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Gut microbiota and pediatric disease.Background: Researchers have made every effort to assess the role of gut microbiota in pediatric diseases like inflammatory bowel disease (IBD), celiac disease, asthma, allergy, and autism. The leading hypothesis is that an altered microbial composition is present (other than the presence of a specific pathogen) and that it could be involved in the pathogenesis or progression of such disorders. Methods: Cultural, molecular, metabolomic, and metagenomic approaches are trying to define the pediatr ...201122179208
whole-genome phylogeny of escherichia coli/shigella group by feature frequency profiles (ffps).a whole-genome phylogeny of the escherichia coli/shigella group was constructed by using the feature frequency profile (ffp) method. this alignment-free approach uses the frequencies of l-mer features of whole genomes to infer phylogenic distances. we present two phylogenies that accentuate different aspects of e. coli/shigella genomic evolution: (i) one based on the compositions of all possible features of length l = 24 (∼8.4 million features), which are likely to reveal the phenetic grouping a ...201121536867
rapid situation & response assessment of diarrhoea outbreak in a coastal district following tropical cyclone aila in india.background & objectives : cyclone aila hit indian states on eastern coast on may 25, 2009. an investigation was conducted to examine if aila was responsible for increased reporting of diarrhoea cases from the district of east-medinipur in west bengal. identifying causative organisms for diarrhoea and assessing their antibiotic susceptibility profile were other objectives. methods: rapid situation and response assessment technique was employed to triangulate primary and secondary data collected t ...201121537092
toxic megacolon from sexually transmitted shigella sonnei infection. 201121538050
development of a new guinea-pig model of shigellosis.shigellosis is a major form of bacillary dysentery caused by shigella spp. to date, there is no suitable animal model to evaluate the protective efficacy of vaccine candidates against this pathogen. here, we describe a successful experimental shigellosis in the guinea-pig model, which has shown the characteristic features of human shigellosis. this model yielded reproducible results without any preparatory treatment besides cecal ligation. in this study, guinea-pigs were discretely infected with ...201121539623
effects of probiotic fermentation on the enhancement of biological and pharmacological activities of codonopsis lanceolata extracted by high pressure treatment.this study was designed to evaluate the enhancement of antioxidant, antimicrobial, enzymatic, cytotoxic, and cognitive activities of codonopsis lanceolata extracted by high pressure treatment followed by probiotic fermentation. dried c. lanceolata samples were subjected to 400mpa for 20min and then fermented with bifidobacterium longum b6 (hpe-blf) and lactobacillus rhamnosus (hpe-lrf) at 37°c for 7days. compared to conventional extraction (ce-nf, 6.69mg gae/g), the phenol amounts of hpe-blf and ...201121543255
evaluation of the selective and differential et medium for detection of edwardsiella tarda in aquaculture systems.aims:  edwardsiella tarda is an important pathogen in aquaculture where it can cause serious losses. a rapid detection of it is vital to minimize the mortalities caused by this disease, and in this work, the effectiveness of the selective differential edw. tarda medium (et) was evaluated for the diagnosis of edwardsiellosis as well as for its possible use in epidemiological studies. methods and results:  et medium was evaluated in parallel with the commercial salmonella-shigella agar (ss), which ...201121554344
human immunodeficiency virus-associated gastrointestinal disease: common endoscopic biopsy diagnoses.the gastrointestinal (gi) tract is a major site of disease in hiv infection: almost half of hiv-infected patients present with gi symptoms, and almost all patients develop gi complications. gi symptoms such as anorexia, weight loss, dysphagia, odynophagia, abdominal pain, and diarrhea are frequent and usually nonspecific among these patients. endoscopy is the diagnostic test of choice for most hiv-associated gi diseases, as endoscopic and histopathologic evaluation can render diagnoses in patien ...201121559197
food-specific attribution of selected gastrointestinal illnesses: estimates from a canadian expert elicitation survey.abstract the study used a structured expert elicitation survey to derive estimates of food-specific attribution for nine illnesses caused by enteric pathogens in canada. it was based on a similar survey conducted in the united states and focused on campylobacter spp., escherichia coli o157:h7, listeria monocytogenes, nontyphoidal salmonella enterica, shigella spp., vibrio spp., yersinia enterocolitica, cryptosporidium parvum, and norwalk-like virus. a snowball approach was used to identify food ...201121561379
the decoupling between genetic structure and metabolic phenotypes in escherichia coli leads to continuous phenotypic diversity.to assess the extent of intra-species diversity and the links between phylogeny, lifestyle (habitat and pathogenicity) and phenotype, we assayed the growth yield on 95 carbon sources of 168 escherichia strains. we also correlated the growth capacities of 14 e. coli strains with the presence/absence of enzyme-coding genes. globally, we found that the genetic distance, based on multilocus sequence typing data, was a weak indicator of the metabolic phenotypic distance. besides, lifestyle and phylog ...201121569155
a tecpr1-dependent selective autophagy pathway targets bacterial pathogens.selective autophagy of bacterial pathogens represents a host innate immune mechanism. selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. in this study we identified a highly conserved tectonin domain-containing protein, tecpr1, as an atg5 binding partner that colocalized with atg5 at shigella-containing phagophores. tecpr1 activity is necessary for effici ...201121575909
a shigella boydii bacteriophage which resembles salmonella phage vii.abstract: background: lytic bacteriophages have been applied successfully to control the growth of various foodborne pathogens. sequencing of their genomes is considered as an important preliminary step to ensure their safety prior to food applications. results: the lytic bacteriophage, phisbom-ag3, targets the important foodborne pathogen, shigella. it is morphologically similar to phage vii of salmonella enterica serovar typhi and a series of phages of acinetobacter calcoaceticus and rhizobium ...201121595934
shigella sonnei vaccine candidates wrss2 and wrss3 are as immunogenic as wrss1, a clinically tested vaccine candidate, in a primate model of infection.shigella causes diarrhea and dysentery through contaminated food and water. shigella sonnei live vaccine candidates wrss2 and wrss3 are attenuated principally by the loss of virg(icsa) that prevents bacterial spread within the colonic epithelium. in this respect they are similar to the clinically tested vaccine candidate wrss1. however, wrss2 and wrss3 are further attenuated by loss of sena, senb and wrss3 also lacks msbb2. as previously shown in cell culture assays and in small animal models, t ...201121596086
transient suppression of shigella flexneri type 3 secretion by a protective o-antigen-specific monoclonal iga.abstract mucosal immunity to the enteric pathogen shigella flexneri is mediated by secretory iga (s-iga) antibodies directed against the o-antigen (o-ag) side chain of lipopolysaccharide. while secretory antibodies against the o-ag are known to prevent bacterial invasion of the intestinal epithelium, the mechanisms by which this occurs are not fully understood. in this study, we report that the binding of a murine monoclonal iga (igac5) to the o-ag of s. flexneri serotype 5a suppresses activity ...201121610121
dynamic aspects of antibody:oligosaccharide complexes characterized by molecular dynamics simulations and std-nmr.carbohydrates are likely to maintain significant conformational flexibility in antibody:carbohydrate complexes. as demonstrated herein for the protective monoclonal antibody f22-4 recognizing the shigella flexneri 2a o-antigen and numerous synthetic oligosaccharide fragments thereof, the combination of molecular dynamics simulations and nmr saturation transfer difference experiments, supported by physicochemical analysis, allows to determine the binding epitope and its various contributions to a ...201121610193
identification of small-molecule inhibitors of yersinia pestis type iii secretion system yscn atpase.yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. the pathogen uses a type iii secretion system (t3ss) to deliver virulence factors directly from bacterium into host mammalian cells. the system contains a single atpase, yscn, necessary for delivery of virulence factors. in this work, we show that deletion of the catalytic domain of the yscn gene in y. pestis co92 attenuated the strain over three million-fold in the swiss-webster ...201121611119
bacterial load of fresh vegetables and their resistance to the currently used antibiotics in saudi arabia.abstract this study was carried out to describe the bacterial load and the occurrence of some disease-causing enteric bacteria on raw vegetables sold in saudi markets. the study further aimed to analyze antibiotic resistance rates, production of extended-spectrum beta lactamase, and plasmid carriage among bacterial population of raw vegetables. results revealed that none of them contained bacillus cereus, salmonella, and escherichia coli o157:h7. however, staphylococcus aureus and shigella were ...201121612423
a novel compound from the marine bacterium bacillus pumilus s6-15 inhibits biofilm formation in gram-positive and gram-negative species.biofilm formation is a critical problem in nosocomial infections and in the aquaculture industries and biofilms show high resistance to antibiotics. the aim of the present study was to reveal a novel anti-biofilm compound from marine bacteria against antibiotic resistant gram-positive and gram-negative biofilms. the bacterial extract (50 μg ml(-1)) of s6-01 (bacillus indicus = mtcc 5559) showed 80-90% biofilm inhibition against escherichia coli, shigella flexneri, proteus mirabilis and s6-15 (ba ...201121614700
prevalence of the plasmid mediated quinolone resistance determinants among clinical isolates of shigella sp. in andaman & nicobar islands, india.aims:  the present study was carried out to find the prevalence of various plasmid mediated quinolone resistant (pmqr) determinants among the quinolone resistant clinical isolates of shigella sp. from pediatric patients in andaman & nicobar islands. methods and results:  a total of 106 quinolone resistant shigella isolates obtained from pediatric patients during hospital based surveillance from january 2003 to june 2010 were screened for the presence of various pmqr determinants. out of 106 isol ...201121615433
complete (1)h and (13)c nmr chemical shift assignments of mono-, di-, and trisaccharides as basis for nmr chemical shift predictions of polysaccharides using the computer program casper.the computer program casper uses (1)h and (13)c nmr chemical shift data of mono- to trisaccharides for the prediction of chemical shifts of oligo- and polysaccharides. in order to improve the quality of these predictions the (1)h and (13)c, as well as (31)p when applicable, nmr chemical shifts of 30 mono-, di-, and trisaccharides were assigned. the reducing sugars gave two distinct sets of nmr resonances due to the α- and β-anomeric forms. in total 35 (1)h and (13)c nmr chemical shift data sets ...201121621752
antagonistic bacteria from live corals, tuticorin coastal waters, southeastern india.the objective of this study is to isolate and production of secondary metabolites with bioactive substances by coral reef (acropora formosa and favia palida) associated bacteria was carried out from the tuticorin coastal waters, southeastern india. the isolated coral associated bacteria were found to have an antagonistic effect against 10 human pathogens. the pathogens were escherichia coli, shigella dysentriae, staphylococcus epidermidis, s. aureus, klebsiella pneumoniae, pseudomonas aerogenosa ...201121454167
[invasive gastroenteritis, anything new?].invasive gastroenteritis is characterized by fever and inflammatory diarrhea and can be caused by nontyphoideal salmonella serotypes and shigella spp.-enteroinvasive escherichia coli (eiec), among other pathogens. this review describes emerging monophasic variants of salmonella enterica serotype 1,4,[5],12:i:- and provides an evolutionary consideration of shigella spp.-eiec as a single pathotype. in 1997, a monophasic variant of s. enterica serotype 1,4,[5],12:i:-, phage-type u302, multidrug res ...201121458713
vinculin activators target integrins from within the cell to increase melanoma sensitivity to chemotherapy.metastatic melanoma is an aggressive skin disease for which there are no effective therapies. emerging evidence indicates that melanomas can be sensitized to chemotherapy by increasing integrin function. current integrin therapies work by targeting the extracellular domain, resulting in complete gains or losses of integrin function that lead to mechanism-based toxicities. an attractive alternative approach is to target proteins, such as vinculin, that associate with the integrin cytoplasmic doma ...201121460181
autophagy and the cytoskeleton: new links revealed by intracellular pathogens.actin-based motility is used by various pathogens such as listeria and shigella for dissemination within cells: and tissues, yet host factors counteracting this process have not been identified. we have recently discovered that infected host cells can prevent actin-based motility of shigella by compartmentalizing bacteria inside 'septin cages,' revealing a novel mechanism of host defense that restricts dissemination. because bacterial proteins controlling actin-based motility also regulate the a ...201121464614
antimicrobial activity against shigella sonnei and probiotic properties of wild lactobacilli from fermented food.four lactobacilli strains (lactobacillus paracasei subp. paracasei m5-l, lactobacillus rhamnosus j10-l, lactobacillus casei q8-l and l. rhamnosus gg (lgg), were systematically assessed for the production of antimicrobial substances active towards shigella sonnei, escherichia coli and salmonella typhimurium. agar-well assay showed that the four lactobacilli strains displayed strong antibacterial activity towards s. sonnei. the nature of antimicrobial substances was also investigated and shown to ...201121466951
assessment of the antibacterial activity and the antidiarrheal function of flavonoids from bayberry fruit.chinese bayberry fruits are used as a folk medicine to cure diarrhea. however, the active compounds have not yet been reported. we found that bayberry fruit extract showed significant antibacterial activity against salmonella, listeria, and shigella, and the minimal inhibitory concentration (mic) ranged from 2.07 to 8.28 mg/ml. positive relationships were found between the antibacterial activity and the total polyphenol (r = 0.88) and flavonoid contents (r = 0.92) of samples using different extr ...201121469731
genetic diversity and antibiotic resistance in shigella dysenteriae and shigella boydii strains isolated from children aged <5 years in egypt.summarydiversity within shigella dysenteriae (n=40) and shigella boydii (n=30) isolates from children living in egypt aged <5 years was investigated. shigella-associated diarrhoea occurred mainly in summer months and in children aged <3 years, it commonly presented with vomiting and fever. serotypes 7 (30%), 2 (28%), and 3 (23%) accounted for most of s. dysenteriae isolates; 50% of s. boydii isolates were serotype 2. s. dysenteriae and s. boydii isolates were often resistant to ampicillin, chlor ...201121470441
new developments in traveler's diarrhea.traveler's diarrhea (td) is a crucial area for research, as it affects millions of tourists each year and creates a large economic burden. more than 60% of td cases are caused by a variety of bacterial enteropathogens: diarrhea-producing escherichia coli, shigella, campylobacter, salmonella, aeromonas, plesiomonas, and noncholera vibrios. noroviruses are also an important cause of morbidity among travelers. recent studies have identified host genetic risk factors associated with susceptibility t ...201121475415
behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri and shigella sonnei during production of pulque, a traditional mexican beverage.pulque is a typical fermented alcoholic beverage of central mexico, produced from the nectar of maguey agave plants. production systems are largely artisanal, with inadequate hygiene conditions and exposure to multiple contamination sources. no data exist on pulque microbiological safety and the behavior of pathogenic microorganisms in agave nectar and pulque. an initial trial was done of the behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri ...201121477472
dissemination of ndm-1 positive bacteria in the new delhi environment and its implications for human health: an environmental point prevalence study.not all patients infected with ndm-1-positive bacteria have a history of hospital admission in india, and extended-spectrum β-lactamases are known to be circulating in the indian community. we therefore measured the prevalence of the ndm-1 gene in drinking water and seepage samples in new delhi.201121478057
corn flake-like morphology of iron nanoparticles and its antibacterial property. 201121478648
an integrated approach for finding overlooked genes in shigella.the completion of numerous genome sequences introduced an era of whole-genome study. however, many genes are missed during genome annotation, including small rnas (srnas) and small open reading frames (sorfs). in order to improve genome annotation, we aimed to identify novel srnas and sorfs in shigella, the principal etiologic agents of bacillary dysentery.201121483688
phytochemical screening and antibacterial activities of vernonia ambigua, vernonia blumeoides and vernonia oocephala (asteraceae).some vernonia species (vernonia ambigua, vernonia blumeoides and vernonia oocephala) used in northern nigerian traditional medicine, were subjected to phytochemical screening using standard procedures. the antibacterial activity using the disc diffusion method as outlined by the nccls was carried out on klebsiella pneumoniae, streptococcus pyogenes, staphylococcus aureus, corynbacterium ulcerans, methicillin resistant staphylococcus aureus (mrsa), salmonella typhi, pseudomonas aeruginosa, shigel ...201121485703
outbreak of shigella sonnei infections in the orthodox jewish community of antwerp, belgium, april to august 2008.in the beginning of april 2008 three cases of shigella sonnei infection were identified among the orthodox jewish community of antwerp, belgium. we conducted a descriptive study and a household cohort study to identify potential risk factors. stool samples were cultured and antibiotic susceptibility of the isolates was determined. between april and august 2008, 42 cases were registered. all characterised isolates (n=20) shared an identical pulsed-field gel electrophoresis profile and were indist ...201121492526
zidovudine (azt) has a bactericidal effect on enterobacteria and induces genetic modifications in resistant strains.the spread of multiresistant bacteria increases the need for new antibiotics. the observation that some nucleoside analogues have antibacterial activity led us to further investigate the antimicrobial activity and resistance of zidovudine (azt). we determined the minimum inhibition concentration (mic), studied time-kill curves, induced resistant bacteria and sequenced the gene for thymidine kinase. we demonstrate that azt has a bactericidal effect on some enterobacteria. however, azt could induc ...201121494911
microbiological quality of grey-mullet roe.the greek grey-mullet roe is produced from the fully developed gonads of the female mullet (mugil cephalus) couth in lagoons during their reproductive migration. the traditional processing method of the roe includes, air drying, salting, shape formation and covering with multiple layers of natural beeswax for preservation and distribution. fish roe brands have been a staple in local diet and is increasingly becoming popular in the international market. as a ready-to-eat food it's microbial quali ...201121497664
a unique arabinose 5-phosphate isomerase found within a genomic island associated with the uropathogenicity of escherichia coli cft073.previous studies showed that deletion of genes c3405 to c3410 from pai-metv, a genomic island from escherichia coli cft073, results in a strain that fails to compete with wild-type cft073 after a transurethral cochallenge in mice and is deficient in the ability to independently colonize the mouse kidney. our analysis of c3405 to c3410 suggests that these genes constitute an operon with a role in the internalization and utilization of an unknown carbohydrate. this operon is not found in e. coli k ...201121498648
shigella targets t cells.using a syringe-like device, shigella delivers an array of virulence factors into host cells to facilitate bacterial colonization and disable the host's innate immune defense. in this issue of cell host & microbe, konradt and colleagues (konradt et al., 2011) show that shigella also subverts adaptive immunity by targeting t cells through a mechanism involving pip(2) breakdown.201121501822
the shigella flexneri type three secretion system effector ipgd inhibits t cell migration by manipulating host phosphoinositide metabolism.shigella, the gram-negative enteroinvasive bacterium that causes shigellosis, relies on its type iii secretion system (ttss) and injected effectors to modulate host cell functions. however, consequences of the interaction between shigella and lymphocytes have not been investigated. we show that shigella invades activated human cd4(+) t lymphocytes. invasion requires a functional ttss and results in inhibition of chemokine-induced t cell migration, an effect mediated by the ttss effector ipgd, a ...201121501826
enteric virulence associated protein vapc inhibits translation by cleavage of initiator trna.eukaryotic pin (pilt n-terminal) domain proteins are ribonucleases involved in quality control, metabolism and maturation of mrna and rrna. the majority of prokaryotic pin-domain proteins are encoded by the abundant vapbc toxin-antitoxin loci and inhibit translation by an unknown mechanism. here we show that enteric vapcs are site-specific endonucleases that cleave trna(fmet) in the anticodon stem-loop between nucleotides +38 and +39 in vivo and in vitro. consistently, vapc inhibited translation ...201121502523
evaluation of low-copy genetic targets for waterborne bacterial pathogen detection via qpcr.recent developments in water quality research have highlighted difficulties in accurately predicting the incidence of pathogens within freshwater based on the viability, culturability and metabolic activity of indicator organisms. qpcr-driven assays are candidates to replace standard culture-based methods, however, protocols suitable for routine use have yet to be sufficiently validated. the objective of this study was to evaluate five oligonucleotide primers sets (etir, sinv, exot, vs1 and ipah ...201121514618
functional domains and motifs of bacterial type iii effector proteins and their roles in infection.a key feature of the virulence of many bacterial pathogens is the ability to deliver effector proteins into eukaryotic cells via a dedicated type three secretion system (t3ss). many bacterial pathogens, including species of chlamydia, xanthomonas, pseudomonas, ralstonia, shigella, salmonella, escherichia and yersinia, depend on the t3ss to cause disease. t3ss effectors constitute a large and diverse group of virulence proteins that mimic eukaryotic proteins in structure and function. a salient f ...201121517912
a novel vinculin binding site of the ipaa invasin of shigella.internalization of shigella into host epithelial cells, where the bacteria replicates and spreads to neighboring cells, requires a type 3 secretion system (t3ss) effector coined ipaa. ipaa binds directly to and activates the cytoskeletal protein vinculin after injection in the host cell cytosol and heretofore this was thought to be directed by two amphipathic α-helical vinculin binding sites (vbs) found in the c-terminal tail domain of ipaa. here we report a third vbs, ipaa-vbs3, that is located ...201121525010
synthesis, antibacterial activity and quantum-chemical studies of novel 2-arylidenehydrazinyl-4-arylthiazole analogues.a new series of 2-arylidenehydrazinyl-4-arylthiazole derivatives (2a-k) was designed and synthesized through a rapid, simple, and efficient methodology in excellent isolated yield. these compounds were screened for in vitro antimicrobial activities against eight bacteria, e.g. bacillus cereus, staphylococcus aureus, bacillus subtilis, bacillus megaterium, pseudomonas aeruginosa, shigella dysenteriae, salmonella typhi, escherichia coli, and three fungi e.g. aspergillus oryzae, candida albicans, a ...201121532194
synthesis, characterization and in vitro antimicrobial evaluation of new compounds incorporating oxindole nucleus.new compounds incorporating with the oxindole nucleus were synthesized via the reaction of substituted isatins [5-methyl-, 5-chloro- and 1-hydroxymethyl isatins] with different nucleophiles. the structures of the newly compounds were elucidated on the basis of ftir, (1)h nmr, (13)cmr spectral data, gc/ms and chemical analysis. investigation of antimicrobial activity of the new compounds was evaluated using broth dilution technique in terms of minimal inhibitory concentration (mic) count against ...201121534861
synthesis, characterization and biological studies of sulfonamide schiff's bases and some of their metal derivatives.a new series of schiff base ligands derived from sulfonamide and their metal(ii) complexes [cobalt(ii), copper(ii), nickel(ii) and zinc(ii)] have been synthesized and characterized. the nature of bonding and structure of all the synthesized compounds has been explored by physical, analytical and spectral data of the ligands and their metal(ii) complexes. the authors suggest that all the prepared complexes possess an octahedral geometry. the ligands and metal(ii) complexes have been screened for ...201121534864
diarrheagenic escherichia coli in acute gastroenteritis in infants in north-west italy.enteropathogenic escherichia coli may cause diarrhoea in infancy, but it is not routinely detected and regarded as a major causative agent. the aim of the present study was to estimate the incidence of enteropathogenic e. coli infection and to investigate its epidemiology and pathogenesis from faecal specimens in infants hospitalized for acute gastroenteritis. between march 2008 and june 2009, faecal samples were collected and examined to recognize diarrhoeal aetiology, especially for e. coli, b ...201121344146
age specific aetiological agents of diarrhoea in hospitalized children aged less than five years in dar es salaam, tanzania.this study aimed to determine the age-specific aetiologic agents of diarrhoea in children aged less than five years. the study also assessed the efficacy of the empiric treatment of childhood diarrhoea using integrated management of childhood illness (imci) guidelines.201121345186
autophagy in immunity and cell-autonomous defense against intracellular microbes.autophagy was viewed until very recently primarily as a metabolic and intracellular biomass and organelle quality and quantity control pathway. it has now been recognized that autophagy represents a bona fide immunologic process with a wide array of roles in immunity. the immunologic functions of autophagy, as we understand them now, span both innate and adaptive immunity. they range from unique and sometimes highly specialized immunologic effectors and regulatory functions (referred to here as ...201121349088
function-specific accelerations in rates of sequence evolution suggest predictable epistatic responses to reduced effective population size.changes in effective population size impinge on patterns of molecular evolution. notably, slightly deleterious mutations are more likely to drift to fixation in smaller populations, which should typically also lead to an overall acceleration in the rates of evolution. this prediction has been validated empirically for several endosymbiont and island taxa. here, we first show that rate accelerations are also evident in bacterial pathogens whose recent shifts in virulence make them prime candidate ...201121349981
rapid emergence of third-generation cephalosporin resistance in shigella sp. isolated in andaman and nicobar islands, india.shigellosis is a major cause of diarrheal diseases among children in andaman & nicobar islands, india, which have a population of 350,000 people, including settlers from mainland india and 6 indigenous tribes. from the last one-and-half decade, we have been monitoring the species distribution and emergence of antibiotic resistance among the isolates of shigella. the circulating shigella strains have been found rapidly acquiring resistance to a wide spectrum of antibiotics. the recent data indica ...201121352076
antigen-specific cd8(+) t cells fail to respond to shigella flexneri.cd8(+) t lymphocytes often play a primary role in adaptive immunity to cytosolic microbial pathogens. surprisingly, cd8(+) t cells are not required for protective immunity to the enteric pathogen shigella flexneri, despite the ability of shigella to actively secrete proteins into the host cytoplasm, a location from which antigenic peptides are processed for presentation to cd8(+) t cells. to determine why cd8(+) t cells fail to play a role in adaptive immunity to s. flexneri, we investigated whe ...201121357720
[enterobacteriaceae infection - diagnosis, antibiotic resistance and prevention].intestinal infections caused by rod-shaped bacteria of the enterobacteriaceae genus are one of the major health hazards in countries where sanitation standards are low. strains of shigella, salmonella, escherichia and yersinia are responsible for diarrhea, severe bacillary dysentery, typhoid, other intestinal diseases, as well as genitourinary tract and blood infections. according to the who there are 4.5 billion cases every year, of which 1.9 million end in death. this makes intestinal infectio ...201121357995
microbial safety of tropical fruits.there are approximately 140 million tons of over 3,000 types of tropical fruits produced annually worldwide. tropical fruits, once unfamiliar and rare to the temperate market, are now gaining widespread acceptance. tropical fruits are found in a variety of forms, including whole, fresh cut, dried, juice blends, frozen, pulp, and nectars in markets around the world. documented outbreaks of foodborne disease associated with tropical fruits have occurred. norovirus and salmonella are the leading vi ...201121328109
multidrug resistant salmonella concord is a major cause of salmonellosis in children in ethiopia.s. concord in ethiopia. the objective of this study was to determine the aetiology of febrile and diarrhoeic illness in ethiopian children focussing on salmonella.201121330737
development of a duplex real-time pcr for differentiation between e. coli and shigella spp.the aim of this study was to develop a real-time pcr test for differentiation between shigella spp. and e. coli, in particular enteroinvasive escherichia coli (eiec).201121332893
crystal structure of the autochaperone region from the shigella flexneri autotransporter icsa.the icsa (intracellular spread gene a) autotransporter from shigella flexneri is a key virulence factor. we identified a stable fragment comprising residues 591 to 758, which corresponds to the autochaperone region of the icsa passenger domain. we showed that thermal unfolding of the autochaperone region is reversible and determined its crystal structure at 2.0-å resolution.201121335457
a comparison of disease caused by shigella and campylobacter species: 24 months community based surveillance in 4 slums of karachi, pakistan.despite the efforts of the international community diarrheal diseases still pose a major threat to children in children less than five years of age. bacterial diarrhea has also emerged as a public health concern due to the proliferation of drug resistant species in many parts of the world. there is a paucity of population-based data about the incidence of shigellosis and campylobacter infections in pakistan. we report country specific results for shigella diarrhea that were derived from a multic ...201121338955
shigellosis outbreak linked to canteen-food consumption in a public institution: a matched case-control study.summaryon 13 november 2009, the authorities of flemish brabant, belgium, received an alert concerning a potential outbreak of shigella sonnei at a public institution. a study was conducted to assess the extent, discover the source and to implement further measures. we performed a matched case-control study to test an association between shigellosis and canteen-food consumption. water samples and food handlers' faecal samples were tested. the reference laboratory characterized the retrospectively ...201121281549
enteric glial cells: new players in mucosal defence against bacteria? 201121282131
isolation and partial characterisation of a novel lectin from aegle marmelos fruit and its effect on adherence and invasion of shigellae to ht29 cells.lectins are a class of ubiquitous proteins/glycoproteins that are abundantly found in nature. lectins have unique carbohydrate binding property and hence have been exploited as drugs against various infectious diseases. we have isolated one such novel lectin from the fruit pulp of aegle marmelos. the isolated lectin was partially characterised and its effect against shigella dysenteriae infection was evaluated. the isolated lectin was found to be a dimeric protein with n-acetylgalactosamine, man ...201121283697
purification and characterization of a ca2+-dependent novel lectin from nymphaea nouchali tuber with antiproliferative activities.a lectin (termed nntl) was purified from the extracts of nymphaea nouchali tuber followed by anion-exchange chromatography on deae-cellulose, hydrophobic chromatography on hitrap phenyl hp and by repeated anion-exchange chromatography on hitrap q ff column. the molecular mass of the purified lectin was 27.0 ± 1.0 kda, as estimated by sds/page both in the presence and in the absence of 2-mercaptoethanol. nntl was an o-nitrophenyl ß-d-galactopyranoside sugar-specific lectin that agglutinated rat, ...201121291421
seizure and altered mental status in a 12-year-old child with shigella sonnei gastroenteritis.we report a case of shigella-associated altered mental status and seizure in a 12-year-old boy. although seizure is a known complication of shigellosis, it is quite unusual in patients older than 9 years. this case illustrates the importance of considering the diagnosis of shigellosis in any pediatric patient with altered mental status or seizure in the context of gastrointestinal symptoms such as diarrhea.201121293224
development of a dna microarray for detection and identification of legionella pneumophila and ten other pathogens in drinking water.the safety and accessibility of drinking water are major concerns throughout the world. consumption of water contaminated with infectious agents, toxic chemicals or radiological hazards represents a significant health risk and is strongly associated with mortality. therefore, we have developed an oligonucleotide-based microarray using the sequences of 16s-23s rdna internal transcribed spacer regions (its) and the gyrase subunit b gene (gyrb) found in the most prevalent and devastating waterborne ...201121276629
strategies to overcome extended-spectrum ß-lactamases (esbls) and ampc ß-lactamases in shigellae.oral cephalosporins and mecillinam are used to treat shigella infections, but are compromised by extended-spectrum ß-lactamases (esbls) and plasmid ampc ß-lactamases. potential solutions include combining an oral or intravenous cephalosporin with a ß-lactamase inhibitor (bli) or using an oral penem. these strategies were examined using escherichia coli transconjugants and clinical isolates with esbls or ampc, as a proxy for shigellae. the clinical and laboratory standards institute agar dilution ...201121276715
efficient screening of a novel antimicrobial peptide from jatropha curcas by cell membrane affinity chromatography.a novel method named cell membrane affinity chromatography was used to screen antimicrobial peptides from jatropha curcas . a cationic antimicrobial peptide (kvflglk, jcpep7) was successfully isolated and identified. antimicrobial assays indicated that jcpep7 was active against the tested microorganisms ( salmonella typhimurium atcc 50013, shigella dysenteriae atcc 51302, pseudomonas aeruginosa atcc 27553, staphylococcus aureus atcc 25923, bacillus subtilis atcc 23631, and streptococcus pneumoni ...201121268582
monitoring shigella flexneri vacuolar escape by flow cytometry.invasive bacterial pathogens such as shigella flexneri force their uptake into non-phagocytic host cells. upon internalization, they rupture the endocytic vacuole and escape into the host cell cytoplasm. recent studies applying fluorescence resonance energy transfer (fret) based methods to track host-pathogen interactions have provided insights into the process of bacterial infection at the single cell level. we have previously reported that the vacuolar escape of invasive bacteria into the host ...201121317555
the effect of handwashing with water or soap on bacterial contamination of hands.handwashing is thought to be effective for the prevention of transmission of diarrhoea pathogens. however it is not conclusive that handwashing with soap is more effective at reducing contamination with bacteria associated with diarrhoea than using water only. in this study 20 volunteers contaminated their hands deliberately by touching door handles and railings in public spaces. they were then allocated at random to (1) handwashing with water, (2) handwashing with non-antibacterial soap and (3) ...201121318017
synthesis, spectral analysis and in vitro microbiological evaluation of novel ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates and 4,5-dihydro-6-(napthalen-2-yl)-4-aryl-2h-indazol-3-ols.a series of ethyl 4-(naphthalen-2-yl)-2-oxo-6-arylcyclohex-3-enecarboxylates 8-14 and 4,5-dihydro-6-(naphthalen-2-yl)-4-aryl-2h-indazol-3-ols 15-21 were synthesised and characterised by their spectroscopic data. in vitro microbiological evaluations were carried out for all the newly synthesised compounds 8-21 against clinically isolated bacterial and fungal strains. compounds 9, 12 and 20 against staphylococcus aureus, 10, 12, 20 against ß-haemolytic streptococcus, 11, 17 against bacillus subtil ...201121299432
extended spectrum beta-lactamase production in shigella isolates - a matter of concern. 201121304205
synthesis, characterization and biological properties of thienyl derived triazole schiff bases and their oxovanadium(iv) complexes.a new series of biologically active thienyl derived triazole schiff bases and their oxovanadium(iv) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (ir, (1)h and (13)c nmr, electronic and mass spectrometry) and microanalytical data. all the schiff base ligands and their oxovanadium(iv) complexes have been subjected to in vitro antibacterial activity against four gram-negative (escherichia coli, shigella flexner ...201121635212
structure-guided investigation of lipopolysaccharide o-antigen chain length regulators reveals regions critical for modal length control.the o-antigen component of the lipopolysaccharide (lps) represents a population of polysaccharide molecules with a non-random (modal) chain length distribution. the number of the repeat o-units in each individual o-antigen polymer depends on the wzz chain-length regulator, an inner membrane protein belonging to the polysaccharide co-polymerase (pcps) family. different wzz proteins confer vastly different ranges of modal lengths (4 to >100 repeat units) despite having remarkably conserved structu ...201121642455
production of bioactive sheep β-defensin-1 in pichia pastoris.previous research has shown that sheep β-defensin-1 (sbd-1), a small cationic peptide with a broad range of antimicrobial activities, could inhibit the growth of both gram-positive and gram-negative bacteria as well as that of fungi. in order to increase the yield of current ovine defensin purification methods, mature sbd-1 (msbd-1) was added with a 6-his tag on the c-terminus (msbd-1-t) and expressed in pichia pastoris in the presented work. the msbd-1 and msbd-1-t were expressed in the pichia ...201121643707
p62 and ndp52 target intracytosolic shigella and listeria to different autophagy pathways.autophagy is an important mechanism of innate immune defense. we have recently shown that autophagy components are recruited with septins, a new and increasingly characterized cytoskeleton component, to intracytosolic shigella that have started to polymerize actin. on the other hand, intracytosolic listeria avoids autophagy recognition by expressing acta, a bacterial effector required for actin polymerization. here we exploit shigella and listeria as intracytosolic tools to characterize differen ...201121646350
bacteriophage-encoding cytolethal distending toxin type-v gene induced from non-clinical escherichia coli isolates.cytolethal distending toxin (cdt) is produced by a variety of pathogenic bacteria, including pathogenic serotypes of shiga toxin-producing escherichia coli (stec). the cdt family comprises five variants (cdt-i to cdt-v) encoded by three genes located within the chromosome, plasmids or, in the case of cdt-i, within bacteriophages. in this study we evaluated the occurrence of cdt in a collection of 140 environmental stec isolates. cdt was detected in 12.1% of strains, of which five strains carried ...201121646456
development of multiplex loop-mediated isothermal amplification-rflp (mlamp-rflp) to detect salmonella spp. and shigella spp. in milk.a multiplex loop-mediated isothermal amplification-rflp (mlamp-rflp) was developed and validated for simultaneous detection of salmonella strains and shigella strains in milk. in this system, two sets of lamp primers were designed to specifically target inva of salmonella spp. and ipah of shigella spp. under isothermal conditions at 63 °c, ladder pattern of dna bands could be amplified within 60 min in the presence of genomic dnas of salmonella strains and shigella strains, which could be distin ...201121652102
gisul2, a genomic island carrying the sul2 sulphonamide resistance gene and the small mobile element cr2 found in the enterobacter cloacae subspecies cloacae type strain atcc 13047 from 1890, shigella flexneri atcc 700930 from 1954 and acinetobacter baumannii atcc 17978 from 1951. 201121653606
a 9-year study of shigellosis in northeast malaysia: antimicrobial susceptibility and shifting species dominance.aims: in malaysia, shigella spp. is the third most common bacterial agent responsible for childhood diarrhoea. this study was conducted to determine the prevalence and antimicrobial susceptibility patterns of shigella spp. isolated from patients admitted to the hospital universiti sains malaysia from january 2001 to december 2009. subjects and methods: a hospital-based retrospective study was used. stool samples from patients were cultured using a standard culture method. shigella spp. isolates ...201121654922
modulation of connexin signaling by bacterial pathogens and their toxins.inherent to their pivotal tasks in the maintenance of cellular homeostasis, gap junctions, connexin hemichannels, and pannexin hemichannels are frequently involved in the dysregulation of this critical balance. the present paper specifically focuses on their roles in bacterial infection and disease. in particular, the reported biological outcome of clinically important bacteria including escherichia coli, shigella flexneri, yersinia enterocolitica, helicobacter pylori, bordetella pertussis, aggr ...201121656255
genetic characteristics and changing antimicrobial resistance among shigella spp isolated from hospitalized diarrhoeal patients in kolkata, india.to study the prevalence pattern and trends in the phenotypic and genetic characteristics of shigellae, we tested 212 isolates isolated from diarrhoeal patients admitted at the infectious diseases hospital, kolkata, india from november 2007 to october 2009. prevalence of shigella spp was more in more than 5 years age group (69%) than the children >5 years age group (31%). serotypes 2a, 3a and untypable isolates of the subtype s. flexneri were frequently detected. increase in the isolation of s. s ...201121659504
vital signs: incidence and trends of infection with pathogens transmitted commonly through food--foodborne diseases active surveillance network, 10 u.s. sites, 1996-2010.in the united states, contaminated food causes approximately 1,000 reported disease outbreaks and an estimated 48 million illnesses, 128,000201121659984
shigella gets captured to gain entry.the type iii secretion system-dependent epithelial invasion and dissemination of shigella is stimulated by atp released through hemichannels. romero et al. (2011) show that prior to epithelial contact, shigella is captured by nanometer-thin micropodial extensions at a distance from the cell surface, in a process involving atp and connexin-mediated signaling.201121669393
atp-mediated erk1/2 activation stimulates bacterial capture by filopodia, which precedes shigella invasion of epithelial cells.shigella, the causative agent of bacillary dysentery in-áhumans, invades epithelial cells, using a type iii secretory system (t3ss) to inject bacterial effectors into host cells and remodel the actin cytoskeleton. atp released through connexin hemichanels on the epithelial membrane stimulates shigella invasion and dissemination in epithelial cells. here, we show that prior to contact with the cell body, shigella is captured by nanometer-thin micropodial extensions (nmes) at a distance from the c ...201121669399
deaths associated with bacterial pathogens transmitted commonly through food: foodborne diseases active surveillance network (foodnet), 1996-2005.foodborne diseases are typically mild and self-limiting but can cause severe illness and death. we describe the epidemiology of deaths associated with bacterial pathogens using data from the foodborne diseases active surveillance network (foodnet) in the united states.201121673037
phenylbutyrate counteracts shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.cathelicidins and defensins are endogenous antimicrobial peptides (amps) that are downregulated in the mucosal epithelia of the large intestine in shigellosis. oral treatment of shigella infected rabbits with sodium butyrate (nab) reduces clinical severity and counteracts the downregulation of cathelicidin (cap-18) in the large intestinal epithelia.201121673991
analysis of distribution and significance of simple sequence repeats in enteric bacteria shigella dysenteriae sd197.we have explored the possible role of ssr density in genome to generate biological information. in our study, we have checked the ssr (simple sequence repeats) status in virulent and non virulent genes of enteric bacteria to see whether the ssrs distribution contributes to virulence. the genome, plasmid and virulent genes sequences in fasta format were downloaded from ncbi genbank and vfdb. the sequences were subjected to ssr analysis using software tool ssr.exe. the resulting data was pasted in ...201121814393
the future is cold: cryo-preparation methods for transmission electron microscopy of cells.our knowledge of the organization of the cell is linked, to a great extent, to light and electron microscopy. choosing either photons or electrons for imaging has many consequences on the image obtained, as well as on the experiment required in order to generate the image. one apparent effect on the experimental side is in the sample preparation, which can be quite elaborate for electron microscopy. in recent years, rapid freezing, cryo-preparation and cryo-electron microscopy have been more wid ...201121812762
a live noninvasive shigella dysenteriae 1 strain induces homologous protective immunity in a guinea pig colitis model.a noninvasive live transconjugant shigella hybrid (ltsh?stx) strain was constructed from a shiga toxin gene deleted mutant of shigella dysenteriae 1 by introducing a plasmid vector ppr1347 that carried a lipopolysaccharide biosynthesis gene (rfb and rfc) of salmonella typhimurium. in guinea pigs, four successive oral administrations of ltsh?stx showed complete protection against rectal challenge with wild type s. dysenteriae 1 strain. exponential increase of the serum igg and iga titer against l ...201121806676
[waterborne outbreak of shigella sonnei caused by consumption of public supply water.]objective: to investigate a waterborne outbreak in the population of valència d'àneu (lleida, spain). methods: a cohort study of consumption of mains water, bottled water and spring water was carried out. the sample was obtained by telephone contact with all private numbers in the municipality. we surveyed 58.3% of the population census (105/180) for water consumption, number of glasses drunk daily and symptoms. the water supply in the municipal system was sampled, and the presence of enterobact ...201121802793
physical, chemical and microbiological quality of ice used to cool drinks and foods in greece and its public health implications.ice used for direct human consumption or to preserve foods and cool down drinks can be contaminated with pathogenic microorganisms and may potentially become a vehicle for consumer's infection. to evaluate physical, chemical and microbiological quality of commercial ice and ice used for fish and seafood, 100 ice samples collected at 10 different retail points in the region of epirus were studied. the following microbiological parameters were determined: total coliforms, fecal coliforms, salmonel ...201121802520
the role of tecpr1 in selective autophagy as a cargo receptor.bacterial intrusion of host cells can be recognized by the innate immune system, including autophagy, via multiple cellular pathways. we have identified tecpr1 as an atg5-binding partner, and found that tecpr1 interacts with the atg12-atg5-atg16l1 complex via binding to atg5. in shigella infected cells, tecpr1 colocalizes with atg5 and lc3 at shigella-containing phagophores. tecpr1 activity is required for efficient autophagy to target bacteria, but a deficiency of tecpr1 in host cells does not ...201121795850
synthesis and studies of novel 2-(4-cyano-3-trifluoromethylphenyl amino)-4-(quinoline-4-yloxy)-6-(piperazinyl/piperidinyl)-s-triazines as potential antimicrobial, antimycobacterial and anticancer agents.a series of novel s-triazine analogs were synthesized and characterized by ir, (1)h nmr, (13)c nmr, (19)f nmr spectroscopy and elemental analysis. preliminary screening of target compounds against eight bacteria (staphylococcus aureus, bacillus cereus, escherichia coli, pseudomonas aeruginosa, klebsiella pneumoniae, salmonella typhi, proteus vulgaris, shigella flexneria), four fungi (aspergillus niger, aspergillus fumigatus, aspergillus clavatus, candida albicans) and mycobacterium tuberculosis ...201121794959
multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.clin microbiol infect abstract: many different definitions for multidrug-resistant (mdr), extensively drug-resistant (xdr) and pandrug-resistant (pdr) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. a group of international experts came together through a joint initiative by the european centre for disease prevention and control (ecdc) and the centers for disease control and p ...201121793988
use of pyrosequencing and denaturing gradient gel electrophoresis to examine the effects of probiotics and essential oil blends on digestive microflora in broilers under mixed eimeria infection.abstract a protective digestive microflora helps prevent and reduce broiler infection and colonization by enteropathogens. in the current experiment, broilers fed diets supplemented with probiotics and essential oil (eo) blends were infected with a standard mixed eimeria spp. to determine effects of performance enhancers on ileal and cecal microbial communities (mcs). eight treatment groups included four controls (uninfected-unmedicated [uu], unmedicated-infected, the antibiotic bmd plus the ion ...201121793655
regulating iron storage and metabolism with rna: an overview of posttranscriptional controls of intracellular iron homeostasis.iron (fe) is a double-edged sword for most living organisms. although it is essential for the catalytic activity of a large number of enzymes, ferrous iron (fe(2+) ) becomes cytotoxic in the presence of normal respiratory by-products such as h(2) o(2) . because of this toxicity, intracellular iron concentrations ought to be regulated by elaborated homeostasis systems that, despite decades of extensive studies, have not yet revealed all of their surprising arrays of mechanistic details. within th ...201121793218
the vibrio cholerae vctpdgc system transports catechol siderophores and a siderophore-free iron ligand.vibrio cholerae, the causative agent of cholera, has an absolute requirement for iron. it transports the catechol siderophores vibriobactin, which it synthesizes and secretes, and enterobactin. these siderophores are transported across the inner membrane by one of two periplasmic binding protein-dependent abc transporters, vctpdgc or viupdgc. we show here that one of these inner membrane transport systems, vctpdgc, also promotes iron acquisition in the absence of siderophores. plasmids carrying ...201121790806
safety, and immunogenicity of an intranasal shigella flexneri 2a invaplex 50 vaccine.background: shigella flexneri 2a invaplex 50 is a nasally delivered subunit vaccine consisting of a macromolecular complex composed of lps, ipab, ipac and ipad. the current study examined vaccine safety and immunogenicity across a dose range and the clinical performance of a new intranasal delivery device. methods: volunteers (n=36) were randomized to receive vaccine via the dolphin™ (valois of america, congers, new york) intranasal spray device at one of three doses (240, 480, and 690µg) on day ...201121787825
pathogenic bacteria prime the induction of toll-like receptor signalling in human colonic cells by the gal/galnac lectin carbohydrate recognition domain of entamoebahistolytica.in mixed intestinal infections with entamoeba histolytica trophozoites and enteropathogenic bacteria, which are wide-spread in areas of endemic amebiasis, interaction between the pathogens could be an important factor in the occurrence of invasive disease. it has been reported that exposure of human colonic cells to enteropathogenic bacteria increased trophozoite adherence to the cells and their subsequent damage. we report here that the carbohydrate recognition domain (crd) of the amebic gal/ga ...201121787776
rodz regulates the post-transcriptional processing of the shigella sonnei type iii secretion system.the expression of the type iii secretion system-a main determinant of virulence in shigella-is controlled by regulator cascades virf-inve (virb) and cpxar two-component system. a screen for mutants that restore virulence in the cpxa background led to the isolation of a mutant of rodz, a cytoskeletal protein that maintains the rod-shaped morphology of bacilli. inve is normally repressed at 30 °c because of decreased messenger rna (mrna) stability, but rodz mutants markedly increase inve-mrna stab ...201121779005
multi-functional characteristics of the pseudomonas aeruginosa type iii needle-tip protein, pcrv; comparison to orthologs in other gram-negative bacteria.pseudomonas aeruginosa possesses a type iii secretion system (t3ss) to intoxicate host cells and evade innate immunity. this virulence-related machinery consists of a molecular syringe and needle assembled on the bacterial surface, which allows delivery of t3 effector proteins into infected cells. to accomplish a one-step effector translocation, a tip protein is required at the top end of the t3 needle structure. strains lacking expression of the functional tip protein fail to intoxicate host ce ...201121772833
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