mxic is secreted by and controls the substrate specificity of the shigella flexneri type iii secretion apparatus.many gram-negative pathogenic bacteria use a type iii secretion (t3s) system to interact with cells of their hosts. mechanisms controlling the hierarchical addressing of needle subunits, translocators and effectors to the t3s apparatus (t3sa) are still poorly understood. we investigated the function of mxic, the member of the yopn/inve/sepl family in the shigella flexneri t3s system. inactivation of mxic led specifically to a deregulated secretion of effectors (including ipaa, ipgd, icsb, ipgb2, ...200919017268
shigella flexneri type iii secretion system effectors ospb and ospf target the nucleus to downregulate the host inflammatory response via interactions with retinoblastoma protein.ospf, ospg and ipah(9.8) are type iii secretion system (t3ss) effectors of shigella flexneri that downregulate the host innate immune response. ospf modifies mitogen-activated protein kinase pathways and polymorphonuclear leucocyte transepithelial migration associated with shigella invasion. ospf also localizes in the nucleus to mediate chromatin remodelling, resulting in reduced transcription of inflammatory cytokines. we now report that ospb can be added to the set of s. flexneri t3ss effector ...200919017275
spa32 interaction with the inner-membrane spa40 component of the type iii secretion system of shigella flexneri is required for the control of the needle length by a molecular tape measure mechanism.the effectors of enterocyte invasion by shigella are dependent on a type iii secretion system that contains a needle whose length average does not exceed 50 nm. previously, we reported that spa32 is required for needle length control as well as to switch substrate specificity from mxih to ipa proteins secretion. to identify functional domains of spa32, 11 truncated variants were constructed and analysed for their capacity (i) to control the needle's length; (ii) to secrete the ipa proteins; and ...200819019157
antigen-specific b memory cell responses to lipopolysaccharide (lps) and invasion plasmid antigen (ipa) b elicited in volunteers vaccinated with live-attenuated shigella flexneri 2a vaccine candidates.we evaluated b memory responses in healthy adult volunteers who received one oral dose of live-attenuated shigella flexneri 2a vaccine. lps-specific b(m) cells increased from a median of 0 at baseline to 20 spot forming cells (sfc)/10(6) expanded cells following vaccination (p=0.008). a strong correlation was found between post-vaccination anti-lps b(m) cell counts and peak serum anti-lps igg titers (rs=0.95, p=0.0003). increases in b(m) specific for ipab approaching significance were also obser ...200919022324
interaction of enteric bacterial pathogens with murine embryonic stem cells.embryonic stem (es) cells are susceptible to genetic manipulation and retain the potential to differentiate into diverse cell types, which are factors that make them potentially attractive cells for studying host-pathogen interactions. murine es cells were found to be susceptible to invasion by salmonella enterica serovar typhimurium and shigella flexneri and to the formation of attaching and effacing lesions by enteropathogenic escherichia coli. s. enterica serovar typhimurium and s. flexneri c ...200919029302
the acrab-tolc pump is involved in multidrug resistance in clinical shigella flexneri isolates.the two multiple-antibiotic resistance (mar) phenotypes (n = 8, respectively) and susceptible isolates (n = 4) of shigella flexneri from china were characterized involving the efflux pump acrab-tolc. the accumulation of ciprofloxacin, acrab-tolc pcr, and levels of mrna with northern blots were performed in three groups. sequencing of acrab-tolc was performed in selected isolates. an efflux inhibition was performed with phe-arg-beta-naphthylamide. the accumulation of ciprofloxacin at steady state ...200819035770
lactobacilli facilitate maintenance of intestinal membrane integrity during shigella dysenteriae 1 infection in rats.lactobacilli are used in various dairy products and fermented foods for their potential health beneficial effects. recently we reported the protective role of lactobacillus rhamnosus and lactobacillus acidophilus during shigella dysenteriae 1 infection. nevertheless, investigations on the membrane-stabilizing effect of l. rhamnosus and l. acidophilus have not been done. hence, the present study evaluated the effect of l. rhamnosus and l. acidophilus on the maintenance of intestinal membrane inte ...200919036564
selective ccr2-targeted macrophage depletion ameliorates experimental mesangioproliferative glomerulonephritis.the ccl2/ccr2 chemokine/receptor axis directs the chemotaxis of infiltrating monocytes/macrophages and t cells and plays a pivotal role in tissue damage and fibrosis in kidney diseases. the eradication of the activated leucocytes should diminish the production of inflammatory mediators, limit tissue damage and ameliorate disease. a recombinant fusion protein (opl-ccl2-lpm) comprised of the human ccl2 (monocyte chemoattractant protein-1) chemokine fused to a truncated form of the enzymatically ac ...200919040610
gef-h1 mediated control of nod1 dependent nf-kappab activation by shigella effectors.shigella flexneri has evolved the ability to modify host cell function with intracellular active effectors to overcome the intestinal barrier. the detection of these microbial effectors and the initiation of innate immune responses are critical for rapid mucosal defense activation. the guanine nucleotide exchange factor h1 (gef-h1) mediates rhoa activation required for cell invasion by the enteroinvasive pathogen shigella flexneri. surprisingly, gef-h1 is requisite for nf-kappab activation in re ...200819043560
outbreaks where food workers have been implicated in the spread of foodborne disease. part 4. infective doses and pathogen this article, the fourth in a series reviewing the role of food workers in foodborne outbreaks, background information on the presence of enteric pathogens in the community, the numbers of organisms required to initiate an infection, and the length of carriage are presented. although workers have been implicated in outbreaks, they were not always aware of their infections, either because they were in the prodromic phase before symptoms began or because they were asymptomatic carriers. pathoge ...200819044283
contribution of the periplasmic chaperone skp to efficient presentation of the autotransporter icsa on the surface of shigella flexneri.icsa is an outer membrane protein in the autotransporter family that is required for shigella flexneri pathogenesis. following its secretion through the sec translocon, icsa is incorporated into the outer membrane in a process that depends on yaet, a component of an outer membrane beta-barrel insertion machinery. we investigated the role of the periplasmic chaperone skp in icsa maturation. skp is required for the presentation of the mature amino terminus (alpha-domain) of icsa on the bacterial s ...200919047350
characterization of shigella spp. by antimicrobial resistance and pcr detection of ipa genes in an infantile population from porto velho (western amazon region), brazil.the incidence of shigella spp. was assessed in 877 infants from the public hospital in rondônia (western amazon region, brazil) where shigella represents the fourth cause of diarrhea. twenty-five isolates were identified: 18 were shigella flexneri, three shigella sonnei, three shigella boydii and one shigella dysenteriae. with the exception of s. dysenteriae, all shigella spp. isolated from children with diarrhea acquired multiple antibiotic resistances. pcr detection of ipa virulence genes and ...200819057826
tight junctions as targets of infectious agents.the epithelial barrier is a critical border that segregates luminal material from entering tissues. essential components of this epithelial fence are physical intercellular structures termed tight junctions. these junctions use a variety of transmembrane proteins coupled with cytoplasmic adaptors, and the actin cytoskeleton, to attach adjacent cells together thereby forming intercellular seals. breaching of this barrier has profound effects on human health and disease, as barrier deficiencies ha ...200919059200
seasonal stability of cladophora-associated salmonella in lake michigan watersheds.the bacterial pathogens shigella, salmonella, campylobacter, and shiga toxin-producing e. coli (stec) were recently found to be associated with cladophora growing in southern lake michigan. preliminary results indicated that the salmonella strains associated with cladophora were genetically identical to each other. however, because of the small sample size (n=37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between cladophora and salmonella ...200919059626
prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the united kingdom.the prevalences of three sulfonamide resistance genes, sul1, sul2, and sul3 and sulfachloropyridazine (scp) resistance were determined in bacteria isolated from manured agricultural clay soils and slurry samples in the united kingdom over a 2-year period. slurry from tylosin-fed pigs amended with scp and oxytetracycline was used for manuring. isolates positive for sul genes were further screened for the presence of class 1 and 2 integrons. phenotypic resistance to scp was significantly higher in ...200919064898
antibacterial activity of the broad bean extracts on resistant bacteria.the antimicrobial activities of four different extracts (ethanol, methanol, distilled water and 2-methylbutan-1-01) obtained from different parts of broad bean (vicia faba l.) such as flowers, leaves, seeds and seed hulls and were tested against bacillus subtilis, serratia marcescens, staphylococcus aureus, escherichia coli, klebsiella peneumoniua, shigella sp. and micrococcus pyogenes. better antimicrobial activity was observed with the leaves of broad bean sterile distilled water extract with ...200719069508
increased isolation and characterization of shigella sonnei obtained from hospitalized children in tehran, iran.shigella flexneri has been the most frequent cause of shigellosis in children in iran. to evaluate the changes in frequency of serogroups, 302 shigella species were isolated in 2003 from hospitalized children, aged less than 12 years, with acute diarrhoea in tehran, iran. the number of collected s. sonnei, s. flexneri, s. boydii, and s. dysenteriae isolates was 178 (58.9%), 110 (37.4%), 10 (3.3%), and 4 (1.3%) respectively. most (94%) s. sonnei isolates were resistant to co-trimoxazole. they wer ...200819069621
prevalence of bacteria and intestinal parasites among food-handlers in gondar town, northwest with poor personal hygiene working in food-service establishments could be potential sources of infection due to pathogenic organisms. the study was undertaken to determine the prevalence of bacteria and intestinal parasites among 127 food-handlers working in the cafeterias of the university of gondar and the gondar teachers training college, gondar, ethiopia. fingernail contents of both the hands and stool specimens were collected from all the 127 food-handlers. the samples were e ...200819069624
prevalence of shigella serogroups and their antimicrobial resistance patterns in southern trinidad.the serogroup distribution and antimicrobial susceptibility patterns of shigella isolates obtained from stool specimens of persons with acute diarrhoea in community-based studies from southern trinidad during 1997-2006 were reviewed. of the 5,187 stool specimens, 392 (8%) were positive for shigella organisms. from these 392 isolates, 88.8% were recovered from children aged >0-10 year(s). shigella sonnei was the most frequently-isolated serogroup (75%), followed by s. flexneri (19%), s. boydii (4 ...200819069625
the prevalence and antibiotic resistance of shigella sp. recovered from patients admitted to bouali hospital, tehran, iran during 1999-2001.the present study was conducted to determine the prevalence of serotypes and antibiotic resistance in shigella spp. isolated from patients admitted to bouali hospital, tehran, iran during 1999 to 2001. all cases of shigellosis that were diagnosed according to their clinical pictures and microbial cultures were included in current study. patients' age ranged from 12 to 89 years. overall, 52 patients (56%) and 41(44%) were males and female, respectively. from a total of 90 shigella isolates, 40 st ...200719070104
molecular detection of all 34 distinct o-antigen forms of shigella.shigella is the cause of shigellosis or bacillary dysentery, the occurrence of which is estimated to be 165 million cases per year worldwide, resulting in 1.1 million deaths. rapid and reliable assays for detecting and identifying shigella in food, environmental and clinical samples are therefore necessary. shigella species are traditionally identified by their o antigens. this study developed a dna microarray targeting o-serotype-specific genes to detect all 34 distinct o-antigen forms of shige ...200919074655
shigella from humans in thailand during 1993 to 2006: spatial-time trends in species and serotype thailand during 1993-2006, a total of 9063 shigella isolates from different medical centers were serotyped and trends over time and spatial clustering analyzed. of 3583 cases with age information, 1315 (37%) cases were from children between 0 and 4 years and 684 (19%) from children between 5 and 8 years. most infections were recorded during 1993-1994 (> 1500 per year), decreasing to < 200 in 2006. the relative species distribution also changed. during 1993-1994, shigella flexneri accounted fo ...200819086804
[structures of o-polysaccharides from two shigella dysenteriae type 8 strains].the structure of the o-polysaccharide (o-antigen) from shigella dysenteriae type 8 bacteria (strain 599) was corrected using modern nmr techniques (structure 1). the revisions concerned the position of the glc residue (in the main, but not the side, chain), the site of its substitution, and the configuration of the o-glycoside linkage of the glcnac residue. the s. dysenteriae type 8 bacterium (strain g1221), the second investigated representative, was found to produce another structural variant ...200819088755
fungal and bacterial killing by neutrophils.neutrophils are professional phagocytes of the innate immune system that are essential to control bacterial and fungal infections. these cells engulf and kill invading microbes. additionally, activated neutrophils are able to release neutrophil extracellular traps (nets). these fibers consist of chromatin decorated with antimicrobial proteins to trap and kill microbes. appropriate quantitative methods are required to understand the nature of interactions of neutrophils with pathogens. here we pr ...200919089391
genomic analysis of bacteriophage epsilon 34 of salmonella enterica serovar anatum (15+).the presence of prophages has been an important variable in genetic exchange and divergence in most bacteria. this study reports the determination of the genomic sequence of salmonella phage epsilon 34, a temperate bacteriophage that was important in the early study of prophages that modify their hosts' cell surface and is of a type (p22-like) that is common in salmonella genomes.200819091116
analysis of plasmid genes by phylogenetic profiling and visualization of homology relationships using blast2network.phylogenetic methods are well-established bioinformatic tools for sequence analysis, allowing to describe the non-independencies of sequences because of their common ancestor. however, the evolutionary profiles of bacterial genes are often complicated by hidden paralogy and extensive and/or (multiple) horizontal gene transfer (hgt) events which make bifurcating trees often inappropriate. in this context, plasmid sequences are paradigms of network-like relationships characterizing the evolution o ...200819099604
[detection and identification of seven clinical common pathogenic bacteria by oligonucleotide microarray].using 16s rdna and 23s rdna genes as the target sequences to develop a system based on oligonucleotide microarray and to detect the seven clinical pathogenic bacteria, commonly seen.200819103121
water-related diseases outbreaks reported in italy.water related disease outbreak (wrdo) statistics in italy from 1998 to 2005 have been discussed in this paper. the true incidence of wrdo is not reflected in the national surveillance system (nss), although this study has provided information on pathogens associated to different water sources, incidence in regions and inadequacy of regulations. 192 outbreaks and 2546 cases of wrd were reported to the nss, an average of 318 cases per year. cases were associated to shellfish (58.79%), drinking wat ...200819108563
extensive antibody cross-reactivity among infectious gram-negative bacteria revealed by proteome microarray analysis.antibodies provide a sensitive indicator of proteins displayed by bacteria during sepsis. because signals produced by infection are naturally amplified during the antibody response, host immunity can be used to identify biomarkers for proteins that are present at levels currently below detectable limits. we developed a microarray comprising approximately 70% of the 4066 proteins contained within the yersinia pestis proteome to identify antibody biomarkers distinguishing plague from infections ca ...200919112181
antimicrobial activity of prulifloxacin tested against a worldwide collection of gastroenteritis-producing pathogens, including those causing traveler's diarrhea.prulifloxacin, the prodrug of ulifloxacin (active component), is a newer fluoroquinolone with broad activity against enteric and nonenteric gram-negative bacilli. ulifloxacin and other oral comparator agents were tested for activity against 582 gastroenteritis strains from global surveillance studies. ulifloxacin was highly active against escherichia coli, salmonella spp., shigella spp., yersinia spp., vibrio spp., aeromonas spp., and plesiomonas spp. (mic(50)s and mic(90)s, <or=0.03 microg/ml a ...200919114678
diagnosis and prevalence of enteropathogenic bacteria in children less than 5 years of age with acute diarrhea in tehran children's hospitals.acute diarrhea disease is the second cause of death among all infectious diseases in children younger than 5 years of age worldwide. the aim of this study was to employ a combination of biochemical, microbiological and molecular diagnostic techniques to investigate the stools of iranian children with acute diarrhea for bacterial enteropathogens.200919117609
oral immunization: an update.oral immunization with vaccines against intestinal infectious diseases has been extensively explored for several decades. despite the immunologic and economic rationale behind oral immunization, only a few mucosal vaccines are available for the prevention of mucosal infections. here, we summarize the current status of such vaccines, with a focus on intestinal infectious diseases, describe alternative approaches, and analyze advantages and difficulties encountered with a broad implementation of t ...200819122521
antifungal and antibacterial activities of mexican tarragon (tagetes lucida).mexican tarragon (tagetes lucida cv. asteraceae: campanulatae) is an important, nutritious plant and an effective herbal medicine. seven coumarins, 7,8-dihydroxycoumarin (4), umbelliferone (7-hydroxycoumarin) (5), scoparone (6,7-dimethoxycoumarin) (7), esculetin (6,7-dihydroxycoumarin) (11), 6-hydroxy-7-methoxycoumarin (12), herniarin (7-methoxycoumarin) (13), and scopoletin (6-methoxy-7-hydroxycoumarin) (14), and three flavonoids, patuletin (18), quercetin (19), and quercetagetin (20), were iso ...200619127719
bacterial particle endocytosis by epithelial cells is selective and enhanced by tumor necrosis factor receptor ligands.bacterial pathogens use virulence strategies to invade epithelial barriers, but active processes of epithelial cells may also contribute to the endocytosis of microbial particles. to focus on the latter, we studied the uptake of fixed and fluorescently labeled bacterial particles in intestinal and bronchoepithelial cell cultures and found it to be enhanced in caco-2bbe and nci-h292 cells after treatment with tumor necrosis factor alpha and an agonist antibody against the lymphotoxin beta recepto ...200919129472
genetics and environmental regulation of shigella iron transport systems.shigella spp. have transport systems for both ferric and ferrous iron. the iron can be taken up as free iron or complexed to a variety of carriers. all shigella species have both the feo and sit systems for acquisition of ferrous iron, and all have at least one siderophore-mediated system for transport of ferric iron. several of the transport systems, including sit, iuc/iuta (aerobactin synthesis and transport), fec (ferric di-citrate uptake), and shu (heme transport) are encoded within pathogen ...200919130265
outbreaks of shigella sonnei infections in denmark and australia linked to consumption of imported raw baby corn.we investigated an outbreak of shigella sonnei infections in denmark and australia associated with imported baby corn from one packing shed in thailand. we reviewed nationwide surveillance and undertook case finding, food trace-back and microbiological investigation of human, food and environmental samples. a recall of baby corn and sugar snaps was based on descriptive epidemiological evidence. in denmark, we undertook a retrospective cohort study in one workplace. in total, 215 cases were labor ...200919134229
frequency of isolation of various subtypes and antimicrobial resistance of shigella from urban slums of karachi, pakistan.shigellosis remains a major public health problem in developing countries. antimicrobial resistance has complicated the empirical treatment. knowledge of serotypes is crucial in vaccine development, as cross-protection between various serotypes is limited. therefore we conducted a prospective study to determine the frequency of isolation of shigella serotypes and antimicrobial resistance.200919135399
safety and immunogenicity of sc599, an oral live attenuated shigella dysenteriae type-1 vaccine in healthy volunteers: results of a phase 2, randomized, double-blind placebo-controlled trial.sc599 vaccine is a live shigella dysenteriae 1 strain attenuated by deletion of invasion [icsa], iron chelation [ent, fep] and shiga toxin a subunit [stxa] genes. in a preliminary phase 1 single dose prospective study, we showed that sc599 vaccine was well tolerated, and the maximum tolerable dose was greater than 10(8) cfu [sadorge c, ndiaye a, beveridge n, frazer s, giemza r, jolly n, et al. phase 1 clinical trial of live attenuated shigella dysenteriae type-1 deltaicsa deltaent deltafep delta ...200919135496
trends in antimicrobial resistance of fecal shigella and salmonella isolates in tehran, iran.the resistance of bacteria to commonly prescribed antibiotics is increasing both in developing as well as developed countries. resistance has emerged even to newer, more potent antimicrobial agents. the present study was therefore undertaken to report resistance rates to antimicrobial agents in 2487 stool culture isolates in a tertiary care hospital between 1996 and 2000 and 2001 and 2005.200919136781
in silico comparison of simple sequence repeats in high nucleotides-rich genomes of microorganism.this study determined the distribution of a specific group of simple sequence repeats (ssrs), in genome sequences of 7 chromosomes (shigella flexneri 2a str 301 and 2457 t, shigella sonnei, e. coli k12, m. tuberculosis, m. leprae and s. saprophytycus) have downloaded from the genbank database for identifying abundance, distribution and composition of ssrs. the data obtained in the present study show that: (i) tandem repeats are widely distributed throughout the genomes. (ii) ssrs are differentia ...200819137845
rapid emergence of third generation cephalosporin resistant shigella spp. in southern vietnam. 200919141753
giardia duodenalis assemblages associated with diarrhea in children in south india identified by pcr-rflp.giardial diarrhea in a birth cohort of 452 children in an urban slum in south india was characterized. of the 155 episodes that occurred in 99 children, 73% were acute diarrhea. children with better educated mothers and a toilet at home had lower odds of acquiring giardial diarrhea, whereas low socioeconomic status and drinking municipal water were associated with greater risk. children with co-infections tended to have a slightly longer duration of diarrhea (p = 0.061) and showed significantly ...200919141832
improvement in detection of enterotoxigenic escherichia coli in patients with travelers' diarrhea by increasing the number of e. coli colonies cause of one-third of travelers' diarrhea (td) cases can be detected despite microbiologic assessment. we propose that these pathogen-negative td cases include undetected enterotoxigenic escherichia coli (etec). as a standard in diagnostic microbiology, samples of five e. coli colonies were tested to detect etec from stool cultures. we compared the sensitivities and the number of etec detected by 20 colonies with those of 5, 10, and 15 colonies. the percent detection of etec with five e. coli ...200919141833
septins regulate bacterial entry into host cells.septins are conserved gtpases that form filaments and are required in many organisms for several processes including cytokinesis. we previously identified sept9 associated with phagosomes containing latex beads coated with the listeria surface protein inlb.200919145258
etiology of acute gastroenteritis in three sentinel general practices, austria 2007.we studied the etiology of acute gastroenteritis in a village with a total population of approximately 6,000. this is the first study in austria that has investigated a broad range of pathogens recovered from an unselected population of patients who had consulted general practitioners because of gastroenteritis.200919148576
[typing of shigella sonnei strains isolated in some provinces of turkey using antimicrobial resistance and pulsed field gel electrophoresis methods].shigella species may lead to large epidemics owing to their low infective doses and frequent transmission from person to person with high secondary attack rates. shigella sonnei is one of the most prevalent causative agent of infectious gastroenteritis in developing and developed countries and it is the most frequently reported shigella serotype from turkey in recent years. the aim of this study was to determine the types of s. sonnei strains isolated in different provinces of turkey [in marmara ...200819149077
[evaluation of laboratory diagnosis of the first norovirus outbreak in turkey in 2008].norovirus (nov) is one of the most prominent agents of gastroenteritis and water/food-borne outbreaks affecting all of the age groups in the world. as the identification of the etiologic agent is important during gastroenteritis outbreaks, it is recommended to combine two different methods for rapid and reliable laboratory diagnosis of nov. although nov outbreaks have been observed in many different countries of the world, there was no report on "nov outbreak" in turkey till 2008 due to the abse ...200819149082
functions and pathologies of bip and its interaction partners.the endoplasmic reticulum (er) is involved in a variety of essential and interconnected processes in human cells, including protein biogenesis, signal transduction, and calcium homeostasis. the central player in all these processes is the er-lumenal polypeptide chain binding protein bip that acts as a molecular chaperone. bip belongs to the heat shock protein 70 (hsp70) family and crucially depends on a number of interaction partners, including co-chaperones, nucleotide exchange factors, and sig ...200919151922
overexpression, purification, characterization and preliminary crystallographic study of phosphoglycolate phosphatase from shigella flexneri 2a strain 301.phosphoglycolate phosphatase has a salvage function in the metabolism of the 2-phosphoglycolate formed during bacterial dna repair. in order to better understand its dimerization behaviour, the influence of metal ions on its activity and its catalytic mechanism at the molecular level, recombinant phosphoglycolate phosphatase from shigella flexneri was overexpressed, purified, characterized and crystallized by the hanging-drop vapour-diffusion method at 291 k using polyethylene glycol 3500 as a p ...200919153451
simultaneous detection of multifood-borne pathogenic bacteria based on functionalized quantum dots coupled with immunomagnetic separation in food samples.this paper reports a method that simultaneously detects three food-borne pathogenic bacteria, salmonella typhimurium, shigella flexneri, and escherichia coli o157:h7, via an approach that combines magnetic microparticles for the enrichment and antibody-conjugated semiconductor quantum dots (qds) as fluorescence markers. using the water-in-oil reverse microemulsions method, the gamma-fe(2)o(3) magnetic nanoparticles were coated with silica to empower the particles with high dispersibility and bro ...200919154162
shigella type iii secretion effectors: how, where, when, for what purposes?bacteria of shigella spp., the causative agents of shigellosis in humans, possess a repertoire of approximately 25-30 effectors injected into host cells by a type iii secretion apparatus (t3sa). the t3sa activity is activated upon contact of bacteria with cells and controls expression of some effectors. recent structural and functional studies suggest that two different sets of effectors are involved in inducing actin cytoskeleton reorganization to promote entry of bacteria into epithelial cells ...200919157960
rapid dna amplification using a battery-powered thin-film resistive thermocycler.a prototype handheld, compact, rapid thermocycler was developed for multiplex analysis of nucleic acids in an inexpensive, portable configuration. instead of the commonly used peltier heating/cooling element, electric thin-film resistive heater and a miniature fan enable rapid heating and cooling of glass capillaries leading to a simple, low-cost thin-film resistive thermocycler (tfrt). computer-based pulse width modulation control yields heating rates of 6-7 k/s and cooling rates of 5 k/s. the ...200919159110
organised genome dynamics in the escherichia coli species results in highly diverse adaptive paths.the escherichia coli species represents one of the best-studied model organisms, but also encompasses a variety of commensal and pathogenic strains that diversify by high rates of genetic change. we uniformly (re-) annotated the genomes of 20 commensal and pathogenic e. coli strains and one strain of e. fergusonii (the closest e. coli related species), including seven that we sequenced to completion. within the approximately 18,000 families of orthologous genes, we found approximately 2,000 comm ...200919165319
the ipac carboxyterminal effector domain mediates src-dependent actin polymerization during shigella invasion of epithelial cells.shigella, the causative agent of bacillary dysentery, invades epithelial cells by locally reorganizing the actin cytoskeleton. shigella invasion requires actin polymerization dependent on the src tyrosine kinase and a functional bacterial type iii secretion (t3s) apparatus. using dynamic as well as immunofluorescence microscopy, we show that the t3s translocon component ipac allows the recruitment of the src kinase required for actin polymerization at bacterial entry sites during the initial sta ...200919165331
shigella and salmonella serogroups and their antibiotic susceptibility patterns in this study, the serogroup and susceptibility patterns of shigella and salmonella spp. isolated from stool cultures were determined using standard laboratory procedures. among the 76 shigella isolates serogroup b (sh. flexeneri) was the most prevalent species (54.0%) and among the 37 salmonella strains serogroup b was also the most prevalent (81.1%). antibiograms of shigella and salmonella spp. showed 100% resistance to erythromycin and high resistance rates (> or = 75%) to ampicillin, cephalo ...200819166157
phage-mediated shiga toxin 2 gene transfer in food and water.shiga toxin (stx) transduction in various food matrices has been evaluated with lysogens of stx phages. stx transduction events were observed for many phages under appropriate conditions. transduction did not occur at low ph and low temperatures. a total of 10(3) to 10(4) cfu ml(-1) was the minimal amount of donor and recipient strains necessary to generate transductants.200919168651
short report: high prevalence of serine protease autotransporter cytotoxins among strains of enteroaggregative escherichia coli.enteroaggregative escherichia coli (eaec) pathogenesis is thought to comprise intestinal colonization followed by the release of enterotoxins and cytotoxins. here, we use a polymerase chain reaction (pcr) to determine the prevalence of 10 genes encoding serine protease autotransporter toxins (spates) in a collection of clinical eaec isolates. eighty-six percent of eaec strains harbored genes encoding one or more class i cytotoxic spate proteins (pet, sat, espp, or siga). two class ii, non-cytoto ...200919190229
molecular epidemiological characteristics of shigella spp. isolated from river narmada during 2005-2006.shigellosis is an acute gastroenteritis caused by shigella species. forty isolates of shigella spp. were obtained from the river narmada during 2005-2006. twenty-three isolates were identified as s. flexneri, 10 as s. sonnei, and seven as s. dysenteriae on the basis of biochemical tests and serotyping. all the isolates harbored at least one plasmid (range: 1-4) and exhibited 12 distinct plasmid profile patterns. out of 40 isolates, 90% were found to be resistant against more than two antibiotics ...200919192746
crystal structure analysis and in silico pka calculations suggest strong pka shifts of ligands as driving force for high-affinity binding to tgt.a novel ligand series is presented to inhibit trna-guanine transglycosylase (tgt), a protein with a significant role in the pathogenicity mechanism of shigella flexneri, the causative agent of shigellosis. the enzyme exchanges guanine in the wobble position of trna(asn,asp,his,tyr) against a modified base. to prevent the base-exchange reaction, several series of inhibitors have already been designed, synthesized, and tested. one aim of previous studies was to address a hydrophobic pocket with di ...200919199329
streptococcus-, shigella-, and listeria-induced autophagy.autophagy has recently been described as an intrinsic host defense system for recognizing and eliminating intracellular-invading bacterial pathogens. some cytoplasmic-invading bacteria are trapped through the process of autophagy and are ultimately degraded within autolysosomal compartments. however, others exhibit highly evolved maneuvers for circumventing autophagic recognition and are capable of surviving and replicating within the cytoplasm. in this chapter, we describe bacterial infectious ...200919200893
a synthetic carbohydrate-protein conjugate vaccine candidate against shigella flexneri 2a infection.the protective ag of shigella, the gram-negative enteroinvasive bacterium causing bacillary dysentery, or shigellosis, is its o-specific polysaccharide (o-sp) domain of the lps, the major bacterial surface component. as an alternative to the development of detoxified lps-based conjugate vaccines, recent effort was put into the investigation of neoglycoproteins encompassing synthetic oligosaccharides mimicking the protective ags of the o-sp. we previously reported that when coupled to tetanus tox ...200919201878
development of prophylactic recombinant hpv58-attenuated shigella live vector vaccine and evaluation of its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis develop a prophylactic recombinant hpv58l1-attenuated shigella live vector vaccine and evaluate its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model, the hpv58l1 gene was cloned into vector pucmt, and then subcloned into the suicide vector pcvd442. the recombinant plasmid pcvd442-hpv58l1 was introduced into attenuated shigella (sf301:deltavirg) with the helper plasmid prk2013 by filter mating. the positive colonies were harvested and confirmed by polymerase ...200919204831
antimicrobial activity of some macrophytes from lake manzalah (egypt).the antimicrobial activities of aqueous and organic solvents (chloroform, ethanol and methanol) extracts of four plants ceratophyllum demersum l., eichhornia crassipes, potamogeton crispus and potamogeton pectinatus were tested in vitro against seventeen different microorganisms including gram-positive and gram-negative bacteria and fungi. nine of these identified organisms were obtained from different sources, bacillus subtilis 1020, bacillus cereus 1080, staphylococcus aureus, erwinia carotovo ...200819205264
the poultry red mite (dermanyssus gallinae): a potential vector of pathogenic agents.the poultry red mite, d. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans. nowadays, few effective methods are available to control the ectoparasite in poultry farms. consequently, this is an emerging problem which must be taken into account to maintain good health in commercial egg production. this paper addresses the vector capacity of the ectoparasite with special emphasis on salmonellae, pathogenic agents re ...200919205905
pathogen trafficking pathways and host phosphoinositide metabolism.phosphoinositide (pi) glycerolipids are key regulators of eukaryotic signal transduction, cytoskeleton architecture and membrane dynamics. the host cell pi metabolism is targeted by intracellular bacterial pathogens, which evolved intricate strategies to modulate uptake processes and vesicle trafficking pathways. upon entering eukaryotic host cells, pathogenic bacteria replicate in distinct vacuoles or in the host cytoplasm. vacuolar pathogens manipulate pi levels to mimic or modify membranes of ...200919208094
a look back at an ongoing problem: shigella dysenteriae type 1 epidemics in refugee settings in central africa (1993-1995).shigella dysenteriae type 1 (sd1) is a cause of major dysentery outbreaks, particularly among children and displaced populations in tropical countries. although outbreaks continue, the characteristics of such outbreaks have rarely been documented. here, we describe the sd1 outbreaks occurring between 1993 and 1995 in 11 refugee settlements in rwanda, tanzania and democratic republic of the congo (drc). we also explored the links between the different types of the camps and the magnitude of the o ...200919214226
antimicrobial pentacyclic triterpenoids from terminalia superba.antibacterial bioassay-guided fractionation of the methanol extract of the stem bark of terminalia superba led to the isolation of four new triterpene glucosides (1-4) which were characterized as 2 alpha,3 beta-dihydroxyolean-12-en-28-oic acid 28-o-beta-d-glucopyranoside (1), 2 alpha,3 beta, 21 beta-trihydroxyolean-12-en-28-oic acid 28-o-beta-d-glucopyranoside (2), 2 alpha,3 beta, 29-trihydroxyolean-12-en-28-oic acid 28-o-beta-d-glucopyranoside (3) and 2 alpha,3 beta,23,27-tetrahydroxyolean-12-e ...200919214947
apyrase-based colorimetric test for detection of shigella and enteroinvasive escherichia coli in stool.for lack of simple inexpensive early detection methods for shigella spp. and enteroinvasive escherichia coli (eiec), bacillary dysentery remains a major cause of childhood mortality and morbidity in india and other developing countries. rapid stool testing for apyrase, a specific periplasmic enzyme essential for the pathogen's intracellular spread, may provide a solution. we have developed a whole-cell colorimetric pyrophosphate hydrolysis assay based on cheap, stable, and locally available reag ...200919216937
shigella targets the mitochondrial checkpoint of programmed nonmyeloid cells, shigella hijacks the mitochondrial checkpoint of cell death, thereby inducing a regulated form of necrosis depending on bnip3 and cyclophilin d. carneiro et al. (2009) describe the interplay between this program and a prosurvival response transmitted via the nod1/rip2/nf-kappab/bcl-2 axis, which determines the fate of infected cells.200919218080
shigella induces mitochondrial dysfunction and cell death in nonmyleoid cells.shigella rapidly kills myeloid cells via a caspase-1 inflammasome-dependent cell death mechanism. however, despite a critical role for nonmyeloid cells in the physiopathology of shigella infection, the mechanism by which shigella kills nonmyeloid cells remains uncharacterized. here we demonstrate that, in nonmyeloid cells, shigella infection induces loss of mitochondrial inner membrane potential, mitochondrial damage, and necrotic cell death through a pathway dependent on bnip3 and cyclophilin d ...200919218084
the 3'-to-5' exoribonuclease (encoded by hp1248) of helicobacter pylori regulates motility and apoptosis-inducing genes.the human gastric pathogen helicobacter pylori has many virulence factors involved in pathogenesis, but the mechanisms regulating these virulence factors are not yet fully understood. in this study, we cloned hp1248, which is similar in sequence to escherichia coli vacb, which was previously shown to be associated with the expression of virulence in shigella and enteroinvasive e. coli. e. coli vacb encodes rnase r. rnase r is involved in the posttranscriptional regulation of mrna stability. by g ...200919218383
the expression of lipopolysaccharide by strains of shigella dysenteriae, shigella flexneri and shigella boydii and their cross-reacting strains of escherichia coli.strains of shigella dysenteriae, shigella flexneri and shigella boydii express lipopolysaccharides, that enable the serotyping of strains based on their antigenic structures. certain strains of s. dysenteriae, s. flexneri and s. boydii are known to share epitopes with strains of escherichia coli; however, the lipopolysaccharide profiles of the cross-reacting organisms have not been compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) lipopolysaccharides profiling. in ...200919222579
[distribution and antibiotic resistance of pathogens isolated from children with infectious diarrhea in guangzhou].to study the distribution and antibiotic resistance of the isolated pathogens from children with infectious diarrhea in guangzhou.200919222945
mucosal adjuvanticity of a shigella invasin complex with dna-based against many infectious diseases may require the induction of cell-mediated and mucosal immunity. immunization with plasmid dna-based vaccines has successfully induced cell-mediated immune responses in small animals but is less potent in humans. therefore, several methods are under investigation to augment dna vaccine immunogenicity. in the current study, a mucosal adjuvant consisting of an invasin protein-lipopolysaccharide complex (invaplex) isolated from shigella spp. was evaluated ...200919225079
utility of multilocus variable-number tandem-repeat analysis as a molecular tool for phylogenetic analysis of shigella sonnei.a panel of 916 isolates, including 703 closely related ist1 isolates, were characterized by inter-is1 spacer typing (ist), pulsed-field gel electrophoresis (pfge), and multilocus variable-number tandem-repeat (vntr) analysis (mlva) to evaluate the utility of mlva as a molecular tool for the phylogenetic analysis of shigella sonnei. the global phylogenetic patterns determined by ist, pfge, and mlva were concordant. mlva was carried out using 26 vntr loci with a range of degrees of variability. ml ...200919225095
eliminylation: a post-translational modification catalyzed by phosphothreonine lyases.we propose the classification of a protein post-translational modification, eliminylation, based on the recently delineated mechanism of the shigella ospf and salmonella spvc phosphothreonine lyases. these bacterial type-iii secretion-system virulence factors are injected into eukaryotic cells and inhibit signalling by irreversibly inactivating mitogen-activated protein kinases (mapks). remarkably, they employ an unusual beta-elimination reaction, removing the phosphate from phosphothreonine and ...200919233656
analytical specificity and sensitivity of a real-time polymerase chain reaction assay for identification of bovine mastitis pathogens.intramammary infection (imi), also known as mastitis, is the most frequently occurring and economically the most important infectious disease in dairy cattle. this study provides a validation of the analytical specificity and sensitivity of a real-time pcr-based assay that identifies 11 major pathogen species or species groups responsible for imi, and a gene coding for staphylococcal beta-lactamase production (penicillin resistance). altogether, 643 culture isolates originating from clinical bov ...200919233788
coliforms and prevalence of escherichia coli and foodborne pathogens on minimally processed spinach in two packing plants.minimally processed spinach has been recently associated with outbreaks of foodborne illnesses. this study investigated the effect of commercial minimal processing of spinach on the coliform and escherichia coli counts and the prevalence of e. coli o157:h7, salmonella, shigella spp., and listeria monocytogenes on two types of spinach before and after minimal processing. a total of 1,356 spinach samples (baby spinach, n = 574; savoy spinach, n = 782) were collected daily in two processing plants ...200819244890
a similarity in the o-acetylation pattern of the o-antigens of shigellaflexneri types 1a, 1b, and 2a.shigella flexneri type 2a is the first, and type 1b is the second, most prevalent isolates from patients with shigellosis in russia. the o-specific polysaccharides (opss, o-antigens) of s. flexneri types 1-5 possess a common -->2)-alpha-l-rhapiii-(1-->2)-alpha-l-rhapii-(1-->3)-alpha-l-rhapi-(1-->3)-beta-d-glcpnac-(1--> backbone and differ from each other in its glucosylation or/and o-acetylation at various positions, the modifications being responsible for various o-factors. it was suggested tha ...200919246033
interactions of the intestinal epithelium with the pathogen and the indigenous microbiota: a three-way crosstalk.the mucosal surfaces of the gastrointestinal tract harbor a vast number of commensal microbiota that have coevolved with the host, and in addition display one of the most complex relationships with the host. this relationship affects several important aspects of the biology of the host including the synthesis of nutrients, protection against infection, and the development of the immune system. on the other hand, despite the existence of several lines of mucosal defense mechanisms, pathogenic org ...200819259328
the clinical course of postinfectious irritable bowel syndrome: a five-year follow-up study.irritable bowel syndrome (ibs) is a common disorder seen in general practice. bacterial gastroenteritis has been known to be a risk factor for ibs. we investigated the clinical course, risk factors, and prognosis of postinfectious ibs (pi-ibs) 5 years after shigella infection.200919262407
the mere protein encoded by transposon tn21 is a broad mercury transporter in escherichia order to clarify the physiological role of the mere gene of transposon tn21, a pe4 plasmid that contained the merr gene of plasmid pmr26 from pseudomonas strain k-62, and the mere gene of tn21 from the shigella flexneri plasmid nr1 (r100) was constructed. bacteria with plasmid pe4 (merr-o/p-mere) were more hypersensitive to ch(3)hg(i) and hg(ii), and took up significantly more ch(3)hg(i) and hg(ii), than the isogenic strain. the mere protein encoded by pe4 was localized in the membrane cell f ...200919265693
piscidin 4, a novel member of the piscidin family of antimicrobial peptides.piscidins are linear, amphipathic, antimicrobial peptides (amps) with broad, potent, activity spectrum. piscidins and other members of the piscidin family appear to comprise the most common group of amps in teleost fish. all piscidins and related members of the piscidin family described to date are 18-26 amino acids long.we report here the isolation of a novel 5329.25 da, 44-residue (ffrhlfrgakaifrgarqgxrahkvvsryrnrdvpetdnnqeep) antimicrobial peptide from hybrid striped bass (morone chrysops fem ...200919266617
high-let ion radiolysis of water: oxygen production in is known that molecular oxygen is a product of the radiolysis of water with high-linear energy transfer (let) radiation, a result that is of particular significance in radiobiology and of practical relevance in radiotherapy. in fact, it has been suggested that the radiolytic formation of an oxygenated microenvironment around the tracks of high-let heavy ions is an important factor in their enhanced biological efficiency in the sense that this may be due to an "oxygen effect" by o(2) produced ...200919267566
the effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance.bactericidal activity of traditional titanium dioxide (tio2) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of tio2 for use in our living environments. recently carbon-containing tio2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. evidenced from scanning e ...200919272171
characterisation of early mucosal and neuronal lesions following shigella flexneri infection in human colon.shigella, an enteroinvasive bacteria induces a major inflammatory response responsible for acute rectocolitis in humans. however, early effect of shigella flexneri (s. flexneri) infection upon the human mucosa and its microenvironement, in particular the enteric nervous system, remains currently unknown. therefore, in this study, we sought to characterize ex vivo the early events of shigellosis in a model of human colonic explants. in particular, we aimed at identifying factors produced by s. fl ...200919274103
efficient synthesis of six tri- to hexasaccharide fragments of shigella flexneri serotypes 3a and/or x o-antigen, including a study on acceptors containing n-trichloroacetylglucosamine versus n-acetylglucosamine.six tri- to hexasaccharide fragments of the {2)-[alpha-d-glcp-(1-->3)]-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-[ac-->2]-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->}(n) polymer ([(e)ab(ac)cd](n)) were synthesized as their propyl glycosides. all targets share the (e)ab sequence. following a thorough investigation on the use of n-trichloroacetylglucosamine- versus n-acetylglucosamine-containing tri- and tetrasaccharide acceptors, the successful strategy was based on an efficient combination of the ...200919278208
foodborne outbreaks, austria 2007 austria reported a total of 438 foodborne outbreaks affecting 1715 people, including 286 hospitalized patients and one death. salmonella spp. and campylobacter spp. accounted for 95% of all reported outbreaks. forty-eight (11%) of the 438 austrian outbreaks were acquired abroad. of the 390 domestically acquired foodborne outbreaks, bacterial infection caused 376, viruses (norovirus and 1-time hepatitis a virus) caused 11, and intoxications (staphylococcus aureus enterotoxins, alkaloid to ...200919280130
a food-borne outbreak of shigella sonnei gastroenteritis, austria, 2008.we report on the first foodborne outbreak of shigella sonnei described in austria. on july 14 2008, ages was informed of a cluster of 22 laboratory-confirmed cases of infection with s. sonnei restricted to public health district x in the province of salzburg. all cases had attended a youth-group trip to a small village in the province of tyrol from july 7 to july 9. an outbreak case among the trip participants was a person who (1) attended the trip and (2) fell ill with diarrhea in the period be ...200919280143
tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children.the aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (rei) caused by bacteria, specifically campylobacter, salmonella, escherichia coli o157, or shigella (rei-b).200919281302
application of a multiplex pcr assay for the detection of shigella, escherichia coli and shiga toxin-producing esch. coli in milk.a multiplex pcr (mpcr) assay using previously known genetic markers of shigella, escherichia coli and shiga-toxic esch. coli was standardized. uida gene was targeted for the common detection of esch. coli and shigella, whereas ipah and stx1 genes were used as markers for the detection of shigella and shiga-toxin producing strains, respectively. the standardized assays detected the target organism specifically and selectively. the mpcr developed by combining all the three reactions generated spec ...200919281632
antibacterial antibodies for some enterobacteria in sera of patients with reactive arthritis and other rheumatoid diseases.the presence of the specific antibodies for some enterobacteria--yersinia, salmonella and shigella was investigated in patients hospitalized in the period 2000-2007 with reactive arthritis and other rheumatoid diseases. the antibacterial antibodies in the diagnosis titres were found in 172 out of 1102 (15.6%) patients. increased antibodies levels to yersinia were detected in the sera from 113 (65.7%) of the 172 patients, for shigella in 47 (27.3%) and for salmonella in 12 (7.0%) cases. from all ...200819284164
genetics and virulence association of the shigella flexneri sit iron transport system.the sit-encoded iron transport system is present within pathogenicity islands in all shigella spp. and some pathogenic escherichia coli strains. the islands contain numerous insertion elements and sequences with homology to bacteriophage genes. the shigella flexneri sit genes can be lost as a result of deletion within the island. the formation of deletions was dependent upon reca and occurred at relatively high frequency. this suggests that the sit region is inherently unstable, yet sit genes ar ...200919289511
acute non-outbreak shigellosis: ten years experience in southern taiwan.we conducted a retrospective study of both the clinical and laboratory characteristics of shigellosis in southern taiwan.200919292940
the changing panorama of bacterial enteric infections.we studied the age-specific population-based incidence of bacterial enteric infections caused by shigella, salmonella and campylobacter, in jerusalem. during 1990-2008, 32,408 cases were reported (incidence rate 232.1/100,000 per annum). the patterns of shigella (47.4% of cases), salmonella (34.4%) and campylobacter (18.2%) infections evolved noticeably. campylobacter rates increased from 15.0 to 110.8/100,000 per annum. salmonella rates increased from 74.2 to 199.6/100,000 in 1995 then decrease ...200919296872
characterization of fluoroquinolone-resistant shigella flexneri in hangzhou area of china.the aim of this study was to characterize fluoroquinolone-resistant shigella and determine whether the qnr and aac(6')-ib-cr genes could contribute to sporadic shigellosis at the clinic in the hangzhou area of china.200919297378
serodiversity and antimicrobial resistance pattern of shigella isolates at gondar university teaching hospital, northwest ethiopia.the aims of this study were to determine the distribution of serogroups and serotypes as well as the antimicrobial resistance pattern of shigella isolates from gondar patients with acute diarrhea. a cross-sectional study was conducted from august 2006 to february 2008. stool specimens were received from study subjects and cultured. isolates were confirmed by biochemical and serological tests. the isolates were tested for antimicrobial susceptibility by the disc diffusion method. of the 1,200 sto ...200919305047
green banana reduces clinical severity of childhood shigellosis: a double-blind, randomized, controlled clinical trial.mature green banana (gb) fruit is rich in amylase-resistant starch that stimulates colonic production of short-chain fatty acids (referred to as fatty acid) and is useful in treating diarrheal diseases. we studied therapeutic effects of gb in childhood shigellosis by determining colonic fatty acid production in a double-blind, randomized, controlled, clinical trial.200919319017
structure and heme binding properties of escherichia coli o157:h7 chux.for many pathogenic microorganisms, iron acquisition from host heme sources stimulates growth, multiplication, ultimately enabling successful survival and colonization. in gram-negative escherichia coli o157:h7, shigella dysenteriae and yersinia enterocolitica the genes encoded within the heme utilization operon enable the effective uptake and utilization of heme as an iron source. while the complement of proteins responsible for heme internalization has been determined in these organisms, the f ...200919319934
surveillance of antibiotic susceptibility patterns among shigella sonnei strains isolated in belgium during the 18-year period 1990 to 2007.this study was conducted to determine the frequency and pattern of antimicrobial susceptibility of shigella sonnei, the predominant species causing shigellosis in belgium. between 1990 and 2007, a total of 7,307 strains, mainly (98.2%) isolated from stools, were diagnosed by peripheral laboratories before being confirmed as shigella strains by serotyping by the national reference center of salmonella and shigella. a significant increase in resistances to tetracycline, streptomycin, trimethoprim, ...200919321731
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