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research progress in shigella in the postgenomic era.gram-negative, facultative intracellular anaerobes of the genus shigella, the principal etiologic agents of shigellosis, continue to pose a threat to public health. shigellosis causes 1.1 million deaths with over 164 million annual cases. the shigella spp. can be divided into four serogroups: shigella dysenteriae, shigella flexneri, shigella boydii and shigella sonnei. the completion of seven shigella genome sequences of representative strains from each of the shigella species has introduced an ...201021046319
detection of representative enteropathogenic bacteria, vibrio spp., pathogenic escherichia coli, salmonella spp., shigella spp., and yersinia enterocolitica, using a virulence factor gene-based oligonucleotide microarray.rapid identification of enteropathogenic bacteria in stool samples is critical for clinical diagnosis and antimicrobial therapy. in this study, we describe the development of an approach that couples multiplex pcr with hybridization to a dna microarray, to allow the simultaneous detection of the 10 pathogens. the microarray was synthesized with 20-mer oligonucleotide probes that were designed to be specific for virulence-factor genes of each strain. the detection limit for genomic dna from a sin ...201021046348
controlled study on enteropathogens in travellers returning from the tropics with and without diarrhoea.clin microbiol infect abstract: diarrhoea is the most frequent health problem among travellers in the tropics. however, data on the spectrum and relevance of enteropathogens in international travellers with and without diarrhoea are limited. stool samples from 114 cases of diarrhoea in travellers returning from the tropics were collected for microbiological examination and pcr for norovirus genogroups i and ii, enteroaggregative escherichia coli (eaec), and enterotoxigenic e. coli (etec) produci ...201021054662
[detection and drug resistance analysis of extended-spectrum beta-lactamases-producing shigella in pediatric patients].to investigate the occurrence and drug resistance of extended-spectrum beta-lactamases (esbls)-producing strains of shigella in pediatric patients, so as to provide information for clinical treatment.201021055309
biochemical characterization of udp-gal:glcnac-pyrophosphate-lipid β-1,4-galactosyltransferase wfed, a new enzyme from shigella boydii type 14 that catalyzes the second step in o-antigen repeating-unit synthesis.the o antigen is the outer part of the lipopolysaccharide (lps) in the outer membrane of gram-negative bacteria and contains many repeats of an oligosaccharide unit. it contributes to antigenic variability and is essential to the full function and virulence of bacteria. shigella is a gram-negative human pathogen that causes diarrhea in humans. the o antigen of shigella boydii type 14 consists of repeating oligosaccharide units with the structure [→6-d-galpα1→4-d-glcpaβ1→6-d-galpβ1→4-d-galpβ1→4-d ...201021057010
[secondary structure of ssoii-like (cytosine-5)-dna methyltransferases n-terminal region determined by circular dichroism spectroscopy].(cytosine-5)-dna methyltransferase ssoii (m.ssoii) has a long n-terminal region (1-71 residues) preceding the sequence with conservative motifs, which are characteristic for all dna methyltransferases of such kind. the presence of this region provides m.ssoii capability to act as a transcription regulator in ssoii restriction-modification system. to perform its regulatory function, m.ssoii binds specifically to a 15-mer inverted repeat in the promoter region of ssoii restriction-modification sys ...201021090246
enteropathogenic e. coli non-lee encoded effectors nleh1 and nleh2 attenuate nf-κb activation.enteric bacterial pathogens have evolved sophisticated strategies to evade host immune defences. some pathogens deliver anti-inflammatory effector molecules into the host cell cytoplasm via a type iii secretion system (t3ss). enteropathogenic escherichia coli (epec) inhibits inflammation by an undefined, t3ss-dependent mechanism. two proteins encoded outside of the epec locus of enterocyte effacement (lee) pathogenicity island, non-lee-encoded effector h1 (nleh1) and h2 (nleh2), display sequence ...201021091507
cell-cell propagation of nf-κb transcription factor and map kinase activation amplifies innate immunity against bacterial infection.the enteroinvasive bacterium shigella flexneri uses multiple secreted effector proteins to downregulate interleukin-8 (il-8) expression in infected epithelial cells. yet, massive il-8 secretion is observed in shigellosis. here we report a host mechanism of cell-cell communication that circumvents the effector proteins and strongly amplifies il-8 expression during bacterial infection. by monitoring proinflammatory signals at the single-cell level, we found that the activation of the transcription ...201021093316
isolation and characterization of shigella flexneri g3, capable of effective cellulosic saccharification under mesophilic conditions.a novel shigella strain (shigella flexneri g3) showing high cellulolytic activity under mesophilic, anaerobic conditions was isolated and characterized. the bacterium is gram negative, short rod shaped, and nonmotile and displays effective production of glucose, cellobiose, and other oligosaccharides from cellulose (avicel ph-101) under optimal conditions (40°c and ph 6.5). approximately 75% of the cellulose was hydrolyzed in modified atcc 1191 medium containing 0.3% cellulose, and the oligosacc ...201021097577
development of a quantitative rt-pcr assay to examine the kinetics of ribosome depurination by ribosome inactivating proteins using saccharomyces cerevisiae as a model.ricin produced by the castor bean plant and shiga toxins produced by pathogenic escherichia coli (stec) and shigella dysenteriae are type ii ribosome inactivating proteins (rips), containing an enzymatically active a subunit that inhibits protein synthesis by removing an adenine from the α-sarcin/ricin loop (srl) of the 28s rrna. there are currently no known antidotes to shiga toxin or ricin, and the ability to screen large chemical libraries for inhibitors has been hindered by lack of quantitat ...201021098653
thrombotic microangiopathies: thrombotic thrombocytopenic purpura / hemolytic uremic syndrome.thrombotic microangiopathies (tmas) are pathological conditions characterized by generalized microvascular occlusion by platelet thrombi, thrombocytopenia, and microangiopathic hemolytic anemia. two typical phenotypes of tmas are hemolytic- uremic syndrome (hus) and thrombotic thrombocytopenic purpura (ttp). other disorders occasionally present with similar manifestations. depending on whether renal or brain lesions prevail, two pathologically indistinguishable but somehow clinically different d ...201021103695
environmental contamination of hokersar wetland waters in kashmir himalayan valley, india.this paper investigates the environmental contamination of himalayan wetland ecosystem (hokersar, kashmir) by analyzing the distribution and loading of bacterial population in waters. seven locations representing heterogeneous spatial habitat zonation of the wetland were studied. site-specific variability in bacterial load was markedly discernible at doodhganga inlet and zainakoot locations, with maximum values in the range of 242-276/100 ml against soziath, an outlet, with minimum value of 157- ...201021114125
predation of human pathogens by the predatory bacteria micavibrio aeruginosavorus and bdellovibrio bacteriovorus.the focus of this study was to evaluate the potential use of the predatory bacteria bdellovibrio bacteriovorus and micavibrio aeruginosavorus to control the pathogens associated with human infection.201021114596
laboratory detection of extended-spectrum-beta-lactamase-producing enterobacteriaceae: evaluation of two screening agar plates and two confirmation techniques.the worldwide prevalence of extended-spectrum-beta-lactamase-producing esbl-producing enterobacteriaceae (esbl-e) is increasing, making the need for optimized detection techniques more urgent. in this study we investigated the performance of two esbl-e screening and two esbl-e confirmation techniques. in accordance with the dutch national guidelines (www.wip.nl), a collection of 642 highly resistant enterobacteriaceae strains, as identified by vitek2, was used to test the performances of two scr ...201021123527
conformational changes in ipad from shigella flexneri upon binding bile salts provide insight into the second step of type iii secretion.shigella flexneri uses its type iii secretion apparatus (ttsa) to inject host-altering proteins into targeted eukaryotic cells. the ttsa is composed of a basal body and an exposed needle with invasion plasmid antigen d (ipad) forming a tip complex that controls secretion. the bile salt deoxycholate (doc) stimulates recruitment of the translocator protein ipab into the maturing ttsa needle tip complex. this process appears to be triggered by a direct interaction between doc and ipad. fluorescence ...201021126091
lactobacillus plantarum lipoteichoic acid down-regulated shigella flexneri peptidoglycan-induced inflammation.bacterial peptidoglycans (pgns) are recognized by the host's innate immune system. this process is mediated by the nod/card family of proteins, which induces inflammation by activating nuclear factor (nf)-κb. excessive activation of monocytes by shigella flexneri pgn (flexpgn) leads to serious inflammatory diseases such as intestinal bowel diseases (ibd) and crohn's disease. in this study, we examined whether lactobacillus plantarum lipoteichoic acid (plta) could attenuate the pro-inflammatory s ...201021129777
shigellosis from an interactive fountain: implications for regulation.in july 2003, the authors investigated an outbreak of shigella sonnei infections in marion county, oregon. nineteen confirmed and 37 presumptive cases, mostly young children, were identified. a case-control study implicated play in an interactive fountain in a city park (matched odds ratio undefined; p < .002). the association was confirmed by a cohort study among local schoolchildren (rr [relative risk] = 12.6, p < .001) that allowed the authors to estimate that > 500 persons became ill. founta ...201021133311
arginine-dependent acid-resistance pathway in shigella boydii.ability to survive the low ph of the human stomach is considered be an important virulent determinant. it was suggested that the unique acid tolerance of shigella boydii 18 cdph, the strain implicated in a 1998 outbreak, may have played an important role in surviving the acidic food (bean salad). the strain was capable of inducing arginine-dependent acid-resistance (adar) pathway. this pathway was assumed to be absent in shigella sp. here, we have examined occurrence and efficacy of adar pathway ...201021136041
enteric glia protect against shigella flexneri invasion in intestinal epithelial cells: a role for s-nitrosoglutathione.enteric glial cells (egcs) are important regulators of intestinal epithelial barrier (ieb) functions. egc-derived s-nitrosoglutathione (gsno) has been shown to regulate ieb permeability. whether egcs and gsno protect the ieb during infectious insult by pathogens such as shigella flexneri is not known.201021139062
facile synthesis and antibacterial activity of naturally occurring 5-methoxyfuroflavone.a convenient synthesis of 5-methoxyfuroflavone (6, pongaglabol methyl ether), a constituent of some pongamia or millettia genus, was achieved by starting from 2,4-dihydroxy-6-methoxyacetophenone via a chalcone precursor, followed by treatment with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq). this five-step reaction (total yield: 21.6%) is more facile with that of previously utilized procedures using each different starting material. antibacterial activities of the above compound and its prec ...201021139271
the shigella t3ss needle transmits a signal for mxic release, which controls secretion of effectors.type iii secretion systems (t3sss) are key determinants of virulence in many gram-negative bacteria, including animal and plant pathogens. they inject 'effector' proteins through a 'needle' protruding from the bacterial surface directly into eukaryotic cells after assembly of a 'translocator' pore in the host plasma membrane. secretion is a tightly regulated process, which is blocked until physical contact with a host cell takes place. host cell sensing occurs through a distal needle 'tip comple ...201021143311
antimicrobial resistance patterns and prevalence of class 1 and 2 integrons in shigella flexneri and shigella sonnei isolated in uzbekistan.abstract:201021143880
prevalence and characterization of human shigella infections in henan province, china, in 2006.in 2006, 3,531 fecal samples were collected from patients with diarrhea in henan province, china. a total of 467 (13.2%) shigella strains were isolated and serotyped. seventy-one shigella flexneri strains were characterized by mic determination, pulsed-field gel electrophoresis (pfge), and detection of genes encoding cephalosporin resistance. most infections were caused by s. flexneri variant x [iv:(7),8] (27.6%), s. sonnei (24.2%), and s. flexneri 2a (20.8%). however, large regional differences ...201021068291
the host outer membrane proteins ompa and ompc are associated with the shigella phage sf6 virion.assembly of dsdna bacteriophage is a precisely programmed process. potential roles of host cell components in phage assembly haven't been well understood. it was previously reported that two unidentified proteins were present in bacteriophage sf6 virion (casjens et al, 2004, j.mol.biol. 339, 379-394, fig. 2a). using tandem mass spectrometry, we have identified the two proteins as outer membrane proteins (omps) ompa and ompc from its host shigella flexneri. the transmission electron cryo-microsco ...201021071053
anaerobic environment of the intestine primes pathogenic shigella for infection.marteyn et al. have investigated the role of oxygen and the regulator fnr in infection by the intracellular enteric pathogen shigella flexneri. fnr is active under anaerobic conditions like those present in the lumen of the distal intestine. fnr causes elongation of a secretion apparatus required for bacterial entry into cells and represses secretion of proteins that trigger entry. higher oxygen levels present at the intestinal cell surface are sufficient to inactivate fnr, thereby derepressing ...201021073287
the structure of the escherichia coli o148 lipopolysaccharide core region and its linkage to the o-specific polysaccharide.recently it was demonstrated that shigella dysenteriae type 1, a cause of severe dysentery epidemics, gained its o-specific polysaccharide (o-sp) from escherichia coli o148. the o-sps of these bacteria differ only by a galactose residue in the repeat unit of s. dysenteriae type 1 in place of a glucose residue in e. coli o148. herein, we analyzed the core structure and its linkage to the o-sp in e. coli o148 lps. both were found to be identical to those of s. dysenteriae type 1 structures, furthe ...201021074753
shigella flexneri spa15 crystal structure verified in solution by double electron electron resonance.shigella flexneri spa15 is a chaperone of the type 3 secretion system, which binds a number of effectors to ensure their stabilization prior to secretion. one of these effectors is ipgb1, a mimic of the human ras-like rho guanosine triphosphatase rhog. in this study, spa15 alone and in complex with ipgb1 has been studied by double electron electron resonance, an experiment that gives distance information showing the spacial separation of attached spin labels. this distance is explained by determ ...201021075116
caging targets for destruction.intracellular bacterial pathogens engage in a tug-of-war with innate host defenses. in this issue of cell host & microbe, mostowy et al. (2010) identify a role for the septin family of cytoskeletal proteins in targeting intracellular shigella to the autophagy pathway.201021075349
entrapment of intracytosolic bacteria by septin cage-like structures.actin-based motility is used by various pathogens for dissemination within and between cells. yet host factors restricting this process have not been identified. septins are gtp-binding proteins that assemble as filaments and are essential for cell division. however, their role during interphase has remained elusive. here, we report that septin assemblies are recruited to different bacteria that polymerize actin. we observed that intracytosolic shigella either become compartmentalized in septin ...201021075354
microbiological quality of blue mussels (mytilus edulis) in nunavik, quebec: a pilot study.this pilot study was aimed at documenting the presence of fecal indicators and enteric pathogens in blue mussels (mytilus edulis) from 6 communities in nunavik, quebec. one to four 2 kg samples of mussels were collected at low tide in each community. samples were investigated by enumeration methods for the fecal indicators enterococci, escherichia coli, f-specific coliphages, clostridium perfringens, and by molecular identification for the pathogens norovirus, salmonella spp., campylobacter jeju ...201021076488
extended-spectrum ß-lactamase production in shigella flexneri.emergence of multidrug-resistant strains of shigella is a growing concern across the globe. third-generation cephalosporins are used for treating infections caused by multidrug-resistant shigellae. however, resistance to these cephalosporin antibiotics due to extended-spectrum ß-lactamases, has emerged as a new problem. so far extended-spectrum ß-lactamases producing shigella has not been reported from pakistan. we report such a case in shigella flexneri from an 8-year old girl with acute dysent ...201021078255
assessment of the underestimation of childhood diarrhoeal disease burden in israel.summarywe determined the extent by which mandatory reporting on isolates of shigella and salmonella underestimates the burden of diarrhoeal diseases in individuals aged <17 years in israel and examined paediatricians' knowledge, attitudes and practices related to patient visits with diarrhoeal diseases. sources of data were a nationwide population-based telephone survey for presence of diarrhoeal diseases, maccabi healthcare services databases and a mail survey among its paediatricians. monte ca ...201021087537
comparison of chromogenic biolog rainbow agar shigella/aeromonas with xylose lysine desoxycholate agar for isolation and detection of shigella spp. from foods.shigella outbreaks are widely reported throughout the world. however, it remains a challenge to isolate shigella spp. from foods by using conventional microbiological media. the main objective of this study was to determine the effectiveness of a novel chromogenic medium, rainbow agar shigella/aeromonas (rainbow agar), for the isolation and detection of shigella spp. in foods. all four shigella species, s. sonnei, s. flexneri, s. dysenteriae, and s. boydii, were studied. rainbow agar was compare ...201020819355
[antibacterial antibodies in human immunoglobulins and sera: past and present].to measure levels of several types of antibacterial antibodies in preparations of normal human immunoglobulin as well as in samples of donor sera obtained in 1965 and 2009.201021061576
[microsporidium spp. infection in an immunocompromised child diagnosed by polymerase chain reaction].microsporidium spp. may lead to a variety of clinical pictures like sinusitis, keratoconjunctivitis, hepatitis, myositis, peritonitis, nephritis, encephalitis and pneumonia in case of immune deficiencies. in this report, a case of diarrhea due to microsporidium spp. has been presented. a four years old male patient who was followed with the diagnosis of myotonic dystrophia, was admitted to the hospital with the complaints of respiratory distress and fever. due to the history of recurrent infecti ...201021063982
cutting edge: nlrc5-dependent activation of the inflammasome.the nucleotide-binding domain leucine-rich repeat-containing proteins, nlrs, are intracellular sensors of pathogen-associated molecular patterns and damage-associated molecular patterns. a subgroup of nlrs can form inflammasome complexes, which facilitate the maturation of procaspase 1 to caspase 1, leading to il-1β and il-18 cleavage and secretion. nlrc5 is predominantly expressed in hematopoietic cells and has not been studied for inflammasome function. rna interference-mediated knockdown of n ...201021191067
prevalent organisms on ostrich carcasses found in a commercial abattoir.the prevalent microbial growth on carcasses before and after overnight cooling in an ostrich abattoir and de-boning plant was investigated. the effect of warm or cold trimming of the carcasses was examined together with possible causes of contamination along the processing line. an attempt was made to link the prevalent microorganisms that were identified from carcasses to those from specific external contamination sources. samples of carcasses and possible contaminants were collected in the pla ...201021247040
microbial evaluation and public health implications of urine as alternative therapy in clinical pediatric cases: health implication of urine therapy.cultural means of pediatric treatment during ill health is a mainstay in africa, and though urine has been known to contain enteric pathogens, urine therapy is still culturally applicable in some health conditions and also advocated as alternative therapy. the study therefore, is to evaluate the microbial contents and safety of urine.201021293739
antibacterial activity of thai medicinal plants pikutbenjakul.bacterial infections caused by resistant strains have been increased dramatically. pikutbenjakul, a thai medicinal plant formula containing piper longum, piper sarmentosum, piper interruptum, plumbago indica and zingiber officinale have been widely used in thai traditional medicine.201021298838
[type three secretion system and pathogenesis of shigella spp.--a review].the powerful weapon of shigella spp. is type three secretion system, which remains the focus of pathogenic research. the regulation and function of type three secretion system of shigella spp. are summarized in this review.201021268888
bacteriological profile and resistant pattern of clinical isolates from pediatric patients, gondar university teaching hospital, gondar, northwest ethiopia.infectious diseases are major causes of morbidity and mortality among children in the developing world antibiotic resistance is increasing. knowledge of pathogens causing infection in pediatrics patients is essential for devising management strategies.201021280431
molecular structure and vibrational spectra of three substituted 4-thioflavones by density functional theory and ab initio hartree-fock calculations.the vibrational frequencies of three substituted 4-thioflavones in the ground state have been calculated using the hartree-fock and density functional method (b3lyp) with 6-31g* and 6-31+g** basis sets. the structural analysis shows that there exists h-bonding in the selected compounds and the hydrogen bond lengths increase with the augment of the conjugate parameters of the substituent group on the benzene ring. a complete vibrational assignment aided by the theoretical harmonic wavenumber anal ...201021156350
notes from the field: emergence of shigella flexneri 2a resistant to ceftriaxone and ciprofloxacin --- south carolina, october 2010.on october 20, 2010, the south carolina department of health and environmental control and cdc began investigating a cluster of three diarrheal illnesses caused by multidrug-resistant shigella flexneri 2a. the index case occurred in a girl aged 2 years who experienced the onset of diarrhea on september 25 and was hospitalized the next day because of a seizure and fever. on september 30, her brother, aged 6 years, was hospitalized with vomiting, bloody diarrhea, and hyponatremia. three days later ...201021160457
[study on the integration site and arrangement of sfii and sfx prophages in shigella flexneri serotype 2b strains.]objective: to study the integration site and arrangement of sfii and sfx prophages in shigella flexneri serotype 2b strains. methods: a series of primers were designed based on potential integration site of sfii and sfx prophages in shigella flexneri serotype 2b strains, and pcr were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. pcr products were sequenced to identify integration sites and arrangement of sfii and sfx. results: in all the serotype 2b ...201021162847
emergence of a novel shigella flexneri serotype 4s strain that evolved from a serotype x variant in china.this paper describes the first isolation of a new shigella flexneri serotype, designated 4s, in beijing, china. genotypic and phenotypic profiling suggests that this isolate is a clone of the s. flexneri serotype x variant reference strain. of particular concern is the multidrug resistance exhibited by this isolate.201021177890
reinforcement of epithelial cell adhesion to basement membrane by a bacterial pathogen as a new infectious stratagem.the intestinal epithelium undergoes a rapid turnover in addition to rapid exfoliation in response to bacterial infection, thus acting as an intrinsic defense against microbial intruders. it has long been questioned how mucosal pathogens can circumvent the intestinal defense systems. our recent discovery of a bacterial ploy used by shigella provided us with fresh insight. shigella delivers ospe via the type iii secretion system during multiplication within epithelial cells. this effector protein ...201021178415
mapping the selection mechanisms by bacterial gefs.mimicry of eukaryotic signaling enzymes is a common strategy used by bacterial pathogens to manipulate host cellular signaling. the e. coli type iii effector protein map belongs to a large family of bacterial virulence factors that activate host rho gtpase signaling pathways through an unknown molecular mechanism. our recent structural study, coupled with biochemical and functional assays, establishes that this family protein, including map, ipgb1/2 and sifa/b secreted by e. coli, shigella, and ...201021178423
convergent synthesis of a common pentasaccharide corresponding to the o-antigen of escherichia coli o168 and shigella dysenteriae type 4.a convenient synthetic strategy of the common acidic pentasaccharide repeating unit corresponding to the o-antigen of enterotoxigenic e. coli o168 and shigella dysenteriae type 4 has been successfully developed. a stereoselective [2 + 3] block glycosylation method has been exploited to get the target pentasaccharide derivative. most of the synthetic intermediates were solid and prepared in high yields from commercially available reducing sugars following a series of protection-deprotection react ...201021181263
imperatorin a furocoumarin inhibits periplasmic cu-zn sod of shigella dysenteriae their by modulates its resistance towards phagocytosis during host pathogen interaction.shigella dysenteriae continues to be a major health problem, which leads to death, due to diarrhoea and dysentery, predominantly in children below the age of 5. bacterial invasion of the colonic epithelium leads to severe inflammation together with bacterial dissemination generates abscesses and ulcerations. periplasmic copper, zinc super oxide dismutase of shigella protects it from exogenous superoxide produced by host, during its invasion. hence, in present study an attempt was made to study t ...201021194882
synthesis and evaluation of a class of new coumarin triazole derivatives as potential antimicrobial agents.a series of new coumarin-based 1,2,4-triazole derivatives were designed, synthesized and evaluated for their antimicrobial activities in vitro against four gram-positive bacteria (staphylococcus aureus, mrsa, bacillus subtilis and micrococcus luteus), four gram-negative bacteria (escherichia coli, proteus vulgaris, salmonella typhi and shigella dysenteriae) as well as three fungi (candida albicans, saccharomyces cerevisiae and aspergillus fumigatus) by two-fold serial dilution technique. the bio ...201021215620
etiology of childhood diarrhea in the northeast of brazil: significant emergent diarrheal pathogens.in a study conducted in joão pessoa, northeast of brazil, 2344 escherichia coli isolated from 290 infants with diarrhea and 290 healthy matched controls were analyzed for virulence traits. enteroaggregative e. coli (eaec) was the most prevalent pathogen associated to acute diarrhea. based on the results of colony blot hybridization, serotyping, and hep-2 cell adherence assays, strains were separated in categories as typical enteropathogenic e. coli (epec) (1.7%), atypical epec (a-epec) (9.3%), e ...201018508227
a bacterial e3 ubiquitin ligase ipah9.8 targets nemo/ikkgamma to dampen the host nf-kappab-mediated inflammatory response.nf-kappab (nuclear factor kappab) has a pivotal role in many cellular processes, including the inflammatory and immune responses and, therefore, its activation is tightly regulated by the ikk (ikappab kinase) complex and by ikappabalpha degradation. when shigella bacteria multiply within epithelial cells they release peptidoglycans, which are recognized by nod1 and stimulate the nf-kappab pathway, thus leading to a severe inflammatory response. here, we show that ipah9.8, a shigella effector pos ...201020010814
pivotal advance: bifidobacteria and gram-negative bacteria differentially influence immune responses in the proinflammatory milieu of celiac disease.cd is a chronic inflammatory disorder of the small intestine that presents in genetically predisposed individuals following gluten consumption. in this study, the effects of bifidobacterium (bifidobacterium bifidum iata-es2 and bifidobacterium longum atcc15707) and gram-negative bacteria (bacteroides fragilis dsm2451, escherichia coli cbl2, and shigella cbd8 isolated from cd patients), alone and in the presence of cd triggers (gliadins and/or ifn-gamma) on surface marker expression and cytokine ...201020007908
identification of antibacterial and antifungal pharmacophore sites for potent bacteria and fungi inhibition: indolenyl sulfonamide derivatives.synthesis of seven new indolenyl sulfonamides, have been prepared by the condensation reaction of indole-3-carboxaldehyde with different sulfonamides such as, sulphanilamide, sulfaguanidine, sulfathiazole, sulfamethoxazole, sulfisoxazole, sulfadiazine and sulfamethazine. these synthesized compounds have been used as potential ligands for complexation with some selective divalent transition metal ions (cobalt, copper, nickel & zinc). structure of the synthesized ligands has been deduced from thei ...201020005022
solution nmr structures of proteins vpa0419 from vibrio parahaemolyticus and yiis from shigella flexneri provide structural coverage for protein domain family pfam 04175. 201019927321
emergence of resistance to third-generation cephalosporin in shigella--a case report.the emergence of ciprofloxacin resistance in shigella has shifted the attention to cephalosporins. the first occurrence of third generation cephalosporin-resistant shigella flexneri was from france. this article reports the first case of cephalosporin-resistant s. flexneri from india. a 12-month-old child was admitted for a 20-day episode of loose stools, non-fetid, with mucus and blood. the stool sample showed the presence of blood and mucus and s. flexneri which was resistant to ampicillin, na ...201019955258
emergence of a new multidrug-resistant serotype x variant in an epidemic clone of shigella flexneri.shigella spp. are the causative agent of shigellosis with shigella flexneri serotype 2a being the most prevalent in developing countries. epidemiological surveillance in china found that a new serotype of s. flexneri appeared in 2001 and replaced serotype 2a in 2003 as the most prevalent serotype in henan province. the new serotype also became the dominant serotype in 7 of the 10 other provinces under surveillance in china by 2007. the serotype was identified as a variant of serotype x. it diffe ...201019955273
antilisterial activity of a broad-spectrum bacteriocin, enterocin lr/6 from enterococcus faecium lr/6.enterocin lr/6, a purified bacteriocin, exhibited broad inhibitory spectrum both against related as well as some food-borne pathogens such as listeria monocytogenes, yersinia enterocolitica, aeromonas sp., shigella sp., and bacillus licheniformis. in this investigation, we have focused on l. monocytogenes as the target organism, as it is not only an important pathogen but can also survive over a wide range of environmental conditions such as refrigeration temperature, low ph, and high-salt conce ...201019957209
interference of the cadc regulator in the arginine-dependent acid resistance system of shigella and enteroinvasive e. coli.a typical pathoadaptive mutation of shigella and enteroinvasive escherichia coli (eiec) is the inactivation of the cad locus which comprises the genes necessary for lysine decarboxylation, an enzyme involved in ph homoeostasis. in e. coli, the cadba operon, encoding lysine decarboxylase (cada) and a lysine cadaverine antiporter (cadb), is submitted to the control of cadc, a positive activator whose gene maps upstream the operon, and is transcribed independently from the same strand. cadc is an i ...201019959396
combined effects of probiotic fermentation and high-pressure extraction on the antioxidant, antimicrobial, and antimutagenic activities of deodeok (codonopsis lanceolata).this study was designed to evaluate the combined effects of probiotic fermentation and high-pressure extraction (hpe) on the functional properties of codonopsis lanceolata. the ground c. lanceolata samples were anaerobically fermented with lactobacillus acidophilus adh, bifidobacterium longum b6, lactobacillus rhamnosus gg, or lactobacillus paracasei at 37 degrees c for 10 days and subjected to 500 mpa at 50 degrees c for 30 min. the extraction yields of c. lanceolata samples were noticeably inc ...201020000575
global analysis of a plasmid-cured shigella flexneri strain: new insights into the interaction between the chromosome and a virulence plasmid.shigella flexneri is an important human pathogen that causes dysentery, and remains a significant threat to public health, particularly in developing countries. the virulence of this pathogen is dependent on an acquired virulence plasmid. to investigate the crosstalk between the bacterial chromosome and the exogenous virulence plasmid, a virulence plasmid-cured strain was constructed using plasmid incompatibility. the global patterns of gene expression of this strain compared with the wild-type ...201020000779
osmoregulated periplasmic glucans synthesis gene family of shigella flexneri.osmoregulated periplasmic glucans (opgs) of food- and water-borne enteropathogen shigella flexneri were characterized. opgs were composed of 100% glucose with 2-linked glucose as the most abundant residue with terminal glucose, 2-linked and 2,6-linked glucose also present in high quantities. most dominant backbone polymer chain length was seven glucose residues. individual genes from the opg gene family comprising of a bicistronic operon opggh, opgb, opgc and opgd were mutagenized to study their ...201020062978
nlrc4/ipaf/clan/card12: more than a flagellin sensor.nlrc4 is a member of the nod-like receptors (nlrs), a family of cytosolic receptors involved in sensing bacterial molecules. nlrs are a group of proteins containing spans of leucine-rich repeats that senses bacterial factors within the eukaryotic cytosol. the recognition of bacterial factors provokes the formation of the inflammasome complex which includes specific nlrs. the inflammasome is responsible for caspase-1 activation which leads to the cleavage and maturation of inflammatory cytokines ...201020067841
tracking the dynamic interplay between bacterial and host factors during pathogen-induced vacuole rupture in real time.escape into the host cell cytosol following invasion of mammalian cells is a common strategy used by invasive pathogens. this requires membrane rupture of the vesicular or vacuolar compartment formed around the bacteria after uptake into the host cell. the mechanism of pathogen-induced disassembly of the vacuolar membrane is poorly understood. we established a novel, robust and sensitive fluorescence microscopy method that tracks the precise time point of vacuole rupture upon uptake of gram-nega ...201020070313
age-related efficacy of shigella o-specific polysaccharide conjugates in 1-4-year-old israeli children.despite its high worldwide morbidity and mortality, there is yet no licensed vaccine for shigellosis. we reported the safety and immunogenicity of shigella o-specific polysaccharide-protein conjugates in adults and young children and efficacy of shigella sonnei conjugate in young adults.201020056180
the structure of the salmonella typhimurium type iii secretion system needle shows divergence from the flagellar system.the type iii secretion system (t3ss) is essential for the infectivity of many pathogenic gram-negative bacteria. the t3ss contains proteins that form a channel in the inner and outer bacterial membranes, as well as an extracellular needle that is used for transporting and injecting effector proteins into a host cell. the homology between the t3ss and the bacterial flagellar system has been firmly established, based upon both sequence similarities between respective proteins in the two systems an ...201020060835
antibodies against recombinant shiga toxin subunit b neutralize shiga toxin toxicity in hela cells.shigella dysenteriae type 1 and escherichia coli o157:h7 produce shiga toxin 1 (stx) and shiga toxin1 (stx1), respectively and these two toxins are almost identical. e. coli o157:h7 is the major cause of diarrhea-associated hemolytic uremic syndrome. stx and stx1 are ab5 type of toxin with a molecular weight of 70 kda, comprising an enzymaticaly-active a subunit (32 kda) and five receptor-binding b subunits (7.7 kda). in this study dna fragment (289 bp, gene bank accn no. ef685161) coding for b ...201020044923
rifaximin-induced alteration of virulence of diarrhoea-producing escherichia coli and shigella sonnei.rifaximin shortens the duration of travellers' diarrhoea without important alteration of colonic flora. this study investigated the expression of virulence factors [heat-stable (st) and heat-labile (lt) enterotoxins, surface adhesion factors (cs2/cs3, cs6) and matrix metalloproteinase-9 (mmp-9)] as well as the interleukin (il)-8 induction potential of diarrhoeagenic escherichia coli and shigella sonnei strains exposed to rifaximin (8, 32 and 64mg/l) for 4, 8, 18 and 24h. following exposure to ri ...201020045287
increased immunoendocrine cells in intestinal mucosa of postinfectious irritable bowel syndrome patients 3 years after acute shigella infection--an observation in a small case control study.postinfectiously irritable bowel syndrome (pi-ibs) develops in 3-30% of individuals with bacterial gastroenteritis. recent studies demonstrated increases in inflammatory components in gut mucosa of pi-ibs patients even after complete resolution of infection. we aimed to investigate histological changes in colon and rectum of pi-ibs subjects after long term period of infection.201020046513
characteristics of children with shigella encephalopathy: experience from a large urban diarrhea treatment center in bangladesh.encephalopathy is a serious neurologic complication from shigellosis often with fatal outcome but data on simple clinical and sociodemographic predicting factors are limited. we sought to identify those factors in children.201020016394
cem-101, a novel fluoroketolide: antimicrobial activity against a diverse collection of gram-positive and gram-negative bacteria.cem-101 is a novel fluoroketolide with reported high potency against diverse groups of gram-positive (micrococcus spp., viridans group streptococci, corynebacterium spp. listeria monocytogenes, clostridium spp., etc.) and gram-negative bacteria (neisseria gonorrhoeae, campylobacter jejuni, helicobacter pylori, bacteroides fragilis, shigella spp., etc.), including mycoplasma and ureaplasma, as well as bacteria commonly associated with community-acquired respiratory tract infections and skin and s ...201020022192
reactive arthritis after enteric infections in the united states: the problem of definition.bacterial enteric infections cause substantial morbidity in the united states both from acute illness and sequelae that follow. reactive arthritis (rea) is a poorly defined term that is used to describe a variety of rheumatologic phenomena that may occur after salmonella, shigella, campylobacter, and yersinia infection, as well as other types of infections (eg, chlamydia). this review focuses on clinical and epidemiologic investigations of rea following bacterial enteric infection in the united ...201020025528
transcriptional profile of the shigella flexneri response to an alkaloid: berberine.berberine, a natural isoquinoline alkaloid found in many medicinal herbs, has been shown to be active against a variety of microbial infections. to examine the potential effects of berberine on shigella flexneri, a whole-genome dna microarray was constructed and a transcriptome analysis of the cellular responses of s. flexneri when exposed to berberine chloride (bc) was performed. our data revealed that bc upregulated a group of genes involved in dna replication, repair and division. intriguingl ...201020030725
immobilization of bacteriophages on modified silica particles.bacteriophages are selective anti-bacterial agents, which are receiving increasing acceptance by regulatory agencies for use both in the food industry and in clinical settings for biocontrol. while immobilized phage could be particularly useful to create antimicrobial surfaces, current immobilization strategies require chemical bioconjugation to surfaces or more difficult processes involving modification of their head proteins to express specific binding moieties, for example, biotin or cellulos ...201019945158
galectin-3, a marker for vacuole lysis by invasive pathogens.shigella bacteria invade macrophages and epithelial cells and following internalization lyse the phagosome and escape to the cytoplasm. galectin-3, an abundant protein in macrophages and epithelial cells, belongs to a family of beta-galactoside-binding proteins, the galectins, with many proposed functions in immune response, development, differentiation, cancer and infection. galectins are synthesized as cytosolic proteins and following non-classical secretion bind extracellular beta-galactoside ...201019951367
characterization of wrss2 and wrss3, new second-generation virg(icsa)-based shigella sonnei vaccine candidates with the potential for reduced reactogenicity.live, attenuated shigella vaccine candidates, such as shigella sonnei strain wrss1, shigella flexneri 2a strain sc602, and shigella dysenteriae 1 strain wrsd1, are attenuated principally by the loss of the virg(icsa) protein. these candidates have proven to be safe and immunogenic in volunteer trials and in one study, efficacious against shigellosis. one drawback of these candidate vaccines has been the reactogenic symptoms of fever and diarrhea experienced by the volunteers, that increased in a ...201019932216
development of a serogroup-specific dna microarray for identification of escherichia coli strains associated with bovine septicemia and diarrhea.escherichia coli strains belonging to serogroups o8, o9, o15, o26, o35, o78, o86, o101, o115 and o119 are commonly associated with septicemia or diarrhea in calves and pose a significant threat to the cattle industry worldwide. in this study, a microarray detection system targeting o-antigen-specific genes was developed for the identification of those serogroups. by testing against 186 e. coli and shigella o-serogroup reference strains, 36 e. coli clinical isolates, and 9 representative strains ...201019932572
antimicrobial lipids from the hemolymph of brachyuran crabs.the potential of marine crabs as a source of biologically active products is largely unexplored. in the present study, antimicrobial activity of the hemolymph (plasma) and hemocytes (plasma cells) of six brachyuran crabs was investigated against 16 pathogenic strains. among the 16 strains tested maximum zone of inhibition was recorded in the hemolymph of hyas araneus against shigella flexineri. interestingly staphylococcus aureus and salmonella typhi were susceptible to all the hemolymph and hem ...201019937399
inactivation of escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves by x-ray.several recent foodborne disease outbreaks associated with leafy green vegetables, including spinach, have been reported. x-ray is a non-thermal technology that has shown promise for reducing pathogenic and spoilage bacteria on spinach leaves. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves using x-ray at different doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) was studied. the effect of x-ray on col ...201019913687
effects of x-ray radiation on escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri inoculated on shredded iceberg lettuce.the main goal of this investigation was to study the efficacy of x-ray doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) on inoculated escherichia coli o157: h7, listeria monocytogenes, salmonella enterica and shigella flexneri on shredded iceberg lettuce. the second goal was to study the effect of x-ray on the inherent microflora counts and visual color of shredded iceberg lettuce during storage at 4 degrees c for 30 days. treatment with 1.0 kgy x-ray significantly reduced the population o ...201019913700
yersinia enterocolitica in slaughter pig tonsils: enumeration and detection by enrichment versus direct plating culture.tonsil samples from 139 slaughter pigs were examined for the presence of pathogenic yersinia enterocolitica by enrichment procedures based on the standard method iso 10273:2003. in addition, samples were tested by direct plating method to evaluate its efficiency compared to the enrichment culture methods and to quantify the level of contamination in porcine tonsils. in total, 52 samples (37.4%) were positive for pathogenic y. enterocolitica, all belonging to bioserotype 4/o:3. fifty out of the 5 ...201019913707
adaptive immune responses during shigella dysenteriae type 1 infection: an in vitro stimulation with 57 kda major antigenic omp in the presence of anti-cd3 antibody.an effort was made to understand the role of the 57 kda major antigenic fraction of shigella outer membrane protein (omp) in the presence of t-cell antigen receptor in activation of adaptive immune responses of the cell mediated immune (cmi) restored patients. the expression of hla-dr/cd4 out of cd3(+) t-cells was significantly dominant over the hla-dr/cd8 and comparable to unstimulated cells of infected or healthy controls. cd4(+) t-cell activation together with hla-dr is associated with the ex ...201019915959
differentiation and identification of shigella spp. and enteroinvasive escherichia coli in environmental waters by a molecular method and biochemical test.both shigella spp. and enteroinvasive escherichia coli (eiec) are important human pathogens that are responsible for the majority of cases of endemic bacillary dysentery. however, they are difficult to identify and differentiate by biochemical tests or molecular methods alone. in this study, we developed a procedure to detect shigella spp. and eiec from environmental water samples using membrane filtration followed by nutrient broth enrichment, isolation using selective culture plates, and ident ...201019917511
the australian bush fly (musca vetustissima) as a potential vector in the transmission of foodborne pathogens at outdoor eateries.abstract australian outdoor activities are often accompanied by a barbeque (bbq) with family, friends, and guests, which are often interrupted by uninvited guests in the form of the australian bush fly, musca vetustissima. we investigated the bacterial loading associated with the australian bush in three different environments: on a cattle farm, in a typical urban area (shopping center car park), and at a bbq. the highest bacterial populations per fly were found to occur in a farm environment ( ...201019895260
caspase-8-mediated cleavage of bid and protein phosphatase 2a-mediated activation of bax are necessary for verotoxin-1-induced apoptosis in burkitt's lymphoma cells.verotoxin (vt-1) is a cytotoxin, produced by shigella dysenteriae type 1 or by shiga toxin-producing escherichia coli, which binds specifically to globotriaosylceramide (gb3). this glycosphingolipid is a b cell differentiation antigen (gb3/cd77) strongly expressed on burkitt's lymphoma cells. we have previously shown that, in these cells, vt-1 induces apoptosis via a caspase- and mitochondria-dependent pathway. in this report, we provide new insights into this signal transduction pathway. first, ...201019895884
evaluation of new chromogenic substrates for the detection of coliforms.to evaluate a new range of chromogenic substrates for the detection of beta-galactosidase activity in coliforms and to compare their performance in agar media and broths.201019878523
virulence, inflammatory potential, and adaptive immunity induced by shigella flexneri msbb mutants.the ability of genetically detoxified lipopolysaccharide (lps) to stimulate adaptive immune responses is an ongoing area of investigation with significant consequences for the development of safe and effective bacterial vaccines and adjuvants. one approach to genetic detoxification is the deletion of genes whose products modify lps. the msbb1 and msbb2 genes, which encode late acyltransferases, were deleted in the shigella flexneri 2a human challenge strain 2457t to evaluate the virulence, infla ...201019884336
a versatile internal control for use as dna in real-time pcr and as rna in real-time reverse transcription pcr assays.to develop and evaluate a taqman-based internal amplification control (iac) that can be used as dna in real-time pcr (qpcr) or as rna in reverse transcription real-time pcr (qrt-pcr) to identify the presence of assay inhibition and to evaluate its incorporation into existing qpcr and qrt-pcr methods for bacterial detection.201020149084
characterisation of pathogenic bacteria in a uasb-polishing pond system using molecular techniques.molecular techniques have been commonly used to detect and quantify pathogenic bacteria in food, clinical and environmental samples, but in wastewater treatment plants few studies have been carried out. this work applied pcr with a specific set of primers to investigate pathogenic bacteria in a wastewater plant comprised of a uasb reactor followed by polishing ponds. in addition, in-situ hybridisation technique (fish) was used to estimate the abundance of escherichia coli in the system. accordin ...201020150719
food-borne diseases - the challenges of 20 years ago still persist while new ones continue to emerge.the burden of diseases caused by food-borne pathogens remains largely unknown. importantly data indicating trends in food-borne infectious intestinal disease is limited to a few industrialised countries, and even fewer pathogens. it has been predicted that the importance of diarrhoeal disease, mainly due to contaminated food and water, as a cause of death will decline worldwide. evidence for such a downward trend is limited. this prediction presumes that improvements in the production and retail ...201020153070
development of a multiplex real-time polymerase chain reaction for simultaneous detection of enterohemorrhagic escherichia coli and enteropathogenic escherichia coli strains.a multiplex real-time polymerase chain reaction (pcr) was developed for the simultaneous detection of genes encoding intimin (eae) and all variants of shiga toxins 1 and 2 (stx1 and stx2) in diagnostic samples. the uida gene encoding a beta-glucuronidase specific for escherichia coli and shigella spp. was included in the multiplex pcr assay as an internal amplification control. the multiplex pcr was tested on 30 e. coli reference strains and 174 diagnostic samples already characterized as harbor ...201020156086
a challenge model for shigella dysenteriae 1 in cynomolgus monkeys (macaca fascicularis).shigella dysenteriae type 1 can cause devastating pandemics with high case fatality rates; a vaccine for shigella is unavailable currently. because of the risks associated with performing challenge studies with wild-type s. dysenteriae 1 in human clinical trials to advance vaccine development, an improved nonhuman primate model is needed urgently. in the present study, cynomolgus macaques (macaca fascicularis) were challenged with various doses of s. dysenteriae 1 strain 1617 to establish a dose ...201020158950
extended-spectrum beta-lactamase-producing escherichia coli in patients with travellers' diarrhoea.the identification of patients carrying extended-spectrum beta-lactamase (esbl)-producing bacteria is important, since these patients are at risk of receiving inappropriate empirical therapy if they become infected. the purpose of this study was to investigate the occurrence of esbl-producing bacteria in patients with travellers' diarrhoea. patients with travellers' diarrhoea (n = 242) having delivered stool samples for the diagnosis of salmonella, shigella, yersinia or campylobacter, were also ...201020121649
campylobacteriosis and other bacterial gastrointestinal diseases in sofia, bulgaria for the period 1987-2008.campylobacter is the most commonly reported enteric bacterial pathogen in humans. we still do not have any systematic data concerning campylobacteriosis in bulgaria. for that reason, we present data of the thermophilic campylobacter jejuni and campylobacter coli in the aetiology of diarrhoeal diseases in sofia, for the period from 1987 to 2008. the study included patients from 0 to over 65 years-old. a total of 51,607 faecal specimens were screened for campylobacter. c. jejuni and c. coli were d ...201020122383
bacterial guanine nucleotide exchange factors sope-like and wxxxe effectors.subversion of rho family small gtpases, which control actin dynamics, is a common infection strategy used by bacterial pathogens. in particular, salmonella enterica serovar typhimurium, shigella flexneri, enteropathogenic escherichia coli (epec), and enterohemorrhagic escherichia coli (ehec) translocate type iii secretion system (t3ss) effector proteins to modulate the rho gtpases rhoa, cdc42, and rac1, which trigger formation of stress fibers, filopodia, and lamellipodia/ruffles, respectively. ...201020123714
a novel antisense rna regulates at transcriptional level the virulence gene icsa of shigella flexneri.the virulence gene icsa of shigella flexneri encodes an invasion protein crucial for host colonization by pathogenic bacteria. within the intergenic region vira-icsa, we have discovered a new gene that encodes a non-translated antisense rna (named rnag), transcribed in cis on the complementary strand of icsa. in vitro transcription assays show that rnag promotes premature termination of transcription of icsa mrna. transcriptional inhibition is also observed in vivo by monitoring the expression p ...201020129941
cesarean delivery and risk of intestinal bacterial infection.an individual's intestinal bacterial flora is established soon after birth. delivery by cesarean section (c-section) deprives the newborn of colonization with maternal vaginal bacteria. we determined whether delivery by c-section is associated with an altered risk of infection with intestinal bacterial pathogens.201020132034
bacteriocin production by shigella sonnei isolated from faeces of children with acute diarrhoea.shigella is a common agent of diarrhoea, a worldwide major health problem. the bacterium produces bacteriocins; however, the role of these substances as a virulence factor is completely unknown. with the aim to search for colicin production by shigella sonnei, to evaluate the influence of culture conditions on bacteriocin expression, and to characterize the substance partially, 16 s. sonnei strains isolated from children with diarrhoea were tested for antagonism against members of the intestinal ...201020132176
a quantitative pcr assay for rapid detection of shigella species in fresh produce.a quantitative pcr (qpcr) assay with two primers and a taqman probe targeting conserved regions of the specific ipah gene of shigella species and enteroinvasive escherichia coli (eiec) were developed. this qpcr assay was used to identify 206 shigella strains (including four shigella species with all serotypes and two provisional shigella species), 3 eiec strains, and 113 non-shigella strains with 100% accuracy. pure cultures of six shigella reference strains were used to derive standard curves t ...201020132666
innate immune detection of the type iii secretion apparatus through the nlrc4 inflammasome.the mammalian innate immune system uses toll-like receptors (tlrs) and nod-lrrs (nlrs) to detect microbial components during infection. often these molecules work in concert; for example, the tlrs can stimulate the production of the proforms of the cytokines il-1beta and il-18, whereas certain nlrs trigger their subsequent proteolytic processing via caspase 1. gram-negative bacteria use type iii secretion systems (t3ss) to deliver virulence factors to the cytosol of host cells, where they modula ...201020133635
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