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role of escherichia coli in acute diarrhoea in tribal preschool children of central india.five hundred and eighty preschool children belonging to tribal areas of madhya pradesh were followed up daily for the presence of diarrhoea for a period of 1 year. in all, 1236 episodes of diarrhoea were recorded with an average of 2.13 episodes per child per year. stool samples were collected during 780 episodes. they were cultured to isolate escherichia coli as well as non-e. coli enteropathogens. ten different genes were detected to identify all diarrhoeagenic e. coli using multiplex polymera ...200818173783
diarrheagenic escherichia coli and shigella strains isolated from children in a hospital case-control study in hanoi, vietnam.this case-control study detected and characterized shigella and diarrheagenic escherichia coli (dec) types among vietnamese children less than 5 years old. in 249 children with diarrhea and 124 controls, shigella spp. was an important cause of diarrhea (p < 0.05). we used multiplex pcr and dna probes to detect enteroinvasive e. coli (eiec), enteroaggregative e. coli (eaggec), enteropathogenic e. coli (epec), attaching and effacing e. coli (a/eec), verocytotoxin-producing e. coli (vtec), and ente ...200818174300
full structural characterization of shigella flexneri m90t serotype 5 wild-type r-lps and its delta galu mutant: glycine residue location in the inner core of the lipopolysaccharide.shigella flexneri is a gram-negative bacterium responsible for serious enteric infections that occur mainly in the terminal ileum and colon. high interest in shigella, as a human pathogen, is driven by its antibiotic resistance and the necessity to develop a vaccine against its infections. vaccines of the last generation use carbohydrate moieties of the lipopolysaccharide as probable candidates. for this reason, the primary structure of the core oligosaccharide from the r-lps produced by s. flex ...200818174310
ph sensitivity of type iii secretion system tip proteins.many pathogenic gram-negative bacteria employ type iii secretion systems to transport proteins into the host cell membrane and cytoplasm to subvert normal cellular functions. the type iii secretion apparatus consists of a basal body spanning the inner and outer bacterial membranes and a needle which extends away from the bacterium. recent work has found that a special class of proteins localizes to the tip of the needle to control secretion of effector proteins. five of these tip proteins are ip ...200818175320
international foodborne outbreak of shigella sonnei infection in airline passengers.during 22-24 august 2004, an outbreak of shigella sonnei infection affected air travellers who departed from hawaii. forty-seven passengers with culture-confirmed shigellosis and 116 probable cases who travelled on 12 flights dispersed to japan, australia, 22 us states, and american samoa. all flights were served by one caterer. pulsed-field gel electrophoresis of all 29 s. sonnei isolates yielded patterns that matched within one band. food histories and menu reviews identified raw carrot served ...200918177516
differential activation of human tlr4 by escherichia coli and shigella flexneri 2a lipopolysaccharide: combined effects of lipid a acylation state and tlr4 polymorphisms on signaling.the lipid a of lps activates tlr4 through an interaction with myeloid differentiation protein-2 (md-2) and the degree of lipid a acylation affects tlr4 responsiveness. two tlr4 single nucleotide polymorphisms (asp299gly and thr399ile) have been associated with lps hyporesponsiveness. we hypothesized that the combination of hypoacylation and these single nucleotide polymorphisms would exhibit a compounded effect on tlr4 signaling. hek293t transfectants expressing wild-type or polymorphic tlr4 wer ...200818178854
death from multi-resistant shigelloses: a case study from fiji.death from shigellosis is rare in developed countries, however it causes over a million deaths in developing countries worldwide annually. death from shigellosis is rare in fiji. however, the global problem of emerging multi-drug resistance raises some issues about the management of shigellosis in this country. within fiji, shigella is a notifiable disease. the fiji ministry of health recorded 68 cases of shigella in 1996, 173 cases in 1997 and 334 cases in 1998 (no data available for 1999). the ...200618181399
serotonin, inflammation, and ibs: fitting the jigsaw together?unexplained diarrhoea is a frequent indication for gastroenterologic referral, and after full investigation the most common final diagnosis is irritable bowel syndrome (ibs). some patients with ibs describe an acute onset of symptoms following infective gastroenteritis. postinfective ibs affects 7% to 31% of individuals infected, and appears to be a nonspecific response to injury which has been reported following salmonella-, campylobacter-, and shigella-related ibs. the strongest risk factor fo ...200718185071
cytoplasmic targeting of ipac to the bacterial pole directs polar type iii secretion in shigella.type iii secretion (t3s) systems are largely used by pathogenic gram-negative bacteria to inject multiple effectors into eukaryotic cells. upon cell contact, these bacterial microinjection devices insert two t3s substrates into host cell membranes, forming a so-called 'translocon' that is required for targeting of type iii effectors in the cell cytosol. here, we show that secretion of the translocon component ipac of invasive shigella occurs at the level of one bacterial pole during cell invasio ...200818188151
bacterial actin assembly requires toca-1 to relieve n-wasp autoinhibition.actin polymerization in the mammalian cytosol can be locally activated by mechanisms that relieve the autoinhibited state of n-wasp, an initiator of actin assembly, a process that also requires the protein toca-1. several pathogenic bacteria, including shigella, exploit this host feature to infect and disseminate efficiently. the shigella outer membrane protein icsa recruits n-wasp, which upon activation at the bacterial surface mediates localized actin polymerization. the molecular role of toca ...200818191793
antibacterial activities and cytotoxicity of terpenoids isolated from spirostachys africana.spirostachys africana sond. stem bark is used traditionally for the treatment of diarrhoea and dysentery in limpopo province of south africa. bioassay-guided fractionation of ethanolic extract from bark of spirostachys africana led to the isolation of four known compounds, two triterpenoids, compound 1 [d-friedoolean-14-en-oic acid (3-acetyl aleuritolic acid)] and compound 2 (lupeol), and two diterpenes, compound 3 [ent-2,6alpha-dihydroxy-norbeyer-1,4,15-trien-3-one (diosphenol 2)] and compound ...200818191928
the chaperone ipgc copurifies with the virulence regulator mxie.the expression of a subset of shigella flexneri virulence genes is dependent upon a cytoplasmic chaperone, ipgc, and an activator from the arac/xyls family, mxie. in this paper, we report that the chaperone forms a specific and stable heteromer with mxie.200818192384
role and regulation of iron-sulfur cluster biosynthesis genes in shigella flexneri virulence.shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called suf and isc. s. flexneri strains containing deletion mutations in the entire suf operon (ur011) or the iscsua genes (ur022) were constructed. both mutants were defective in surviving exposure to oxidative stress. the suf mutant showed growth that was comparable to that of the parental strain in both iron-replete and iron-limiting media; however, the isc mutant show ...200818195027
evaluation of faecal occult blood test and lactoferrin latex agglutination test in screening hospitalized patients for diagnosing inflammatory and non-inflammatory diarrhoea in dhaka, bangladesh.inflammatory diarrhoea (id) resulting from shigella, salmonella, campylobacter and entamoeba histolytica requires specific diagnosis for therapy. differentiation between id and non-inflammatory diarrhoea (nid) is often not clinically possible. a faecal occult blood test (fobt) correlates with faecal leucocytes. lactoferrin indicates an inflammatory process as a marker for faecal leucocytes. we evaluated diagnostic values of lactoferrin latex agglutination test (lt) either alone or in combination ...200818196900
new information about pediatric foodborne infections: the view from foodnet.diarrheal illness is a significant burden to children and their parents. recent studies describing the etiologic agents that cause diarrheal illness and examining the risk factors for the most common bacterial enteric pathogens are presented.200818197044
molecular pathogenesis of shigella spp.: controlling host cell signaling, invasion, and death by type iii secretion.shigella spp. are gram-negative pathogenic bacteria that evolved from harmless enterobacterial relatives and may cause devastating diarrhea upon ingestion. research performed over the last 25 years revealed that a type iii secretion system (t3ss) encoded on a large plasmid is a key virulence factor of shigella flexneri. the t3ss determines the interactions of s. flexneri with intestinal cells by consecutively translocating two sets of effector proteins into the target cells. thus, s. flexneri co ...200818202440
a comparison of self-reported joint symptoms following infection with different enteric pathogens: effect of hla-b27.we conducted a case-case comparison study to estimate the attack-rate of reactive joint pain (jprea) following intestinal infections, and evaluated whether the susceptibility and severity of joint symptoms was associated with the tissue-type hla-b27.200818203313
phase 1 clinical trial of live attenuated shigella dysenteriae type-1 deltaicsa deltaent deltafep deltastxa:hgr oral vaccine sc599 in healthy human adult volunteers.twenty-eight adults received between 10(2) and 10(8)colony forming units of live shigella dysenteriae type-1 vaccine sc599, attenuated by deletion of invasion (icsa), iron chelation (ent, fep) and shiga toxin a-subunit (stxa) genes, followed by ciprofloxacin on day 4. dose-independent diarrhea or change in bowel habit was seen in 3 subjects, without dysentery, vaccinaemia or serious adverse events. hematology and biochemical parameters were unchanged. doses of 10(5) or greater induced dose-indep ...200818207287
a functional genomic yeast screen to identify pathogenic bacterial proteins.many bacterial pathogens promote infection and cause disease by directly injecting into host cells proteins that manipulate eukaryotic cellular processes. identification of these translocated proteins is essential to understanding pathogenesis. yet, their identification remains limited. this, in part, is due to their general sequence uniqueness, which confounds homology-based identification by comparative genomic methods. in addition, their absence often does not result in phenotypes in virulenc ...200818208325
nitrate and bacterial contamination in well waters in vinh phuc province, vietnam.measurements were made of the nitrate concentration and bacterial contamination of groundwater samples taken from both dug wells and bores in the commune of hop thinh', in the administrative district of vinh phuc, vietnam. a significant number (18%) of samples had nitrate concentrations in excess of the who guideline value for drinking water of 50 mg l(-1), with a higher proportion in the dug wells (29%) than the bores (3.8%). high concentrations of thermotolerant coliforms were found in many of ...200818209289
selection and validation of a multilocus variable-number tandem-repeat analysis panel for typing shigella spp.the shigella genus has historically been separated into four species, based on biochemical assays. the classification within each species relies on serotyping. recently, genome sequencing and dna assays, in particular the multilocus sequence typing (mlst) approach, greatly improved the current knowledge of the origin and phylogenetic evolution of shigella spp. the shigella and escherichia genera are now considered to belong to a unique genomospecies. multilocus variable-number tandem-repeat (vnt ...200818216214
[antimicrobial effect of 4-(adamantyl-1)-1-(1-aminobutyl)benzol].antimicrobial activity in vitro of adamantine derivative in respect of aerobic and anaerobic microorganisms has been studied. in these conditions gram-positive bacteria and some representatives of gram-negative microorganisms (shigella flexneri, s. newvcastle, enterobacter aerogenes etc.) had maximal sensitivity (mic 0.6-5.0 and 0.1-5.0 mg/ml, respectively). pseudomonas aeruginosa were resistant to this substance (mic >1 mg/ml).200718217353
nlrx1 is a mitochondrial nod-like receptor that amplifies nf-kappab and jnk pathways by inducing reactive oxygen species production.nod-like receptors (nlrs) are a family of intracellular sensors of microbial- or danger-associated molecular patterns. here, we report the identification of nlrx1, which is a new member of the nlr family that localizes to the mitochondria. nlrx1 alone failed to trigger most of the common signalling pathways, including nuclear factor-kappab (nf)-kappab- and type i interferon-dependent cascades, but could potently trigger the generation of reactive oxygen species (ros). importantly, nlrx1 synergis ...200818219313
[season and age related structure of acute intestinal infections morbidity in the russian federation].to study seasonal and age features of etiological structure of acute intestinal infections (aii) in the territory of the rf.200718219965
regulation of expression and secretion of nleh, a new non-locus of enterocyte effacement-encoded effector in citrobacter rodentium.together with enterohemorrhagic escherichia coli and enteropathogenic escherichia coli, citrobacter rodentium is a member of the attaching-and-effacing (a/e) family of bacterial pathogens. a/e pathogens use a type iii secretion system (t3ss) to translocate an assortment of effector proteins, encoded both within and outside the locus of enterocyte effacement (lee), into the colonized host cell, leading to the formation of a/e lesions and disease. here we report the identification and characteriza ...200818223087
the origin of a novel gene through overprinting in escherichia coli.overlapped genes originate by a) loss of a stop codon among contiguous genes coded in different frames; b) shift to an upstream initiation codon of one of the contiguous genes; or c) by overprinting, whereby a novel open reading frame originates through point mutation inside an existing gene. although overlapped genes are common in viruses, it is not clear whether overprinting has led to new genes in prokaryotes.200818226237
actin-based motility assay.actin-based movement can be reconstituted by using microspheres functionalized with the enzymes n-wasp or acta, which use the arp2/3 complex and actin to catalyze the formation of a branched actin filament network that is maintained in rapid turnover by three proteins (capping protein, profilin, and adf). the particles continuously initiate filament assembly at their surface and are propelled, mimicking bacteria or the leading edge of motile cells. this biomimetic assay offers advantages over ap ...200418228440
estimation of the diagnostic accuracy of the inva-gene-based pcr technique and a bacteriological culture for the detection of salmonella spp. in caecal content from slaughtered pigs using bayesian analysis.the goal of this study was to estimate the accuracy of the inva-gene-based polymerase chain reaction (pcr) and a culture technique based on pre-enrichment with buffered peptone water, three selective enrichment media (selenite, tetrathionate and rappaport-vassiliadis broths) and four selective, solid media (xylose-lysine-tergitol-4, salmonella/shigella, hekton-enteric and macconkey), for the detection of salmonella organisms from caecal samples from slaughter pigs. for this purpose a latent-clas ...200818234030
aeromonas-related diarrhoea in nasarawa, nigeria.two hundred and fifty volunteer patients attending 5 major hospitals in nasarawa town, nasarawa state, nigeria were involved in this study to determine the prevalence of aeromonas spp in persons with diarrhoea. the study population consisted of 133 males and 117 females between the ages of 0-70 years.200718240708
cmy-2-type plasmid-mediated ampc beta-lactamase finally emerging in argentina. 200818242960
on-line monitoring of microbial volatile metabolites by proton transfer reaction-mass spectrometry.a method for analysis of volatile organic compounds (vocs) from microbial cultures was established using proton transfer reaction-mass spectrometry (ptr-ms). a newly developed sampling system was coupled to a ptr-ms instrument to allow on-line monitoring of vocs in the dynamic headspaces of microbial cultures. the novel ptr-ms method was evaluated for four reference organisms: escherichia coli, shigella flexneri, salmonella enterica, and candida tropicalis. headspace vocs in sampling bottles con ...200818245241
eukaryotic expression and antimicrobial spectrum determination of the peptide tachyplesin ii.ta0-a, the gene encoding the mature antimicrobial peptide tachyplesin ii, was engineered to optimize the coding sequence according to codon usage bias in yeast. ta0-a was efficiently expressed in the methylotrophic yeast pichia pastoris strain smd1168. the recombinant peptide ta0 reached 150mg/l after methanol induction for 6 d. ta0 was rapidly purified to homogeneity by a single step of size-exclusion chromatography. the minimal lethal concentrations of ta0 to the escherichia coli strain k12 wa ...200818249136
traveler's myopericarditis.colitis caused by shigella is an uncommon etiology of infectious diarrhea in developed countries, usually presenting as traveler's diarrhea. aside from clinical intestinal manifestations, shigellosis can present with a wide variety of extra-intestinal symptoms. we present the case of a 38-year-old man with diarrhea, fever, and chest pain that started after a holiday in cape verde (africa). blood samples revealed an increase in cardiac enzymes. an electrocardiogram revealed a widespread elevation ...200818249314
[effects of huoxiang zhengqi liquid on enteric mucosal immune responses in mice with bacillus dysenteriae and salmonella typhimurium induced diarrhea].to explore the effects of huoxiang zhengqi liquid (hxzq) on enteric mucosal immune responses in mice with bacillus dysenteriae and salmonella typhimurium induced diarrhea (bsd).200718257268
timeliness of enteric disease surveillance in 6 us states.we reviewed timeline information for a sample of salmonella spp., shigella spp., campylobacter spp., and escherichia coli o157:h7 cases and all confirmed foodborne outbreaks reported in 6 states during 2002. increasing the timeliness of case follow-up, molecular subtyping, and linkage of results are critical to reducing delays in the investigation of foodborne outbreaks.200818258128
[shigella spp infections in children living in the metropolitan region, chile, during summer of 2004-2005].shigella spp is a frequent cause of diarrhea in children. antimicrobials decrease the duration of diarrhea and pathogen excretion. however, the increasing resistance limits their therapeutic value.200818259649
[shigellosis outbreak with 146 cases related to a fair].on september 3, 2005, the ciudad real public health service (spain) received a report of 20 cases of gastroenteritis in the municipality of daimiel. we conducted an investigation to determine the cause or causes of the outbreak and to implement control measures. most of the cases involved young people who visited the municipality's fair.200818261440
extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells.shigella, the causative agent of bacillary dysentery, invades colonic epithelial cells to elicit an intense inflammatory reaction leading to destruction of the mucosa. atp-dependent paracrine signalling induced by connexin (cx) hemichannel opening was previously shown to favor shigella flexneri invasion and dissemination in transfectants of hela cells [g. tran van nhieu, c. clair, r. bruzzone, m. mesnil, p. sansonetti and l. combettes. (2003). connexin-dependent intercellular communication incre ...200818267319
retrograde traffic in the biosynthetic-secretory route.in the biosynthetic-secretory route from the rough endoplasmic reticulum, across the pre-golgi intermediate compartments, the golgi apparatus stacks, trans golgi network, and post-golgi organelles, anterograde transport is accompanied and counterbalanced by retrograde traffic of both membranes and contents. in the physiologic dynamics of cells, retrograde flow is necessary for retrieval of molecules that escaped from their compartments of function, for keeping the compartments' balances, and mai ...200818270728
conserved amphiphilic feature is essential for periplasmic chaperone hdea to support acid resistance in enteric bacteria.the extremely acidic environment of the mammalian stomach (ph 1-3) represents a stressful challenge for enteric pathogenic bacteria, including escherichia coli, shigella and brucella. the hdea (hns-dependent expression a) gene was found to be crucial for the survival of these enteric bacteria under extremely low ph conditions. we recently demonstrated that hdea is able to exhibit chaperone-like activity exclusively within the stomach ph range by transforming from a well-folded conformation at hi ...200818271752
reactive arthritis following culture-confirmed infections with bacterial enteric pathogens in minnesota and oregon: a population-based study.to describe the epidemiology and clinical spectrum of reactive arthritis (rea) following culture-confirmed infection with bacterial enteric pathogens in a population-based study in the usa.200818272671
immunogenicity and efficacy of highly purified invasin complex vaccine from shigella flexneri 2a.development of a subunit vaccine for shigellosis requires identification of protective antigens and delivering these antigens in a manner that stimulates immunity comparable to that induced by natural infection. the shigella invasin complex (invaplex) vaccine is an ion-exchange-purified extract from virulent shigella that consists of lps and several other proteins, including the invasins ipab and ipac. intranasal delivery of invaplex stimulates protective immunity in small animal models for shig ...200818276045
distribution and antibiotic susceptibility of shigella isolates in bangui, central african republic.we conducted a prospective study in four urban health care centres between january 2004 and november 2005 to determine the distribution and susceptibility patterns of shigella strains causing invasive diarrhoea in bangui, central african republic. of the 155 shigella isolated, shigella flexneri (51%) and shigella dysenteriae (30%) were the most common and the most resistant to usual antibiotics, including amoxicillin, sulphamethoxazole-trimethoprim and chloramphenicol. though multi-drug resistan ...200818282240
reaching a consensus on management practices and vaccine development targets for mitigation of infectious diarrhoea among deployed us military forces.this study is part of a research effort to identify and quantify factors related to the cost-effectiveness of a vaccine acquisition strategy to reduce the burden of infectious diarrhoea on us military personnel deployed overseas. where evidence is lacking in the scientific literature, or considerable uncertainty exists, it is often necessary to develop best estimates with ranges of certainty. to this end, a modified 'delphi' survey technique to obtain the best estimates for uncertain parameters ...200818284518
comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with salmonella enteritidis by eric-pcr.to analyze the difference of intestinal microbial community diversity between healthy and (s. enteritidis) orally infected ducklings.200818286697
the shf gene of a shigella flexneri homologue on the virulent plasmid paa2 of enteroaggregative escherichia coli 042 is required for firm biofilm formation.enteroaggregative escherichia coli (eaec) is an increasingly important cause of diarrhea in both developing and industrialized countries, and is characterized by strong biofilm formation on the intestinal mucosa. sequencing of the virulent plasmid paa2 of the prototype eaec 042 revealed a cluster of three open reading frames (orfs; shf, capu, and virk) ca. 93% identical to a similar cluster located in shigella flexneri. the function of the first orf shf protein is not known, but the closest well ...200818293034
terpenoid compositions, and antioxidant and antimicrobial properties of the rhizome essential oils of different hedychium species.a phytochemical study of the rhizome essential oils of four different hedychium species was performed by means of gc and gc/ms analyses. h. ellipticum mainly contained 1,8-cineole, sabinene, and terpin-4-ol, while h. aurantiacum possessed terpin-4-ol, para-cymene, and bornyl acetate as the major entities. similarly, trans-meta-mentha-2,8-diene and linalool were noticed in h. coronarium. three different collections (i-iii) of h. spicatum showed amazing differences in the relative contents of thei ...200818293443
diverse antimicrobial killing by enterococcus faecium e 50-52 bacteriocin.an effective bacteriocin was identified and characterized. lactic acid bacteria were screened against campylobacter jejuni. one bacteriocin producer, enterococcus faecium (nrrl b-30746), was studied. the isolate was grown, and the bacteriocin was purified to single-band homogeneity. biochemical traits indicated that the peptide was a class iia bacteriocin, and it was named e 50-52. the bacteriocin had a molecular weight of 3339.7 and an isoelectric point of 8.0. the minimal inhibitory concentrat ...200818293921
association of a factor h mutation with hemolytic uremic syndrome following a diarrheal illness.hemolytic uremic syndrome (hus) takes 2 forms: diarrheal hus and nondiarrheal hus. as its name suggests, diarrheal hus classically follows an enteric infection. the classic infective organism is the escherichia coli o157 serotype, although other bacteria, including shigella species, can produce the verocytotoxin required to cause hus. the usual clinical course is an episode of bloody diarrhea followed by thrombotic microangiopathy and acute renal failure. supportive treatment sees recovery of re ...200818295065
single residue determines the specificity of neutrophil elastase for shigella virulence factors.human neutrophil elastase (ne) is a key host defense protease that cleaves virulence factors of gram-negative bacteria. ne and cathepsin g (cg) are chymotrypsin-like serine proteases with sequence and structural similarities, and both are abundant in neutrophil granules. unlike ne, cg does not cleave virulence factors of enteric bacteria. through structure-function analysis, we identified regions in ne that are essential for cleaving shigella virulence proteins. ne residues at eight different po ...200818295791
geographic analysis of shigellosis in vietnam.geographic and ecological analysis may provide investigators useful ecological information for the control of shigellosis. this paper provides distribution of individual shigella species in space, and ecological covariates for shigellosis in nha trang, vietnam. data on shigellosis in neighborhoods were used to identify ecological covariates. a bayesian hierarchical model was used to obtain joint posterior distribution of model parameters and to construct smoothed risk maps for shigellosis. neigh ...200818296100
socioeconomic risk factors for bacterial gastrointestinal infections.bacterial gastrointestinal infections cause considerable morbidity in industrialized countries, but little is known about socioeconomic factors affecting the risk of infection.200818300694
a five-year antimicrobial resistance pattern of shigella isolated from stools in the gondar university hospital, northwest ethiopia.shigellosis is a global health problem. however, developing countries, where there is poor hygiene and unsafe water supplies, are especially affected. in the last two decades shigella isolates have become increasingly resistant to many commonly used drugs. we investigated the antibiotic susceptibility pattern of shigella isolated from stool specimens processed over five years in the bacteriology laboratory of the university of gondar teaching hospital in northwest ethiopia. stool specimens were ...200818302868
structures of the shigella flexneri type 3 secretion system protein mxic reveal conformational variability amongst homologues.many gram-negative pathogenic bacteria use a complex macromolecular machine, known as the type 3 secretion system (t3ss), to transfer virulence proteins into host cells. the t3ss is composed of a cytoplasmic bulb, a basal body spanning the inner and outer bacterial membranes, and an extracellular needle. secretion is regulated by both cytoplasmic and inner membrane proteins that must respond to specific signals in order to ensure that virulence proteins are not secreted before contact with a euk ...200818304577
the o-polysaccharide of escherichia coli o112ac has the same structure as that of shigella dysenteriae type 2 but is devoid of o-acetylation: a revision of the s. dysenteriae type 2 o-polysaccharide structure.the o-antigen structure of shigella dysenteriae type 2 was reinvestigated using chemical modifications along with high-resolution 2d (1)h and (13)c nmr spectroscopy. the o-antigen was found to contain a pyruvic acid acetal, which was overlooked in an early study, and the following revised structure of the pentasaccharide repeating unit was established: where approximately 70% glcnac residues bear an o-acetyl group at position 3. the o-antigen of escherichia coli o112ac was found to have the same ...200818308298
nlrx1: friend or foe? 200818311173
ipgb1 and ipgb2, two homologous effectors secreted via the mxi-spa type iii secretion apparatus, cooperate to mediate polarized cell invasion and inflammatory potential of shigella flexenri.type iii secretion systems (t3ss) are present in many pathogenic gram-negative bacteria and mediate the translocation of bacterial effector proteins into host cells. here, we report the phenotypic characterization of s. flexneri ipgb1 and ipgb2 mutants, in which the genes encoding the ipgb1 and ipgb2 effectors have been inactivated, either independently or simultaneously. like ipgb1, we found that ipgb2 is secreted by the t3ss and its secretion requires the spa15 chaperone. upon infection of sem ...200818316224
[new perspectives of the phage therapy].a solution to the problem of the increasing number of antibiotic-resistant bacterial strains can be the use of rational phage therapy. in the past, bacteriophages (phages) were often used for the treatment and prevention of infections and unlike antibiotic therapy, phage therapy caused almost no serious side effects. while previously several preparations containing whole phage particles were available for phage therapy, currently, the isolation of well characterised and purified phage components ...200718320502
delivery of biologically active anti-inflammatory cytokines il-10 and il-1ra in vivo by the shigella type iii secretion apparatus.pathogenicity of many gram-negative bacteria relies on a type iii secretion (t3s) apparatus, which is used for delivery of bacterial effectors into the host cell cytoplasm allowing the bacteria to manipulate host cell cytoskeleton network as well as to interfere with intracellular signaling pathways. in this study, we investigated the potential of the shigella flexneri t3sa as an in vivo delivery system for biologically active molecules such as cytokines. the anti-inflammatory cytokines il-10 an ...200818322242
impact of infections and normal flora in nonhuman primates on drug development.preclinical safety studies that are required for the marketing approval of a pharmaceutical include single and repeat dose studies in rodent and nonrodent species. the use of nonhuman primates (nhps), primarily macaques, as the nonrodent species has increased in recent years, in part due to the increase in development of biopharmaceuticals and immunomodulatory agents. depending on the source of the macaques, they may vary in genetic background, normal flora, and/or the incidence of preexisting p ...200818323580
pyrosequencing analysis of the gyrb gene to differentiate bacteria responsible for diarrheal diseases.pathogens causing acute diarrhea include a large variety of species from enterobacteriaceae and vibrionaceae. a method based on pyrosequencing was used here to differentiate bacteria commonly associated with diarrhea in china; the method is targeted to a partial amplicon of the gyrb gene, which encodes the b subunit of dna gyrase. twenty-eight specific polymorphic positions were identified from sequence alignment of a large sequence dataset and targeted using 17 sequencing primers. of 95 isolate ...200818324428
salmonellosis in lagos, nigeria: incidence of plasmodium falciparum-associated co-infection, patterns of antimicrobial resistance, and emergence of reduced susceptibility to fluoroquinolones.the present study was undertaken to examine the status of antimicrobial resistance in salmonella-associated diseases, by verifying possible emergence of reduced susceptibility to fluoroquinolones in salmonella isolates and determining the incidence of plasmodium falciparum-associated co-infection with salmonella serotypes. antimicrobial resistance in clinical isolates of salmonellae was examined for a 12-month period. four hundred and forty-one patients comprising two groups were recruited. grou ...200718330069
insecticidal properties and microbial contaminants in a spodoptera exigua multiple nucleopolyhedrovirus (baculoviridae) formulation stored at different temperatures.the spodoptera exigua (hübner) multiple nucleopolyhedrovirus (semnpv) is currently being tested as a biological insecticide for use in greenhouse crops in southern spain. we performed a study in which semipurified semnpv occlusion bodies (obs) were formulated in phosphate-buffered saline, ph 6.5, with 5% (vol:vol) glycerol and 0.15% (wt:vol) sorbic acid, and they were stored at -20, 4, or 25 degrees c during 18 mo. initial aerobic counts (+/-se) averaged 1.4 (+/-0.17) x 10(7) colony-forming unit ...200818330114
subversion of actin dynamics by espm effectors of attaching and effacing bacterial pathogens.rho gtpases are common targets of bacterial toxins and type iii secretion system effectors. ipgb1 and ipgb2 of shigella and map of enteropathogenic (epec) and enterohemorrhagic (ehec) escherichia coli were recently grouped together on the basis that they share a conserved wxxxe motif. in this study, we characterized six wxxxe effectors from attaching and effacing pathogens: trca and espm1 of epec strain b171, espm1 and espm2 of ehec strain sakai and espm2 and espm3 of citrobacter rodentium. we s ...200818331467
prevalence of gastrointestinal bacterial pathogens in a population of zoo animals.faecal prevalence of gastrointestinal bacterial pathogens, including campylobacter, escherichia coli o157:h7, salmonella, shigella, yersinia, as well as arcobacter, were examined in 317 faecal specimens from 44 animal species in belfast zoological gardens, during july-september 2006. thermophilic campylobacters including campylobacter jejuni, campylobacter coli and campylobacter lari, were the most frequently isolated pathogens, where members of this genus were isolated from 11 animal species (1 ...200818331520
prevalence of acute diarrhoea in kathmandu valley.this retrospective study was conducted during january to september in the year 1997. three hundred and forty nine stool samples were collected from diarrhoea patients from different places of kathmandu valley and examined at national public health laboratory (nphl), teku, kathmandu. acute diarrhoea becomes epidemic in rainy season and is a major public health problem of the city. in this study, people with poor hygiene practice and poor education were infected more than other people. among the 3 ...200718340369
cold shock exoribonuclease r (vacb) is involved in aeromonas hydrophila pathogenesis.in this study, we cloned and sequenced a virulence-associated gene (vacb) from a clinical isolate ssu of aeromonas hydrophila. we identified this gene based on our recently annotated genome sequence of the environmental isolate atcc 7966(t) of a. hydrophila and the vacb gene of shigella flexneri. the a. hydrophila vacb protein contained 798 amino acid residues, had a molecular mass of 90.5 kda, and exhibited an exoribonuclease (rnase r) activity. the rnase r of a. hydrophila was a cold-shock pro ...200818344363
maturation of paneth cells induces the refractory state of newborn mice to shigella infection.the intestinal tract of adult mice is naturally resistant to infection by shigella, the causative agent of bacillary dysentery in humans. conversely, newborn mice are highly susceptible to intragastric shigella infection and develop inflammatory lesions of the jejunal mucosa, very similar to those observed in the colon of dysenteric patients. however, the susceptibility period is short and one week after birth, animals have acquired a status of resistance characteristic of adult animals. to iden ...200818354217
high rate of resistance to locally used antibiotics among enteric bacteria from children in northern ghana.information on antimicrobial susceptibility of bacterial pathogens is scarce in resource-poor settings. we determined the susceptibility of bacterial enteric pathogens and faecal escherichia coli isolates obtained from children in urban tamale, northern ghana, to antibiotics widely used in the that area [ampicillin or amoxicillin, trimethoprim/sulfamethoxazole (sxt) and chloramphenicol] and to alternative drugs.200818356156
differential expression of ompc and ompf in multidrug-resistant shigella dysenteriae and shigella flexneri by aqueous extract of aegle marmelos, altering its susceptibility toward beta-lactam antibiotics.steadily increasing resistance among shigella to beta-lactams, aminoglycosides, and tetracycline has compromised the utility of these commonly used antimicrobial agents. also, undesirable side effects of certain antibiotics have triggered immense interest in search of alternative therapies using medicinal plants. one such medicinal plant used since ancient times to cure diarrhea is aegle marmelos. the present study exemplifies the susceptibility of beta-lactam-resistant shigella dysenteriae and ...200818358664
differential regulation by magnesium of the two msbb paralogs of shigella flexneri.shigella flexneri, a gram-negative enteric pathogen, is unusual in that it contains two nonredundant paralogous genes that encode the myristoyl transferase msbb (lpxm) that catalyzes the final step in the synthesis of the lipid a moiety of lipopolysaccharide. msbb1 is encoded on the chromosome, and msbb2 is encoded on the large virulence plasmid present in all pathogenic shigellae. we demonstrate that myristoyl transferase activity due to msbb2 is detected in limited magnesium medium, but not in ...200818359815
ctx-m-3 type beta-lactamase producing shigella sonnei isolates from pediatric bacillary dysentery cases.in this study, 153 clinical isolates of shigella were screened for extended-spectrum beta-lactamase (esbl) production by double-disk synergy test. after being confirmed by the combined disk-test and inhibitor-combined e-test strips, all positive isolates were tested for the bla gene by pcr and the enzymes by isoelectric focusing. dna sequencing of pcr products revealed that five shigella sonnei isolates had ctx-m-3 type esbl enzymes. all of them were resistant to ampicillin, sulfamethoxazole and ...200818362404
[antigenic polysaccharides of bacteria: 40. the structures of o-specific polysaccharides from shigella dysenteriae types 3 and 9 and s. boydii type 4 revised by nmr spectroscopy].the reported structures of o-specific polysaccharides from three standard strains of shigella bacteria were corrected by modern nmr techniques. the revisions concerned the configuration of the o-glycoside linkage (s. dysenteriae type 3, structure 1), the positions of monosaccharide residue glycosylation and acetylation by pyruvic acid (s. dysenteriae type 9, structure 2), and the attachment position of the side monosaccharide chain (s. boydii type 4, structure 3) [struxture in text].200818365747
contamination of a blood culture with shigella sonnei. 200818371521
analysis of rho-gtpase mimicry by a family of bacterial type iii effector proteins.microbial pathogens may hijack the actin cytoskeleton machinery to facilitate actin-based motility, cellular invasion, and intracellular trafficking through the endocytic pathway. of particular interest has been a large class of virulence factors collectively termed the type iii "effector" proteins. following contact with a eukaryotic cell, gram-negative bacterial pathogens employ a dedicated protein secretion apparatus termed type iii to translocate effector proteins into the cellular cytoplasm ...200818374161
coiled-coil regions play a role in the function of the shigella flexneri o-antigen chain length regulator wzzphs2.regulation of the length of the o-antigen (oag) chain attached to lps in shigella flexneri is important for virulence and is dependent on the inner-membrane protein wzz. a lack of high-resolution structural data for wzz has hampered efforts so far to correlate mutations affecting function of wzz with structure and describe a mechanism for chain length regulation. here we have used secondary structure prediction to show that the periplasmic domain of the wzz(phs2) protein has three regions of sig ...200818375803
ospf directly attenuates the activity of extracellular signal-regulated kinase during invasion by shigella flexneri in human dendritic cells.shigella spp., gram-negative pathogenic bacteria, deliver various effector molecules into the host cell cytoplasm through their type iii secretion system to facilitate their invasive process and control the host innate immune responses. although the function of these effectors is well characterized in epithelial cells during shigella infection, it has not been elucidated in the dendritic cell (dc), a major antigen presenting cell playing an important role in the initiation of immune responses. i ...200818378312
antimicrobial resistance among salmonella and shigella isolates in five canadian provinces (1997 to 2000).to describe rates of antimicrobial resistance (amr) among salmonella and shigella isolates reported in five canadian provinces, focusing on clinically important antimicrobials.200618382635
a pharmacokinetic study of enrofloxacin and its active metabolite ciprofloxacin after oral and intramuscular dosing of enrofloxacin in rhesus monkeys (macaca mulatta).enrofloxacin is used for treating shigellosis in non-human primates; however, there are no reports describing its pharmacokinetics in rhesus monkeys. pharmacokinetic data in intended target species (rhesus) help to determine the proper dose regimen. blood levels of enrofloxacin and ciprofloxacin (enrofloxacin's active metabolite), were determined after either intramuscular or oral dosing of enrofloxacin for 7 days in a cross-over study. levels of both antibiotics were determined by solid phase e ...200818384536
antimicrobial activity of 2,5-dihydroxy-3-methyl-1,4-benzoquinone from embelia schimperi.chromatographic separation of an ethyl acetate extract from embelia schimperi led to the isolation of a new compound identified as 2,5-dihydroxy-3-methyl-1,4-benzoquinone (1) on the basis of spectroscopic and physical data. the plant's crude extract and pure compound 1 were assayed for in vitro antimicrobial activity against clinical strains of salmonella spp., proteus spp., pseudomonas aeruginosa, klebsiella pneumoniae, escherichia coli, cryptococcus neoformans, shigella dysentriae and staphylo ...200818386487
a cost function analysis of shigellosis in thailand.the purpose of this study was to develop a cost function model to estimate the public treatment cost of shigellosis patients in thailand.200818387071
human-derived probiotic lactobacillus reuteri demonstrate antimicrobial activities targeting diverse enteric bacterial pathogens.lactobacillus reuteri is a commensal-derived anaerobic probiotic that resides in the human gastrointestinal tract. l. reuteri converts glycerol into a potent broad-spectrum antimicrobial compound, reuterin, which inhibits the growth of gram-positive and gram-negative bacteria. in this study, we compared four human-derived l. reuteri isolates (atcc 55730, atcc pta 6475, atcc pta 4659 and atcc pta 5289) in their ability to produce reuterin and to inhibit the growth of different enteric pathogens i ...200818396068
[multiplex real-time pcr detecting salmonella, shigella and diarrheagenic escherichia coli].to develop a multiplex real-time pcr for the detection of salmonella invasion protein a gene (inva), enterotoxigenic escherichia coli (etec) heat-labile i enterotoxin gene (elt), and shigella or enteroinvasive e. coli (eiec) invasive plasmid antigen h gene (ipah).200718399125
preliminary foodnet data on the incidence of infection with pathogens transmitted commonly through food--10 states, 2007.the foodborne diseases active surveillance network (foodnet) of cdc's emerging infections program collects data from 10 u.s. states regarding diseases caused by pathogens commonly transmitted through food. foodnet quantifies and monitors the incidence of these infections by conducting active, population-based surveillance for laboratory-confirmed infections. this report describes preliminary surveillance data for 2007 and compares them with data for previous years. in 2007, the estimated inciden ...200818401330
characterisation of escherichia coli strains involved in transcytosis across gut epithelial cells exposed to metabolic and inflammatory stress.translocation of normally non-pathogenic bacteria across the gut may drive inflammatory responses associated with sepsis and inflammatory bowel disease. recent evidence suggests translocation may not be purely passive, but occurs via novel transcellular pathways activated in enterocytes by inflammatory and metabolic stress. the specificity of this pathway with respect to different e. coli strains and other bacterial species, and possible molecular determinants of the "translocating" phenotype ha ...200818403240
the emergence and fate of horizontally acquired genes in escherichia coli.bacterial species, and even strains within species, can vary greatly in their gene contents and metabolic capabilities. we examine the evolution of this diversity by assessing the distribution and ancestry of each gene in 13 sequenced isolates of escherichia coli and shigella. we focus on the emergence and demise of two specific classes of genes, orfans (genes with no homologs in present databases) and hops (genes with distant homologs), since these genes, in contrast to most conserved ancestral ...200818404206
[the pathogens responsible for waterborne infections: the biological risk for agricultural laborer].the presence of microbiological agents in waters intended for human consumption, irrigation and recreational activity, is a significant risk for the human health. recent epidemiological data demonstrate an increase of the diseases caused by waterborne pathogens, especially of the gastroenteritis infections, in the industrialized countries. numerous studies have evidenced the contamination of deep and surface waters; bacteria within contaminated water represent a highly diversified group, that ar ...200718409935
analysis of bacterial dna in synovial tissue of tunisian patients with reactive and undifferentiated arthritis by broad-range pcr, cloning and sequencing.bacteria and/or their antigens have been implicated in the pathogenesis of reactive arthritis (rea). several studies have reported the presence of bacterial antigens and nucleic acids of bacteria other than those specified by diagnostic criteria for rea in joint specimens from patients with rea and various arthritides. the present study was conducted to detect any bacterial dna and identify bacterial species that are present in the synovial tissue of tunisian patients with reactive arthritis and ...200818412942
containment of tumor-colonizing bacteria by host neutrophils.administration of facultative anaerobic bacteria like salmonella typhimurium, shigella flexneri, and escherichia coli to tumor-bearing mice leads to a preferential accumulation and proliferation of the microorganisms within the solid tumor. until now, all known tumor-targeting bacteria have shown poor dissemination inside the tumors. they accumulate almost exclusively in large necrotic areas and spare a rim of viable tumor cells. interestingly, the bacteria-containing necrotic region is separate ...200818413765
development of a travelers' diarrhea vaccine for the military: how much is an ounce of prevention really worth?infectious diarrhea is one of the many threats to the deployed military, and given limited resources, a decision to pursue a vaccine acquisition strategy should be based on best evidence that weighs costs and benefits compared to alternatives. an economic model was developed to estimate the marginal cost to avert a duty day lost due to diarrhea for a vaccine acquisition strategy compared to current clinical management, for both multiplex and pathogen-specific vaccines. vaccines against campyloba ...200818417259
rupture, invasion and inflammatory destruction of the intestinal barrier by shigella: the yin and yang of innate immunity.shigella is a gram-negative bacterial species of the family enterobacteriaceae that causes bacillary dysentery in humans. this acute colitis reflects the capacity of the microorganism to disrupt, invade and cause the inflammatory destruction of the intestinal epithelium. the pathogenesis of the shigella infection can be seen as a disruption of the homeostatic balance that protects the gut against inflammation in the presence of its commensal flora. this provides the unified view that enteroinvas ...200618418486
structure and genetics of shigella o antigens.this review covers the o antigens of the 46 serotypes of shigella, but those of most shigella flexneri are variants of one basic structure, leaving 34 shigella distinct o antigens to review, together with their gene clusters. several of the structures and gene clusters are reported for the first time and this is the first such group for which structures and dna sequences have been determined for all o antigens. shigella strains are in effect escherichia coli with a specific mode of pathogenicity ...200818422615
role of rna polymerase sigma-factor (rpos) in induction of glutamate-dependent acid-resistance of escherichia albertii under anaerobic conditions.escherichia albertii is a potential enteric food-borne pathogen with poorly defined genetic and biochemical properties. acid resistance is perceived to be an important property of enteric pathogens, enabling them to survive passage through stomach acidity so that they may colonize the mammalian gastrointestinal tract. we analyzed glutamate-dependent acid-resistance pathway (gdar) in five e. albertii strains that have been identified so far. we observed that the strains were unable to induce gdar ...200818422618
comparing the antimicrobial effectiveness of nacl and kcl with a view to salt/sodium replacement.a study using a small range of pathogenic bacterial species (aeromonas hydrophila, enterobacter sakazakii, shigella flexneri, yersinia enterocolitica and 3 strains of staphylococcus aureus) has shown that potassium chloride has an equivalent antimicrobial effect on these organisms when calculated on a molar basis. combined nacl and kcl experiments were carried out and data was analysed using a modification to the lambert and lambert [lambert, r.j.w., and lambert, r., 2003. a model for the effica ...200818423764
virulent shigella flexneri subverts the host innate immune response through manipulation of antimicrobial peptide gene expression.antimicrobial factors are efficient defense components of the innate immunity, playing a crucial role in the intestinal homeostasis and protection against pathogens. in this study, we report that upon infection of polarized human intestinal cells in vitro, virulent shigella flexneri suppress transcription of several genes encoding antimicrobial cationic peptides, particularly the human beta-defensin hbd-3, which we show to be especially active against s. flexneri. this is an example of targeted ...200818426984
ctx-m-15-producing shigella sonnei strain from a czech patient who traveled in asia. 200818434554
alternative hand contamination technique to compare the activities of antimicrobial and nonantimicrobial soaps under different test conditions.antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. however, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. the aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimi ...200818441107
nonbloody, red stools from coadministration of cefdinir and iron-supplemented infant formulas.cefdinir is an extended-spectrum, third-generation cephalosporin that may be used for treatment of acute otitis media in patients allergic to penicillin. when administered with iron-containing products, including infant formulas, cefdinir or one of its metabolites may bind to ferric ions, forming a nonabsorbable complex that imparts a reddish color to the stool. we describe a 9-month-old infant with failure to thrive and acute otitis media who developed an erythematous maculopapular rash during ...200818447664
shigellosis: the current status of vaccine development.shigellosis, a major form of bacillary dysentery, is caused by infection with shigella organisms. in poor countries, shigella-caused dysentery is endemic and causes an estimated 163 million illness episodes annually and more than one million deaths. although several strategies have been used to develop vaccines targeting shigellosis, none has been licensed for use outside china. owing to the wide range of shigella serotypes and subtypes, there is a need for a multivalent vaccine representing pre ...200818448978
deoxycholate interacts with ipad of shigella flexneri in inducing the recruitment of ipab to the type iii secretion apparatus needle tip.type iii secretion (tts) is an essential virulence function for shigella flexneri that delivers effector proteins that are responsible for bacterial invasion of intestinal epithelial cells. the shigella tts apparatus (ttsa) consists of a basal body that spans the bacterial inner and outer membranes and a needle exposed at the pathogen surface. at the distal end of the needle is a "tip complex" composed of invasion plasmid antigen d (ipad). ipad not only regulates tts, but is required for the rec ...200818450744
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