality factor faced by bacteria in the environment. vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of vibrio polysaccharide (vps). in addition to neg ... | 2013 | 23441178 |
| functional characterization of triclosan-resistant enoyl-acyl-carrier protein reductase (fabv) in pseudomonas aeruginosa. | pseudomonas aeruginosa is extremely resistant to triclosan. previous studies have shown that p. aeruginosa encodes a triclosan-resistant enoyl-acyl-carrier protein reductase (enr), fabv, and that deletion of fabv causes p. aeruginosa to be extremely sensitive to triclosan. in this report, we complemented a p. aeruginosa fabv deletion strain with several triclosan-resistant enr encoding genes, including vibrio cholerae fabv, bacillus subtilis fabl and enterococcus faecalis fabk. all complemented ... | 2016 | 27965638 |
| multicenter evaluation of the biofire filmarray gastrointestinal panel for etiologic diagnosis of infectious gastroenteritis. | the appropriate treatment and control of infectious gastroenteritis depend on the ability to rapidly detect the wide range of etiologic agents associated with the disease. clinical laboratories currently utilize an array of different methodologies to test for bacterial, parasitic, and viral causes of gastroenteritis, a strategy that suffers from poor sensitivity, potentially long turnaround times, and complicated ordering practices and workflows. additionally, there are limited or no testing met ... | 2015 | 25588652 |
| non-o157:h7 shiga toxin producing diarrhoeagenic escherichia coli (stec) in southern india: a tinderbox for starting epidemic. | outbreaks due to non-o157:h7 shiga toxin producing escherichia coli (stec) resulting in haemolytic uraemic syndrome (hus) have garnered much attention because of associated mortality transcending across continents and also because diarrhoea due to e.coli itself is rare in developed countries. the actual incidence of non-o157:h7 stec in sporadic acute diarrhoea is not fully elucidated, both in developing as well as in developed countries. due to larger extent of faecal-oral transmission in develo ... | 2016 | 27891338 |
| serendipitous isolation of non-vibrio bacterial strains carrying the cholera toxin gene from environmental waters in indonesia. | we initially attempted to isolate a vibrio cholerae o1 el tor biotype that carries a novel variant of the cholera toxin gene (ctxab) from environmental waters of indonesia, where the seventh cholera pandemic by v. cholerae o1 el tor biotype began. nested pcr targeting the gene revealed that a total of eight strains were found to carry ctxab. however, sequencing of the 16s rrna genes of these isolates showed they were not v. cholerae but were either klebsiella, enterobacter, pantoea, or aeromonas ... | 2013 | 24368914 |
| lytic activity of the vibrio cholerae type vi secretion toxin vgrg-3 is inhibited by the antitoxin tsab. | the type vi secretion system (t6ss) of gram-negative bacteria has been implicated in microbial competition; however, which components serve purely structural roles, and which serve as toxic effectors remains unresolved. here, we present evidence that vgrg-3 of the vibrio cholerae t6ss has both structural and toxin activity. specifically, we demonstrate that the c-terminal extension of vgrg-3 acts to degrade peptidoglycan and hypothesize that this assists in the delivery of accessory t6ss toxins ... | 2013 | 23341465 |
| non-o1/non-o139 vibrio cholerae avian isolate from france cocarrying the bla(vim-1) and bla(vim-4) genes. | we describe here a non-o1/non-o139 vibrio cholerae isolate producing both vim-1 and vim-4 carbapenemases. it was isolated from a yellow-legged gull in southern france. the blavim genes were part of a class 1 integron structure located in an inca/c plasmid. this study emphasizes the presence of carbapenemase genes in wildlife microbiota. | 2015 | 26169421 |
| chimeric adaptor proteins translocate diverse type vi secretion system effectors in vibrio cholerae. | vibrio cholerae is a diverse species of gram-negative bacteria, commonly found in the aquatic environment and the causative agent of the potentially deadly disease cholera. these bacteria employ a type vi secretion system (t6ss) when they encounter prokaryotic and eukaryotic competitors. this contractile puncturing device translocates a set of effector proteins into neighboring cells. translocated effectors are toxic unless the targeted cell produces immunity proteins that bind and deactivate in ... | 2015 | 26194724 |
| reduced susceptibility to extended-spectrum β-lactams in vibrio cholerae isolated in bangladesh. | β-lactams are antibiotic molecules able to inhibit cell wall biosynthesis. among other mechanisms, resistance in gram-negative bacteria is mostly associated with production of β-lactamase enzymes able to bind and hydrolyze the β-lactam ring. extended-spectrum β-lactamases extend this ability also to third- and fourth-generation cephalosporins, as well as to carbapenems and monobactams. vibrio cholerae is the causative agent of epidemic cholera and a public health burden for developing countries ... | 2016 | 27803895 |
| pathogenicity island cross talk mediated by recombination directionality factors facilitates excision from the chromosome. | pathogenicity islands (pais) are mobile integrated genetic elements (miges) that contain a diverse range of virulence factors and are essential in the evolution of pathogenic bacteria. pais are widespread among bacteria and integrate into the host genome, commonly at a trna locus, via integrase-mediated site-specific recombination. the excision of pais is the first step in the horizontal transfer of these elements and is not well understood. in this study, we examined the role of recombination d ... | 2016 | 26668266 |
| mutations in the imd pathway and mustard counter vibrio cholerae suppression of intestinal stem cell division in drosophila. | vibrio cholerae is an estuarine bacterium and an intestinal pathogen of humans that causes severe epidemic diarrhea. in the absence of adequate mammalian models in which to study the interaction of v. cholerae with the host intestinal innate immune system, we have implemented drosophila melanogaster as a surrogate host. we previously showed that immune deficiency pathway loss-of-function and mustard gain-of-function mutants are less susceptible to v. cholerae infection. we find that although the ... | 2013 | 23781070 |
| a dodecameric ring-like structure of the n0 domain of the type ii secretin from enterotoxigenic escherichia coli. | in many bacteria, secretins from the type ii secretion system (t2ss) function as outer membrane gated channels that enable passage of folded proteins from the periplasm into the extracellular milieu. cryo-electron microscopy of the t2ss secretin gspd revealed previously the dodecameric cylindrical architecture of secretins, and crystal structures of periplasmic secretin domains showed a modular domain organization. however, no high-resolution experimental data has as yet been provided about how ... | 2013 | 23820381 |
| assembly of the type ii secretion system such as found in vibrio cholerae depends on the novel pilotin asps. | the type ii secretion system (t2ss) is a molecular machine that drives the secretion of fully-folded protein substrates across the bacterial outer membrane. a key element in the machinery is the secretin: an integral, multimeric outer membrane protein that forms the secretion pore. we show that three distinct forms of t2sss can be distinguished based on the sequence characteristics of their secretin pores. detailed comparative analysis of two of these, the klebsiella-type and vibrio-type, showed ... | 2013 | 23326233 |
| biodegradable polymeric microsphere-based vaccines and their applications in infectious diseases. | vaccination, which provides effective, safe infectious disease protection, is among the most important recent public health and immunological achievements. however, infectious disease remains the leading cause of death in developing countries because several vaccines require repeated administrations and children are often incompletely immunized. microsphere-based systems, providing controlled release delivery, can obviate the need for repeat immunizations. here, we review the function of sustain ... | 0 | 25839217 |
| spectrum of outpatient illness in a school-based cohort in haiti, with a focus on diarrheal pathogens. | currently, there are only limited data available on rates of major diagnostic categories of illnesses among haitian children. we have established a cohort of 1,245 students attending schools run by the christianville foundation in the gressier/leogane region of haiti, for whom our group provides primary medical care. among 1,357 clinic visits during the 2012-2013 academic year, the main disease categories (with rates per 1,000 child years of observation) included acute respiratory infection (ari ... | 2015 | 25732684 |
| cholera toxin b: one subunit with many pharmaceutical applications. | cholera, a waterborne acute diarrheal disease caused by vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. the major virulence factor is cholera toxin (ct), which consists of two subunits: the a subunit (cta) and the b subunit (ctb). ctb is a 55 kd homopentameric, non-toxic protein binding to the gm1 ganglioside on mammalian cells with high affinity. currently, recombinantly produced ctb is used as a component o ... | 2015 | 25802972 |
| the repertoire of glycosphingolipids recognized by vibrio cholerae. | the binding of cholera toxin to the ganglioside gm1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. in contrast, the knowledge about the mechanisms for attachment of vibrio cholerae bacterial cells to the intestinal epithelium is limited. in order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of el tor v. cholerae. several specific interactions with minor complex non-acid glycosphingolipids were thereby detect ... | 2013 | 23349777 |
| from escherichia coli heat-stable enterotoxin to mammalian endogenous guanylin hormones. | the isolation of heat-stable enterotoxin (sta) from escherichia coli and cholera toxin from vibrio cholerae has increased our knowledge of specific mechanisms of action that could be used as pharmacological tools to understand the guanylyl cyclase-c and the adenylyl cyclase enzymatic systems. these discoveries have also been instrumental in increasing our understanding of the basic mechanisms that control the electrolyte and water balance in the gut, kidney, and urinary tracts under normal condi ... | 2014 | 24652326 |
| enterotoxigenic escherichia coli secretes a highly conserved mucin-degrading metalloprotease to effectively engage intestinal epithelial cells. | enterotoxigenic escherichia coli (etec) is a leading cause of death due to diarrheal illness among young children in developing countries, and there is currently no effective vaccine. many elements of etec pathogenesis are still poorly defined. here we demonstrate that yghj, a secreted etec antigen identified in immunoproteomic studies using convalescent patient sera, is required for efficient access to small intestinal enterocytes and for the optimal delivery of heat-labile toxin (lt). furtherm ... | 2013 | 24478067 |
| a combined vaccine approach against vibrio cholerae and etec based on outer membrane vesicles. | enteric infections induced by pathogens like vibrio cholerae and enterotoxigenic escherichia coli (etec) remain a massive burden in developing countries with increasing morbidity and mortality rates. previously, we showed that the immunization with genetically detoxified outer membrane vesicles (omvs) derived from v. cholerae elicits a protective immune response based on the generation of o antigen antibodies, which effectively block the motility by binding to the sheathed flagellum. in this stu ... | 2015 | 26322032 |
| shift in phenotypic characteristics of enterotoxigenic escherichia coli (etec) isolated from diarrheal patients in bangladesh. | enterotoxigenic escherichia coli (etec) is one of the most common causes of bacterial diarrhea. over the last decade, from 1996 to 2012, changes in the virulence antigen properties of etec such as heat labile (lt) and heat stable (st) toxins, colonization factors (cfs), and 'o'-serogroups have been observed. the aim of this prospective study was to compare changes in antigenic profiles of etec strains isolated from a 2% surveillance system at the icddr,b hospital in dhaka, bangladesh between 200 ... | 2014 | 25032802 |
| enumeration of gut-homing β7-positive, pathogen-specific antibody-secreting cells in whole blood from enterotoxigenic escherichia coli- and vibrio cholerae-infected patients, determined using an enzyme-linked immunosorbent spot assay technique. | vibrio cholerae and enterotoxigenic escherichia coli (etec) are noninvasive mucosal pathogens that cause acute watery diarrhea in people in developing countries. direct assessment of the mucosal immune responses to these pathogens is problematic. surrogate markers of local mucosal responses in blood are increasingly being studied to determine the mucosal immune responses after infection. however, the volume of blood available in children and infants has limited this approach. we assessed whether ... | 2015 | 26512047 |
| three-dimensional structure of a protozoal double-stranded rna virus that infects the enteric pathogen giardia lamblia. | giardia lamblia virus (glv) is a small, nonenveloped, nonsegmented double-stranded rna (dsrna) virus infecting giardia lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. glv (genus giardiavirus) is a member of family totiviridae, along with several other groups of protozoal or fungal viruses, including leishmania rna viruses and trichomonas vaginalis viruses. interestingly, glv is more closely related than other totivir ... | 2014 | 25378500 |
| antioxidant, antibacterial and cytotoxic effects of the phytochemicals of whole leucas aspera extract. | to investigate the antioxidant, antibacterial and cytotoxic activity of whole leucas aspera (labiatae) (l. aspera) alcoholic extract. | 0 | 23620850 |
| structure of the n-terminal domain of the metalloprotease prtv from vibrio cholerae. | the metalloprotease prtv from vibrio cholerae serves an important function for the ability of bacteria to invade the mammalian host cell. the protein belongs to the family of m6 proteases, with a characteristic zinc ion in the catalytic active site. prtv constitutes a 918 amino acids (102 kda) multidomain pre-pro-protein that undergoes several n- and c-terminal modifications to form a catalytically active protease. we report here the nmr structure of the prtv n-terminal domain (residues 23-103) ... | 2015 | 26434928 |
| pathogenic enterobacteria in lemurs associated with anthropogenic disturbance. | as human population density continues to increase exponentially, speeding the reduction and fragmentation of primate habitat, greater human-primate contact is inevitable, making higher rates of pathogen transmission likely. anthropogenic effects are particularly evident in madagascar, where a diversity of endemic lemur species are threatened by rapid habitat loss. despite these risks, knowledge of how anthropogenic activities affect lemur exposure to pathogens is limited. to improve our understa ... | 2014 | 25328106 |
| revealing the glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of vibrio cholerae o1, serotype ogawa with the bsa protein carrier using lc-esi-qqtof-ms/ms. | in this manuscript, we present the determination of glycation sites in synthetic neoglycoconjugates formed by conjugation of the antigenic monosaccharide hapten of vibrio cholerae o1 serotype ogawa to bsa using nano- liquid chromatography electrospray ionization quadrupole time-of-flight tandem mass spectroscopy (lc-esi-qqtof-ms/ms). the matrix-assisted laser desorption/ionization-tof/tof-ms/ms analyses of the tryptic digests of the glycoconjugates having a hapten:bsa ratio of 4.3:1, 6.6:1 and 1 ... | 0 | 22791257 |
| host-derived sialic acids are an important nutrient source required for optimal bacterial fitness in vivo. | a major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota.vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. in this study, we demonstrated that v. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite atp-independent periplasmic siapqm strain, transport ... | 2016 | 27073099 |
| antimicrobial activity of the mycotoxin citrinin obtained from the fungus penicillium citrinum. | the mycotoxin citrinin was obtained from the fungus penicillium citrinum. it was tested for it's minimum inhibitory concentration (mic) against some gram positive strains viz. staphylococcus aureus, bacillus pumilus, bacillus subtillis, bacillus cereus, klebsiella pneumoniae, streptococcus pneumoniae, lactobacillus arabinosus and gram negative strains e.coli, shigella dysenteriae, shigella sonnei, shigella boydii, salmonella typhimurium, proteus mirabilis and vibrio cholerae. further the zones o ... | 2002 | 22557053 |
| antimicrobial action of the leaf extract of lagerstroemia parviflora roxb. | the benzene extract of the leaves of lagerstroemia paviflora roxb was tested for its minimum inhibitory concentration (mic) against gram positive staphylococcus aureus, bacillus subtilis, bacillus cereus, klebsiella pneumoniae, streptococcus pneumoniae, lactobacillus arabinosus and gram negative strains e.coli, shigella dysenteriae, shigella sonnei, shigella boydii, salmonella typhimurium, proteus mirabilis and vibrio cholerae. further the zones of inhibition produced by the crude extract agains ... | 2002 | 22557054 |
| a comparative study on the effect of plant extracts with the antibiotics on organisms of hospital origin. | thirty five plants belonging to twenty families were studied for their antimicrobial activity. among the plants tested, 43 % showed antimicrobial activity. fifteen plants belonging to 10 families exhibited activity against gram positive bacteria and gram negative bacteria. four plants namely azadirachta indica, garadenia jasminoides, magnifera indica, and wrightia tinctora showed an appreciable activity against the gram positive bacteria and seven plants against gram negative organisms. leaf ext ... | 2006 | 22557227 |
| toxr of vibrio cholerae affects biofilm, rugosity and survival with acanthamoeba castellanii. | vibrio cholerae causes the diarrheal disease cholera and utilizes different survival strategies in aquatic environments. v. cholerae can survive as free-living or in association with zooplankton and can build biofilm and rugose colonies. the bacterium expresses cholera toxin (ct) and toxin-coregulated pilus (tcp) as the main virulence factors. these factors are co-regulated by a transcriptional regulator toxr, which modulates expression of outer membrane proteins (ompu) and (ompt). the aims of t ... | 2012 | 22248371 |
| the expanding role of type ii secretion in bacterial pathogenesis and beyond. | type ii secretion (t2s) is one means by which gram-negative pathogens secrete proteins into the extracellular milieu and/or host organisms. based upon recent genome sequencing, it is clear that t2s is largely restricted to the proteobacteria, occurring in many, but not all genera in the α-, β-, γ-, and δ- classes. prominent human and/or animal pathogens that express a t2s system(s) include acinetobacter baumannii, burkholderia pseudomallei, chlamydia trachomatis, escherichia coli, klebsiella pne ... | 2017 | 28264910 |
| emergence of a competence-reducing filamentous phage from the genome of acinetobacter baylyi adp1. | bacterial genomes commonly contain prophage sequences as a result of past infections with lysogenic phages. many of these integrated viral sequences are believed to be cryptic, but prophage genes are sometimes coopted by the host, and some prophages may be reactivated to form infectious particles when cells are stressed or mutate. we found that a previously uncharacterized filamentous phage emerged from the genome of acinetobacter baylyi adp1 during a laboratory evolution experiment. this phage ... | 2016 | 27645387 |
| fitness cost of antibiotic susceptibility during bacterial infection. | advances in high-throughput dna sequencing allow for a comprehensive analysis of bacterial genes that contribute to virulence in a specific infectious setting. such information can yield new insights that affect decisions on how to best manage major public health issues such as the threat posed by increasing antimicrobial drug resistance. much of the focus has been on the consequences of the selective advantage conferred on drug-resistant strains during antibiotic therapy. it is thought that the ... | 2015 | 26203082 |
| virstatin inhibits biofilm formation and motility of acinetobacter baumannii. | acinetobacter baumannii has emerged as an opportunistic nosocomial pathogen causing infections worldwide. one reason for this emergence is due to its natural ability to survive in the hospital environment, which may be explained by its capacity to form biofilms. cell surface appendages are important determinants of the a. baumannii biofilm formation and as such constitute interesting targets to prevent the development of biofilm-related infections. a chemical agent called virstatin was recently ... | 2014 | 24621315 |
| comparison of in vitro antibacterial activities of two cationic peptides cm15 and cm11 against five pathogenic bacteria: pseudomonas aeruginosa, staphylococcus aureus, vibrio cholerae, acinetobacter baumannii, and escherichia coli. | in recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. these peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistan ... | 2012 | 26781855 |
| paar-repeat proteins sharpen and diversify the type vi secretion system spike. | the bacterial type vi secretion system (t6ss) is a large multicomponent, dynamic macromolecular machine that has an important role in the ecology of many gram-negative bacteria. t6ss is responsible for translocation of a wide range of toxic effector molecules, allowing predatory cells to kill both prokaryotic as well as eukaryotic prey cells. the t6ss organelle is functionally analogous to contractile tails of bacteriophages and is thought to attack cells by initially penetrating them with a tri ... | 2013 | 23925114 |
| availability of safe drinking-water: the answer to cholera outbreak? nabua, camarines sur, philippines, 2012. | in may 2012, there were increasing diarrhoea cases and deaths reported from nabua, camarines sur to the philippines event-based surveillance system. an investigation was conducted to identify risk factors and determine transmission dynamics. | 2015 | 26668761 |
| [monitoring and research on pathogen spectrum in patients with acute diarrhea from sentinel hospital of zhejiang province during 2009 to 2014]. | objective: to explore pathogen spectrum constitution of acute diarrhea in outpatient and emergency of zhejiang province, and provide basis for treatment, prevention and control of the disease. methods: during january 2009 to december 2014, we selected seven sentinel hospitals in different regions of zhejiang, monitored and researched on pathogen spectrum in patients with acute diarrhea from outpatient and emergency. we recorded patients' personal basic information, the main symptoms and signs, a ... | 2016 | 28057113 |