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a microbial diagnostic microarray technique for the sensitive detection and identification of pathogenic bacteria in a background of nonpathogens.a major challenge in microbial diagnostics is the parallel detection and identification of low-bundance pathogens within a complex microbial community. in addition, a high specificity providing robust, reliable identification at least at the species level is required. a microbial diagnostic microarray approach, using single nucleotide extension labeling with gyrb as the marker gene, was developed. we present a novel concept applying competitive oligonucleotide probes to improve the specificity o ...200717123456
occurrence of campylobacter jejuni in shiraz, southwest iran.to investigate the occurrence of campylobacter jejuni among other bacterial agents of acute diarrhea.200717159366
an injected bacterial effector targets chromatin access for transcription factor nf-kappab to alter transcription of host genes involved in immune responses.phosphorylation of histone h3 at ser10 increases chromatin accessibility to transcription factor nf-kappab on a subset of genes involved in immune responses. here we report that a bacterial pathogen abrogated phosphorylation of histone h3 to 'shape' the transcriptional responses of infected host cells. we identify the shigella flexneri protein effector ospf as a dually specific phosphatase that dephosphorylated mitogen-activated protein kinases in the nucleus, thus preventing histone h3 phosphor ...200717159983
revisiting the molecular evolutionary history of shigella spp.the theory that shigella is derived from multiple independent origins of escherichia coli (pupo et al. 2000) has been challenged by recent findings that the virulence plasmids (vps) and the chromosomes share a similar evolutionary history (escobar-paramo et al. 2003), which suggests that an ancestral vp entered an e. coli strain only once, which gave rise to shigella spp. in an attempt to resolve these conflicting theories, we constructed three phylogenetic trees in this study: a robust chromoso ...200717160643
serological cross-reactivity of environmental isolates of enterobacter, escherichia, stenotrophomonas, and aerococcus with shigella spp.-specific antisera.using protocols designed for the isolation of shigella from environmental freshwater samples from different regions of bangladesh, 11 bacterial strains giving rise to shigella-like colonies on selective agar plates and showing serological cross-reaction with shigella-specific antisera were isolated. phylogenetic analyses revealed that three of the isolates were most closely related to escherichia coli, four to enterobacter sp., two to stenotrophomonas, and two isolates belonged to the gram-posit ...200717171463
shigella ipgb1 promotes bacterial entry through the elmo-dock180 machinery.shigella use a special mechanism to invade epithelial cells called 'the trigger mechanism of entry', which allows epithelial cells to trap several bacteria simultaneously. on contact, shigella deliver effectors into epithelial cells through the type iii secretion system. here, we show that one of the effectors, ipgb1, has a pivotal role in producing membrane ruffles by exploiting the rhog-elmo-dock180 pathway to stimulate rac1 activity. using pulldown assays, we identified engulfment and cell mo ...200717173036
vaccine potential for inactivated shigellae.we used human monocyte-derived dendritic cells (dc) and balb/c mice as models to establish the immunogenic and protective potential of formalin-inactivated shigella spp. incubation of dc with inactivated or live bacteria induced dc maturation and cytokine release. mice immunized orally or intranasally with killed s. flexneri, s. sonnei, or s. dysenteriae developed igg and fecal iga titers to the homologous lps. following respiratory challenge with the live homologous organisms, 80-100% survival ...200717178431
shigella rewrites host transcriptional responses. 200717179964
villin severing activity enhances actin-based motility in vivo.villin, an actin-binding protein associated with the actin bundles that support microvilli, bundles, caps, nucleates, and severs actin in a calcium-dependant manner in vitro. we hypothesized that the severing activity of villin is responsible for its reported role in enhancing cell plasticity and motility. to test this hypothesis, we chose a loss of function strategy and introduced mutations in villin based on sequence comparison with capg. by pyrene-actin assays, we demonstrate that this mutant ...200717182858
structural and genetic evidence that the escherichia coli o148 o antigen is the precursor of the shigella dysenteriae type 1 o antigen and identification of a glucosyltransferase gene.shigella dysenteriae type 1 is the most virulent serotype of shigella. enterotoxigenic escherichia coli o148 is pathogenic and can cause diarrhoea. the following structure was established for the tetrasaccharide repeating unit of the e. coli o148 o antigen: -->3)-alpha-l-rhap-(1-->3)-alpha-l-rhap-(1-->2)-alpha-d-glcp-(1-->3)-alpha-d-glcpnac-(1-->. this differs from the structure reported earlier for s. dysenteriae type 1 by having a glucose (glc) residue in place of a galactose (gal) residue. th ...200717185542
gene cluster analysis method identifies horizontally transferred genes with high reliability and indicates that they provide the main mechanism of operon gain in 8 species of gamma-proteobacteria.the formation mechanism of operons remains unresolved: operons may form by rearrangements within a genome or by acquisition of genes from other species, that is, horizontal gene transfer (hgt). one hindrance to its elucidation is the unavailability of a method to accurately identify hgt, although it is generally considered to occur. it is critically important first to select horizontally transferred (ht) genes reliably and then to determine the extent to which hgt is involved in operon formation ...200717185745
use of linear, weibull, and log-logistic functions to model pressure inactivation of seven foodborne pathogens in milk.survival curves of six foodborne pathogens suspended in ultra high-temperature (uht) whole milk and exposed to high hydrostatic pressure at 21.5 degrees c were obtained. vibrio parahaemolyticus was treated at 300 mpa and other pathogens, listeria monocytogenes, escherichia coli o157:h7, salmonella enterica serovar enteritidis, salmonella enterica serovar typhimurium, and staphylococcus aureus were treated at 600 mpa. all the survival curves showed a rapid initial drop in bacterial counts followe ...200717188197
polar positional information in escherichia coli spherical cells.shigella surface protein icsa and its cytoplasmic derivatives are localized to the old pole of rod-shaped cells when expressed in escherichia coli. in spherical mreb cells, icsa is targeted to ectopic sites and close to one extremity of actin-like mamk filament. to gain insight into the properties of the sites containing polar material, we studied the icsa localization in spherical cells. gfp was exported into the periplasm via the tat pathway and used as a periplasmic space marker. gfp displaye ...200717188233
case-control study of shigellosis in san francisco: the role of sexual transmission and hiv infection.shigella species infect approximately 450,000 persons annually in the united states. person-to-person transmission of shigella species, which have a low infectious dose, occurs frequently, particularly in areas with poor sanitation and hygiene. sexual transmission of shigella species among men who have sex with men (msm) has been inferred from outbreaks of shigellosis among that population, and limited studies have suggested the importance of human immunodeficiency virus (hiv) infection as a ris ...200717205436
another perfect storm: shigella, men who have sex with men, and hiv. 200717205437
shigella's ways of manipulating the host intestinal innate and adaptive immune system: a tool box for survival?shigella, a gram-negative invasive enteropathogenic bacterium, causes the rupture, invasion and inflammatory destruction of the human colonic epithelium. this complex and aggressive process accounts for the symptoms of bacillary dysentery. the so-called invasive phenotype of shigella is linked to expression of a type iii secretory system (ttss) injecting effector proteins into the epithelial cell membrane and cytoplasm, thereby inducing local but massive changes in the cell cytoskeleton that lea ...200717213832
shigella chromosomal ipah proteins are secreted via the type iii secretion system and act as effectors.shigella possess 220 kb plasmid, and the major virulence determinants, called effectors, and the type iii secretion system (ttss) are exclusively encoded by the plasmid. the genome sequences of s. flexneri strains indicate that several ipah family genes are located on both the plasmid and the chromosome, but whether their chromosomal ipah cognates can be secreted from shigella remains unknown. here we report that s. flexneri strain, ysh6000 encodes seven ipah cognate genes on the chromosome and ...200717214743
an h-ns-like stealth protein aids horizontal dna transmission in bacteria.the sfh protein is encoded by self-transmissible plasmids involved in human typhoid and is closely related to the global regulator h-ns. we have found that sfh provides a stealth function that allows the plasmids to be transmitted to new bacterial hosts with minimal effects on their fitness. introducing the plasmid without the sfh gene imposes a mild h-ns(-) phenotype and a severe loss of fitness due to titration of the cellular pool of h-ns by the a+t-rich plasmid. this stealth strategy seems t ...200717218529
erosion of interaction networks in reduced and degraded genomes.unlike eukaryotes, which often recruit duplicated genes into existing protein-protein interaction (ppi) networks, the low levels of gene duplication coupled with the high probability of lateral transfer of novel genes alters the manner in which ppi networks can evolve in bacteria. by inferring the ppis present in the ancestor to contemporary gammaproteobacteria, we were able to trace the changes in gene repertoires, and their consequences on ppi network evolution, in several bacterial lineages t ...200717219366
analysis of strategies to successfully vaccinate infants in developing countries against enterotoxigenic e. coli (etec) disease.enterotoxigenic escherichia coli (etec) is the most common bacterial cause of diarrhoea in the world, annually affecting up to 400,000,000 children under 5 years of age living in developing countries (dcs). although etec possesses numerous antigens, the relatively conserved colonization factor (cf) antigens and the heat labile enterotoxin (lt) have been associated with protection and most vaccine candidates have exploited these antigens. a safe and effective vaccine against etec is a feasible go ...200717224212
antibacterial activity and in vitro anti-tumor activity of the extract of the larvae of the housefly (musca domestica).one of the significant characteristics of traditional chinese medicine is the use of insects, other terrestrial arthropods and their products as drugs. in the present work, the extract of housefly (musca domestica) larvae was studied by an agar well diffusion assay and minimum bactericidal concentration (mbc) determination for detection of antimicrobial activity and by mtt assay method to test its in vitro anti-tumor activity. in our studies, the extract inhibited six tested bacterial pathogens ...200717227700
immunogenicity and characterization of wrsf2g11: a second generation live attenuated shigella flexneri 2a vaccine strain.recent clinical trials involving live attenuated shigella vaccine strains sc602 and wrss1 have revealed that deletion of the virg(icsa) gene dramatically reduces virulence in human volunteers. these strains can be given at low oral doses and induce a strong, and in some cases, protective immune responses. however, residual vaccine associated reactogenicity suggests that further attenuation is required. a recent clinical trial indicated that the set and sen enterotoxin genes contribute to the sym ...200717229494
role of infection in irritable bowel syndrome.infection by pathogenic organisms leads to mucosal damage and disruption of the gut's extensive commensal flora, factors which may lead to prolonged bowel dysfunction. six to 17% of unselected irritable bowel syndrome (ibs) patients believe their symptoms began with an infection, which is supported by prospective studies showing a 4%-31% incidence of postinfectious ibs-(pi) following bacterial gastroenteritis. the wide range of incidence can be accounted for by differences in risk factors, which ...200717238025
using european travellers as an early alert to detect emerging pathogens in countries with limited laboratory resources.the volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. by collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. we present the results of a case study using reported cases of shigella dysenteriae serotyp ...200717239228
high genetic stability of integrons in clinical isolates of shigella spp. of worldwide origin.over a 12-year period, 68 shigella strains (31 s. sonnei, 30 s. flexneri, 4 s. dysenteriae, and 3 s. boydii strains) were collected in a french university hospital from the stools of patients who generally had a recent history of travel to various parts of the world (91%), particularly africa (67%). these strains were often resistant (streptomycin, spectinomycin, trimethoprim, tetracycline, and sulfonamides, 66 to 84%; ampicillin and chloramphenicol, 34 to 38%; nalidixic acid, 4%) and even multi ...200717242143
the catalase reaction of shigella species and its use in rapid screening for epidemic shigella dysenteriae type 1.as epidemic dysentery caused by shigella dysenteriae type 1 is associated with high mortality, early identification of outbreaks is important. since s. dysenteriae type 1 differs from most of the enterobacteriaceae in that it does not produce catalase, a test for catalase may provide a useful screening method. the ability of a catalase test to provide rapid identification of s. dysenteriae type 1 has now been assessed, using isolates of this pathogen from five continents, shigella of other speci ...200717244412
extended-spectrum beta-lactamase-producing shigella strains in israel, 2000-2004.routine susceptibility testing of 5,616 shigella isolates at the national shigella reference centre in israel over a 5-year period (2000-2004) revealed resistance to ceftriaxone in one strain of shigella boydii 2 and in two strains each of shigella flexneri 2a, s. flexneri 6, and shigella sonnei. all seven isolates were confirmed as producers of extended-spectrum beta-lactamase (esbl) by the combination disk method, the vitek 1 system, and a modification of the double-disk synergy test, which is ...200717265070
epidemiological characterization of resistance and pcr typing of shigella flexneri and shigella sonnei strains isolated from bacillary dysentery cases in southeast brazil.shigella spp are gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the enterobacteriaceae family responsible for "shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. however, despite this, there are very few epidemiological studies about this bacterium in brazil. we studied the antibiotic resistance profiles and the clonal structure of 60 shigella strains (30 s. flexneri and 30 s. sonnei) isolated from shigellosis cases in d ...200717273662
evaluation of the growth inhibitory activities of triphala against common bacterial isolates from hiv infected patients.the isolation of microbial agents less susceptible to regular antibiotics and the rising trend in the recovery rates of resistant bacteria highlights the need for newer alternative principles. triphala has been used in traditional medicine practice against certain diseases such as jaundice, fever, cough, eye diseases etc. in the present study phytochemical (phenolic, flavonoid and carotenoid) and antibacterial activities of aqueous and ethanol extracts of triphala and its individual components ( ...200717273983
new animal model of shigellosis in the guinea pig: its usefulness for protective efficacy studies.it has been difficult to evaluate the protective efficacy of vaccine candidates against shigellosis, a major form of bacillary dysentery caused by shigella spp. infection, because of the lack of suitable animal models. to develop a proper animal model representing human bacillary dysentery, guinea pigs were challenged with virulent shigella flexneri serotype 2a (strains 2457t or ysh6000) or s. flexneri 5a (strain m90t) by the intrarectal (i.r.) route. interestingly, all guinea pigs administered ...200717277155
bioluminescent signal system: bioluminescence immunoassay of pathogenic organisms.the ca(2+)-regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. the hepatitis b virus (hbsag) and the bacteria escherichia coli and shigella sonnei lipopolysaccharide (lps) were chosen as model antigens. chemically synthesized obelin-corresponding antibody conjugates were used in a solid-phase microplate immunoassay. the sensitivities achieved by the assay were 0.25 ng/ml for s. sonnei lps and 0.375 ng/ml for hbsag. a novel, filter-based ...200717286244
gene expression profiling of the ph response in shigella flexneri 2a.the ph response of shigella flexneri 2a 301 was identified by gene expression profiling. gene expression profiles of cells grown in ph 4.5 or 8.6 were compared with the profiles of cells grown at ph 7.0. differential expression was observed for 307 genes: 97 were acid up-regulated, 102 were acid down-regulated, 91 were base up-regulated, and 86 were base down-regulated. twenty-seven genes were found to be both acid and base up-regulated, and 29 genes were both acid and base down-regulated. this ...200717286558
o-specific [corrected] polysaccharide conjugate vaccine-induced [corrected] antibodies prevent invasion of shigella into caco-2 cells and may be curative.the o-specific polysaccharide (o-sp) domain of shigella lps is both an essential virulence factor and a protective antigen for this genus. a critical level of serum igg anti-o-sp was shown to confer immunity to shigellosis, likely by complement-mediated bacteriolysis of the inoculum. conjugate shigella o-sp vaccines were shown to be safe and immunogenic in children, and, in a preliminary study, shigella sonnei vaccine was protective in young adults. characteristic of shigellosis is bacterial inv ...200717287349
capping of actin filaments by vinculin activated by the shigella ipaa carboxyl-terminal domain.shigella, the causative agent of bacillary dysentery, invades epithelial cells. upon bacterial-cell contact, the type iii bacterial effector ipaa binds to the cytoskeletal protein vinculin to promote actin reorganization required for efficient bacterial uptake. we show that the last 74 c-terminal residues of ipaa (a559) bind to human vinculin (hv) and promotes its association with actin filaments. polymerisation experiments demonstrated that a559 was sufficient to induce hv-dependent partial cap ...200717289036
seasonality in six enterically transmitted diseases and ambient temperature.we propose an analytical and conceptual framework for a systematic and comprehensive assessment of disease seasonality to detect changes and to quantify and compare temporal patterns. to demonstrate the proposed technique, we examined seasonal patterns of six enterically transmitted reportable diseases (eds) in massachusetts collected over a 10-year period (1992-2001). we quantified the timing and intensity of seasonal peaks of ed incidence and examined the synchronization in timing of these pea ...200717291363
study of polymorphic variable-number of tandem repeats loci in the ecor collection and in a set of pathogenic escherichia coli and shigella isolates for use in a genotyping assay.the escherichia coli (e. coli) reference collection, ecor, consists of 72 strains that are representative of the genotypic diversity, as indexed by multilocus enzyme electrophoresis (mlee), in the species as a whole. mlee revealed 4 main phylogenetic groups designated a, b1, b2 and d. we present a study of the relationship between the ecor strains as determined by polymorphisms in seven variable-number of tandem repeats (vntr) loci. seven tandem repeats that were present in more than one of the ...200717291612
norovirus outbreak in a district general hospital--new strain identified.media reports about norovirus outbreaks, especially in hospitals and nursing homes, have accumulated in the past years. the reasons for this increasing problem are manifold: resistance against common disinfectants, a high level of contagion (a dose of less than 100 particles may be infective); variability of the virus-genome documented by polymerase chain reaction-studies, as well as further factors concerning modern life-style. the following study describes and analyses a norovirus outbreak in ...200717299671
evaluation of an enzyme immunoassay-based stool antigen test to detect campylobacter jejuni and campylobacter coli.an enzyme immunoassay-based antigen test (ridascreen campylobacter; r-biopharm, darmstadt, germany) was evaluated for the detection of campylobacter jejuni and campylobacter coli in 1050 clinical stool samples as compared with culture on selective medium. after routine inoculation for salmonella, shigella, yersinia, aeromonas, plesiomonas, and campylobacter, the same swab specimens were used for the antigen test. the positivity rate for campylobacter was 9.3% in culture, and the antigen test gav ...200717300899
the phosphothreonine lyase activity of a bacterial type iii effector family.pathogenic bacteria use the type iii secretion system to deliver effector proteins into host cells to modulate the host signaling pathways. in this study, the shigella type iii effector ospf was shown to inactivate mitogen-activated protein kinases (mapks) [extracellular signal-regulated kinases 1 and 2 (erk1/2), c-jun n-terminal kinase, and p38]. ospf irreversibly removed phosphate groups from the phosphothreonine but not from the phosphotyrosine residue in the activation loop of mapks. mass sp ...200717303758
yeast functional genomic screens lead to identification of a role for a bacterial effector in innate immunity regulation.numerous bacterial pathogens manipulate host cell processes to promote infection and ultimately cause disease through the action of proteins that they directly inject into host cells. identification of the targets and molecular mechanisms of action used by these bacterial effector proteins is critical to understanding pathogenesis. we have developed a systems biological approach using the yeast saccharomyces cerevisiae that can expedite the identification of cellular processes targeted by bacter ...200717305427
the role of the vacb gene in the pathogenesis of brucella abortus.brucella species are important zoonotic pathogens affecting a wide variety of mammals. therefore, the identification of new brucella virulence factors is of great interest in understanding bacterial pathogenesis and immune evasion. in this study, we have identified brucella abortus vacb gene that presents 2343 nucleotides and 781 amino acids and it shows 39% identity with shigella flexneri vacb gene that encodes an exoribonuclease rnase r involved in bacterial virulence. further, we have inactiv ...200717306588
h-ns antagonism in shigella flexneri by virb, a virulence gene transcription regulator that is closely related to plasmid partition factors.the virb protein of shigella flexneri is a positive regulator of the major virulence operons of this enteroinvasive intracellular pathogen. virb resembles no other transcription factor but is strongly homologous to plasmid partition proteins. we found that the binding of the virb protein to the promoter region of the icsb virulence gene induced hypersensitivity to cleavage by dnase i over a region to which the h-ns repressor protein binds and completely abolished the protection of this sequence ...200717307842
heme inhibits the dna binding properties of the cytoplasmic heme binding protein of shigella dysenteriae (shus).heme uptake and utilization by pathogenic bacteria are critical for virulence and disease, since heme and heme proteins are a major source of iron within the host. although the role of outer membrane heme receptors in this process has been extensively characterized at the genetic and biochemical level, the role of the cytoplasmic heme binding proteins is not yet clear. the shigella dysenteriae cytoplasmic heme binding protein, shus, has previously been shown to promote utilization of heme as an ...200717323920
conformational stability and differential structural analysis of lcrv, pcrv, bipd, and sipd from type iii secretion systems.diverse gram-negative bacteria use type iii secretion systems (t3ss) to translocate effector proteins into the cytoplasm of eukaryotic cells. the type iii secretion apparatus (t3sa) consists of a basal body spanning both bacterial membranes and an external needle. a sensor protein lies at the needle tip to detect environmental signals that trigger type iii secretion. the shigella flexneri t3sa needle tip protein, invasion plasmid antigen d (ipad), possesses two independently folding domains in v ...200717327391
a method for fast and simple detection of major diarrhoeagenic escherichia coli in the routine diagnostic laboratory.a multiplex pcr was developed for the detection of the following genes characteristic of diarrhoeagenic escherichia coli (dec): verocytotoxins 1 (vtx1) and 2 (vtx2), characteristic of verocytotoxin-producing e. coli (vtec); intimin (eae), found in enteropathogenic e. coli (epec), attaching and effacing e. coli and vtec; heat-stable enterotoxin (esta) and heat-labile enterotoxin (elta), characteristic of enterotoxigenic e. coli (etec); and invasive plasmid antigen (ipah), characteristic of entero ...200717331124
porin of shigella dysenteriae activates mouse peritoneal macrophage through toll-like receptors 2 and 6 to induce polarized type i response.porin of shigella dysenteriae type 1 coexpressed toll-like receptor (tlr) 2 and tlr6 on peritoneal cavity (perc) macrophages (mphi) of c57bl/6 mice implicating that both the tlrs are essential as a combinatorial repertoire to recognize the protein. besides tlrs, mrna for myd88 and traf6, and nuclear translocation of nf-kappab were enhanced that indicate their involvement in tandem in the activity of porin. the protein selectively up-regulated cd80 on the activated mphi together with mhc class ii ...200716750567
in vitro efficacy of bioactive extracts of 15 medicinal plants against esbetal-producing multidrug-resistant enteric bacteria.alcoholic crude extracts and some fractions from 15 traditionally used indian medicinal plants were investigated for their ability to inhibit the growth of extended spectrum beta-lactamases (esbetal)-producing multidrug-resistant enteric bacteria. the test bacteria eschrichia coli and shigella were resistant to 16-23 antibiotics with intermediate or resistance to beta-lactams (minimum inhibitory concentration (mic) value range 16-1024 microg/ml). the crude plant extracts demonstrated zone of inh ...200716875811
socioeconomic correlates of antibody levels to enteric pathogens among israeli adolescents.we examined the association between socioeconomic status and the level of serum antibodies to selected faeco-orally transmitted pathogens among israeli adolescents. random samples of eighty volunteers aged 12-15 years from high (hsl), medium (msl) and low (lsl) standard of living towns were included in the study. serum samples were examined by radioimmunoassay for hav and by in-house-developed elisa systems for iga and igg antibody levels against shigella sonnei, s. flexneri, e. coli o157:h7 lip ...200716740193
cholesterol is required to trigger caspase-1 activation and macrophage apoptosis after phagosomal escape of shigella.pro-inflammatory macrophage apoptosis is pivotal in the aetiology of bacillary dysentery, an acute inflammatory diarrhoea caused by shigella spp. s. flexneri triggers its uptake by macrophages, escapes the phagosome and kills the host cell by a cytotoxic pathway, which activates and requires caspase-1 [interleukin (il)-1beta-converting enzyme] and releases mature il-1beta. the bacterial type iii-secreted translocator/effector protein ipab triggers cell death and directly binds to caspase-1. here ...200716925787
phylogenetic analysis of enteric species of the family enterobacteriaceae using the oric-locus.phylogenetic analysis of 38 enteric species belonging to the enterobacteraceae family was carried out using the non-coding locus oric, the chromosomal replication origin. the oric loci were amplified with conserved oligonucleotides and the pcr fragments were sequenced directly. the results establish a phylogenetic tree for the classification of different species of the genera escherichia, shigella, salmonella, enterobacter, citrobacter, klebsiella, raoultella, kluyvera, cedecea and buttiauxella. ...200716904857
structural organization of the needle complex of the type iii secretion apparatus of shigella flexneri.the secretion apparatus known as the needle complex (nc) from the bacterium shigella flexneri was studied by single particle electron microscopy. the isolated intact nc appears in projection to be composed of a basal body consisting of seven rings and a protruding needle appendage. a comparison of averaged projections of the intact nc and its fragments revealed the organization of the nc into several major subcomplexes. one of these lacks an inner membrane ring of the basal body but still presen ...200716920362
short report: analysis of clonal relationship among shigella sonnei isolates circulating in argentina.thirty-five isolates of shigella sonnei from patients with diarrhoea in three geographic regions of argentina were examined for genetic diversity by pulsed-field gel electrophoresis (pfge) and plasmid profile. pfge of xbai and blni dna digests confirmed the occurrence of outbreaks in two regions caused by two separate predominant clones of s. sonnei. the third region was characterized by three circulating clones, one of which was possibly associated with an outbreak. similar plasmids were found ...200716999876
screening antimicrobial activity of various extracts of artemisia dracunculus l.the antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of artemisia dracunculus l. were studied. these extracts were tested against nine bacteria and four yeasts strains by the disc diffusion method. the results indicated that the methanol extract of a. dracunculus is more effective against tested microorganisms than chloroform or acetone extracts. the chloroform and acetone extracts were inhibitory only towards pseudomonas aeruginosa (atcc 2785 ...200716986171
acanthamoeba: could it be an environmental host of shigella?shigellosis is a serious public health problem in korea, because large outbreaks of shigella sonnei infections were recorded in many parts of the country during the period 1998-2000. however, the epidemiological features of shigellosis are not well known. in this study, we devised conditions suitable for the growth and replication of shigella in an amoebic intracellular environment, and investigate whether medium conditions affect the survival and replication of shigella within acanthamoeba. we ...200716978610
bacteriocin-like inhibitor substances produced by mexican strains of bacillus thuringiensis.bacteriocins are antimicrobial peptides synthesized and secreted by bacteria and could potentially be used as natural food preservatives. here, we report the production of bacteriocin-like inhibitor substances (bt-blis) by five mexican strains of bacillus thuringiensis. bacillus thuringiensis subsp. morrisoni (lbit 269), b. thuringiensis subsp. kurstaki (lbit 287), b. thuringiensis subsp kenyae (lbit 404), b. thuringiensis subsp. entomocidus (lbit 420) and b. thuringiensis subsp. tolworthi (lbit ...200717031616
detection of genogroup i and ii human picobirnaviruses showing small genomic rna profile causing acute watery diarrhoea among children in kolkata, india.picobirnaviruses (pbvs) with bisegmented small rna genome profile (1.75 and 1.55kbp for segment 1 and 2, respectively) were detected from 1999 to 2003 in faecal specimens of acute watery diarrhoea cases, largely children (n=20) and an adult in kolkata, india. varying degrees of dehydration necessitated their visit to hospital for further treatment and management of acute watery diarrhoea. pbv was associated with rotavirus (n=3) or astrovirus (n=3) and with both in one case. no co-infection with ...200717049316
an outbreak of extended-spectrum beta-lactamase (esbl)-producing shigella sonnei at a day care nursery in sakai city, 2006. 200718032848
antibiotic resistance and resistance mechanisms in campylobacter jejuni and campylobacter coli.campylobacter jejuni and campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world and infections with these organisms occur more frequently than do infections due to salmonella species, shigella species, or escherichia coli 0157:h7. the incidence of human campylobacter infections has increased markedly in both developed and developing countries worldwide and, more significantly, so has the rapid emergence of antibiotic-resistant campylobacte ...200718031331
the distribution of insertion sequences in the genome of shigella flexneri strain 2457t.shigella flexneri, which causes shigellosis in humans, evolved from escherichia coli. the sequencing of shigella genomes has revealed that a large number of insertion sequence (is) elements (over 200 elements) reside in the genome. although the presence of these elements has been noted previously and summarized, more detailed analyses are required to understand their evolutionary significance. here, the genome of s. flexneri strain 2457t is used to investigate the spatial distribution of is copi ...200718031340
antibacterial activity directed isolation of compounds from punica granatum.chemical investigation of the methanolic extract of pomegranate fruit following antibacterial activity directed isolation led to the isolation of pelargonidin-3-galactose, cyanidin-3-glucose, gallic acid, quercetin, and myricetin. all these compounds exhibited substantial activity against species of corynebacteria, staphylococci, streptococci, bacillus subtilis, shigella, salmonella, vibrio cholera, and escherichia coli. however, all these compounds were more active against gram-positive species ...200718034726
synthesis and evaluation of the antimicrobial activity of novel quinazolinones.a simple and efficient microwave-assisted methodology for regioselective alkylation of exocyclic nitrogen of cyclic amidines was developed and novel n-alkylated 3,4-dihydropyrazino [2,1-b] quinazolin-6-ones were prepared. although none of the molecules tested have any specific anti-quorum sensing (-qs) activity, our result validates the growth tests devised to control the bias of the anti-qs tests. among the molecules studied, compound 2b exhibits interesting activity against the gram-negative b ...200718035826
[characteristic of the etiologic structure of acute enteric infections in adults based on the data from infectious diseases hospital].study of the etiologic spectrum of sporadic cases of causative agents of acute enteric infections (aei) in 753 patients aged 15-85 years old using polymerase chain reaction (pcr) was performed in the infectious diseases hospital during 12 months. it was shown that detection of the causative agents of aei by pcr was 2.2 times more effective than routine microbiologic diagnostics supplemented with test of feces on rotavirus by elisa method and allowed to detect etiologic agent in 54.3% of the pati ...200718038539
changing patterns of antimicrobial susceptibility of shigella serotypes isolated from children with acute diarrhea in manipal, south india, a 5 year study.this study was carried out to determine the current pattern of shigella serogroups and their antimicrobial resistance in children with acute gastroenteritis in manipal, south india. a total of 1,200 stool samples were collected from april 2001 to may 2006 in children suffering from acute gastroenteritis attending the out-patient department of pediatrics at kasturba hospital, manipal, south india. these samples were cultured for enteric pathogens. the isolates were confirmed to be shigella by bio ...200718041303
environmental stress regulates shigella virulence: interplay between anerobiosis and iron acquisition. 200718041901
secretory iga mediates bacterial translocation to dendritic cells in mouse peyer's patches with restriction to mucosal compartment.in addition to fulfilling its function of immune exclusion at mucosal surfaces, secretory iga (siga) ab exhibits the striking feature to adhere selectively to m cells in the mouse and human intestinal peyer's patches (pps). subsequent uptake drives the siga ab to dendritic cells (dcs), which become partially activated. using freshly isolated mouse dcs, we found that the interaction with siga was tissue and dc subtype dependent. only dcs isolated from pps and mesenteric lymph nodes interacted wit ...200718025221
epidemiology and clinical presentation of shigellosis in children less than five years of age in rural mozambique.rectal swabs were collected from 1354 children <5 years of age with diarrhea attending manhiça district hospital and from 227 healthy community controls. shigellosis incidence was high among children aged 12-47 months (488.4/10(5) child-years at risk). fever and dysentery were prominent clinical findings. shigella was more frequently isolated from cases than controls (6.7% versus 0.4%, p = 0.004), and from dysentery than nondysenteric diarrhea (24.1% versus 3.5%, p < 0.001). shigella flexneri 2a ...200717984817
increasing spectrum in antimicrobial resistance of shigella isolates in bangladesh: resistance to azithromycin and ceftriaxone and decreased susceptibility to ciprofloxacin.antimicrobial resistance of shigella isolates in bangladesh, during 2001-2002, was studied and compared with that of 1991-1992 to identify the changes in resistance patterns and trends. a significant increase in resistance to trimethoprim-sulphamethoxazole (from 52% to 72%, p < 0.01) and nalidixic acid (from 19% to 51%, p < 0.01) was detected. high, but unchanged, resistance to tetracycline, ampicillin, and chloramphenicol, low resistance to mecillinam (resistance 3%, intermediate 3%), and to em ...200717985817
outbreaks of shigellosis in denmark and australia associated with imported baby corn, august 2007--final summary.the recently reported concurrent outbreaks of shigella sonnei infections in denmark and australia have been found to be linked to a common baby corn packing house in thailand via trace-back of the distribution chain. distribution records indicated that three additional countries received affected product from the implicated thai packing house during the period of potential contamination. these countries were notified through the world health organization's international food safety authorities n ...200717991373
cross-border investigation of a shigella sonnei outbreak in a group of norwegian tourists after a trip to russia.in early september 2006, the norwegian institute of public health was alerted to an outbreak of shigella sonnei infections (shigellosis) among 23 norwegian passengers who had taken a bus tour from kirkenes, norway to murmansk, russia. the trip lasted from 27 to 31 august, and the group stayed in various hotels and visited several restaurants in both kirkenes and murmansk during this period. stool samples from three ill passengers yielded s. sonnei; an additional 10 passengers had gastrointestina ...200717991389
acute gastrointestinal infection, respiratory illness, and noncombat injury among us military personnel during operation bright star 2005, in northern egypt.in the fall 2005, approximately 7,500 us military personnel participated in an exercise in the egyptian desert. the epidemiology of disease and noncombat injury among deployed troops is important in the context of assessing current mitigation strategies and the development of future ones.200717995535
inactivation of shigella boydii 18 idph and listeria monocytogenes scott a with power ultrasound at different acoustic energy densities and temperatures.the effect of acoustic energy density (aed) on inactivation of shigella boydii 18 idph and listeria monocytogenes scott a in a cell suspension was studied at sublethal temperatures and at aeds of 0.49, 0.85, and 1.43 w/ml. the effect of temperature on ultrasonic inactivation of l. monocytogenes scott a at 35, 50, and 65 degrees c was examined at an aed of 1.43 w/ml. increasing aed increased the rate of inactivation for both s. boydii and l. monocytogenes. the destruction of s. boydii and l. mono ...200717995776
antibacterial activity of some 3-(arylideneamino)-2-phenylquinazoline-4(3h)-ones: synthesis and preliminary qsar studies.synthesis of ten 3-(arylideneamino)-2-phenylquinazoline-4(3h)-ones is reported. all the compounds contained a common phenyl group at the 2-position, while the substituents on the arylideneamino group were varied. the compounds were investigated for their antimicrobial activity against both gram-positive (staphylococcus aureus 6571 and bacillus subtilis) and gram-negative bacteria (escherichia coli k12 and shigella dysenteriae 6) using a turbidometric assay method. it was found that the incorpora ...200717978766
shigella: a sexually transmitted infection in men who have sex with men. 200717983823
type iii secretion effectors of the ipah family are e3 ubiquitin ligases.many bacteria pathogenic for plants or animals, including shigella spp., which is responsible for shigellosis in humans, use a type iii secretion apparatus to inject effector proteins into host cells. effectors alter cell signaling and host responses induced upon infection; however, their precise biochemical activities have been elucidated in very few cases. utilizing saccharomyces cerevisiae as a surrogate host, we show that the shigella effector ipah9.8 interrupts pheromone response signaling ...200718005683
microbial pathogen-induced necrotic cell death mediated by the inflammasome components cias1/cryopyrin/nlrp3 and asc.cryopyrin (cias1, nlrp3) and asc are components of the inflammasome, a multiprotein complex required for caspase-1 activation and cytokine il-1beta production. cias1 mutations underlie autoinflammation characterized by excessive il-1beta secretion. disease-associated cryopyrin also causes a program of necrosis-like cell death in macrophages, the mechanistic details of which are unknown. we find that patient monocytes carrying disease-associated cias1 mutations exhibit excessive necrosis-like dea ...200718005730
uspa of shigella sonnei.one of the strategies that bacteria utilize to combat environmental stress is to synthesize stress-responding proteins. in escherichia coli, adverse environmental factors, such as starvation, heat, and the presence of acid, oxidants, heavy metals, and antibiotics, trigger the expression of the universal stress protein (usp). the gene of the usp, uspa, in e. coli k-12 and e. coli o157:h7 has been identified and sequenced. in this study, the nucleotide sequence of uspa in a strain of shigella sonn ...200717969624
[rapid detection of three foodborne pathogenic bacteria by multiplex polymerase chain reaction-capillary electrophoresis with laser induced fluorescence detector].a method for monitoring foodborne pathogenic bacteria by multiplex polymerase chain reaction (pcr)--capillary electrophoresis (ce) with a laser induced fluorescence detector was developed. three sets of primers were designed to amplify the gene segments of uida gene in e. coli. o157:h7, inva gene in salmonella and ipah gene in shigella, individually. the multiple pcr system and the separation conditions of ce were optimized. using a capillary coated with linear polyacrylamide and sieving buffer ...200717970100
multilocus sequence typing analysis of shigella flexneri isolates collected in asian countries.the multilocus sequence typing scheme used previously for phylogenetic analysis of escherichia coli was applied to 107 clinical isolates of shigella flexneri. dna sequencing of 3423 bp throughout seven housekeeping genes identified eight new allele types and ten new sequence types among the isolates. s. flexneri serotypes 1-5, x and y were clustered together in a group containing many allelic variants while serotype 6 formed a distinct group, as previously established.200717965345
a new asset for pathogen informatics--the enteropathogen resource integration center (eric), an niaid bioinformatics resource center for biodefense and emerging/re-emerging infectious disease.eric (enteropathogen resource information center) is one of the national institute of allergy and infectious diseases (niaid) bioinformatics resource centers for biodefense and emerging/re-emerging infectious disease. eric serves as a comprehensive information resource for five related pathogens: yersinia enterocolitica, yersinia pestis, diarrheagenic e. coli, shigella spp., and salmonella spp. eric integrates genomics, proteomics, biochemical and microbiological information to facilitate the in ...200717966403
[medication in infectious acute diarrhea in children].acute infectious diarrhea in children remain still a frequent cause of morbidity. 50 % of them are due to rotavirus. oral rehydration therapy and early realimentation have drastically reduced their mortality and morbidity. beside oral or eventually iv rehydration therapy no medication has proven its efficacy based on the main hmo criteria (reduction of over 30 % of the stool output) except racecadotril and loperamide which is contre-indicated for the last one in children less than 2 years old. o ...200717961811
crystal structure of an apo form of shigella flexneri arsh protein with an nadph-dependent fmn reductase activity.the arsh gene or its homologs are a frequent part of the arsenic resistance system in bacteria and eukaryotes. although a specific biological function of the gene product is unknown, the arsh protein was annotated as a member of the nadph-dependent fmn reductase family based on a conserved (t/s)xrxxsx(t/s) fingerprint motif common for fmn binding proteins. presented here are the first crystal structure of an arsh protein from shigella flexneri refined at 1.7 a resolution and results of enzymatic ...200717962405
holo- and apo-bound structures of bacterial periplasmic heme-binding proteins.an essential component of heme transport in gram-negative bacterial pathogens is the periplasmic protein that shuttles heme between outer and inner membranes. we have solved the first crystal structures of two such proteins, shut from shigella dysenteriae and phut from pseudomonas aeruginosa. both share a common architecture typical of class iii periplasmic binding proteins. the heme binds in a narrow cleft between the n- and c-terminal binding domains and is coordinated by a tyr residue. a comp ...200717925389
vinculin binding in its closed conformation by a helix addition mechanism.vinculin links integrin receptors to the actin cytoskeleton by binding to talin. vinculin is held in an inactive, closed-clamp conformation through hydrophobic interactions between its head and tail domains, and vinculin activation has long been thought to be dependent upon severing the head-tail interaction. talin, alpha-actinin, and the invasin ipaa of shigella flexneri sever vinculin's head-tail interaction by inserting an alpha-helix into vinculin's n-terminal four-helical bundle, provoking ...200717932491
[serotype distribution and antimicrobial resistance rates of shigella spp. isolates in tehran, iran].in this study, antimicrobial resistance patterns and serotype distributions of shigella spp. isolated from pediatric and adult patients with diarrhea, inhabiting in tehran, were investigated. stool specimens of 1350 patients with diarrhea who were admitted to the seven different hospitals in tehran from november 2003 till march 2005 were taken into the study. antibacterial susceptibility patterns of shigella spp. isolates were determined by standard disk diffusion method. overall isolation rate ...200717933258
[viable but non-culturable form of bacteria].viable but non-culturable (vbnc) bacteria concept has been defined in 1982 when it has been shown that there exists bacteria whose metabolic activity continue and which can have the ability to reproduce in suitable conditions although they have lost their capability to reproduce in culture. recent studies have shown that most of the human pathogens (campylobacter spp., escherichia coli, francisella tularensis, helicobacter pylori, legionella pneumophila, listeria monocytogenes, mycobacterium tub ...200717933263
safety and immunogenicity of cvd 1208s, a live, oral deltaguaba deltasen deltaset shigella flexneri 2a vaccine grown on animal-free media.a previous phase 1 trial demonstrated that shigella flexneri 2a deleted in guaba, sen and set (strain cvd 1208) is well-tolerated and immunogenic after a single oral dose of 10(8) or 10(9) cfu. to facilitate further clinical development, the strain was reconstructed using animal-free media to conform to regulatory guidelines, and designated cvd1208s. healthy inpatient volunteers were randomized (double-blind) to receive a single oral dose of either cvd 1208s (10(8) [n = 7] or 10(9) [n = 7] cfu) ...200717938573
[infectious aetiologies of travelers' diarrhoea].traveler's diarrhoea (td) occurs in 20 to 60% of european or north-american travelers in intertropical areas. following return from endemic zone, malaria must always be evocated in front of febrile diarrhoea. many causative infectious agents are involved in td and their frequency may vary according to destination and seasons. the main agents involved in td are escherichia coli pathovars (especially enterotoxigenic and enteroaggregative e. coli) followed by enteroinvasive bacteria (campylobacter ...200717942257
transcription-termination-mediated immunity and its prevention in bacteriophage sfv of shigella flexneri.the temperate phage sfv encodes the genes responsible for the serotype conversion of shigella flexneri strains from serotype y to 5a. bacteriophages often encode proteins that prevent subsequent infection by homologous phages; the mechanism by which this is accomplished is referred to as superinfection immunity. the serotype conversion mediated following lysogenization of sfv is one such mechanism. another mechanism is the putative lambda-like ci protein within sfv. this study reports the charac ...200717947546
[acute gastroenteritis: the cost of an ambulatory care sensitive condition].acute gastroenteritis (age) has been defined as an ambulatory care sensitive condition. the recommended treatment consists of oral rehydration and rapid reintroduction of food. nevertheless, age remains an important cause of hospitalization. the objective of the present study was to analyze the patient characteristics, management, and costs associated with hospitalizations due to age in a pediatrics department.200717949647
wasp-interacting protein (wip): working in polymerisation and much more.the migration of cells and the movement of some intracellular pathogens, such as shigella and vaccinia, are dependent on the actin-based cytoskeleton. many proteins are involved in regulating the dynamics of the actin-based microfilaments within cells and, among them, wasp and n-wasp have a significant role in the regulation of actin polymerisation. the activity and stability of wasp is regulated by its cellular partner wasp-interacting protein (wip) during the formation of actin-rich structures ...200717949983
increasing antimicrobial resistance--an emerging problem in the treatment of shigellosis.shigellosis is a major cause of diarrhoea-related morbidity and mortality, especially in developing countries. effective antibiotic treatment reduces the average duration of illness by reducing faecal excretion of the bacterium and preventing further transmission and potentially lethal complications. treatment of shigellosis is currently limited by the high prevalence of multidrug-resistant strains of shigella. although fluoroquinolones are currently effective in treating adults, resistance to f ...200717953700
[dysentery in poland in 2005].the number of notified dysentery cases in the three last years (2003, 2004, 2005) is the lowest of all years since 1918 when notification started. only 80 cases were notified in the year 2005 (incidence rate 0.21 /100,000 population), while 74 cases in 2004 (incidence rate 0.19 /100,000 population. no one-death case was notified. the last three death cases were notified in 1999. all together 6 outbreaks were registered, one suspected. out of three dysentery outbreaks, due to s. flexneri 3a--two ...200717956039
[epidemiological analysis of campylobacteriosis reported by sanitary epidemiological station in bielsko-biala, silesia, in poland].the results of the epidemiological analysis of campylobacteriosis reported by regional laboratory of sanitary epidemiological station in bielsko-biala (psse bielsko-biala), silesia voivodeship in poland are presented. from august 2005 to july 2006, stool samples from 723 diarrhea cases were examined for the presence of campylobacter as well as salmonella, shigella, yersinia, enteropathogenic (epec) and enterohaemorrhagic (ehec) e. coli. from stool samples of 163 patients 170 bacterial etiologica ...200717956062
potent inhibitors of trna-guanine transglycosylase, an enzyme linked to the pathogenicity of the shigella bacterium: charge-assisted hydrogen bonding. 200717902085
a new alpha-galactosyl-binding protein from the mushroom lyophyllum decastes.a new alpha-galactosyl binding lectin was isolated from the fruiting bodies of the mushroom lyopyllum decastes. it is a homodimer composed of noncovalently-associated monomers of molecular mass 10,276da. the lectin's amino acid sequence was determined by cloning from a cdna library using partial sequences determined by automated edman sequencing and by mass spectrometry of enzyme-derived peptides. the sequence shows no significant homology to any known protein sequence. analysis of carbohydrate ...200717904093
biochemical characterization of dtdp-d-qui4n and dtdp-d-qui4nac biosynthetic pathways in shigella dysenteriae type 7 and escherichia coli o7.o-antigen variation due to the presence of different types of sugars and sugar linkages is important for the survival of bacteria threatened by host immune systems. the o antigens of shigella dysenteriae type 7 and escherichia coli o7 contain 4-(n-acetylglycyl)amino-4,6-dideoxy-d-glucose (d-qui4nglyac) and 4-acetamido-4,6-dideoxy-d-glucose (d-qui4nac), respectively, which are sugars not often found in studied polysaccharides. in this study, we characterized the biosynthetic pathways for dtdp-d-q ...200717905981
o-antigen modal chain length in shigella flexneri 2a is growth-regulated through rfah-mediated transcriptional control of the wzy gene.shigella flexneri 2a 2457t produces lipopolysaccharide (lps) with two o-antigen (oag) chain lengths: a short (s-oag) controlled by wzzb and a very long (vl-oag) determined by wzz(phs-2). this study demonstrates that the synthesis and length distribution of the s. flexneri oag are under growth-phase-dependent regulation. quantitative electrophoretic analysis showed that the vl-oag increased during growth while the s-oag distribution remained constant. increased production of vl-oag correlated wit ...200717906147
in vitro antimicrobial activity of rifaximin against enteropathogens causing traveler's diarrhea.the in vitro activity of rifaximin against 84 diarrheagenic escherichia coli and 11 shigella sonnei causing traveler's diarrhea was evaluated. the mic of rifaximin ranged between <0.007 and 32 mg/l; other agents tested had an mic of >256 mg/l in most cases. the results showed the potential use of rifaximin to treat these infections.200717889485
[modulation of virulence expression in escherichia coli and shigella spp. by environmental factors]. 200717891998
dynamic proteome changes of shigella flexneri 2a during transition from exponential growth to stationary phase.shigella flexneri is an infectious pathogen that causes dysentery to human, which remains a serious threat to public health, particularly in developing countries. in this study, the global protein expression patterns of s. flexneri during transition from exponential growth to stationary phase in vitro were analyzed by using 2-d page combined with maldi-tof ms. in a time-course experiment with five time points, the relative abundance of 49 protein spots varied significantly. interestingly, a puta ...200717893076
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