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akara ogbomoso: microbiological examination and identification of hazards and critical control points.akara ogbomoso was examined toward the establishment of hazard analysis and critical control point (haccp). the akara was produced in residential buildings with the attendant consequence of contamination. there was ample growth of aerobes, coliforms, staphylococci, shigella and yeast/mold from the samples, water and cowpea pastes. microbial contaminations occur through the processing, which can be corrected through education by adopting good hygienic and manufacturing practices. the critical con ...201021339157
[shigellosis--epidemiological situation in montenegro in period 1996-2005].introduction shigellosis is the most common cause of diarrhoea in the world. it is estimated to cause 165 million cases per a year, and two third of all diseases and most of the deaths are among children under 10 years of age. the aim of this descriptive epidemiologic study was to analyze the incidence of shigellosis in montenegro during the period 1996-2005 and to find out which species of shigella were dominant in this region.201021446148
evaluation of antibacterial activity of 3-butenyl, 4-pentenyl, 2-phenylethyl, and benzyl isothiocyanate in brassica vegetables.this study investigated antibacterial activities of 4 isothiocyanates (3-butenyl, 4-phentenyl, 2-phenylethyl, and benzyl isothiocyanate) against 4 gram-positive bacteria (bacillus cereus, bacillus subtilis, listeria monocytogenes, and staphylococcus aureus) and 7 gram-negative bacteria (aeromonas hydrophila, pseudomonas aeruginosa, salmonella choleaesuis, salmonella enterica, serratia marcescens, shigella sonnei, and vibrio parahaemolyticus) by an agar disc diffusion assay. benzyl isothiocyanate ...201021535549
osmosonication of blackberry juice: impact on selected pathogens, spoilage microorganisms, and main quality parameters.osmosonication combines ultrasound with nonthermal concentration. it was applied on tropical highland blackberry (rubus adenotrichus) juice over different periods of time to assess reductions in microorganism and the impact on main quality parameters. this juice had been inoculated with salmonella spp., shigella sp., a lactic acid bacterium, yeasts, and molds. it was then sonicated for 5.9 to 34.1 min at 20 khz and 0.83 w/ml. nonthermal concentration was simulated by mixing the juice with a conc ...201021535558
lactobacillus fermentum isolated from human colonic mucosal biopsy inhibits the growth and adhesion of enteric and foodborne pathogens.a number of lactobacillus species are used as probiotic strains in order to benefit health. we have isolated l. fermentum from human colonic mucosal biopsy samples that possess antimicrobial activities against entroinvasive and foodborne pathogens such as escherichia coli, salmonella paratyphi a, shigella sonnei, staphylococcus aureus, enterococcus faecalis, proteus mirabilis, pseudomonas aeruginosa, and vibrio sp. in addition to lactic acid, l. fermentum secretes antimicrobial proteinacious com ...201021535608
effect of nacl on the biofilm formation by foodborne pathogens.this study was designed to evaluate the effect of nacl on the biofilm formation of listeria monocytogenes, staphylococcus aureus, shigella boydii, and salmonella typhimurium. the biofilm cells were cultured in media containing different nacl concentrations (0% to 10%) for 10 d of incubation at 37 °c using a 24-well polystyrene microtiter plate, collected by swabbing methods, and enumerated using plate count method. the attachment and detachment kinetic patterns were estimated according to the mo ...201021535614
sensitivity and specificity of bloody diarrhea in shigella gastroenteritis.the sensitivity and specificity of bloody diarrhea in the diagnosis of shigella gastroenteritis in a shigella sonnei prevalent center was investigated. the shigella-proven gastroenteritis cases who were admitted to hacettepe university ihsan doğramaci children's hospital diarrheal diseases unit (jan 2003 - oct 2006) constituted the study group (n=65). age- and sex-matched children admitting to the same center with non-shigella diarrhea constituted the control group (n=65). the sensitivity, speci ...201021434533
the modulation of hela cells secretory patterns by invasive shigella spp. and enteroinvasive e. coli bacterial cells and their soluble components.considering the important role of cytokines in the initiation and evolution of the inflammatory process induced by shigella and eiec strains, the purpose of this study was the characterization of the secretory patterns of hela cells induced by shigella ssp. and eiec strains and to link the obtained results with the invasiveness level of bacterial strains on this cellular line. during this study there were analyzed two eiec strains and 12 strains of the following shigella species: 2 sh. flexneri ...201021434590
shiga toxins: intracellular trafficking to the er leading to activation of host cell stress responses.despite efforts to improve hygenic conditions and regulate food and drinking water safety, the enteric pathogens, shiga toxin-producing escherichia coli (stec) and shigella dysenteriae serotype 1 remain major public health concerns due to widespread outbreaks and the severity of extra-intestinal diseases they cause, including acute renal failure and central nervous system complications. shiga toxins are the key virulence factors expressed by these pathogens mediating extra-intestinal disease. de ...201022069648
shiga toxin is transported into the nucleoli of intestinal epithelial cells via a carrier-dependent process.shiga toxin (stx) produced by the invasive shigella dysenteriae serotype 1 (s. dysenteriae1) causes gastrointestinal and kidney complications. it has been assumed that stx is released intracellularly after enterocyte invasion by s. dysenteriae1. however, there is little information about stx distribution inside s. dysenteriae1-infected enterocytes. here, we use intestinal epithelial t84 cells to characterize the trafficking of stx delivered into the cytosol, in ways that mimic aspects of s. dyse ...201022069640
ceftriaxone resistant shigella flexneri, an emerging problem.shigellosis is a disease of public health importance in developing countries. it may cause self-limited diarrhea to severe dysentery. emergence of multi drug resistant (mdr) strains is a growing concern globally. ceftriaxone and ciprofloxacin are the drugs of choice for mdr cases. here, we report a case of mdr shigella flexneri from an immunocompromised patient. the strain was resistant to ceftriaxone [minimum inhibitory concentration (mic) ≥ 64 μg/ml], limiting the treatment option. simultaneou ...201021258157
serine protease autotransporters of enterobacteriaceae (spates): biogenesis and function.serine protease autotransporters of enterobacteriaceae (spates) constitute a large family of proteases secreted by escherichia coli and shigella. spates exhibit two distinct proteolytic activities. first, a c-terminal catalytic site triggers an intra-molecular cleavage that releases the n-terminal portion of these proteins in the extracellular medium. second, the secreted n-terminal domains of spates are themselves proteases; each contains a canonical serine-protease catalytic site. some of thes ...201022069633
shigella-associated diarrhea in children in south jakarta, indonesia.a surveillance of shigella infections was conducted on 612 children aged 0-12 years-old presenting with diarrhea to mampang and tebet community health centers in south jakarta, indonesia, during february 2005 through september 2007. shigella was isolated from 9.3% of diarrhea patients in the health centers. s.flexneri which was found in 5.9% of patients, and was the most frequent species isolated, comprising 63.2% (36/57) of all shigella species isolated. shigella species were found significantl ...201020578526
newer insights into the mechanism of action of psidium guajava l. leaves in infectious diarrhoea.psidium guajava l., myrtaceae, is used widely in traditional medicine for the treatment of diarrhoea, dysentery, gastroenteritis, stomachaches, and indigestion. however, the effect of the leaf extract of p. guajava on the pathogenesis of infectious diarrhoea has not been studied. the present study evaluates the effect of a hot aqueous extract (decoction) of dried leaves of p. guajava on parameters associated with pathogenicity of infectious diarrhoea. the aim was to understand its possible mecha ...201020584265
a pathoadaptive deletion in an enteroaggregative escherichia coli outbreak strain enhances virulence in a caenorhabditis elegans model.enteroaggregative escherichia coli (eaec) strains are important diarrheal pathogens. eaec strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent e. coli subtypes of shigella and enterohemorrhagic e. coli. to test the hypothesis that cad deletions might account fo ...201020584976
bacterial pathogens associated with bloody diarrhea in uruguayan children.diarrheal disease continues to be a serious health problem, especially in developing countries. bloody diarrhea represents approximately 20-30% of all cases and has higher morbidity and mortality. treatment with antibiotics is beneficial in cases of shigella, campylobacter, yersinia and salmonella infection, principally in those children with a higher risk of invasive disease. the aims of this study were to detect the bacterial agents associated with bloody diarrhea in children and to determine ...201020589332
progressivemauve: multiple genome alignment with gene gain, loss and rearrangement.multiple genome alignment remains a challenging problem. effects of recombination including rearrangement, segmental duplication, gain, and loss can create a mosaic pattern of homology even among closely related organisms.201020593022
cladophora in the great lakes: impacts on beach water quality and human health.cladophora in the great lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. cladophora provides protection and nutrients, which allow enteric bacteria such as escherichia coli, enterococci, shigella, campylobacter, and salmonella to persist and potentially regrow in the presence of the algae. as a result of wind and wave action, these microorganisms can detach an ...201020595755
probiotic administration effect on fecal mutagenicity and microflora in the goat's gut.the application of potentially beneficial microorganisms to increase host defense is a new trend to increase health benefits. in this paper the first specific host probiotics for goats from a mixture isolated from healthy animals (lactobacillus reuteri ddl 19, lactobacillus alimentarius ddl 48, enterococcus faecium dde 39 and bifidobacterium bifidum ddba) was assayed. the effect of probiotic oral administration on goats' weight, gut microbiota, as well as on the production of mutagen compounds a ...201020598940
escape of intracellular shigella from autophagy requires binding to cholesterol through the type iii effector, icsb.type iii secretion systems are present in many pathogenic bacteria and mediate the translocation of bacterial effectors into host cells. identification of host targets of these effectors is crucial for understanding bacterial virulence. icsb, a type iii secretion effector, helps shigella to evade the host autophagy defense system by binding to the autophagy protein, atg5. here, we show that icsb is able to interact specifically with cholesterol. the cholesterol binding domain (cbd) of icsb is lo ...201020599519
enterocyte-like caco-2 cells as a model for in vitro studies of diarrhoeagenic providencia alcalifaciens invasion.the entry of providencia alcalifaciens into the enterocyte-like cell line caco-2 compared to hep-2 was studied. of the 22 p. alcalifaciens strains, 13 and 21 were invasive for caco-2 and hep-2 cells, respectively. in contrast to hep-2 cells, p. alcalifaciens was internalised by caco-2 cells via receptor-mediated endocytosis. tyrosine kinases play an important role in p. alcalifaciens uptake, also microfilaments and microtubules are engaged in this process. inhibition of endosome acidification by ...201020600792
inhibition of shigella sonnei adherence to ht-29 cells by lactobacilli from chinese fermented food and preliminary characterization of s-layer protein involvement.in this study, seven lactobacilli with a high degree of antagonistic activity against three pathogens and good adherence to ht-29 cells were selected. the ability of these seven lactobacilli to inhibit adhesion of shigella sonnei to intestinal mucosa was studied on cultured ht-29 cells. lactobacilli were added simultaneously with, before or after s. sonnei to test for their effectiveness in exclusion, competition and displacement assays, respectively. lactobacillus paracasei subp. paracasei m5-l ...201020600857
microbial contamination of raw meat and its environment in retail shops in karachi, pakistan.this study was conducted to examine the frequency of contamination in retail meat available in karachi, pakistan.201020601790
isoprenoid metabolism as a therapeutic target in gram-negative pathogens.gram-negative enterobacteria include a variety of human pathogens, perhaps most notably e. coli, salmonella, shigella, yersinia, and proteus. while there are treatment options for the diseases caused by these organisms, multi-drug resistance is often a problem and development of novel antibiotics has lagged over recent years. in humans, the isoprenoid biosynthetic pathway has become a subject of intense research for therapeutic modulation of human enzymes in diseases including hypercholesterolem ...201020615187
methods for monitoring trends in the incidence of foodborne diseases: foodborne diseases active surveillance network 1996-2008.foodborne illnesses are a substantial health burden in the united states. the foodborne diseases active surveillance network (foodnet) is the principal foodborne disease component of the centers for disease control and prevention's emerging infections program. foodnet is a collaborative project among centers for disease control and prevention, emerging infections program sites, the u.s. department of agriculture, and the u.s. food and drug administration. one of foodnet's main objectives is to m ...201020617933
safety and immunogenicity of a shigella flexneri 2a invaplex 50 intranasal vaccine in adult volunteers.shigellosis is a leading cause of diarrhea worldwide prompting vaccine development. the shigella flexneri invaplex 50 is a macromolecular complex containing ipab, ipac, and lps, formulated from an aqueous extract of virulent shigella delivered via nasal administration. preclinical vaccine testing demonstrated safety, immunogenicity and efficacy. an open-label dose-escalating phase 1 study evaluated a 3-dose (2-week intervals) regimen via nasal pipette delivery. thirty-two subjects were enrolled ...201020619378
production of antimicrobial silver nanoparticles in water extracts of the fungus amylomyces rouxii strain ksu-09.a fungal strain, ksu-09, isolated from the roots of date palm (phoenix dactylifera), was identified as amylomyces rouxii based on sequence analysis of the internal transcribed spacer (its) region of its rrna genes. mycelia-free water extracts obtained from mycelium suspended in water for 72h facilitated the production of stable, predominantly monodispersed and spherical silver nanoparticles (agnps) in the size range of 5-27nm upon addition of 1mm silver nitrate, as determined by the xrd, afm and ...201020619641
synthesis, structure and in vitro antibacterial activities of new hybrid disinfectants quaternary ammonium compounds: pyridinium and quinolinium stilbene benzenesulfonates.the series of pyridinium (1-10) and quinolinium (11-20) stilbene benzenesulfonates have been synthesized and their structures were investigated by uv-vis, ft-ir and (1)h nmr spectroscopy. in addition, compound 5 was also determined by single crystal x-ray diffraction technique. the antibacterial activity of the synthesized compounds against both gram-positive and gram-negative bacteria has been determined. the quinolinium derivatives exhibited two very potent characteristic activities, namely, ( ...201020619939
comparison of 61 sequenced escherichia coli genomes.escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. sixty-one publically available e. coli and shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics trees, and to identify the pan- and core genomes of this set of sequenced strains. a hierarchical clustering of variable genes allowed clear separation of the strains into clusters, including known pathoty ...201020623278
reduced azithromycin susceptibility in shigella sonnei, united states.to investigate azithromycin susceptibility in shigella sonnei in the united states, we examined the azithromycin minimum inhibitory concentrations (mics) of outbreak and routine human s. sonnei isolates. isolate susceptibility clustered at 8 mg/l, but three isolates displayed higher mics (>64  mg/l) to azithromycin. all three isolates contained a plasmid-encoded mpha gene, known to encode a macrolide-2'-phosphotransferase enzyme. transformation of the mpha gene into escherichia coli dh10b allowe ...201020624094
evidence for alternative quaternary structure in a bacterial type iii secretion system chaperone.type iii secretion systems are a common virulence mechanism in many gram-negative bacterial pathogens. these systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. prior to translocation specialized chaperones maintain proper effector protein conformation. the class ii chaperone, invasion plasmid gene (ipg) c, stabilizes ...201020633281
prolonged episodes of acute diarrhea reduce growth and increase risk of persistent diarrhea in children.prolonged episodes of acute diarrhea (prod; duration 7-13 days) or persistent diarrhea (pd; duration ≥14 days) are important causes of undernutrition, yet the epidemiology and nutritional impact of prod are poorly understood.201020638937
the omptins of yersinia pestis and salmonella enterica cleave the reactive center loop of plasminogen activator inhibitor 1.plasminogen activator inhibitor 1 (pai-1) is a serine protease inhibitor (serpin) and a key molecule that regulates fibrinolysis by inactivating human plasminogen activators. here we show that two important human pathogens, the plague bacterium yersinia pestis and the enteropathogen salmonella enterica serovar typhimurium, inactivate pai-1 by cleaving the r346-m347 bait peptide bond in the reactive center loop. no cleavage of pai-1 was detected with yersinia pseudotuberculosis, an oral/fecal pat ...201020639337
shiga toxin b subunits induce vwf secretion by human endothelial cells and thrombotic microangiopathy in adamts13-deficient mice.diarrhea-associated hemolytic uremic syndrome (d+hus) is the most common cause of acute renal failure among children. renal damage in d+hus is caused by shiga toxin (stx), which is elaborated by shigella dysenteriae and certain strains of escherichia coli, in north america principally e coli o157:h7. recent studies demonstrate that stx also induces von willebrand factor (vwf) secretion by human endothelial cells and causes thrombotic thrombocytopenic purpura, a disease with similarities to d+hus ...201020644116
photodynamic antimicrobial chemotherapy by liposome-encapsulated water-soluble photosensitizers.photodynamic antimicrobial chemotherapy is an alternative method for killing bacterial cells in view of the increasing problem of multi-antibiotic resistance. we examined the effect of three water-soluble photosensitizers (phs): methylene blue (mb), neutral red (nr) and rose bengal (rb) on gram-positive and gram-negative bacteria. we compared the efficacy of phs in their free form and encapsulated in liposomal formulations against various bacterial strains, and determined conditions for the effe ...201020644595
[structure of the oligosaccharide region (core) of the lipopolysaccharides of shigella flexneri types 2a and 5b].the full structure of the lipopolysaccharide core of bacteria shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional nmr spectroscopy. the structure of the o-antigen repeating unit and the configuration and position of the linkage between the o-antigen and the core were determined in the lipopolysaccharide of s. flexneri type 2a.201020644600
antibacterial properties of essential oils and methanol extracts of sweet basil ocimum basilicum occurring in bangladesh.the antibacterial potential of essential oils and methanol extracts of sweet basil ocimum basilicum l. (lamiaceae) was evaluated for controlling the growth range of food-borne pathogenic bacteria. essential oils extracted by hydrodistillation from the leaves and stems were analyzed by gc-ms. fifty-seven compounds representing 94.9 and 96.1% of the total leaf and stem oils, respectively, were identified, of which methyl chavicol (36.7 and 29.9%), gitoxigenin (9.3 and 10.2%), trimethoquinol (10.3 ...201020645791
enteropathogenic escherichia coli, samonella, shigella and yersinia: cellular aspects of host-bacteria interactions in enteric diseases.abstract: a successful infection of the human intestine by enteropathogenic bacteria depends on the ability of bacteria to attach and colonize the intestinal epithelium and, in some cases, to invade the host cell, survive intracellularly and disseminate from cell to cell. to accomplish these processes bacteria have evolved an arsenal of molecules that are mostly secreted by dedicated type iii secretion systems, and that interact with the host, subverting normal cellular functions. here we overvi ...201020649986
in silico characterization of shikimate kinase of shigella flexneri: a potential drug target.shigella flexneri is a major pathogen responsible for shigellosis causing massive morbidity among young population and imposes huge socio-economic burden. in this study, shikimate kinase (sk) from s. flexneri was characterized in silico and disordered regions were predicted. motifs and domains were calculated using computational tools. a three dimensional model of shikimate kinase of s.flexneri was constructed using shikimate kinase of e.coli (pdbid: 1kag_a) as template by comparative modeling a ...201020658341
convalescent cultures for control of shigellosis outbreaks.a shigellosis outbreak in the st louis, missouri metropolitan area.201020661101
prevalence of integrons in shigella sonnei from brazil. 201020664608
synthesis and in vitro antibacterial activity of novel fluoroquinolone derivatives containing substituted piperidines.we report herein the synthesis of novel 7-(4-alkoxyimino-3-aminomethyl-3-methylpiperidin-1-yl) fluoroquinolone derivatives. the antibacterial activity of the newly synthesized compounds was evaluated and correlated with their physicochemical properties. results reveal that all of the target compounds have good potency in inhibiting the growth of staphylococcus aureus and staphylococcus epidermidis including mrse (mic: 0.125-4 microg/ml). compounds 12, 13 are more potent than or comparable to lev ...201020667731
glycan encapsulated gold nanoparticles selectively inhibit shiga toxins 1 and 2.shiga toxins (stx) released by escherichia coli o157:h7 and shigella dysentriae cause life-threatening conditions that include hemolytic uremic syndrome (hus), kidney failure, and neurological complications. cellular entry is mediated by the b-subunit of the ab(5) toxin, which recognizes cell surface glycolipids present in lipid raft-like structures. we developed gold glyconanoparticles that present a multivalent display similar to the cell surface glycolipids to compete for these toxins. these ...201020669970
control of coliform bacteria detected from diarrhea associated patients by extracts of moringa oleifera.the aims of this study were to determine the total population of coliform bacteria in the samples collected from diarrhea associated patients from the local area of bangladesh and to examine the antibacterial efficacy of leaf extracts of moringa oleifera (moringaceae) against the isolated coliform bacteria. the coliform bacteria detected in these samples by some microbial-biochemical tests such as escherichia coli, shigella dysenteriae, salmonella sp., enterobacter sp., klebsiella pneumoniae and ...201020677603
impact of diet in shaping gut microbiota revealed by a comparative study in children from europe and rural africa.gut microbial composition depends on different dietary habits just as health depends on microbial metabolism, but the association of microbiota with different diets in human populations has not yet been shown. in this work, we compared the fecal microbiota of european children (eu) and that of children from a rural african village of burkina faso (bf), where the diet, high in fiber content, is similar to that of early human settlements at the time of the birth of agriculture. by using high-throu ...201020679230
facile glycosylation strategy with two-stage activation of allyl glycosyl donors. application to concise synthesis of shigella flexneri serotype y o-antigen.a practical, useful glycosylation method employing only allyl glycoside building blocks has been developed. the donor's glycosylation reactivity is turned on via isomerization of its anomeric allyl protecting group into the corresponding prop-1-enyl moiety. subsequent chemoselective activation with nis/tfoh achieves high yields in glycosidic bond construction at room temperature. the efficacy and efficiency of this approach in carbohydrate synthesis is demonstrated in the concise synthesis of th ...201020683518
antimicrobial resistance and molecular analysis of non-typhoidal salmonella isolates from human in tunisia.during the period from 2006 to 2007, a total of 32 clinical isolates of salmonella enterica were isolated from diarrheagenic stool samples and further examined for their susceptibility to various antibiotics. sixteen of the human isolates were from the capital tunis, 11 were from sousse, four were from nabeul and one was from mahdia, tunisia. the isolates were serotyped and identified at the national centre of enteropathogenic bacteria, pasteur institute, tunis (centre national de salmonella, sh ...201020685046
plasmid-mediated streptomycin and sulfamethoxazole resistance in shigella flexneri 3a.shigellosis is a major cause of diarrhoea-related morbidity and mortality, especially in children in developing countries such as india. recently, it was estimated that 91 million individuals worldwide contract shigellosis each year. the emergence and dissemination of multidrug-resistant strains of shigella is now an emerging global health problem. during the past two decades, much attention was given to re-evaluation of treatment recommendations. in the present study, we investigated a clinical ...201020685089
antibiotic therapy for shigella dysentery.shigella dysentery is a relatively common illness and occasionally causes death, worldwide. mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. the antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.201020687081
hemolysin e (hlye, clya, shea) and related toxins.certain strains of escherichia coli, salmonella enterica and shigella flexneri produce a pore-forming toxin hemolysin e (hlye), also known as cytolysin a (clya) and silent hemolysin, locus a (shea). hlye lyses erythrocytes and mammalian cells, forming transmembrane pores with a minimum internal diameter of-25 a. we review the current knowledge of hlye structure and function in its solution and pore forms, models for membrane insertion, its potential use in biotechnology applications and its rela ...201020687485
shigellosis update: advancing antibiotic resistance, investment empowered vaccine development, and green bananas.shigella is the principal cause of clinical dysentery and an important cause of morbidity and mortality among children in impoverished regions. the purpose of this review is to present key findings in the areas of epidemiology, disease control, and treatment of shigellosis.201020689423
etiology of diarrhea in older children, adolescents and adults: a systematic review.diarrhea is an important cause of morbidity and mortality in all regions of the world and among all ages, yet little is known about the fraction of diarrhea episodes and deaths due to each pathogen.201020689809
crystal structures of phd-doc, higa, and yeeu establish multiple evolutionary links between microbial growth-regulating toxin-antitoxin systems.bacterial toxin-antitoxin (ta) systems serve a variety of physiological functions including regulation of cell growth and maintenance of foreign genetic elements. sequence analyses suggest that ta families are linked by complex evolutionary relationships reflecting likely swapping of functional domains between different ta families. our crystal structures of phd-doc from bacteriophage p1, the higa antitoxin from escherichia coli cft073, and yeeu of the yeeuwv systems from e. coli k12 and shigell ...201020696400
pic, an autotransporter protein secreted by different pathogens in the enterobacteriaceae family, is a potent mucus secretagogue.a hallmark of enteroaggregative escherichia coli (eaec) infection is a formation of biofilm, which comprises a mucus layer with immersed bacteria in the intestines of patients. while studying the mucinolytic activity of pic in an in vivo system, rat ileal loops, we surprisingly found that eaec induced hypersecretion of mucus, which was accompanied by an increase in the number of mucus-containing goblet cells. interestingly, an isogenic pic mutant (eaec δpic) was unable to cause this mucus hypers ...201020696826
diverse pathways for salicin utilization in shigella sonnei and escherichia coli carrying an impaired bgl operon.utilization of the aryl-β-glucosides salicin or arbutin in most wild-type strains of e. coli is achieved by a single-step mutational activation of the bgl operon. shigella sonnei, a branch of the diverse e. coli strain tree, requires two sequential mutational steps for achieving salicin utilization as the bglb gene, encoding the phospho-β-glucosidase b, harbors an inactivating insertion. we show that in a natural isolate of s. sonnei, transcriptional activation of the gene sso1595, encoding a ph ...201020697693
[mucocutaneous abnormalities in chlamydia trachomatis-induced reactive arthritis].reactive arthritis (previously known as reiters syndrome) is an inflammatory arthritis that is a type of spondyloarthropathy. the disease consists of the classical triad of arthritis, urethritis and conjunctivitis, but mucocutaneous abnormalities also frequently appear: balanitis circinata, keratoderma blennorrhagicum, aphthous ulcers in the mouth and nail disorders. these skin lesions are mainly found in reactive arthritis induced by chlamydia trachomatis (ct). reactive arthritis is often trigg ...201020699017
production of glycoprotein vaccines in escherichia coli.conjugate vaccines in which polysaccharide antigens are covalently linked to carrier proteins belong to the most effective and safest vaccines against bacterial pathogens. state-of-the art production of conjugate vaccines using chemical methods is a laborious, multi-step process. in vivo enzymatic coupling using the general glycosylation pathway of campylobacter jejuni in recombinant escherichia coli has been suggested as a simpler method for producing conjugate vaccines. in this study we descri ...201020701771
comparative in vitro activity of tigecycline and other antimicrobial agents against shigella species from kuwait and the united arab of emirates.shigella species isolated from stool samples of symptomatic patients of all age groups at the mubarak al kabir hospital and infectious diseases hospital, kuwait and tawam hospital, uae during a 2-year period were investigated for their susceptibility to tigecycline and several other antibiotics by determining the minimum inhibitory concentrations (mics) using the e test method. a total of 100 and 42 strains were collected from uae and kuwait, respectively. the extent of drug resistance in the sh ...201020701889
foodborne proportion of gastrointestinal illness: estimates from a canadian expert elicitation survey.the study used a structured expert elicitation survey to derive estimates of the foodborne attributable proportion for nine illnesses caused by enteric pathogens in canada. it was based on a similar study conducted in the united states and focused on campylobacter, escherichia coli o157:h7, listeria monocytogenes, nontyphoidal salmonella enterica, shigella spp., vibrio spp., yersinia enterocolitica, cryptosporidium parvum, and norwalk-like virus. for each pathogen, experts were asked to provide ...201020704505
seasonal variation of enteropathogens in infants and preschoolers with acute diarrhea in western mexico.the present study estimates the prevalence of some enteropathogens in infants and preschoolers with acute diarrhea. from 2006 to 2007, 5459 consecutive stool samples were evaluated. cryptosporidium parvum was the parasite identified with the higher frequency (5.1%), followed by giardia lamblia (1.2%). campylobacter jejuni was isolated in 858 cases (15.7%) and was the most frequent enteropathogen overall. the rates of c parvum, shigella, and salmonella were higher in the summer. rotavirus had the ...201020706147
csra and cra influence shigella flexneri pathogenesis.shigella flexneri is a facultative intracellular pathogen that invades and disrupts the colonic epithelium. in order to thrive in the host, s. flexneri must adapt to environmental conditions in the gut and within the eukaryotic cytosol, including variability in the available carbon sources and other nutrients. we examined the roles of the carbon consumption regulators csra and cra in a cell culture model of s. flexneri virulence. csra is an activator of glycolysis and a repressor of gluconeogene ...201020713625
near-atomic resolution analysis of bipd, a component of the type iii secretion system of burkholderia pseudomallei.burkholderia pseudomallei, the causative agent of melioidosis, possesses a type iii protein secretion apparatus that is similar to those found in salmonella and shigella. a major function of these secretion systems is to inject virulence-associated proteins into target cells of the host organism. the bipd gene of b. pseudomallei encodes a secreted virulence factor that is similar in sequence and is most likely to be functionally analogous to ipad from shigella and sipd from salmonella. proteins ...201020823511
molecular mechanisms of necroptosis: an ordered cellular explosion.for a long time, apoptosis was considered the sole form of programmed cell death during development, homeostasis and disease, whereas necrosis was regarded as an unregulated and uncontrollable process. evidence now reveals that necrosis can also occur in a regulated manner. the initiation of programmed necrosis, 'necroptosis', by death receptors (such as tumour necrosis factor receptor 1) requires the kinase activity of receptor-interacting protein 1 (rip1; also known as ripk1) and rip3 (also kn ...201020823910
development of a multiplex real-time pcr assay with internal amplification control for the detection of shigella species and enteroinvasive escherichia coli.shigella species, particularly s. sonnei and s. flexneri, remain some of the leading bacterial etiological agents of gastrointestinal diseases in the united states and globally. the isolation and detection of these foodborne pathogens are critical for preventing the spread of disease and facilitating epidemiological investigations aimed at determining the source of a shigella infection outbreak. a multiplex real-time pcr-based assay was developed that targets all four species of shigella plus en ...201020828467
a disulfide driven domain swap switches off the activity of shigella ipah9.8 e3 ligase.we show that the monomeric form of shigella ipah9.8 e3 ligase catalyses the ubiquitination of human u2af35 in vitro, providing a molecular mechanism for the observed in vivo effect. we further discover that under non-reducing conditions ipah9.8 undergoes a domain swap driven by the formation of a disulfide bridge involving the catalytic cysteine and that this dimer is unable to catalyse the ubiquitination of u2af35. the crystal structure of the domain-swapped dimer is presented. the redox inacti ...201020831869
the effects of x-ray radiation on escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri inoculated on whole roma tomatoes.in the last two decades several foodborne disease outbreaks associated with produce were reported. tomatoes, in particular, have been associated with several multi-state salmonella outbreaks. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole roma tomato surfaces by x-ray at 0.1, 0.5, 0.75, 1.0, and 1.5 kgy was studied. the main purpose of this study was to achieve a 5 log reduction in consistent with the recommendation ...201020832685
transmembrane bax inhibitor motif containing (tmbim) family proteins perturbs a trans-golgi network enzyme, gb3 synthase, and reduces gb3 biosynthesis.globotriaosylceramide (gb3) is a well known receptor for shiga toxin (stx), produced by enterohemorrhagic escherichia coli and shigella dysenteriae. the expression of gb3 also affects several diseases, including cancer metastasis and fabry disease, which prompted us to look for factors involved in its metabolism. in the present study, we isolated two cdnas that conferred resistance to stx-induced cell death in hela cells by expression cloning: ganglioside gm3 synthase and the cooh terminus regio ...201020837469
normal aerobic bacterial conjunctival flora in the crab-eating raccoon (procyon cancrivorus) and coati (nasua nasua) housed in captivity in pernambuco and paraiba (northeast, brazil).to determine the normal aerobic bacterial conjunctival population of the coatis and the crab-eating raccoons housed in captivity in the pernambuco and paraiba states of brazil.201020840103
mass spectrometry biotyper system identifies enteric bacterial pathogens directly from colonies grown on selective stool culture media.we evaluated the performance and cost-effectiveness of a matrix-assisted laser desorption ionization time-of-flight mass spectrometry-based biotyper system for the routine identification of common enteric bacterial pathogens seen in middle tennessee from suspicious colonies grown on selective stool culture media. a total of 304 suspicious colonies were selected and further identified from 605 stool specimens. the suspicious colonies were analyzed by the biotyper system, and the results were comp ...201020844226
formulation and immunogenicity studies of type iii secretion system needle antigens as vaccine candidates.bacterial infections caused by shigella flexneri, salmonella typhimurium, and burkholderia pseudomallei are currently difficult to prevent due to the lack of a licensed vaccine. here we present formulation and immunogenicity studies for the three type iii secretion system (ttss) needle proteins mxih(δ5), prgi(δ5), and bsal(δ5) (each truncated by five residues at its c terminus) as potential candidates for vaccine development. these antigens are found to be thermally stabilized by the presence of ...201020845448
formulation and immunogenicity of a potential multivalent type iii secretion system-based protein vaccine.the virulence of many pathogenic gram-negative bacteria is dependent upon their type iii secretion (tts) systems. here, we discuss initial formulation studies of five tts needle tip proteins ipad (shigella flexneri), bipd (burkholderia pseudomallei), sipd (salmonella spp.), lcrv (yersinia spp.), and pcrv (pseudomonas aeruginosa) as targets for subunit vaccines. excipient screening and subsequent assays lead to the selection of 10% sucrose and 5% dextrose as an optimal stabilizer combination for ...201020845449
assessment of the microbiological safety of dried spices and herbs commercialized in spain.spices and herbs are natural products or their blends that must be free of extraneous matter content. conventional production of these products implicates a number of hygienic problems so spices and herbs may be exposed to a wide range of microbial contamination during pre- and post-harvest and they can present high microbial counts. in this study, we have analyzed the microbial quality of 53 samples of spices and dry herbs collected from spanish markets detecting a contamination of samples of s ...201020848208
dysbiosis of fecal microbiota in crohn's disease patients as revealed by a custom phylogenetic microarray.a custom phylogenetic microarray composed of small subunit ribosomal rna probes, representing ≈500 bacterial species from the human and animal gut, was developed and evaluated for analysis of gut microbial diversity using fecal samples from healthy subjects and crohn's disease (cd) patients.201020848492
predacious bacteria, bdellovibrio with potential for biocontrol.bacteria of the genus of bdellovibrio are highly motile gram-negative predators of other gram-negative bacteria causing lysis of their prey. here we report results of studies on the interactions of bdellovibrio with species of alcaligenes, campylobacter, erwinia, escherichia, helicobacter, pseudomonas, legionella, and shigella in agar lower, liquid media and cells attached to a surface. helicobacter pylori was studied employing both actively growing and viable but nonculturable (vbnc) cells. the ...201020850380
infectious colitis.purpose of review: the incidence of gastrointestinal infections continues to increase and infectious colitis contributes to significant morbidity and mortality worldwide. the purpose of this review is to highlight the recent advances in knowledge of pathogens causing infectious colitis. we describe the various pathogens and specifically focus on enterohemorrhagic escherichia coli (ehec) o157:h7, salmonella, shigella, campylobacter, and entamoeba histolytica infections, and their impact on long-t ...201020856114
prevalence of bacteria and parasites in white ibis in egypt.a field survey was conducted to evaluate the prevalence of bacterial infections among free-living white ibis (nipponia nippon) in which 92 bacterial isolates were recovered from 193 different internal organs of 55 apparently healthy ibis. escherichia coli and salmonella spp. were isolated at rates of 43.6% and 14.5%, respectively. the other bacterial pathogens isolated were shigella spp. (34.5%), enterobacter spp. (21.8%) citrobacter spp. (18.1%), klebsiella pneumonia (16.3), staphylococcus aure ...201020857378
improved detection of five major gastrointestinal pathogens by use of a molecular screening approach.the detection of bacterial and parasitic gastrointestinal pathogens through culture and microscopy is laborious and time-consuming. we evaluated a molecular screening approach (msa) for the detection of five major enteric pathogens: salmonella enterica, campylobacter jejuni, giardia lamblia, shiga toxin-producing escherichia coli (stec), and shigella spp./enteroinvasive e. coli (eiec), for use in the daily practice of a clinical microbiology laboratory. the msa consists of prescreening of stool ...201020861334
antidiarrheal activity of extracts and compound from trilepisium madagascariense stem bark.the present study was performed to evaluate the preventive and curative antidiarrheal effects of the methanol extract, fractions and compound from the stem bark of trilepisium madagascariense in rats.201020871767
defensins play a crucial role in protecting mice against oral shigella flexneri infection.an earlier study revealed that 4-day-old mice, but not older mice, were infected with invasive shigella strains. here we attempted to determine the underlying mechanism that induces inflammation in the intestines of neonate mice after oral shigella infection. wild-type balb/c mice of different ages (7, 14, and 35 days old) were orally administered gfp-expressing shigella flexneri 5a m90t strain (5 x 10⁹ cfu) and analyzed for colonization 6h following infection. we found that shigella localized i ...201020888321
improved fructosylated chondroitin production by kfoc overexpression in e. coli k4.escherichia coli k4 is one of the bacteria expressing a surface polysaccharide, indicated as capsular polysaccharide (k-antigen), showing a chemical structure that resembles that of metabolites commonly used in pharmaceutical applications. in this study we provide evidence that homologous overexpression of the chondroitin polymerase, encoded by the kfoc gene, acts on a potential bottleneck for production of capsular polysaccharide, and increases productivity by 100%. however, we also demonstrate ...201020888875
pediatric diarrhea in southern ghana: etiology and association with intestinal inflammation and malnutrition.diarrhea is a major public health problem that affects the development of children. anthropometric data were collected from 274 children with (n = 170) and without (n = 104) diarrhea. stool specimens were analyzed by conventional culture, polymerase chain reaction for enteroaggregative escherichia coli (eaec), shigella, cryptosporidium, entamoeba, and giardia species, and by enzyme-linked immunosorbent assay for fecal lactoferrin levels. about 50% of the study population was mildly to severely m ...201020889896
selective testing of ß-galactosidase activity in the laboratory identification of salmonella and shigella species.salmonella and shigella species are pathogens of great medical and public health importance. however, laboratory identification of these organisms is time consuming. using current standard laboratory algorithms, the vast majority of organisms submitted for serological typing with salmonella-specific and shigella-specific antisera are not clinically significant.201020924038
bacterial enteropathogens and risk factors associated with childhood diarrhea.to investigate the etiology of bacterial enteropathogens causing diarrhea among children; to elucidate the risk factors, sign and symptoms involved in developing of infection; and to identify the antimicrobial susceptibility pattern.201020924718
[screening of harmine tolerance/degrading bacteria from camel rumen].peganum harmala, a famous traditional chinese drug, contains a variety of alkaloids and toxic for many animals. camels mainly live in desert or semi-desert areas, with the robust gastrointestine system in digesting various feed including toxic plants without disease symptoms.201020931866
viable but nonculturable state of foodborne pathogens in grapefruit juice: a study of laboratory.several foodborne human pathogens, when exposed to harsh conditions, enter viable but nonculturable (vbnc) state; however, still open is the question whether vbnc pathogens could be a risk for public health, because, potentially, they can resuscitate. moreover, cultural methods for food safety control were not able to detect vbnc forms of foodborne bacteria. particularly, it has not been established whether food chemophysical characteristics can induce vbnc state in contaminating pathogen bacter ...201020932087
shigella deploy multiple countermeasures against host innate immune responses.although the intestinal epithelium is equipped with multiple defense systems that sense bacterial components, transmit alarms to the immune system, clear the bacteria, and renew the injured epithelial lining, mucosal bacterial pathogens are capable of efficiently colonizing the intestinal epithelium, because they have evolved systems that modulate the inflammatory and immune responses of the host and exploit the harmful environments as replicative niches. in this review we highlight current topi ...201020934372
domains of the shigella flexneri type iii secretion system ipab protein involved in secretion regulation.type iii secretion systems (t3sss) are key determinants of virulence in many gram-negative bacterial pathogens. upon cell contact, they inject effector proteins directly into eukaryotic cells through a needle protruding from the bacterial surface. host cell sensing occurs through a distal needle "tip complex," but how this occurs is not understood. the tip complex of quiescent needles is composed of ipad, which is topped by ipab. physical contact with host cells initiates secretion and leads to ...201020937761
combination of two separate binding domains defines stoichiometry between type iii secretion system chaperone ipgc and translocator protein ipab.type iii secretion systems (ttsss) utilized by enteropathogenic bacteria require the presence of small, acidic virulence-associated chaperones for effective host cell infection. we adopted a combination of biochemical and cellular techniques to define the chaperone binding domains (cbds) in the translocators ipab and ipac associated with the chaperone ipgc from shigella flexneri. we identified a novel cbd in ipab and furthermore precisely mapped the boundaries of the cbds in both translocator pr ...201020937829
characterization and antimicrobial activity of 4-(β-d-glucopyranosyl-1→4-α-l-rhamnopyranosyloxy)-benzyl thiocarboxamide; a novel bioactive compound from moringa oleifera seed extract.antimicrobial activity of crude seed extract of moringa oleifera was investigated by thin layer chromatography bioassay against escherichia coli, pseudomonas aeruginosa, staphylococcus aureus, cladosporium cladosporioides, and penicillium sclerotigenum; most of them were prominently inhibited by an isolate with r(f) 0.92-0.96. characterization and identification of the extract revealed the occurrence of three bioactive compounds: 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate, methyl n-4-(α-l-r ...201020941575
expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive escherichia coli and shigella flexneri: a comparative study.enteroinvasive escherichia coli (eiec) and shigella spp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. although eiec and shigella share many genetic and biochemical similarities, the illness caused by shigella is more severe. thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on shigella rather than eiec. here we comparatively stud ...201020944993
an fda bioinformatics tool for microbial genomics research on molecular characterization of bacterial foodborne pathogens using microarrays.advances in microbial genomics and bioinformatics are offering greater insights into the emergence and spread of foodborne pathogens in outbreak scenarios. the food and drug administration (fda) has developed a genomics tool, arraytrack™, which provides extensive functionalities to manage, analyze, and interpret genomic data for mammalian species. arraytrack™ has been widely adopted by the research community and used for pharmacogenomics data review in the fda's voluntary genomics data submissio ...201020946615
integron types, gene cassettes, antimicrobial resistance genes and plasmids of shigella sonnei isolates from outbreaks and sporadic cases in taiwan.this study analysed the presence, location and transferability of integrons and antibiotic resistance genes in 103 shigella sonnei outbreak isolates and in 32 sporadic isolates from taiwan. multiple antimicrobial resistance was common in both outbreak (95 %) and sporadic (97 %) isolates. class 1 integrons were present in 34 outbreak isolates (33 %) and in six sporadic isolates (19 %). this study is the first, to our knowledge, to identify an atypical sul3-associated class 1 integron carrying the ...201020947666
rapid multiple-locus variable-number tandem-repeats analysis of shigella spp. using multicolour capillary electrophoresis.the multiple-locus variable-number tandem-repeats analysis (mlva) method for genotyping has proven to be a fast and reliable typing tool in several bacterial species. mlva is in our laboratory the routine typing method for salmonella enterica subsp. enterica serovar typhimurium, escherichia coli (two assays), listeria monocytogenes and yersinia enterocolitica. the gram-negative invasive enteropathogenic bacterium shigella is the most common cause of bacillary dysentery (shigellosis) worldwide, a ...201020951171
surveillance of shigellosis by real-time pcr suggests underestimation of shigellosis prevalence by culture-based methods in a population of rural china.shigellosis is a leading public health issue in china, especially in children under 5 years of age. the disease burden of shigellosis is usually underestimated by conventional culture. in this study, real-time pcr was applied to detect shigella infection in parallel with routine culture, to investigate the true burden of disease caused by shigella spp.201020951728
subtype prevalence, plasmid profiles and growing fluoroquinolone resistance in shigella from kolkata, india (2001-2007): a hospital-based study.shigellosis is a major public health problem, and increasing antimicrobial resistance has complicated its treatment. we report isolation frequency, plasmid profiles and antimicrobial resistance of shigella subtypes in kolkata, india, from a prospective hospital-based study.201020955371
identification of active site residues in the shigella flexneri glucosyltransferase gtrv.the serotype-specific glucosyltransferase, gtrv, is responsible for glucosylation of the o-antigen repeating unit of shigella flexneri serotype 5a strains. gtrv is an integral inner membrane protein with two essential periplasmic loops: the large loop 2 and the c-terminal loop 10. in this study, the full length of the loop 2 was shown to be necessary for gtrv function. site-directed mutagenesis within this loop revealed that conserved aromatic and charged amino acids have a critical role in the ...201020334579
[preparation of a 96-microwell plate dna diagnostic chip for detection of foodborne bacteria and its application in an incident of food poisoning].to develop a 96-microwell plate dna diagnostic chip for simultaneous detection of 9 major foodborne bacteria.201020335099
bacterial enteritis as a risk factor for childhood intussusception: a retrospective cohort study.to assess the relationship between bacterial enteritis and intussusception.201020138300
a repulsive electrostatic mechanism for protein export through the type iii secretion apparatus.many gram-negative bacteria initiate infections by injecting effector proteins into host cells through the type iii secretion apparatus, which is comprised of a basal body, a needle, and a tip. the needle channel is formed by the assembly of a single needle protein. to explore the export mechanisms of mxih needle protein through the needle of shigella flexneri, an essential step during needle assembly, we have performed steered molecular dynamics simulations in implicit solvent. the trajectories ...201020141759
a soluble form of the pilus protein fima targets the vdac-hexokinase complex at mitochondria to suppress host cell apoptosis.inhibition of apoptotic response of host cells during an early phase of infection is a strategy used by many enteroinvasive bacterial pathogens to enhance their survival. here, we report the identification of a soluble form of the pilus protein fima from the culture supernatants of e. coli k1, salmonella, and shigella that can potently inhibit bax-mediated release of cytochrome c from isolated mitochondria. similar to the infected cells, hct116 cells stably expressing fima display a delay in the ...201020347420
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