| synergistic antimicrobial profiling of violacein with commercial antibiotics against pathogenic micro-organisms. | chromobacterium violaceum bergonzini (neisseriaceae), a gram-negative bacterium, secretes a spectacular pigment called violacein. violacein is a quorum-sensing metabolite and is also an active antimicrobial, anticancer agent. however, its efficiency as a potential drug, alone or in synergy with other active principles, has not being completely exploited. with the advent of different multi-drug resistant strains, it becomes essential to find a new natural product(s) that could be effectively used ... | 2014 | 24073823 |
| association of bacteria with marine invertebrates: implications for ballast water management. | bacteria associated with plankton are of importance in marine bioinvasions and the implementation of ship's ballast water treatment technologies. in this study, epibiotic and endobiotic bacteria associated with zooplankton, including barnacle nauplii, veliger larvae, and adults of the copepod oithona sp., were characterized and quantified. barnacle nauplius and veliger larva harbored ~4.4 × 10(5)cells ind(-1) whereas oithona sp. had 8.8 × 10(5)cells ind(-1). computation of bacterial contribution ... | 2013 | 23846742 |
| rapid identification of the etiological factors causing diarrheal diseases. | the main objective of this investigation was to develop and pilot a real-time polymerase chain reaction (rt-pcr) diagnostic system for rapid and simultaneous identification of pathogens with a particular emphasis on diarrheal disease diagnostics. the diarrheal diseases were selected as a target for the pilot because they constitute a primary public health priority in georgia and worldwide. the product developed by our research team "neo_pcr_diagnostics" represents an original system for the iden ... | 2016 | 27770538 |
| in vivo synthesis of cyclic-di-gmp using a recombinant adenovirus preferentially improves adaptive immune responses against extracellular antigens. | there is a compelling need for more effective vaccine adjuvants to augment induction of ag-specific adaptive immune responses. recent reports suggested the bacterial second messenger bis-(3'-5')-cyclic-dimeric-guanosine monophosphate (c-di-gmp) acts as an innate immune system modulator. we recently incorporated a vibrio cholerae diguanylate cyclase into an adenovirus vaccine, fostering production of c-di-gmp as well as proinflammatory responses in mice. in this study, we recombined a more potent ... | 2016 | 26792800 |
| dbdiasnp: an open-source knowledgebase of genetic polymorphisms and resistance genes related to diarrheal pathogens. | diarrhea is a highly common infection among children, responsible for significant morbidity and mortality rate worldwide. after pneumonia, diarrhea remains the second leading cause of neonatal deaths. numerous viral, bacterial, and parasitic enteric pathogens are associated with diarrhea. with increasing antibiotic resistance among enteric pathogens, there is an urgent need for global surveillance of the mutations and resistance genes primarily responsible for resistance to antibiotic treatment. ... | 2015 | 25978092 |
| chemical communication in the gut: effects of microbiota-generated metabolites on gastrointestinal bacterial pathogens. | gastrointestinal pathogens must overcome many obstacles in order to successfully colonize a host, not the least of which is the presence of the gut microbiota, the trillions of commensal microorganisms inhabiting mammals' digestive tracts, and their products. it is well established that a healthy gut microbiota provides its host with protection from numerous pathogens, including salmonella species, clostridium difficile, diarrheagenic escherichia coli, and vibrio cholerae. conversely, pathogenic ... | 2015 | 25958185 |
| recognition of human milk oligosaccharides by bacterial exotoxins. | the affinities of the most abundant oligosaccharides found in human milk for four bacterial exotoxins (from vibrio cholerae and pathogenic escherichia coli) were quantified for the first time. association constants (ka) for a library of 20 human milk oligosaccharides (hmos) binding to shiga toxin type 2 holotoxin (stx2) and the b subunit homopentamers of cholera toxin, heat-labile toxin and shiga toxin type 1 (ctb5, hltb5 and stx1b5) were measured at 25°c and ph 7 using the direct electrospray i ... | 2015 | 25941008 |
| [the application and epidemiological research of xtag gpp multiplex pcr in the diagnosis of infectious diarrhea]. | to investigate the application value of xtag (®) gastrointestinal pathogen panel (xtag9(®) gpp) multiplex pcr in the early diagnosis of infectious diarrhea, and understand the epidemiology of intestinal diarrhea pathogens. | 2015 | 25916780 |
| spectrum of enteropathogens detected by the filmarray gi panel in a multicentre study of community-acquired gastroenteritis. | the european, multicentre, quarterly point-prevalence study of community-acquired diarrhoea (eucodi) analysed stool samples received at ten participating clinical microbiology laboratories (austria, finland, france, germany, greece, ireland, italy, portugal, romania, and the uk) in 2014. on four specified days, each local laboratory submitted samples from ≤20 consecutive patients to the austrian study centre for further testing with the filmarray gi panel (biofire diagnostics, salt lake city, ut ... | 2015 | 25908431 |
| in vitro selection of a single-stranded dna molecular recognition element against clostridium difficile toxin b and sensitive detection in human fecal matter. | toxin b is one of the major virulence factors of clostridium difficile, a bacterium that is responsible for a significant number of diarrhea cases in acute care settings. due to the prevalence of c. difficile induced diarrhea, rapid and correct diagnosis is crucial in the disease management. in this study, we have employed a stringent in vitro selection method to identify single-stranded dna molecular recognition elements (mre) specific for toxin b. at the end of the 12-round selection, one mre ... | 2015 | 25734010 |
| real-time cell analysis for monitoring cholera toxin-induced human intestinal epithelial cell response. | the pathogenic mechanism of vibrio cholerae manifests as diarrhea and causes life-threatening dehydration. here, we observe the human intestinal epithelial cells (hiec) response to cholera toxin (ct) by a real-time cell analysis (rtca) platform, and disclose the difference from ct-induced cytotoxicity and others in hiec. an hiec cell of 1.0 × 10(5) cells/ml was characterized as the suitable concentration for each well. for experimentation, the assay requires an inoculation of ct dissolved in dul ... | 2015 | 25510171 |
| added value of multiplex luminex gastrointestinal pathogen panel (xtag® gpp) testing in the diagnosis of infectious gastroenteritis. | the luminex gastrointestinal pathogen panel (xtag(®) gpp) detects in one assay the most common gastroenteritis-causing pathogens and toxins, namely adenovirus 40/41, norovirus genogroup (ng) i/ii, rotavirus a, clostridium difficile toxin a/b, campylobacter sp., escherichia coli o157, enterotoxigenic e. coli heat-labile enterotoxin/heat-stable enterotoxin, salmonella sp., shiga-toxin producing e. coli, shiga-like toxin (stx)1/2, shigella sp., vibrio cholerae, yersinia enterocolitica, cryptosporid ... | 2014 | 24131399 |
| the c-di-gmp recognition mechanism of the pilz domain of bacterial cellulose synthase subunit a. | in some proteobacteria and firmicutes such as pseudomonas aeruginosa, vibrio cholerae, xanthomonas campestris, and clostridium difficile, cyclic dimeric guanosine monophosphate (c-di-gmp) is known to regulate cellular processes, including motility, biofilm formation, and virulence, as a second messenger. cellulose production in acetobacter xylinum, a model organism of cellulose biosynthesis, also depends on by cellular c-di-gmp level. in cellulose-synthesizing bacteria, a terminal complex locali ... | 2013 | 23291177 |
| rapid oligonucleotide suspension array-based multiplex detection of bacterial pathogens. | a gene-specific microsphere suspension array coupled with 15-plex polymerase chain reaction (pcr) was developed to screen bacterial samples rapidly for 10 strains of bacteria: shigella spp. (s. flexneri, s. dysenteriae, and s. sonnei), staphylococcus aureus, vibrio cholerae (serology o1 and o139), legionella pneumophila, and clostridium botulinum (types a, b, and e). fifteen sets of highly validated primers were chosen to amplify target genes simultaneously. corresponding oligonucleotide probes ... | 2013 | 23947819 |
| targeting and alteration of tight junctions by bacteria and their virulence factors such as clostridium perfringens enterotoxin. | the integrity of tight junctions, which regulate paracellular permeability, is challenged by many bacterial pathogens. this is caused by inflammatory responses triggered by pathogens and direct interaction of bacteria or their toxins with host epithelial cells. in some cases, tight junction proteins represent receptors for cell surface proteins or toxins of the pathogen, such as clostridium perfringens enterotoxin (cpe). cpe causes diarrhea and cramps-the symptoms of a common foodborne illness, ... | 2017 | 27864644 |
| b-cell epitope of beta toxin of clostridium perfringens genetically conjugated to a carrier protein: expression, purification and characterization of the chimeric protein. | beta toxin (btx) is the prime virulence factor for the pathogenesis of clostridium perfringens type c strain, known to cause necrotic enteritis and enterotoxaemia in mammalian species. the existing vaccines targeting btx are formaldehyde inactivated culture filtrates of clostridium. these filtrates raise antigenic load in the host leading to nonspecific and poor responses. the present study aimed to overcome these drawbacks and generate a chimeric protein carrying in silico identified b-cell epi ... | 2014 | 24996028 |
| purification, structural elucidation and bioactivity of tryptophan containing diketopiperazines, from comamonas testosteroni associated with a rhabditid entomopathogenic nematode against major human-pathogenic bacteria. | the cell free culture filtrate of a comamonas testosteroni associated with an entomopathogenic nematode (epn), rhabditis (oscheius) sp. exhibited promising antimicrobial activity. the ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain five diketopiperazines or cyclic dipeptides (dkp 1-5). the structure and absolute stereochemistry of the compounds were determined based on extensive spectroscopic analyses (hr-ms, (1)hnmr, (13)cnmr, ( ... | 2014 | 24120705 |
| a comparative structure-function analysis of active-site inhibitors of vibrio cholerae cholix toxin. | cholix toxin from vibrio cholerae is a novel mono-adp-ribosyltransferase (mart) toxin that shares structural and functional properties with pseudomonas aeruginosa exotoxin a and corynebacterium diphtheriae diphtheria toxin. herein, we have used the high-resolution x-ray structure of full-length cholix toxin in the apo form, nad(+) bound, and 10 structures of the cholix catalytic domain (c-domain) complexed with several strong inhibitors of toxin enzyme activity (nap, pj34, and the p-series) to s ... | 2015 | 25756608 |
| pocket analysis of the full-length cholix toxin. an assessment of the structure-dynamics of the apo catalytic domain. | cholix toxin from vibrio cholerae is the third member of the diphtheria toxin (dt) group of mono-adp-ribosyltransferase (mart) bacterial toxins. it shares structural and functional properties with pseudomonas aeruginosa exotoxin a and corynebacterium diphtheriae dt. cholix toxin is an important model for the development of antivirulence approaches and therapeutics against these toxins from pathogenic bacteria. herein, we have used the high-resolution x-ray structure of full-length cholix complex ... | 2015 | 25559625 |
| novel cholix toxin variants, adp-ribosylating toxins in vibrio cholerae non-o1/non-o139 strains, and their pathogenicity. | cholix toxin (chxa) is a recently discovered exotoxin in vibrio cholerae which has been characterized as a third member of the eukaryotic elongation factor 2-specific adp-ribosyltransferase toxins, in addition to exotoxin a of pseudomonas aeruginosa and diphtheria toxin of corynebacterium diphtheriae. these toxins consist of three characteristic domains for receptor binding, translocation, and catalysis. however, there is little information about the prevalence of chxa and its genetic variations ... | 2013 | 23230295 |
| an unusual cation-binding site and distinct domain-domain interactions distinguish class ii enolpyruvylshikimate-3-phosphate synthases. | enolpyruvylshikimate-3-phosphate synthase (epsps) catalyzes a critical step in the biosynthesis of a number of aromatic metabolites. an essential prokaryotic enzyme and the molecular target of the herbicide glyphosate, epspss are the subject of both pharmaceutical and commercial interest. two epsps classes that exhibit low sequence homology, differing substrate/glyphosate affinities, and distinct cation activation properties have previously been described. here, we report structural studies of t ... | 2016 | 26813771 |
| stress tolerant virulent strains of cronobacter sakazakii from food. | cronobacter sakazakii is considered as an emerging foodborne pathogen. the aim of this study was to isolate and characterize virulent strains of cronobacter sakazakii from food samples of bangladesh. | 2014 | 25723712 |
| expression and assembly of cholera toxin b subunit and domain iii of dengue virus 2 envelope fusion protein in transgenic potatoes. | the rates of mosquito-transmitted dengue virus infection in humans have increased in tropical and sub-tropical areas. domain iii of dengue envelope protein (ediii) is involved in cellular receptor binding and induces serotype-specific neutralizing antibodies. ediii fused to the b subunit of vibrio cholera (ctb-ediii) was expressed in potatoes to develop a plant-based vaccine against dengue virus type 2. ctb-ediii fused to an endoplasmic reticulum (er) retention signal, sekdel, was introduced int ... | 2016 | 27335159 |
| vibrio metoecus sp. nov., a close relative of vibrio cholerae isolated from coastal brackish ponds and clinical specimens. | a gram-staining-negative, curved-rod-shaped bacterium with close resemblance to vibrio cholerae, the aetiological agent of cholera, was isolated over the course of several years from coastal brackish water (17 strains) and from clinical cases (two strains) in the united states. 16s rrna gene identity with v. cholerae exceeded 98 % yet an average nucleotide identity based on genome data of around 86 % and multi locus sequence analysis of six housekeeping genes (mdh, adk, gyrb, reca, pgi and rpob) ... | 2014 | 24972615 |
| dual expression profile of type vi secretion system immunity genes protects pandemic vibrio cholerae. | the vibrio cholerae type vi secretion system (t6ss) assembles as a molecular syringe that injects toxic protein effectors into both eukaryotic and prokaryotic cells. we previously reported that the v. cholerae o37 serogroup strain v52 maintains a constitutively active t6ss to kill other gram-negative bacteria while being immune to attack by kin bacteria. the pandemic o1 el tor v. cholerae strain c6706 is t6ss-silent under laboratory conditions as it does not produce t6ss structural components an ... | 2013 | 24348240 |
| constitutive type vi secretion system expression gives vibrio cholerae intra- and interspecific competitive advantages. | the type vi secretion system (t6ss) mediates protein translocation across the cell membrane of gram-negative bacteria, including vibrio cholerae - the causative agent of cholera. all v. cholerae strains examined to date harbor gene clusters encoding a t6ss. structural similarity and sequence homology between components of the t6ss and the t4 bacteriophage cell-puncturing device suggest that the t6ss functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eu ... | 2012 | 23110230 |
| deploying aptameric sensing technology for rapid pandemic monitoring. | the genome of virulent strains may possess the ability to mutate by means of antigenic shift and/or antigenic drift as well as being resistant to antibiotics with time. the outbreak and spread of these virulent diseases including avian influenza (h1n1), severe acute respiratory syndrome (sars-corona virus), cholera (vibrio cholera), tuberculosis (mycobacterium tuberculosis), ebola hemorrhagic fever (ebola virus) and aids (hiv-1) necessitate urgent attention to develop diagnostic protocols and as ... | 2016 | 26381238 |
| an entamoeba histolytica adp-ribosyl transferase from the diphtheria toxin family modifies the bacterial elongation factor tu. | adp-ribosyl transferases are enzymes involved in the post-translational modification of proteins; they participate in multiple physiological processes, pathogenesis and host-pathogen interactions. several reports have characterized the functions of these enzymes in viruses, prokaryotes and higher eukaryotes, but few studies have reported adp-ribosyl transferases in lower eukaryotes, such as parasites. the locus ehi_155600 from entamoeba histolytica encodes a hypothetical protein that possesses a ... | 2016 | 27234208 |
| serological surveillance development for tropical infectious diseases using simultaneous microsphere-based multiplex assays and finite mixture models. | a strategy to combat infectious diseases, including neglected tropical diseases (ntds), will depend on the development of reliable epidemiological surveillance methods. to establish a simple and practical seroprevalence detection system, we developed a microsphere-based multiplex immunoassay system and evaluated utility using samples obtained in kenya. | 2014 | 25078404 |
| atomic resolution crystal structure of vclmwptp-1 from vibrio cholerae o395: insights into a novel mode of dimerization in the low molecular weight protein tyrosine phosphatase family. | low molecular weight protein tyrosine phosphatase (lmwptp) is a group of phosphotyrosine phosphatase ubiquitously found in a wide range of organisms ranging from bacteria to mammals. dimerization in the lmwptp family has been reported earlier which follows a common mechanism involving active site residues leading to an enzymatically inactive species. here we report a novel form of dimerization in a lmwptp from vibrio cholera 0395 (vclmwptp-1). studies in solution reveal the existence of the dime ... | 2014 | 24909685 |
| comparison of clinical and laboratory characteristics of intestinal amebiasis with shigellosis among patients visiting a large urban diarrheal disease hospital in bangladesh. | between 1993 and 2011, a total of 371 intestinal amebiasis (ia), caused by entamoeba histolytica cases were compared with 1,113 shigellosis (randomly selected) patients of icddr,b, excluding co-infections (rotavirus and vibrio cholerae) in two age stratums: 0-14 years of age and ≥ 15 years of age. the number of ia and shigellosis cases gradually reduced over the study period. in multivariate analysis, individuals 0-14 years of age, slum dwellers (odds ratio [or] 3.51; 95% confidence interval [ci ... | 2013 | 23775017 |
| xer site specific recombination: double and single recombinase systems. | the separation and segregation of newly replicated bacterial chromosomes can be constrained by the formation of circular chromosome dimers caused by crossing over during homologous recombination events. in escherichia coli and most bacteria, dimers are resolved to monomers by site-specific recombination, a process performed by two chromosomally encoded tyrosine recombinases (xerc and xerd). xercd recombinases act at a 28 bp recombination site dif, which is located at the replication terminus reg ... | 2017 | 28373867 |
| coupling mutagenesis and parallel deep sequencing to probe essential residues in a genome or gene. | the sequence of a protein determines its function by influencing its folding, structure, and activity. similarly, the most conserved residues of orthologous and paralogous proteins likely define those most important. the detection of important or essential residues is not always apparent via sequence alignments because these are limited by the depth of any given gene's phylogeny, as well as specificities that relate to each protein's unique biological origin. thus, there is a need for robust and ... | 2013 | 23401533 |
| antimicrobial activity, acute toxicity and cytoprotective effect of crassocephalum vitellinum (benth.) s. moore extract in a rat ethanol-hcl gastric ulcer model. | a decoction of crassocephallum vitellinum (benth.) s. moore (asteraceae) is used in kagera region to treat peptic ulcers. this study seeks to evaluate an aqueous ethanol extract of aerial parts of the plant for safety and efficacy. | 2014 | 24552147 |
| challenges in mucosal vaccines for the control of infectious diseases. | the mucosal surface is the largest route through which pathogens enter the human body. to control the outbreak of mucosal infectious diseases, we must use our knowledge of the mucosal immune system to create vaccines that elicit protective mucosal and systemic immunity. mucosal vaccines have advantages over traditional injectable vaccines in that they not only induce effective mucosal immune responses, but they also do not cause physical or psychological discomfort. mucosal vaccines currently li ... | 2014 | 24914172 |
| fast growth conditions uncouple the final stages of chromosome segregation and cell division in escherichia coli. | homologous recombination between the circular chromosomes of bacteria can generate chromosome dimers. they are resolved by a recombination event at a specific site in the replication terminus of chromosomes, dif, by dedicated tyrosine recombinases. the reaction is under the control of a cell division protein, ftsk, which assembles into active dna pumps at mid-cell during septum formation. previous studies suggested that activation of xer recombination at dif was restricted to chromosome dimers i ... | 2017 | 28358835 |
| ribosome-dependent vibrio cholerae mrnase higb2 is regulated by a β-strand sliding mechanism. | toxin-antitoxin (ta) modules are small operons involved in bacterial stress response and persistence. higba operons form a family of ta modules with an inverted gene organization and a toxin belonging to the rele/pare superfamily. here, we present the crystal structures of chromosomally encoded vibrio cholerae antitoxin (vchiga2), toxin (vchigb2) and their complex, which show significant differences in structure and mechanisms of function compared to the higba module from plasmid rts1, the defin ... | 2017 | 28334932 |
| induction of immunomodulatory mir-146a and mir-155 in small intestinal epithelium of vibrio cholerae infected patients at acute stage of cholera. | the potential immunomodulatory role of micrornas in small intestine of patients with acute watery diarrhea caused by vibrio cholerae o1 or enterotoxigenic escherichia coli (etec) infection was investigated. duodenal biopsies were obtained from study-participants at the acute (day 2) and convalescent (day 21) stages of disease, and from healthy individuals. levels of mir-146a, mir-155 and mir-375 and target gene (irak1, traf6, card10) and 11 cytokine mrnas were determined by qrt-pcr. the cellular ... | 2017 | 28319200 |
| stringent factor and proteolysis control of sigma factor rpos expression in vibrio cholerae. | vibrio cholerae can colonize the gastrointestinal track of humans and cause the disease cholera. during colonization, the alternative sigma factor, rpos, controls a process known as "mucosal escape response," defining a specific spatial and temporal response and effecting chemotaxis and motility. in this report, the expression and proteolytic control of rpos in v. cholerae was characterized. to date, aspects of proteolysis control, the involved components, and proteolysis regulation have not bee ... | 2017 | 28228329 |
| structure and dynamics of type iii periplasmic proteins vcfhud and vchutb reveal molecular basis of their distinctive ligand binding properties. | molecular mechanisms of xenosiderophore and heme acquisitions using periplasmic binding protein (pbp) dependent atp-binding cassette transporters to scavenge the essential nutrient iron are elusive yet in vibrio cholerae. our current study delineates the structures, dynamics and ligand binding properties of two type iii pbps of v. cholerae, vcfhud and vchutb. through crystal structures and fluorescence quenching studies we demonstrate unique features of vcfhud to bind both hydroxamate and catech ... | 2017 | 28216648 |
| surface expression of helicobacter pylori hpaa adhesion antigen on vibrio cholerae, enhanced by co-expressed enterotoxigenic escherichia coli fimbrial antigens. | helicobacter pylori infection can cause peptic ulceration and is associated with gastric adenocarcinoma. this study aimed to construct and characterize a non-virulent vibrio cholerae o1 strain, which grows more rapidly than h. pylori, as vector for h. pylori antigens for possible use as a vaccine strain against h. pylori. this was done by recombinant expression of the h. pylori adhesion antigen hpaa alone or, as a proof of principle, together with different colonization factor (cf) antigens of e ... | 2017 | 28215587 |
| attachment of 13 types of foodborne bacteria to jalapeño and serrano peppers and antibacterial effect of roselle calyx extracts, sodium hypochlorite, colloidal silver, and acetic acid against these foodborne bacteria on peppers. | chili peppers are a very important crop in mexico. however, these peppers have been associated with salmonella infection outbreaks in the united states, and salmonella and diarrheagenic escherichia coli pathotypes have been isolated from jalapeño and serrano peppers in mexico. to decrease microbial contamination of fruits and vegetables, chemical agents are commonly used; however, chemical agents used to eliminate pathogenic bacteria on vegetables have a limited antimicrobial effect. roselle ( h ... | 2017 | 28199144 |
| identification and antimicrobial resistance patterns of bacterial enteropathogens from children aged 0-59 months at the university teaching hospital, lusaka, zambia: a prospective cross sectional study. | bacterial diarrhoeal disease is among the most common causes of mortality and morbidity in children 0-59 months at the university teaching hospital in lusaka, zambia. however, most cases are treated empirically without the knowledge of aetiological agents or antimicrobial susceptibility patterns. the aim of this study was, therefore, to identify bacterial causes of diarrhoea and determine their antimicrobial susceptibility patterns in stool specimens obtained from the children at the hospital. | 2017 | 28152988 |
| cross feeding of glucose metabolism byproducts of escherichia coli human gut isolates and probiotic strains affect survival of vibrio cholerae. | vibrio cholerae converts glucose into either acid or the neutral end product acetoin and its survival in carbohydrate enriched media is linked to the nature of the byproducts produced. it has been demonstrated in this study that escherichia coli strain isolated from the gut of healthy human volunteers and the commonly used probiotic e. coli nissle strain that metabolize glucose to acidic byproducts drastically reduce the survival of v. cholerae strains irrespective of their glucose sensitivity a ... | 2017 | 28105081 |
| structural insights into the secretin translocation channel in the type ii secretion system. | the secretin gspd of the type ii secretion system (t2ss) forms a channel across the outer membrane in gram-negative bacteria to transport substrates from the periplasm to the extracellular milieu. the lack of an atomic-resolution structure of the gspd channel hinders the investigation of substrate translocation mechanism of t2ss. here we report cryo-em structures of two gspd channels (∼1 mda), from escherichia coli k12 and vibrio cholerae, at ∼3 å resolution. the structures reveal a pentadecamer ... | 2017 | 28067918 |
| optimization and characterization of the synthetic secondary chromosome synvicii in escherichia coli. | learning by building is one of the core ideas of synthetic biology research. consequently, building synthetic chromosomes is the way to fully understand chromosome characteristics. the last years have seen exciting synthetic chromosome studies. we had previously introduced the synthetic secondary chromosome synvicii in escherichia coli. it is based on the replication mechanism of the secondary chromosome in vibrio cholerae. here, we present a detailed analysis of its genetic characteristics and ... | 2016 | 28066763 |
| evolution and structural dynamics of bacterial glycan binding adhesins. | infectious disease processes like bacterial adherence or the activity of secreted toxins frequently gain host and tissue specificity by glycan binding interactions with the host glycome. recent functional and structural studies highlight the high niche specialization of bacterial lectins, but also reveal a remarkable plasticity in their glycan binding sites and mechanisms, to adapt to host glycome dynamics or changing environmental conditions at the site of infection. in this review we put empha ... | 2016 | 28043017 |
| single-cell analysis of the plasmablast response to vibrio cholerae demonstrates expansion of cross-reactive memory b cells. | we characterized the acute b cell response in adults with cholera by analyzing the repertoire, specificity, and functional characteristics of 138 monoclonal antibodies (mabs) generated from single-cell-sorted plasmablasts. we found that the cholera-induced responses were characterized by high levels of somatic hypermutation and large clonal expansions. a majority of the expansions targeted cholera toxin (ct) or lipopolysaccharide (lps). using a novel proteomics approach, we were able to identify ... | 2016 | 27999163 |
| immunochromatographic detection of the heat-labile enterotoxin of enterotoxigenic escherichia coli with cross-detection of cholera toxin. | here, we report the development of an immunochromatographic test strip that can detect heat-labile enterotoxin (lt) produced by enterotoxigenic escherichia coli. five types of monoclonal antibody (mab)-producing hybridomas were isolated: three mabs were a subunit specific and two were b subunit specific. four mabs also cross-reacted with both lt proteins derived from swine and human e. coli strains, but only one mab 57b9 additionally cross-reacted with cholera toxin. thus, mab 57b9 was used to f ... | 2017 | 27940044 |
| random versus cell cycle-regulated replication initiation in bacteria: insights from studying vibrio cholerae chromosome 2. | bacterial chromosomes initiate replication at a fixed time in the cell cycle, whereas there is generally no particular time for plasmid replication initiation or chromosomal replication initiation from integrated plasmids. in bacteria with divided genomes, the replication system of one of the chromosomes typically resembles that of bacteria with undivided genomes, whereas the remaining chromosomes have plasmid-like replication systems. for example, in vibrio cholerae, a bacterium with two chromo ... | 2017 | 27903655 |
| biochemical and structural characterization of the novel sialic acid-binding site of escherichia coli heat-labile enterotoxin lt-iib. | the structurally related ab5-type heat-labile enterotoxins of escherichia coli and vibrio cholerae are classified into two major types. the type i group includes cholera toxin (ct) and e. coli lt-i, whereas the type ii subfamily comprises lt-iia, lt-iib and lt-iic. the carbohydrate-binding specificities of lt-iia, lt-iib and lt-iic are distinctive from those of cholera toxin and e. coli lt-i. whereas ct and lt-i bind primarily to the gm1 ganglioside, lt-iia binds to gangliosides gd1a, gd1b and g ... | 2016 | 27562297 |
| competitive survival of escherichia coli, vibrio cholerae, salmonella typhimurium and shigella dysenteriae in riverbed sediments. | studies on the survival of bacterial enteric pathogens in riverbed sediments have mostly focused on individual organisms. reports on the competitive survival of these pathogens in riverbed sediments under the same experimental setup are limited. we investigated the survival of escherichia coli, salmonella enterica ser. typhimurium, vibrio cholerae and shigella dysenteriae in riverbed sediments of the apies river. experiments were performed in flow chambers containing three sediment types and con ... | 2016 | 27193001 |
| killing of vibrio cholerae and escherichia coli strains carrying d-mannose-sensitive ligands by mytilus hemocytes is promoted by a multifunctional hemolymph serum protein. | in aquatic environments, bivalve mollusks represent an important ecological niche for microorganisms. persistence of bacteria in bivalve tissues partly depends on their capacity to survive the bactericidal activity of the hemolymph due to both cellular (hemocyes) and soluble serum factors (e.g., enzymes, lectins, opsonins). the extrapallial protein (ep) present in serum of mytilus galloprovincialis (mgep) has been recently shown to work as an opsonin promoting d-mannose sensitive (ms) interactio ... | 2016 | 27041371 |
| dna replication in engineered escherichia coli genomes with extra replication origins. | the standard outline of bacterial genomes is a single circular chromosome with a single replication origin. from the bioengineering perspective, it appears attractive to extend this basic setup. bacteria with split chromosomes or multiple replication origins have been successfully constructed in the last few years. the characteristics of these engineered strains will largely depend on the respective dna replication patterns. however, the dna replication has not been investigated systematically i ... | 2016 | 27268399 |
| antibacterial activity of polyphenolic fraction of kombucha against enteric bacterial pathogens. | the emergence of multi-drug-resistant enteric pathogens has prompted the scientist community to explore the therapeutic potentials of traditional foods and beverages. the present study was undertaken to investigate the efficacy of kombucha, a fermented beverage of sugared black tea, against enterotoxigenic escherichia coli, vibrio cholerae, shigella flexneri and salmonella typhimurium followed by the identification of the antibacterial components present in kombucha. the antibacterial activity w ... | 2016 | 27638313 |
| ctxϕ: exploring new alternatives in host factor-mediated filamentous phage replications. | for a long time ff phages from escherichia coli provided the majority of the knowledge about the rolling circle replication mechanism of filamentous phages. host factors involved in coliphages replication have been fully identified. based on these studies, the function of rep protein as the accessory helicase directly implicated in filamentous phage replication was considered a paradigm. we recently reported that the replication of some filamentous phages from vibrio cholerae, including the chol ... | 2017 | 27607139 |
| in sickness and in health: the relationships between bacteria and bile in the human gut. | colonization of a human host with a commensal microbiota has a complex interaction in which bacterial communities provide numerous health benefits to the host. an equilibrium between host and microbiota is kept in check with the help of biliary secretions by the host. bile, composed primarily of bile salts, promotes digestion. it also provides a barrier between host and bacteria. after bile salts are synthesized in the liver, they are stored in the gallbladder to be released after food intake. t ... | 2016 | 27565580 |
| biosensing vibrio cholerae with genetically engineered escherichia coli. | cholera is a potentially mortal, infectious disease caused by vibrio cholerae bacterium. current treatment methods of cholera still have limitations. beneficial microbes that could sense and kill the v. cholerae could offer potential alternative to preventing and treating cholera. however, such v. cholerae targeting microbe is still not available. this microbe requires a sensing system to be able to detect the presence of v. cholera bacterium. to this end, we designed and created a synthetic gen ... | 2016 | 27529184 |
| identification and characterization of a putative manganese export protein in vibrio cholerae. | manganese plays an important role in the cellular physiology and metabolism of bacterial species, including the human pathogen vibrio cholerae the intracellular level of manganese ions is controlled through coordinated regulation of the import and export of this element. we have identified a putative manganese exporter (vc0022), named mnea (manganese exporter a), which is highly conserved among vibrio spp. an mnea mutant exhibited sensitivity to manganese but not to other cations. under high-man ... | 2016 | 27481926 |
| screening for transmembrane association in divisome proteins using toxgreen, a high-throughput variant of the toxcat assay. | toxcat is a widely used genetic assay to study interactions of transmembrane helices within the inner membrane of the bacterium escherichia coli. toxcat is based on a fusion construct that links a transmembrane domain of interest with a cytoplasmic dna-binding domain from the vibrio cholerae toxr protein. interaction driven by the transmembrane domain results in dimerization of the toxr domain, which, in turn, activates the expression of the reporter gene chloramphenicol acetyl transferase (cat) ... | 2016 | 27453198 |
| lcp crystallization and x-ray diffraction analysis of vcmn, a mate transporter from vibrio cholerae. | multidrug and toxic compound extrusion (mate) transporters, one of the multidrug exporter families, efflux xenobiotics towards the extracellular side of the membrane. since mate transporters expressed in bacterial pathogens contribute to multidrug resistance, they are important therapeutic targets. here, a mate-transporter homologue from vibrio cholerae, vcmn, was overexpressed in escherichia coli, purified and crystallized in lipidic cubic phase (lcp). x-ray diffraction data were collected to 2 ... | 2016 | 27380372 |
| quantitative microbial risk assessment (qmra) shows increased public health risk associated with exposure to river water under conditions of riverbed sediment resuspension. | although higher microbial concentrations have been reported in sediments than in the overlying water column, most quantitative microbial risk assessment (qmra) studies have not clearly indicated the contribution of sediment-borne pathogens to estimated risks. thus, the present study aimed at determining the public health risk associated with exposure to pathogenic bacteria in polluted river water under undisturbed conditions and conditions of sediment resuspension in the apies river, gauteng, so ... | 2016 | 27297265 |
| human fecal and pathogen exposure pathways in rural indian villages and the effect of increased latrine coverage. | efforts to eradicate open defecation and improve sanitation access are unlikely to achieve health benefits unless interventions reduce microbial exposures. this study assessed human fecal contamination and pathogen exposures in rural india, and the effect of increased sanitation coverage on contamination and exposure rates. in a cross-sectional study of 60 villages of a cluster-randomized controlled sanitation trial in odisha, india, human and domestic animal fecal contamination was measured in ... | 2016 | 27192358 |
| a single gene of a commensal microbe affects host susceptibility to enteric infection. | indigenous microbes inside the host intestine maintain a complex self-regulating community. the mechanisms by which gut microbes interact with intestinal pathogens remain largely unknown. here we identify a commensal escherichia coli strain whose expansion predisposes mice to infection by vibrio cholerae, a human pathogen. we refer to this strain as 'atypical' e. coli (atec) because of its inability to ferment lactose. the atec strain is resistant to reactive oxygen species (ros) and proliferate ... | 2016 | 27173141 |
| strategies to block bacterial pathogenesis by interference with motility and chemotaxis. | infections by motile, pathogenic bacteria, such as campylobacter species, clostridium species, escherichia coli, helicobacter pylori, listeria monocytogenes, neisseria gonorrhoeae, pseudomonas aeruginosa, salmonella species, vibrio cholerae, and yersinia species, represent a severe economic and health problem worldwide. of special importance in this context is the increasing emergence and spread of multidrug-resistant bacteria. due to the shortage of effective antibiotics for the treatment of in ... | 2016 | 27000091 |
| in vitro antibacterial activity of aqueous and ethanol extracts of aristolochia indica and toddalia asiatica against multidrug-resistant bacteria. | bacteria have developed multidrug resistance against available antimicrobial agents. infectious diseases caused by these multidrug-resistant bacteria are major causes of morbidity and mortality in human beings. synthetic drugs are expensive and inadequate for the treatment of diseases, causing side effects and ineffective against multidrug-resistant bacteria. the medicinal plants are promising to have effective antimicrobial property due to presence of phytochemical compounds like alkaloids, fla ... | 2017 | 26997710 |
| immunogenic properties of trivalent recombinant protein composed of b-subunits of lt, stx-2, and ct toxins. | infectious diarrhoea remains an emerging problem in the world health program. among diarrheagenic agents, vibrio cholerae and enterotoxigenic and enterohemorrhagic escherichia coli are critical enteropathogens. ab5 toxin produced by these bacteria, heat-labile enterotoxin (lt), cholera enterotoxin (ct), and shiga-like cytotoxin (stx) can target the immune system and are subunit vaccine candidates. a chemically-synthesized chimeric construct composed of the binding subunits of these toxins (ltb, ... | 2016 | 26970204 |
| prospective study of pathogens in asymptomatic travellers and those with diarrhoea: aetiological agents revisited. | travellers' diarrhoea (td) remains the most frequent health problem encountered by visitors to the (sub)tropics. traditional stool culture identifies the pathogen in only 15% of cases. exploiting pcr-based methods, we investigated td pathogens with a focus on asymptomatic travellers and severity of symptoms. pre- and post-travel stools of 382 travellers with no history of antibiotic use during travel were analysed with a multiplex quantitative pcr for salmonella, yersinia, campylobacter, shigell ... | 2016 | 26970046 |
| diversity of clinical and environmental isolates of vibrio cholerae in natural transformation and contact-dependent bacterial killing indicative of type vi secretion system activity. | the bacterial pathogen vibrio cholerae can occupy both the human gut and aquatic reservoirs, where it may colonize chitinous surfaces that induce the expression of factors for three phenotypes: chitin utilization, dna uptake by natural transformation, and contact-dependent bacterial killing via a type vi secretion system (t6ss). in this study, we surveyed a diverse set of 53 isolates from different geographic locales collected over the past century from human clinical and environmental specimens ... | 2016 | 26944842 |
| transcriptional repression of the vc2105 protein by vibrio fadr suggests that it is a new auxiliary member of the fad regulon. | recently, our group along with others reported that the vibrio fadr regulatory protein is unusual in that, unlike the prototypical fadr product of escherichia coli, which has only one ligand-binding site, vibrio fadr has two ligand-binding sites and represents a new mechanism for fatty acid sensing. the promoter region of the vc2105 gene, encoding a putative thioesterase, was mapped, and a putative fadr-binding site (aa ctg gta aga gca ctt) was proposed. different versions of the fadr regulatory ... | 2016 | 26944841 |
| surveillance for foodborne disease outbreaks in iran, 2006-2011. | the outbreaks of foodborne diseases is a major health problem and occur daily in all countries, from the most to the least developed. this study is the first report of foodborne outbreaks in iran that carried out from 2006 to 2011. | 2015 | 26913248 |
| epidemiologic and drug resistance pattern of vibrio cholerae o1 biotype el tor, serotype ogawa, in the 2011 cholera outbreak, in alborz province, iran. | although the national guidelines recommend special antibiotics, based on the antibiogram of national reference laboratory, it seems that, because of uncontrolled usage of antibiotics in the society and due to the changes in the serotypes causing the disease, it is essential to monitor the status of drug resistance, permanently, and to revise the current prescriptions guidelines. | 2015 | 26855737 |
| cholera toxin b subunit pentamer reassembled from escherichia coli inclusion bodies for use in vaccination. | the cholera toxin b subunit (ctb) is secreted in its pentameric form from escherichia coli if its leader peptide is replaced with one of e. coli origin. however, the secretion of the pentamer is generally severely impaired when the molecule is mutated or fused to a foreign peptide. therefore, we attempted to regenerate pentameric ctb from the inclusion bodies (ibs) of e. coli. stepwise dialysis of the ibs solubilized in guanidine hydrochloride predominantly generated soluble high-molecular-mass ... | 2016 | 26828455 |
| characterization of vcc-1, a novel ambler class a carbapenemase from vibrio cholerae isolated from imported retail shrimp sold in canada. | one of the core goals of the canadian integrated program for antimicrobial resistance surveillance (cipars) is to monitor major meat commodities for antimicrobial resistance. targeted studies with methodologies based on core surveillance protocols are used to examine other foods, e.g., seafood, for antimicrobial resistance to detect resistances of concern to public health. here we report the discovery of a novel ambler class a carbapenemase that was identified in a nontoxigenic strain of vibrio ... | 2016 | 26824956 |
| cytoplasmic heme-binding protein (hutx) from vibrio cholerae is an intracellular heme transport protein for the heme-degrading enzyme, hutz. | hutz is a cytoplasmic heme-binding protein from vibrio cholerae. although we have previously identified hutz as a heme-degrading enzyme [uchida, t., et al. (2012) chem. commun. 48, 6741-6743], the heme transport protein for hutz remained unknown. to identify the heme transport protein for hutz, we focused on the heme utilization operon, hutwxz. to this end, we constructed an expression system for hutx in escherichia coli and purified it to homogeneity. an absorption spectral analysis demonstrate ... | 2016 | 26807477 |
| antibiotic use, its resistance in nepal and recommendations for action: a situation analysis. | antibiotics are crucial, life-saving medicines in the fight against infectious disease, but resistance to these drugs is growing all over. this article presents key findings from a detailed situation analysis produced by the global antibiotic resistance partnership (garp)-nepal working group. in the absence of nationally-representative surveillance, it is not possible to fully describe antibiotic resistance in the country, but many important bacterial pathogens are highly resistant to most first ... | 2016 | 26744193 |
| structural characterization and biomedical properties of sulfated polysaccharide from the gladius of sepioteuthis lessoniana (lesson, 1831). | sulfated polysaccharide was extracted from the internal shell (gladius) of sepioteuthis lessoniana. the sulfated polysaccharide contained 61.3% of carbohydrate, 0.8% of protein, 28.2% of ash and 1.33% of moisture respectively. the elemental composition was analyzed using chns/o analyzer. the molecular weight of sulfated polysaccharide determined through page was found to be as 66 kda. monosaccharides analysis revealed that sulfated polysaccharide was composed of rhamnose, galactose, xylose and g ... | 2016 | 26724686 |
| evaluation of antibacterial activity of plant mediated cao nanoparticles using cissus quadrangularis extract. | an assessment of antibacterial activity of greenly synthesized nanoparticles using aqueous stem extract of cissus quadrangularis was carried out. the synthesized nanoparticles were characterized by uv-vis spectroscopy, sem, xrd, ftir and further subjected for antibacterial activity against the pathogens staphylococcus aureus, escherichia coli, klebsiella pneumoniae, pseudomonas aeruginosa, salmonella typhi, shigella dysenteriae and vibrio cholerae. the sem photograph represents cubic and hexagon ... | 2016 | 26723000 |
| prediction of intra-species protein-protein interactions in enteropathogens facilitating systems biology study. | protein-protein interactions in escherichia coli (e. coli) has been studied extensively using high throughput methods such as tandem affinity purification followed by mass spectrometry and yeast two-hybrid method. this can in turn be used to understand the mechanisms of bacterial cellular processes. however, experimental characterization of such huge amount of interactions data is not available for other important enteropathogens. here, we propose a support vector machine (svm)-based prediction ... | 2015 | 26717407 |
| biochemical characterization of an α1,2-colitosyltransferase from escherichia coli o55:h7. | colitose, also known as 3,6-dideoxy-l-galactose or 3-deoxy-l-fucose, is one of only five naturally occurring 3,6-dideoxyhexoses. colitose was found in lipopolysaccharide of a number of infectious bacteria, including escherichia coli o55 & o111 and vibrio cholera o22 & o139. to date, no colitosyltransferase (colt) has been characterized, probably due to the inaccessibility of the sugar donor, gdp-colitose. in this study, starting with chemically prepared colitose, 94.6 mg of gdp-colitose was prep ... | 2016 | 26703456 |
| antimicrobial activity of the essential oil from the leaves and seeds of coriandrum sativum toward food-borne pathogens. | the increasing incidence of drug-resistant pathogens and toxicity of existing antibacterial compounds has drawn attention toward the antimicrobial activity of natural products. the purpose of this study is to evaluate the antimicrobial activity of the essential oil of the leaves and seeds of coriandrum sativum. the five strains of bacteria comprising escherichia coli, staphylococcus aureus, yersinia enterocolitica, salmonella enterica and vibrio cholerae were used for the antibacterial tests. in ... | 2015 | 26684163 |
| crystal structure and kinetic studies of a tetrameric type ii β-carbonic anhydrase from the pathogenic bacterium vibrio cholerae. | carbonic anhydrase (ca) is a zinc enzyme that catalyzes the reversible conversion of carbon dioxide to bicarbonate (hydrogen carbonate) and a proton. cas have been extensively investigated owing to their involvement in numerous physiological and pathological processes. currently, ca inhibitors are widely used as antiglaucoma, anticancer and anti-obesity drugs and for the treatment of neurological disorders. recently, the potential use of ca inhibitors to fight infections caused by protozoa, fung ... | 2015 | 26627652 |
| vibrio spp. from macrobrachium amazonicum prawn farming are inhibited by moringa oleifera extracts. | to investigate the in vitro antimicrobial potential of extracts of stem, leaves, flowers, pods and seeds of moringa oleifera (m. oleifera) against vibrio spp. from hatchery water and the prawn macrobrachium amazonicum. | 2015 | 26614991 |
| an expeditious synthesis of blood-group antigens, abo histo-blood group type ii antigens and xenoantigen oligosaccharides with amino type spacer-arms. | blood group oligosaccharides are one of the most clinically important antigen families and they may also act as secondary ligands for bacterial toxins from escherichia coli and vibrio cholerae. herein we report the synthesis of spacered (sp = ch2ch2ch2nh2) glycosides of a antigen {α-d-galnac-(l→3)-[α-l-fuc-(l→2)]-β-d-gal-}, b antigen{α-d-gal-(l→3)-[α-l-fuc-(l→2)]-β-d-gal-}, lewisx{α-d-gal-(l→4)-[α-l-fuc-(l→3)]-β-d-glcnac-}, a type-ii {α-d-galnac-(l→3)-[α-l-fuc-(l→2)]-β-d-gal-(1→4)-β-d-glcnac-}, ... | 2016 | 26572140 |
| established microbial colonies can survive type vi secretion assault. | type vi secretion (t6s) is a cell-to-cell injection system that can be used as a microbial weapon. t6s kills vulnerable cells, and is present in close to 25% of sequenced gram-negative bacteria. to examine the ecological role of t6s among bacteria, we competed self-immune t6s+ cells and t6s-sensitive cells in simulated range expansions. as killing takes place only at the interface between sensitive and t6s+ strains, while growth takes place everywhere, sufficiently large domains of sensitive cel ... | 2015 | 26485125 |
| attributes of carbapenemase encoding conjugative plasmid pndm-sal from an extensively drug-resistant salmonella enterica serovar senftenberg. | a carbapenem resistant salmonella enterica serovar senftenberg isolate bch 2406 was isolated from a diarrheal child attending an outpatient unit of b.c. roy hospital in kolkata, india. this isolate was positive for the bla ndm-1 in the pcr assay, which was confirmed by amplicon sequencing. except for tetracycline, this isolate was resistant to all the tested antimicrobials. the bla ndm-1 was found to be located on a 146.13-kb mega plasmid pndm-sal, which could be conjugally transferred into esch ... | 2015 | 26441902 |
| biosynthesis, characterisation and antimicrobial activity of silver nanoparticles using hibiscus rosa-sinensis petals extracts. | green synthesis of metallic nanoparticles has lured the world from the chemical and physical approaches owing to its rapid, non-hazardous and economic aspect of production mechanism. in this study, silver nanoparticles (agnps) were synthesised using petal extracts of hibiscus rosa-sinensis. the agnps displayed characteristic surface plasmon resonance peak at around 421 nm having a mean particle size of 76.25±0.17 nm and carried a charge of -41±0.2 mv. the x-ray diffraction patterns displayed typ ... | 2015 | 26435282 |
| a dye-decolorizing peroxidase from vibrio cholerae. | the dye-decolorizing peroxidase (dyp) protein from vibrio cholerae (vcdyp) was expressed in escherichia coli, and its dyp activity was assayed by monitoring degradation of a typical anthraquinone dye, reactive blue 19 (rb19). its kinetic activity was obtained by fitting the data to the michaelis-menten equation, giving kcat and km values of 1.3 ± 0.3 s(-1) and 50 ± 20 μm, respectively, which are comparable to those of other dyp enzymes. the enzymatic activity of vcdyp was highest at ph 4. a muta ... | 2015 | 26431465 |
| response of vibrio cholerae to the catecholamine hormones epinephrine and norepinephrine. | in escherichia coli or salmonella enterica, the stress-associated mammalian hormones epinephrine (e) and norepinephrine (ne) trigger a signaling cascade by interacting with the qsec sensor protein. here we show that vibrio cholerae, the causative agent of cholera, exhibits a specific response to e and ne. these catecholates (0.1 mm) enhanced the growth and swimming motility of v. cholerae strain o395 on soft agar in a medium containing calf serum, which simulated the environment within the host. ... | 2015 | 26416829 |
| survival of enteroaggregative escherichia coli and vibrio cholerae in frozen and chilled foods. | enteroaggregative escherichia coli (eaec) and vibrio cholerae are common bacteria that infect people in developing countries. nowadays, food preservation by freezing and refrigeration are very common practices that extend the shelf life of food products. unfortunately, eaec and v. cholerae are suspected to survive at low temperatures. | 2015 | 26322875 |
| dual inducer signal recognition by an mlc homologue. | the mlc transcription factor in escherichia coli controls the expression of the phosphotransferase system genes implicated in the transport of glucose into the cell. transport of glucose derepresses mlc-repressed genes by provoking the sequestration of mlc to the membrane, via an interaction with the dephosphorylated eiib domain of the glucose transporter, ptsg. nagc, a paralogue of mlc in e. coli, regulates the use of the amino sugar n-acetylglucosamine (glcnac). both mlc and nagc are members o ... | 2015 | 26293172 |
| functional relbe-family toxin-antitoxin pairs affect biofilm maturation and intestine colonization in vibrio cholerae. | toxin-antitoxin (ta) systems are small genetic elements that typically encode a stable toxin and its labile antitoxin. these cognate pairs are abundant in prokaryotes and have been shown to regulate various cellular functions. vibrio cholerae, a human pathogen that is the causative agent of cholera, harbors at least thirteen ta loci. while functional higba, parde have been shown to stabilize plasmids and phd/doc to mediate cell death in v. cholerae, the function of seven relbe-family ta systems ... | 2015 | 26275048 |
| crystal structure and activity of protein l-isoaspartyl-o-methyltransferase from vibrio cholerae, and the effect of adohcy binding. | the repair enzyme protein l-isoaspartyl-o-methyltransferase (pimt) is widely distributed in various organisms. pimt catalyzes s-adenosylmethionine (adomet) dependent methylation of abnormal l-isoaspartyl residues, formed by the deamidation of asparagines and isomerization of aspartates. we report the crystal structure of pimt of vibrio cholerae (vcpimt), the aetiological agent for cholera, complexed with the demethylated cofactor s-adenosyl-l-homocysteine (adohcy) to 2.05 å resolution. a stretch ... | 2015 | 26255776 |
| molecular dissection of the essential features of the origin of replication of the second vibrio cholerae chromosome. | vibrionaceae family members are interesting models for studying dna replication initiation, as they contain two circular chromosomes. chromosome ii (chrii) replication is governed by two evolutionarily unique yet highly conserved elements, the origin dna sequence oricii and the initiator protein rctb. the minimum functional region of oricii, oricii-min, contains multiple elements that are bound by rctb in vitro, but little is known about the specific requirements for individual elements during o ... | 2015 | 26220967 |
| regulation of biofilm formation and cellular buoyancy through modulating intracellular cyclic di-gmp levels in engineered cyanobacteria. | the second messenger cyclic dimeric (3'→5') gmp (cyclic di-gmp or c-di-gmp) has been implicated in the transition between motile and sessile lifestyles in bacteria. in this study, we demonstrate that biofilm formation, cellular aggregation or flocculation, and cellular buoyancy are under the control of c-di-gmp in synechocystis sp. pcc 6803 (synechocystis) and fremyella diplosiphon. synechocystis is a unicellular cyanobacterium and displays lower levels of c-di-gmp; f. diplosiphon is filamentous ... | 2016 | 26192200 |
| the roles of inflammation, nutrient availability and the commensal microbiota in enteric pathogen infection. | the healthy human intestine is colonized by as many as 1014 bacteria belonging to more than 500 different species forming a microbial ecosystem of unsurpassed diversity, termed the microbiota. the microbiota's various bacterial members engage in a physiological network of cooperation and competition within several layers of complexity. within the last 10 years, technological progress in the field of next-generation sequencing technologies has tremendously advanced our understanding of the wide v ... | 2015 | 26185088 |
| a conserved pattern of primer-dependent transcription initiation in escherichia coli and vibrio cholerae revealed by 5' rna-seq. | transcription initiation that involves the use of a 2- to ~4-nt oligoribonucleotide primer, "primer-dependent initiation," (pdi) has been shown to be widely prevalent at promoters of genes expressed during the stationary phase of growth in escherichia coli. however, the extent to which pdi impacts e. coli physiology, and the extent to which pdi occurs in other bacteria is not known. here we establish a physiological role for pdi in e. coli as a regulatory mechanism that modulates biofilm formati ... | 2015 | 26131907 |
| chemoenzymatic syntheses of sialylated oligosaccharides containing c5-modified neuraminic acids for dual inhibition of hemagglutinins and neuraminidases. | a fast chemoenzymatic synthesis of sialylated oligosaccharides containing c5-modified neuraminic acids is reported. analogues of gm3 and gm2 ganglioside saccharidic portions where the acetyl group of neunac has been replaced by a phenylacetyl (phac) or a propanoyl (prop) moiety have been efficiently prepared with metabolically engineered e. coli bacteria. gm3 analogues were either obtained by chemoselective modification of biosynthetic n-acetyl-sialyllactoside (gm3 nac) or by direct bacterial sy ... | 2015 | 26088695 |
| fabv/triclosan is an antibiotic-free and cost-effective selection system for efficient maintenance of high and medium-copy number plasmids in escherichia coli. | antibiotic resistance genes and antibiotics are frequently used to maintain plasmid vectors in bacterial hosts such as escherichia coli. due to the risk of spread of antibiotic resistance, the regulatory authorities discourage the use of antibiotic resistance genes/antibiotics for the maintenance of plasmid vectors in certain biotechnology applications. overexpression of e. coli endogenous fabi gene and subsequent selection on triclosan has been proposed as a practical alternative to traditional ... | 2015 | 26057251 |
| gut microbial succession follows acute secretory diarrhea in humans. | disability after childhood diarrhea is an important burden on global productivity. recent studies suggest that gut bacterial communities influence how humans recover from infectious diarrhea, but we still lack extensive data and mechanistic hypotheses for how these bacterial communities respond to diarrheal disease and its treatment. here, we report that after vibrio cholerae infection, the human gut microbiota undergoes an orderly and reproducible succession that features transient reversals in ... | 2015 | 25991682 |