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acquired antibiotic resistance: are we born with it?the rapid emergence of antibiotic resistance (ar) is a major public health concern. recent findings on the prevalence of foodborne antibiotic resistant (art) commensal bacteria in ready-to-consume food products suggested that daily food consumption likely serves as a major avenue for disseminating art bacteria from the food chain to the human hosts. to properly assess the impact of various factors including the food chain on ar development in hosts, it is important to determine the baseline of a ...201121821748
single nucleotide polymorphism (snp)-based differentiation of shigella isolates by pyrosequencing.analysis of single nucleotide polymorphisms (snps) is an important genetic tool that provides molecular markers for rapid differentiation of closely related strains. we have applied snp discovery and analysis for distinguishing each of the four shigella serogroups (boydii, dysenteriae, flexneri, and sonnei) and for discriminating individual strains within the same serogroup by using 24 snps selected from nine genes. five snps were identified from sequence analysis of two housekeeping genes (gapa ...201121839856
studies on the activity of cyperus rotundus linn. tubers against infectious diarrhea.to study the antidiarrheal activity of the decoction of cyperus rotundus linn. tubers using representative assays of diarrheal pathogenesis and understand its mechanism of action.antibacterial, antigiardial and antirotaviral activities were studied. effect on adherence of enteropathogenic escherichia coli (epec) and invasion of enteroinvasive e. coli (eiec) and shigella flexneri to hep-2 cells was evaluated as a measure of effect on colonization. effect on enterotoxins such as enterotoxigenic e. ...201121713044
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
recovery and characterization of environmental variants of shigella flexneri from surface water in bangladesh.little is known about the distribution, survival, and transmission of shigella in environmental surface waters. to gain more insight into the environmental biology of shigella we isolated five bacterial strains serotyped as shigella flexneri 2b from a freshwater lake in bangladesh using a modified nutrient broth supplemented with nucleic acid bases. the biochemical properties of the isolates, including inability to ferment lactose and a negative lysine decarboxylase test, indicated common physio ...201121826486
a new class of 2-(4-cyanophenyl amino)-4-(6-bromo-4-quinolinyloxy)-6-piperazinyl (piperidinyl)-1,3,5-triazine analogues with antimicrobial/antimycobacterial activity.this study presents the synthesis and in vitro pharmacological evaluations of novel 2-(4-cyanophenyl amino)-4-(6-bromo-4-quinolinyloxy)-6-piperazinyl (piperidinyl)-1,3,5-triazines. the title compounds were assayed for their in vitro antimicrobial activity against eight bacteria (staphylococcus aureus, bacillus cereus, escherichia coli, pseudomonas aeruginosa, klebsiella pneumoniae, salmonella typhi, proteus vulgaris, shigella flexneria) and four fungi (aspergillus niger, aspergillus fumigatus, a ...201121740100
structural and functional studies on the n-terminal domain of the shigella type iii secretion protein mxig.mxig is a single-pass membrane protein that oligomerizes within the inner membrane ring of the shigella flexneri type iii secretion system (t3ss). the mxig n-terminal domain (mxig-n) is the predominant cytoplasmic structure; however, its role in t3ss assembly and secretion is largely uncharacterized. we have determined the solution structure of mxig-n residues 6-112 (mxig-n(6-112)), representing the first published structure of this t3ss domain. the structure shows strong structural homology to ...201121733840
physicochemical and microbiological assessment of recreational and drinking waters.the present study was aimed to make an assessment of health risk due to pollution and human pathogenic bacteria associated with the recreational and drinking water sources in twin densely populated holy indian cities ayodhya and faizabad. though physicochemical studies revealed that the water available in the area is under recommended limits for human use, it is unsafe on account of poor microbiological quality of surface and ground water in the region. the most probable number (mpn) test result ...201121713494
the rickettsia surface cell antigen 4 applies mimicry to bind to and activate vinculin.pathogenic rickettsiae species cause high morbidity and mortality, especially r. prowazekii the causative agent of typhus. like many intracellular pathogens, rickettsiae exploit the cytoskeleton to enter and spread within the host cell. here we report that the cell surface antigen sca4 of rickettsiae colocalizes with vinculin in cells at sites of focal adhesions, and that sca4 binds to and activates vinculin through two vinculin binding sites (vbss) that are conserved across all rickettsia. rema ...201121841197
espg of enteropathogenic and enterohemorrhagic e. coli binds the golgi matrix protein gm130 and disrupts the golgi structure and function.the enteric pathogens enteropathogenic escherichia coli (epec), enterohaemorrhagic e. coli (ehec) and shigella flexneri all translocate at least one effector protein of the espg protein family into host cells via a type iii secretion system (t3ss). the espg family comprises espg, espg2 and vira. from a y2h screen, we identified the golgi matrix protein gm130 as a potential binding partner of espg. we confirmed espg:gm130 protein interaction by affinity co-purification. in co-immunoprecipitation ...201121740499
in vivo versus in vitro protein abundance analysis of shigella dysenteriae type 1 reveals changes in the expression of proteins involved in virulence, stress and energy metabolism.shigella dysenteriae serotype 1 (sd1) causes the most severe form of epidemic bacillary dysentery. quantitative proteome profiling of shigella dysenteriae serotype 1 (sd1) in vitro (derived from lb cell cultures) and in vivo (derived from gnotobiotic piglets) was performed by 2d-lc-ms/ms and apex, a label-free computationally modified spectral counting methodology.201121702961
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
whole-genome phylogeny of escherichia coli/shigella group by feature frequency profiles (ffps).a whole-genome phylogeny of the escherichia coli/shigella group was constructed by using the feature frequency profile (ffp) method. this alignment-free approach uses the frequencies of l-mer features of whole genomes to infer phylogenic distances. we present two phylogenies that accentuate different aspects of e. coli/shigella genomic evolution: (i) one based on the compositions of all possible features of length l = 24 (∼8.4 million features), which are likely to reveal the phenetic grouping a ...201121536867
identification of small-molecule inhibitors of yersinia pestis type iii secretion system yscn atpase.yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. the pathogen uses a type iii secretion system (t3ss) to deliver virulence factors directly from bacterium into host mammalian cells. the system contains a single atpase, yscn, necessary for delivery of virulence factors. in this work, we show that deletion of the catalytic domain of the yscn gene in y. pestis co92 attenuated the strain over three million-fold in the swiss-webster ...201121611119
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
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
a novel compound from the marine bacterium bacillus pumilus s6-15 inhibits biofilm formation in gram-positive and gram-negative species.biofilm formation is a critical problem in nosocomial infections and in the aquaculture industries and biofilms show high resistance to antibiotics. the aim of the present study was to reveal a novel anti-biofilm compound from marine bacteria against antibiotic resistant gram-positive and gram-negative biofilms. the bacterial extract (50 μg ml(-1)) of s6-01 (bacillus indicus = mtcc 5559) showed 80-90% biofilm inhibition against escherichia coli, shigella flexneri, proteus mirabilis and s6-15 (ba ...201121614700
prevalence of the plasmid mediated quinolone resistance determinants among clinical isolates of shigella sp. in andaman & nicobar islands, india.aims:  the present study was carried out to find the prevalence of various plasmid mediated quinolone resistant (pmqr) determinants among the quinolone resistant clinical isolates of shigella sp. from pediatric patients in andaman & nicobar islands. methods and results:  a total of 106 quinolone resistant shigella isolates obtained from pediatric patients during hospital based surveillance from january 2003 to june 2010 were screened for the presence of various pmqr determinants. out of 106 isol ...201121615433
evaluation of the selective and differential et medium for detection of edwardsiella tarda in aquaculture systems.aims:  edwardsiella tarda is an important pathogen in aquaculture where it can cause serious losses. a rapid detection of it is vital to minimize the mortalities caused by this disease, and in this work, the effectiveness of the selective differential edw. tarda medium (et) was evaluated for the diagnosis of edwardsiellosis as well as for its possible use in epidemiological studies. methods and results:  et medium was evaluated in parallel with the commercial salmonella-shigella agar (ss), which ...201121554344
human immunodeficiency virus-associated gastrointestinal disease: common endoscopic biopsy diagnoses.the gastrointestinal (gi) tract is a major site of disease in hiv infection: almost half of hiv-infected patients present with gi symptoms, and almost all patients develop gi complications. gi symptoms such as anorexia, weight loss, dysphagia, odynophagia, abdominal pain, and diarrhea are frequent and usually nonspecific among these patients. endoscopy is the diagnostic test of choice for most hiv-associated gi diseases, as endoscopic and histopathologic evaluation can render diagnoses in patien ...201121559197
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
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
synthesis, characterization and in vitro antimicrobial evaluation of new compounds incorporating oxindole nucleus.new compounds incorporating with the oxindole nucleus were synthesized via the reaction of substituted isatins [5-methyl-, 5-chloro- and 1-hydroxymethyl isatins] with different nucleophiles. the structures of the newly compounds were elucidated on the basis of ftir, (1)h nmr, (13)cmr spectral data, gc/ms and chemical analysis. investigation of antimicrobial activity of the new compounds was evaluated using broth dilution technique in terms of minimal inhibitory concentration (mic) count against ...201121534861
synthesis, characterization and biological studies of sulfonamide schiff's bases and some of their metal derivatives.a new series of schiff base ligands derived from sulfonamide and their metal(ii) complexes [cobalt(ii), copper(ii), nickel(ii) and zinc(ii)] have been synthesized and characterized. the nature of bonding and structure of all the synthesized compounds has been explored by physical, analytical and spectral data of the ligands and their metal(ii) complexes. the authors suggest that all the prepared complexes possess an octahedral geometry. the ligands and metal(ii) complexes have been screened for ...201121534864
the decoupling between genetic structure and metabolic phenotypes in escherichia coli leads to continuous phenotypic diversity.to assess the extent of intra-species diversity and the links between phylogeny, lifestyle (habitat and pathogenicity) and phenotype, we assayed the growth yield on 95 carbon sources of 168 escherichia strains. we also correlated the growth capacities of 14 e. coli strains with the presence/absence of enzyme-coding genes. globally, we found that the genetic distance, based on multilocus sequence typing data, was a weak indicator of the metabolic phenotypic distance. besides, lifestyle and phylog ...201121569155
a tecpr1-dependent selective autophagy pathway targets bacterial pathogens.selective autophagy of bacterial pathogens represents a host innate immune mechanism. selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. in this study we identified a highly conserved tectonin domain-containing protein, tecpr1, as an atg5 binding partner that colocalized with atg5 at shigella-containing phagophores. tecpr1 activity is necessary for effici ...201121575909
zidovudine (azt) has a bactericidal effect on enterobacteria and induces genetic modifications in resistant strains.the spread of multiresistant bacteria increases the need for new antibiotics. the observation that some nucleoside analogues have antibacterial activity led us to further investigate the antimicrobial activity and resistance of zidovudine (azt). we determined the minimum inhibition concentration (mic), studied time-kill curves, induced resistant bacteria and sequenced the gene for thymidine kinase. we demonstrate that azt has a bactericidal effect on some enterobacteria. however, azt could induc ...201121494911
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
gadd45a activity is the principal effector of shigella mitochondria-dependent epithelial cell death in vitro and ex vivo.modulation of death is a pathogen strategy to establish residence and promote survival in host cells and tissues. shigella spp. are human pathogens that invade colonic mucosa, where they provoke lesions caused by their ability to manipulate the host cell responses. shigella spp. induce various types of cell death in different cell populations. however, they are equally able to protect host cells from death. here, we have investigated on the molecular mechanisms and cell effectors governing the b ...201121368893
Natural Products Modulate Shigella-Host Cell Interaction.This study focussed on identifying possible new options derived from natural sources for the treatment of bacterial infections. Several natural products were investigated for their potential in modulating Shigella-host cell interaction. The proliferation of Shigella sonnei was effectively inhibited inside HEp-2 cells in the presence of 4-methoxycinnamic acid and propolin D. Propolin D also significantly reduced the apopotosis of infected macrophage-like U937 cells, and moderately reduced the sec ...201121719574
gene decay in shigella as an incipient stage of host-adaptation.background: many facultative bacterial pathogens have undergone extensive gene decay processes, possibly due to lack of selection pressure during evolutionary conversion from free-living to intracellular lifestyle. shigella, the causative agents of human shigellosis, have arisen from different e. coli-like ancestors independently by convergent paths. as these bacteria all have lost large numbers of genes by mutation or deletion, they can be used as ideal models for systematically studying the pr ...201122110755
antimicrobial activity of gynostemma pentaphyllum extracts against fungi producing aflatoxin and fumonisin and bacteria causing diarrheal disease.gynostemma pentaphyllum was investigated to determine its antimicrobial activities against human.and animal pathogens that produce aflatoxin, fumonisin, and diarrheal disease. the fungi were aspergillusflavus, aspergillus parasiticus and fusarium verticillioides. the bacteria were vibrio, salmonella, shigella, escherichia coli and staphylococcus aureus. g. pentaphyllum was extracted by five different methods. the obtained extracts were designated extracts a, b, c, d and e. the results of the ant ...201121706950
a multi-center randomized trial to assess the efficacy of gatifloxacin versus ciprofloxacin for the treatment of shigellosis in vietnamese children.the bacterial genus shigella is the leading cause of dysentery. there have been significant increases in the proportion of shigella isolated that demonstrate resistance to nalidixic acid. while nalidixic acid is no longer considered as a therapeutic agent for shigellosis, the fluoroquinolone ciprofloxacin is the current recommendation of the world health organization. resistance to nalidixic acid is a marker of reduced susceptibility to older generation fluoroquinolones, such as ciprofloxacin. w ...201121829747
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
a shigella boydii bacteriophage which resembles salmonella phage vii.abstract: background: lytic bacteriophages have been applied successfully to control the growth of various foodborne pathogens. sequencing of their genomes is considered as an important preliminary step to ensure their safety prior to food applications. results: the lytic bacteriophage, phisbom-ag3, targets the important foodborne pathogen, shigella. it is morphologically similar to phage vii of salmonella enterica serovar typhi and a series of phages of acinetobacter calcoaceticus and rhizobium ...201121595934
shigella sonnei vaccine candidates wrss2 and wrss3 are as immunogenic as wrss1, a clinically tested vaccine candidate, in a primate model of infection.shigella causes diarrhea and dysentery through contaminated food and water. shigella sonnei live vaccine candidates wrss2 and wrss3 are attenuated principally by the loss of virg(icsa) that prevents bacterial spread within the colonic epithelium. in this respect they are similar to the clinically tested vaccine candidate wrss1. however, wrss2 and wrss3 are further attenuated by loss of sena, senb and wrss3 also lacks msbb2. as previously shown in cell culture assays and in small animal models, t ...201121596086
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
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
bacteriophage-encoding cytolethal distending toxin type-v gene induced from non-clinical escherichia coli isolates.cytolethal distending toxin (cdt) is produced by a variety of pathogenic bacteria, including pathogenic serotypes of shiga toxin-producing escherichia coli (stec). the cdt family comprises five variants (cdt-i to cdt-v) encoded by three genes located within the chromosome, plasmids or, in the case of cdt-i, within bacteriophages. in this study we evaluated the occurrence of cdt in a collection of 140 environmental stec isolates. cdt was detected in 12.1% of strains, of which five strains carried ...201121646456
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
modulation of connexin signaling by bacterial pathogens and their toxins.inherent to their pivotal tasks in the maintenance of cellular homeostasis, gap junctions, connexin hemichannels, and pannexin hemichannels are frequently involved in the dysregulation of this critical balance. the present paper specifically focuses on their roles in bacterial infection and disease. in particular, the reported biological outcome of clinically important bacteria including escherichia coli, shigella flexneri, yersinia enterocolitica, helicobacter pylori, bordetella pertussis, aggr ...201121656255
shigella gets captured to gain entry.the type iii secretion system-dependent epithelial invasion and dissemination of shigella is stimulated by atp released through hemichannels. romero et al. (2011) show that prior to epithelial contact, shigella is captured by nanometer-thin micropodial extensions at a distance from the cell surface, in a process involving atp and connexin-mediated signaling.201121669393
atp-mediated erk1/2 activation stimulates bacterial capture by filopodia, which precedes shigella invasion of epithelial cells.shigella, the causative agent of bacillary dysentery in-áhumans, invades epithelial cells, using a type iii secretory system (t3ss) to inject bacterial effectors into host cells and remodel the actin cytoskeleton. atp released through connexin hemichanels on the epithelial membrane stimulates shigella invasion and dissemination in epithelial cells. here, we show that prior to contact with the cell body, shigella is captured by nanometer-thin micropodial extensions (nmes) at a distance from the c ...201121669399
deaths associated with bacterial pathogens transmitted commonly through food: foodborne diseases active surveillance network (foodnet), 1996-2005.foodborne diseases are typically mild and self-limiting but can cause severe illness and death. we describe the epidemiology of deaths associated with bacterial pathogens using data from the foodborne diseases active surveillance network (foodnet) in the united states.201121673037
phenylbutyrate counteracts shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.cathelicidins and defensins are endogenous antimicrobial peptides (amps) that are downregulated in the mucosal epithelia of the large intestine in shigellosis. oral treatment of shigella infected rabbits with sodium butyrate (nab) reduces clinical severity and counteracts the downregulation of cathelicidin (cap-18) in the large intestinal epithelia.201121673991
a multifactor regulatory circuit involving h-ns, virf and an antisense rna modulates transcription of the virulence gene icsa of shigella flexneri.the icsa gene of shigella encodes a structural protein involved in colonization of the intestinal mucosa by bacteria. this gene is expressed upon invasion of the host and is controlled by a complex regulatory circuit involving the nucleoid protein h-ns, the arac-like transcriptional activator virf, and a 450ôçënt antisense rna (rnag) acting as transcriptional attenuator. we investigated on the interplay of these factors at the molecular level. dnase i footprints reveal that both h-ns and virf bi ...201121724612
Mucosal immunization with Shigella flexneri outer membrane vesicles induced protection in mice.Vaccination appears to be the only rational prophylactic approach to control shigellosis. Unfortunately, there is still no safe and efficacious vaccine available. We investigated the protection conferred by a new vaccine containing outer membrane vesicles (OMVs) from Shigella flexneri with an adjuvant based on nanoparticles in an experimental model of shigellosis in mice. OMVs were encapsulated in poly(anhydride) nanoparticles prepared by a solvent displacement method with the copolymer PMV/MA. ...201121911022
antibacterial dimeric copper(ii) complexes with chromone-derived compounds.a new series of six chromone-derived compounds and their cu(ii) complexes have been synthesized and characterized by their physical, spectral and analytical data. the ligands and their cu(ii) complexes were screened for their in vitro antibacterial activity against four gram-negative (escherichia coli, pseudomonas aeruginosa, salmonella typhi, shigella flexneri) and two gram-positive (bacillus subtilis, staphylococcus aureus) bacterial strains by agar-well diffusion method. the ligands were foun ...201121699463
the yersinia enterocolitica type 3 secretion system (t3ss) as toolbox for studying the cell biological effects of bacterial rho gtpase modulating t3ss effector proteins.the bacterial effector proteins ipgb(1) and ipgb(2) of shigella and map of escherichia coli activate the rho gtpases rac1, rhoa and cdc42, respectively, whereas yope and yopt of yersinia inhibit these rho family gtpases. we established a yersinia toolbox which allows to study the cellular effects of these effectors in different combinations in the context of yersinia type 3 secretion system (ysc)-t3ss-mediated injection into hela cells. for this purpose hybrid proteins were constructed by fusion ...201121718421
Prevalence and antimicrobial susceptibility of major foodborne pathogens in imported seafood.Seafood is a leading commodity implicated in foodborne disease outbreaks in the United States. Seafood importation rose dramatically in the past 3 decades and now contributes to more than 80% of the total U.S. seafood supply. However, limited data are available on the microbiological safety of imported seafood. In this study, we obtained a total of 171 salmon, shrimp, and tilapia samples imported from 12 countries in three retail stores in Baton Rouge, LA. The total microbial population and the ...201121902913
investigating the global genomic diversity of escherichia coli using a multi-genome dna microarray platform with novel gene prediction strategies.abstract:201121733163
antisense inhibition of gene expression and growth in gram-negative bacteria by cell-penetrating peptide conjugates of peptide nucleic acids targeted to rpod gene.gram-negative bacteria (gnb) cause common and severe hospital- and community-acquired infections with a high incidence of multidrug resistance (mdr) and mortality. the emergence and spread of mdr-gnb strains limit therapeutic options and highlight the need to develop new therapeutic strategies. in this study, the peptide (rxr)(4)xb- and (kff)(3)k-conjugated peptide nucleic acids (ppnas) were developed to target rpod, which encodes an rna polymerase primary σ(70) that is thought to be essential f ...201122000398
outer membrane protein a (ompa) of shigella flexneri 2a, induces protective immune response in a mouse model.in our earlier studies 34 kda outer membrane protein (omp) of shigella flexneri 2a has been identified as an efficient immunostimulant.201121818362
Third-generation cephalosporin resistance in clinical isolate of Shigella sonnei in Andaman & Nicobar Islands, India. 201121918310
Within-species lateral genetic transfer and the evolution of transcriptional regulation in Escherichia coli and Shigella.Changes in transcriptional regulation underlie many of the phenotypic differences observed within and between species of bacteria. Lateral genetic transfer (LGT) can significantly impact the transcription factor (TF) genes which drive these transcriptional changes. Although much emphasis has been placed on LGT of intact genes, the units of transfer and recombination do not necessarily correspond to regions delineated by exact gene boundaries. Here we apply phylogenetic and network-based methods ...201122035052
Differentiation between Shigella, enteroinvasive Escherichia coli (EIEC) and noninvasive Escherichia coli.Shigella causes bacillary dysentery and is classified into four species based on their antigen characteristics. This classification does not reflect genetic relatedness; in fact, Shigella species are so related to Escherichia coli , they should be classified as one distinctive species in the genus Escherichia. The differentiation of Shigella and E. coli is even more complicated with the description of enteroinvasive E. coli (EIEC). EIEC are strains that possess some of the biochemical characteri ...201121901636
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
Genesis of a novel Shigella flexneri serotype by sequential infection of serotype-converting bacteriophages SfX and SfI.ABSTRACT: BACKGROUND: Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. RESULTS: A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS) was sequentially in ...201122208551
bacteriological assessment of drinking water supply options in coastal areas of bangladesh.this study was conducted to assess the bacteriological quality of alternative drinking water supply options in southwest coastal areas of bangladesh. a total of 90 water samples were collected during both dry and wet seasons from household based rainwater harvesting systems (rwhss), community based rain water harvesting systems (crwhss), pond-sand filters (psfs) and ponds. the samples were evaluated for faecal coliform, escherichia coli and heterotrophic plate count, as well as vibrio cholerae, ...201121942205
recombinant shiga toxin b subunit elicits protection against shiga toxin via mixed th type immune response in mice.shigella dysenteriae is the causative agent of the third commonest bacterial disease for childhood diarrhoea and responsible for millions of deaths per year. it produces potent toxin termed shiga toxin which is listed in category b biological warfare agent of cdc, usa. earlier we have reported production of recombinant shiga toxin b subunit that produced antibodies which neutralized shiga toxin toxicity in hela cells. in the present study, we have evaluated the immunomodulatory potential of rstx ...201121856355
Acid-bile, antibiotic resistance and inhibitory properties of propionibacteria isolated from Turkish traditional home-made cheeses.In this study, a total of 29 Propionibacterium spp. were isolated from traditional home-made Turkish cheese samples. As a result of the identification, isolates were identified as Propionibacterium freudenreichii subsp. freudenreichii (15 strains), Propionibacterium jensenii (12), and Propionibacterium thoenii (2). All isolates and 5 reference strains were examined for their abilities to survive at pH 2.0, 3.0, 4.0, 5.0 and in the presence of 0.06, 0.15 and 0.30% bile salts, their influence on t ...201122019987
Gut microbiota and pediatric disease.Background: Researchers have made every effort to assess the role of gut microbiota in pediatric diseases like inflammatory bowel disease (IBD), celiac disease, asthma, allergy, and autism. The leading hypothesis is that an altered microbial composition is present (other than the presence of a specific pathogen) and that it could be involved in the pathogenesis or progression of such disorders. Methods: Cultural, molecular, metabolomic, and metagenomic approaches are trying to define the pediatr ...201122179208
a broadly protective shigella vaccine based on type iii secretion apparatus proteins.shigella ssp. are food and water-borne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. individuals most often affected are children under 5 years of age in the developing world. the existence of multiple shigella serotypes and the heterogenic distribution of pathogenic strains as well as emerging antibiotic resistance require the development of a broadly protective vaccine. all shigella ssp. utilize a type iii secretion system (ttss) to ...201122202122
epidemiology and outcome of shigella, salmonella and campylobacter infections in travellers returning from the tropics with fever and diarrhoea.during a study on fever after a stay in the tropics, we aimed at investigating the epidemiology and outcome of invasive bacterial enteritis due to shigella, salmonella or campylobacter spp. in patients diagnosed with febrile traveller's diarrhoea.201121837926
differential response of the human renal proximal tubular epithelial cell line hk-2 to shiga toxin types 1 and 2.shiga toxins (stxs) are expressed by the enteric pathogens shigella dysenteriae serotype 1 and certain serotypes of escherichia coli. stx-producing bacteria cause bloody diarrhea with the potential to progress to acute renal failure. stxs are potent protein synthesis inhibitors and are the primary virulence factors responsible for renal damage that may follow diarrheal disease. we explored the use of the immortalized human proximal tubule epithelial cell line hk-2 as an in vitro model of stx-ind ...201121708996
atomic structure of bacteriophage sf6 tail needle knob.podoviridae are double-stranded dna bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. within the tail apparatus of p22-like phages, a dedicated fiber known as the "tail needle" likely functions as a cell envelope-penetrating device to promote ejection of viral dna inside the host. in sf6, a p22-like phage that infects shigella flexneri, the tail needle presents a c-terminal globular knob. this knob, absent in phage p22 but shared in other members of the p22 ...201121705802
Detection of diarrhoeal pathogens in human faeces using an automated, robotic platform.Infectious diarrhoeal diseases represent a major socio-economic burden to humans, and are linked to a range of pathogens, including viruses, bacteria and protists. The accurate detection of such pathogens is central to control. However, detection often relies on methods that have limited diagnostic sensitivity and specificity. Here, we assessed an automated, robotic platform for the simultaneous detection of eight major pathogens associated with infectious diarrhoea. Genomic DNA samples (n = 167 ...201122056326
Genotyping of selected bacterial enteropathogens in Norway.In Norway the Norwegian Institute of Public Health (NIPH) is the primary facility for nationwide surveillance of foodborne infections, and it is vital that we can perform rapid and high resolution identification of foodborne bacteria at the strain level. During the last decade a rapid introduction of DNA-based methods has been introduced, which show promise in enhancing the speed and discriminatory capability of the typing laboratory. The laboratory responsible for genotyping enteropathogens at ...201121975141
applications of pcr (real-time and masstag) and enzyme-linked immunosorbent assay in diagnosis of respiratory infections and diarrheal illness among deployed u.s. military personnel during exercise balikatan 2009, philippines.laboratory-based surveillance for diarrheal and respiratory illness was conducted at the 2009 republic of the philippines-united states balikatan exercise to determine the presence of specific pathogens endemic in the locations where the military exercises were conducted. ten stool and 6 respiratory specimens were obtained from individuals meeting case definitions for diarrhea or respiratory illness. stool specimens were frozen in dry ice and remotely tested using enzyme-linked immunosorbent ass ...201122128641
a school outbreak of shigella sonnei infection in china: clinical features, antibiotic susceptibility and molecular epidemiology.objective: to describe the clinical features of infection, and the antibiotic susceptibility of epidemic strains, and investigate plasmid maps and integrons of the isolates from an outbreak of shigella sonnei infection at an elementary school in southwest china. study design: cross-sectional study. setting: an elementary school and five hospitals in chengdu in southwest china. results: there were 1,134 students in the school. 937 (82.6%) students had signs and symptoms. of the 568 (60.6%, 568/93 ...201121992857
chemical and antidiarrheal studies of plinia cauliflora.plinia cauliflora (mart.) kausel, widespread in south america, has edible fruits, and its bark is commonly used against diarrhea and other disorders, on account of its astringency. because diarrhea is still one of the most important causes of illness and death among children in developing countries, where the population turns to traditional medicine for its treatment, the present study determined the composition of fruit and leaf extracts of p. cauliflora, analyzed the activity against diarrhea ...201121861716
Differential host immune responses to epidemic and endemic strains of Shigella dysenteriae type I.Shigella dysenteriae type 1 causes devastating epidemics in developing countries with high case-fatality rates in all age-groups. The aim of the study was to compare host immune responses to epidemic (T2218) and endemic strains of S. dysenteriae type 1. Shigellacidal activity of serum from rabbits immunized with epidemic or endemic strains, S. dysenteriae type 1-infected patients, and healthy adult controls from Shigella-endemic and non-endemic regions was measured. Immunogenic cross-reactivity ...201122106748
topological characterisation and identification of critical domains within glucosyltransferase iv (gtriv) of shigella flexneri.abstract:201122188643
The effects of solid media type on routine identification of bacterial isolates using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.Background: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis is a rapid method for the identification of bacteria based upon the comparison of protein profiles. Factors that may alter profiles include culture conditions and presence of exogenous substances and could hinder identification. Methods: Bacterial isolates identified using conventional methods were cultured on various media and identified using the MALDI Biotyper system (Bruker Dalton ...201122162546
[Dysentery and amoebiasis in Poland in 2009].Only 30 cases were notified (incidence rate 0.08/100 000 population) in the year 2009, while the 33 cases were notified in 2008 (incidence rate 0.09/100 000), and median in the 2003-2007 years was 74 cases, incidence rate 0.19/100 000 population. Since 2000 no one-death case was notified. In the period of low frequency of Shigella infections, the external quality assessment control of the quality of bacteriological media, laboratory and prae-laboratory procedures for detection of different Shige ...201121913464
[Investigation of verotoxigenic escherichia coli O157:H7 incidence in gastroenteritis patients].Escherichia coli O157:H7 is the most common serotype among verotoxigenic E.coli (VTEC) strains that cause haemolytic uremic syndrome. Although sporadic VTEC cases originating from Turkey and small outbreaks have been reported from our country, VTEC has not been routinely investigated in most of the diagnostic microbiology laboratories in Turkey and studies related to this topic are limited. In this study, the incidence of E.coli O157:H7 in patients who were admitted to Alanya Research and Applic ...201121935785
Nicotinamide dependence of uropathogenic Escherichia coli UTI89 and application of nadB as a neutral insertion site.NAD and NADP function ubiquitously in the metabolism of Escherichia coli K-12. NAD auxotrophy can be rendered by mutation in any of the three genes, nadB, nadA, and nadC. The nadB and nadA genes were defined as anti-virulence loci in Shigella spp., as a mutation (mainly in nadB) disrupting the synthesis of quinolinate is required for virulence. Uropathogenic E. coli (UPEC) isolates, from acute cystitis patients, exhibiting nicotinamide auxotrophy were of serotype O18:K1:H7. E. coli UTI89, the mo ...201122174382
outbreak of shigella sonnei infection in norway linked to consumption of fresh basil, october 2011.we report a shigella sonnei outbreak of 46 cases that occurred in norway during october 2011. two municipalities were involved. a large cluster (42 cases)was concentrated in north norway, while a smallcluster (4 cases) occurred in the south-east region.epidemiological evidence and trace back investigations have linked the outbreak to the consumption of imported fresh basil. the product has been withdrawn from the market. no further cases have been reported since 25 october.201122085618
global distribution of shigella sonnei clones.to investigate global epidemiology of shigella sonnei, we performed multilocus variable number tandem repeat analysis of 1,672 isolates obtained since 1943 from 50 countries on 5 continents and the pacific region. three major clonal groups were identified; 2 were globally spread. type 18 and its derivatives have circulated worldwide in recent decades.201122000369
prevalence and antimicrobial susceptibility patterns of shigella species at felege hiwot referral hospital, northwest ethiopia.shigella species infections coupled with increased levels of antimicrobial resistances are major public health problems in developing countries particularly in children.201121991758
up-regulation of muc2 and il-1β expression in human colonic epithelial cells by shigella and its interaction with mucins.the entire gastrointestinal tract is protected by a mucous layer, which contains complex glycoproteins called mucins. muc2 is one such mucin that protects the colonic mucosa from invading microbes. the initial interaction between microbes and mucins is an important step for microbial pathogenesis. hence, it was of interest to investigate the relationship between host (mucin) and pathogen interaction, including shigella induced expression of muc2 and il-1β during shigellosis.201122073249
foodborne-associated shigella sonnei, india, 2009 and 2010. 201122099103
rational design of an artificial genetic switch: co-option of the h-ns-repressed prou operon by the virb virulence master regulator.the h-ns protein represses the transcription of hundreds of genes in gram-negative bacteria. derepression is achieved by a multitude of mechanisms, many of which involve the binding of a protein to dna at the repressed promoter in a manner that compromises the maintenance of the h-ns-dna nucleoprotein repression complex. the principal virulence gene promoters in shigella flexneri, the cause of bacillary dysentery, are repressed by h-ns. virb, a protein that closely resembles members of the parb ...201121873493
Crystal Structure of the VapBC Toxin-Antitoxin Complex from Shigella flexneri Reveals a Hetero-Octameric DNA-Binding Assembly.Toxin-antitoxin (TA) loci are common in archaea and prokaryotes and allow cells to rapidly adapt to changing environmental conditions through release of active regulators of metabolism. Many toxins are endonucleases that target cellular mRNA and tRNAs, while the antitoxins tightly wrap around the toxins to inhibit them under normal circumstances. The antitoxins also bind to operators in the promoter regions of the cognate TA operon and thereby regulate transcription. For enteric vapBC TA loci, t ...201122037005
the inhibitory activity of lactobacillus spp. isolated from breast milk on gastrointestinal pathogenic bacteria of nosocomial origin.milk acts as a mean for transporting many essential substances from the mother to the child. in human beings, milk includes several predominant bacteria, such as staphylococci, streptococci, micrococci, lactobacilli, enterococci, lactococci and bifidobacteria. besides, its intake favors the predominance of bifidobacteria and lactobacilli in the child's intestinal microbiota. the present work explores the isolation and selection of lactobacilli strains with probiotic potential, focusing in their ...201121846506
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
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
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
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
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
efficient screening of a novel antimicrobial peptide from jatropha curcas by cell membrane affinity chromatography.a novel method named cell membrane affinity chromatography was used to screen antimicrobial peptides from jatropha curcas . a cationic antimicrobial peptide (kvflglk, jcpep7) was successfully isolated and identified. antimicrobial assays indicated that jcpep7 was active against the tested microorganisms ( salmonella typhimurium atcc 50013, shigella dysenteriae atcc 51302, pseudomonas aeruginosa atcc 27553, staphylococcus aureus atcc 25923, bacillus subtilis atcc 23631, and streptococcus pneumoni ...201121268582
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
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
development of a dna microarray for detection and identification of legionella pneumophila and ten other pathogens in drinking water.the safety and accessibility of drinking water are major concerns throughout the world. consumption of water contaminated with infectious agents, toxic chemicals or radiological hazards represents a significant health risk and is strongly associated with mortality. therefore, we have developed an oligonucleotide-based microarray using the sequences of 16s-23s rdna internal transcribed spacer regions (its) and the gyrase subunit b gene (gyrb) found in the most prevalent and devastating waterborne ...201121276629
strategies to overcome extended-spectrum ß-lactamases (esbls) and ampc ß-lactamases in shigellae.oral cephalosporins and mecillinam are used to treat shigella infections, but are compromised by extended-spectrum ß-lactamases (esbls) and plasmid ampc ß-lactamases. potential solutions include combining an oral or intravenous cephalosporin with a ß-lactamase inhibitor (bli) or using an oral penem. these strategies were examined using escherichia coli transconjugants and clinical isolates with esbls or ampc, as a proxy for shigellae. the clinical and laboratory standards institute agar dilution ...201121276715
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
shiga toxin and its use in targeted cancer therapy and imaging.shiga and the shiga-like toxins are related protein toxins produced by shigella dysenteriae and certain strains of escherichia coli. these toxins are composed of two non-covalently attached, modular parts: the a moiety (stxa) containing the enzymatically active a1 fragment, and the non-toxic, pentameric binding moiety (stxb). stx binds specifically to the glycosphingolipid globotriaosylceramide (gb3) at the surface of target cells and is then internalized by endocytosis. subsequently, in toxin-s ...201121255370
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
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