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the crystal structures of the salmonella type iii secretion system tip protein sipd in complex with deoxycholate and chenodeoxycholate.the type iii secretion system (t3ss) is a protein injection nanomachinery required for virulence by many human pathogenic bacteria including salmonella and shigella. an essential component of the t3ss is the tip protein and the salmonella sipd and the shigella ipad tip proteins interact with bile salts, which serve as environmental sensors for these enteric pathogens. sipd and ipad have long central coiled coils and their n-terminal regions form α-helical hairpins and a short helix α3 that pack ...201121031487
a disposable immunosensor for shigella flexneri based on multiwalled carbon nanotube/sodium alginate composite electrode.a novel shigella flexneri immunosensor based on horseradish peroxidase-labeled antibodies to s. flexneri (hrp-anti-s. flexneri) immobilized by physical adsorption on the multiwalled carbon nanotube (mwcnt)/sodium alginate (sa) composite modified screen-printed electrode surface was successfully fabricated. in this strategy, mwcnt/sa biocomposite acted as the matrix to adsorb and immobilize hrp-anti-s. flexneri. the modified electrodes were characterized with an atomic force microscope and cyclic ...201120816661
antidiarrheal activity, chemical and toxicity profile of berberis aristata.context: this study evaluated the in vitro and in vivo antidiarrheal activity, oral acute toxicological profile, and developed a chemical fingerprint of berberis aristata linn. (berberidaceae). materials and methods: the ethanol (by maceration) and aqueous (by soxhlet) extracts of berberis aristata bark were used for the study. the study involved the antimicrobial (minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) by micro dilution) and antidiarrheal (castor oil ...201120738174
effect of freeze-drying on viability and in vitro probiotic properties of a mixture of lactic acid bacteria and yeasts isolated from kefir.the effect of freeze-drying on viability and probiotic properties of a microbial mixture containing selected bacterial and yeast strains isolated from kefir grains (lactobacillus kefir, lactobacillus plantarum, lactococcus lactis, saccharomyces cerevisiae and kluyveromyces marxianus) was studied. the microorganisms were selected according to their potentially probiotic properties in vitro already reported. two types of formulations were performed, a microbial mixture (mm) suspended in milk and a ...201120822567
structural elucidation of the o-antigen of the shigella flexneri provisional serotype 88-893: structural and serological similarities with s. flexneri provisional serotype y394 (1c).the structure of the repeating unit of the o-antigen polysaccharide from shigella flexneri provisional serotype 88-893 has been determined. (1)h and (13)c nmr spectroscopy as well as 2d nmr experiments were employed to elucidate the structure. the carbohydrate part of the hexasaccharide repeating unit is identical to the previously elucidated structure of the o-polysaccharide from s. flexneri prov. serotype y394. the o-antigen of s. flexneri prov. serotype 88-893 carries 0.7 mol o-acetyl group p ...201121392735
shigella flexneri type iii secreted effector ospf reveals new crosstalks of proinflammatory signaling pathways during bacterial infection.shigella flexneri type iii secreted effector ospf harbors a phosphothreonine lyase activity that irreversibly dephosphorylates map kinases (mapks) p38 and erk in infected epithelial cells and thereby, dampens innate immunity. whereas this activity has been well characterized, the impact of ospf on other host signaling pathways that control inflammation was unknown. here we report that ospf potentiates the activation of the mapk jnk and the transcription factor nf-?b during s. flexneri infection. ...201121402152
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
new insights into vinculin function and regulation.vinculin is a cytoplasmic actin-binding protein enriched in focal adhesions and adherens junctions that is essential for embryonic development. much is now known regarding the role of vinculin in governing cell-matrix adhesion. in the past decade that the crystal structure of vinculin and the molecular details for how vinculin regulates adhesion events have emerged. the recent data suggests a critical function for vinculin in regulating integrin clustering, force generation, and strength of adhe ...201121414589
interaction of the salmonella typhimurium effector protein sopb with host cell cdc42 is involved in intracellular replication.the phosphoinositide phosphatase sopb/sigd is a type iii secretion system effector that plays multiple roles in salmonella internalization and intracellular survival. we previously reported that sopb complexed with and inhibited the small gtpase cdc42 when expressed in a yeast model system, independently of its phosphatase activity. here we show that human cdc42, but not rac1, interacts with catalytically inactive sopb when coexpressed in saccharomyces cerevisiae. this interaction occurs with bo ...201121435037
quantification and evaluation of infectivity of shiga toxin-encoding bacteriophages in beef and salad.stx bacteriophages in 68 samples of beef and salad were quantified by real-time quantitative pcr (qpcr). stx phages from the samples were propagated in escherichia coli c600, e. coli o157:h7, and shigella strains and further quantified. fifty percent of the samples carried infectious stx phages that were isolated from plaques generated by lysis.201121441341
[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
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
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
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
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
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
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
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
antimicrobial susceptibilities of enteric bacterial pathogens isolated in kathmandu, nepal, during 2002-2004.the prevalence and antimicrobial susceptibility patterns of the bacterial enteropathogens vibrio cholerae, salmonella species and shigella species were investigated.201121444984
analysis of shigella flexneri-mediated infections in model organism caenorhabditis elegans.shigella flexneri is the causative agent of bacillary dysentery and generates a significant global disease burden. the aim of this study was to analyze the pathogenesis and host immune response, at both the physiological and molecular level, using the model organism caenorhabditis elegans, in response to s. flexneri. c. elegans is a nematode that responds to infection with a simple innate immune system, key aspects of which have been shown to be conserved.201121254954
antibacterial activity of the enniatin b, produced by fusarium tricinctum in liquid culture, and cytotoxic effects on caco-2 cells.the enniatins (ens) are bioactive compounds of hexadepsipeptidic structure produced by several strains of fusarium sp. the en b was purified from extracts of fusarium tricinctum growth on liquid culture of potato dextrose broth (pdb), using a semipreparative liquid chromatography (lc) followed by an analytical lc. the purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (esi-ms) stud ...201121417626
synthesis and in vitro microbiological evaluation of novel diethyl 6,6'-(1,4-phenylene)bis(4-aryl-2-oxo-cyclohex-3-enecarboxylates).novel bis cyclohexenone ester derivatives 14-19 were synthesized and characterized by their spectral data. in vitro microbiological evaluations were carried out for all the novel compounds 14-19 against clinically isolated bacterial and fungal strains. compounds 15, 16, 18 against staphylococcus aureus, 14, 15 against ß-haemolytic streptococcus, 15, 19 against micrococcus luteus, 17, 18 against salmonella typhii, 14, 17 against shigella flexneri, 15 against escherichia coli, 16 against pseudomon ...201121417963
genomic characterization of asymptomatic escherichia coli isolated from the neobladder.the replacement of the bladder with a neobladder made from ileal tissue is the prescribed treatment in some cases of bladder cancer or trauma. studies have demonstrated that individuals with an ileal neobladder have recurrent colonization by escherichia coli and other species that are commonly associated with urinary tract infections; however, pyelonephritis and complicated symptomatic infections with ileal neobladders are relatively rare. this study examines the genomic content of two e. coli i ...201121252277
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
enteric glial cells: new players in mucosal defence against bacteria? 201121282131
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
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
[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
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
autophagy targeting of listeria monocytogenes and the bacterial countermeasure.autophagy acts as an intrinsic defense system against intracellular bacterial survival. recently, multiple cellular pathways that target intracellular bacterial pathogens to autophagy have been described. these include the atg5/lc3 pathway, which targets shigella, the ubiquitin (ub)-ndp52-lc3 pathway, which targets group a streptococcus (gas) and salmonella typhimurium, the ub-p62-lc3 pathway, which targets mycobacterium tuberculosis, listeria monocytogenes and s. typhimurium, and the diacylglyc ...201121193840
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
immunology of gut mucosal vaccines.understanding the mechanisms underlying the induction of immunity in the gastrointestinal mucosa following oral immunization and the cross-talk between mucosal and systemic immunity should expedite the development of vaccines to diminish the global burden caused by enteric pathogens. identifying an immunological correlate of protection in the course of field trials of efficacy, animal models (when available), or human challenge studies is also invaluable. in industrialized country populations, l ...201121198669
volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of pinus densiflora and pinus thunbergii.to investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of pinus densiflora needles (epdn) and pinus thunbergii needles (eptn), the volatile compounds of steam-distilled essential oils were analysed by gas chromatography-mass spectrometry. antibacterial activities were analysed by performing disc-agar diffusion assay and determining the minimum inhibitory concentrations (mics) of the essential oils. antioxidant activities were analysed via radica ...201121213230
extended spectrum beta-lactamase production in shigella isolates - a matter of concern. 201121304205
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
two promoters and two translation start sites control the expression of the shigella flexneri outer membrane protease icsp.the shigella flexneri outer membrane protease icsp proteolytically cleaves the actin-based motility protein icsa from the bacterial surface. the icsp gene is monocistronic and lies downstream of an unusually large intergenic region on the shigella virulence plasmid. in silico analysis of this region predicts a second transcription start site 84 bp upstream of the first. primer extension analyses and beta-galactosidase assays demonstrate that both transcription start sites are used. both promoter ...201121225241
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
etiology of diarrhea in young children and patterns of antibiotic resistance in cambodia.little is known about diarrhea etiology and antibiotic resistance in developing countries where diarrhea is a major public health problem.201121412204
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
fabrication of silver nanoparticles doped in the zeolite framework and antibacterial activity.using the chemical reduction method, silver nanoparticles (ag nps) were effectively synthesized into the zeolite framework in the absence of any heat treatment. zeolite, silver nitrate, and sodium borohydride were used as an inorganic solid support, a silver precursor, and a chemical reduction agent, respectively. silver ions were introduced into the porous zeolite lattice by an ion-exchange path. after the reduction process, ag nps formed in the zeolite framework, with a mean diameter of about ...201121383858
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
postinfective bile acid malabsorption: is this a long-term condition?postinfective bile acid malabsorption comprises a group of patients with a history of an episode of acute gastroenteritis triggering chronic diarrhoea. we identified these patients retrospectively from our medical records and assessed their long-term clinical course.201121389860
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
shigella enterotoxin-2 is a type iii effector that participates in shigella-induced interleukin 8 secretion by epithelial cells.we have previously described a protein termed shigella enterotoxin 2 (shet-2), which induces rises in short-circuit current in rabbit ileum mounted in the ussing chamber. published reports have postulated that shet-2 may be secreted by the shigella type iii secretion system (t3ss). in this study, we show that shet-2 secretion into the extracellular space requires the t3ss in shigella flexneri 2a strain 2457t and a shet-2-tem fusion was translocated into epithelial cells in a t3ss-dependent manne ...201121219446
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
structural and functional studies indicate that the epec effector, espg, directly binds p21-activated kinase.bacterial pathogens secrete effectors into their hosts that subvert host defenses and redirect host processes. espg is a type three secretion effector with a disputed function that is found in enteropathogenic escherichia coli. here we show that espg is structurally similar to vira, a shigella virulence factor; espg has a large, conserved pocket on its surface; espg binds directly to the amino-terminal inhibitory domain of human p21-activated kinase (pak); and mutations to conserved residues in ...201121235237
core and panmetabolism in escherichia coli.escherichia coli exhibits a wide range of lifestyles encompassing commensalism and various pathogenic behaviors which its highly dynamic genome contributes to develop. how environmental and host factors shape the genetic structure of e. coli strains remains, however, largely unknown. following a previous study of e. coli genomic diversity, we investigated its diversity at the metabolic level by building and analyzing the genome-scale metabolic networks of 29 e. coli strains (8 commensal and 21 p ...201121239590
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
role of intestinal bacteria in gliadin-induced changes in intestinal mucosa: study in germ-free rats.celiac disease (cd) is a chronic inflammatory disorder of the small intestine that is induced by dietary wheat gluten proteins (gliadins) in genetically predisposed individuals. the overgrowth of potentially pathogenic bacteria and infections has been suggested to contribute to cd pathogenesis. we aimed to study the effects of gliadin and various intestinal bacterial strains on mucosal barrier integrity, gliadin translocation, and cytokine production.201121249146
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
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
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
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
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
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
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
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
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
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
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
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
anti-enteric bacterial activity and phytochemical analysis of the seed kernel extract of mangifera indica linnaeus against shigella dysenteriae (shiga, corrig.) castellani and chalmers.to evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of mangifera indica (m. indica) against the enteropathogen, shigella dysenteriae (s. dysenteriae), isolated from the diarrhoeal stool specimens.201121771473
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
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
molecular identification of bacteria by total sequence screening: determining the cause of death in ancient human subjects.research of ancient pathogens in ancient human skeletons has been mainly carried out on the basis of one essential historical or archaeological observation, permitting specific pathogens to be targeted. detection of ancient human pathogens without such evidence is more difficult, since the quantity and quality of ancient dna, as well as the environmental bacteria potentially present in the sample, limit the analyses possible. using human lung tissue and/or teeth samples from burials in eastern s ...201121765907
rapid concentration and molecular enrichment approach for sensitive detection of escherichia coli/shigella in potable water samples.in this work, we used a rapid, simple, and efficient concentration and recovery procedure combined with a dna enrichment method (dubbed crename), that we coupled to an escherichia coli/shigella-specific real-time pcr (rtpcr) assay targeting the tuf gene, to sensitively detect e. coli/shigella in water. this integrated method was compared to the usepa culture-based method 1604 on mi agar in terms of analytical specificity, ubiquity, detection limit, and rapidity. none of the 179 non-e. coli/shige ...201121764965
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
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
lipopolysaccharide core structures and their correlation with genetic groupings of shigella strains; a novel core variant in shigella boydii type 16.bacteria shigella, the cause of shigellosis, evolved from intestinal bacteria escherichia coli. based on structurally diverse o-specific polysaccharide chains of the lipopolysaccharides (o-antigens), three from four shigella species are subdivided into multiple serotypes. the central oligosaccharide of the lipopolysaccharide called core is usually conserved within genus but five core types called r1-r4 and k-12 have been recognized in e. coli. structural data on the shigella core are limited to ...201121752864
shiga toxins induce autophagy leading to differential signalling pathways in toxin-sensitive and toxin-resistant human cells.the bacterial virulence factors shiga toxins (stxs) are expressed by shigella dysenteriae serotype 1 and certain escherichia coli strains. stxs are protein synthesis inhibitors and induce apoptosis in many cell types. stxs induce apoptosis via prolonged endoplasmic reticulum stress signalling to activate both extrinsic and intrinsic pathways in human myeloid cells. studies have shown that autophagy, a lysosome-dependent catabolic process, may be associated with activation of pro-survival or deat ...201121722286
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
molecular characterization of fecal microbiota in patients with viral diarrhea.the study provides molecular analyses of fecal microbiota of diarrhea patients infected with four different types of viruses. fecal specimens from 52 patients with viral diarrhea (13 each of adenovirus, norovirus, rotavirus, and astrovirus) and six healthy individuals were collected and etiological viral agent was confirmed by enzyme immunoassay and specific pcr. to assess the changes in microbial diversity in patients with viral diarrhea, dna from stool were extracted and characterized by pcr-d ...201121739252
the effect of quercus castaneifolia extract on pathogenic enteric bacteria.the family of enterobacteriaceae is a major group of gram negative bacteria, some of these microorganisms are pathogen and could cause disease mainly gastroenteritis. recently, due to drug resistant nature of these bacteria specially in developing countries treatment of the patient considered as important investigate. quercus castaneifolia is a native plant of yasuj province in iran, which the people who living in this area consume the fruit of this plant for treatment of enteric disease. hence, ...201121827865
viral-associated thrombotic microangiopathies.thrombotic microangiopathies encompass a group of disorders characterized by microangiopathic hemolytic anemia, thrombocytopenia associated with hyaline thrombi (comprised primarily of platelet aggregates in the microcirculation), and varying degrees of end-organ failure. many primary (genetic) and secondary etiological predisposing factors have been described-namely pregnancy, autoimmune disorders, cancer, drugs and antineoplastic therapy, bone marrow transplantation/solid organ transplantation ...201121727765
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
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
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
epidemiology of food-borne disease outbreaks in the french armed forces: a review of investigations conducted from 1999 to 2009.objective: aim of this study was to describe the main characteristics of food-borne disease outbreaks (fbdos) in the french armed forces from 1999 to 2009. methods: fbdos are reported to the military epidemiological surveillance system, which concerns all active military personnel. investigation reports published from 1999 to 2009 were reviewed. results: among the 180 fbdos reported, 48.3% occurred overseas. the mean reporting rate was 2.4 outbreaks p.100,000 in france and 26.7 p.100,000 oversea ...201121840337
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
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
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
multi-pathogen waterborne disease outbreak associated with a dinner cruise on lake michigan.summarywe report an outbreak associated with a dinner cruise on lake michigan. this took place on the same day as heavy rainfall, which resulted in 42-à4 billion liters of rainwater and storm runoff containing highly diluted sewage being released into the lake. of 72 cruise participants, 41 (57%) reported gastroenteritis. stool specimens were positive for shigella sonnei (n=3), giardia (n=3), and cryptosporidium (n=2). ice consumption was associated with illness (risk ratio 2-à2, p=0-à011). s. s ...201121676362
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
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
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
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