Publications

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effect of iron on cytolysin a expression in salmonella enterica serovar typhi.previously, a novel protein clya (cytolysin a) has been identified in escherichia coli k-12, salmonella enterica serovars typhi and paratyphi a and shigella. salmonella spp. synthesize substantial amounts of clya upon infection of the human host, although the mechanism by which clya is induced in vivo is unclear. since environmental signals could control the expression of virulence determinants, clya expression in s. typhi ty2 was tested by western blotting in the presence of normal pooled human ...200919763423
ptdins5p protects akt from dephosphorylation through pp2a inhibition.phosphatidylinositol 5-phosphate (ptdins5p), the most recently discovered phosphoinositide, has been proposed to play a role as a lipid mediator of intracellular signaling. we have previously shown that ptdins5p generated by ipgd, an effector of the causative agent of dysentery shigella flexneri, activates the pi 3-kinase/akt pathway. here, we demonstrate that ptdins5p is able to protect akt from dephosphorylation. this effect is not due to inhibition of the phosphoinositide phosphatase regulati ...200919576174
high frequency of hotspot mutations in core genes of escherichia coli due to short-term positive selection.core genes comprising the ubiquitous backbone of bacterial genomes are not subject to frequent horizontal transfer and generally are not thought to contribute to the adaptive evolution of bacterial pathogens. we determined, however, that at least one-third and possibly more than one-half of the core genes in escherichia coli genomes are targeted by repeated replacement substitutions in the same amino acid positions-hotspot mutations. occurrence of hotspot mutations is driven by positive selectio ...200919617543
characterization of shigella sonnei isolates from travel-associated cases in japan.shigella sonnei infection in industrialized countries is often associated with foreign travel. a total of 195 s. sonnei isolates in japan, isolated from cases associated with foreign travel, were analysed by biotyping and molecular typing using pfge and multilocus variable-number tandem-repeat analysis (mlva); their antimicrobial susceptibilities were also evaluated. the isolates were from 26 countries, most of which were asian. molecular typing revealed a correlation among the genotypes, biotyp ...200919589900
the pathogenic properties of a novel and conserved gene product, kerv, in proteobacteria.identification of novel virulence factors is essential for understanding bacterial pathogenesis and designing antibacterial strategies. in this study, we uncover such a factor, termed kerv, in proteobacteria. experiments carried out in a variety of eukaryotic host infection models revealed that the virulence of a pseudomonas aeruginosa kerv null mutant was compromised when it interacted with amoebae, plants, flies, and mice. bioinformatics analyses indicated that kerv is a hypothetical methyltra ...200919779606
an integrative approach combining noncovalent mass spectrometry, enzyme kinetics and x-ray crystallography to decipher tgt protein-protein and protein-rna interaction.the trna-modifying enzyme trna-guanine transglycosylase (tgt) is a putative target for new selective antibiotics against shigella bacteria. the formation of a tgt homodimer was suggested on the basis of several crystal structures of tgt in complex with rna. in the present study, noncovalent mass spectrometry was used (i) to confirm the dimeric oligomerization state of tgt in solution and (ii) to evidence the binding stoichiometry of the complex formed between tgt and its full-length substrate tr ...200919627989
purification and characterization of an immunogenic outer membrane protein of shigella flexneri 2a.in the present study we purified 34 kda major outer membrane protein (momp) of shigella flexneri 2a for the first time, which was cross-reactive and antigenically conserved among shigella spp. and the epitope was surface exposed on the intact bacterium. the purified antigen was found to be glycosylated, which aids in binding to macrophages and up-regulated the production of nitric oxide, granulocyte-colony stimulating factor and il-12p70, indicating that the momp is immunogenic and has the abili ...200919660587
study on induction of apoptosis on hela and vero cells by recombinant shiga toxin and its subunits.verotoxin (vt) or shiga toxin (stx) produced by enterohemorrhagic escherichia coli (ehec) and shigella dysenteriae is ab5 holotoxin with potent protein synthesis inhibitor. vt can induce both apoptosis and necrosis depending on the cell type, it has been shown that vt-induced apoptosis and cytotoxicity are distinct processes, and the a subunit can be necessary for apoptosis. in other words, the precise role of each subunit in apoptosis signaling has yet to be established. in this study, inductio ...200919669659
overseas outbreaks of infectious intestinal disease identified in scotland, 2003 to 2007.this article presents information on all potential outbreaks of infectious intestinal disease (iid) identified by health protection scotland (hps) involving residents of scotland. unlike other systems, this alert system covers potential outbreaks of iid rather than apparently sporadic cases and covers all gastrointestinal pathogens, all visited countries, and all groups of travelers.200919796102
review article: anti-inflammatory mechanisms of action of saccharomyces boulardii.saccharomyces boulardii, a well-studied probiotic, can be effective in inflammatory gastrointestinal diseases with diverse pathophysiology, such as inflammatory bowel disease (ibd), and bacterially mediated or enterotoxin-mediated diarrhoea and inflammation.200919706150
effects of enteropathogenic bacteria & lactobacilli on chemokine secretion & toll like receptor gene expression in two human colonic epithelial cell lines.the intestinal epithelium is part of the innate immune system responding to contact with pathogenic or commensal bacteria. the objective of this study was to compare innate responses of intestinal epithelial cell lines to pathogenic bacteria and to lactobacilli.200919797815
virb alleviates h-ns repression of the icsp promoter in shigella flexneri from sites more than one kilobase upstream of the transcription start site.the icsp promoter of shigella spp. is repressed by h-ns and derepressed by virb. here, we show that an inverted repeat located between positions -1144 and -1130 relative to the icsp transcription start site is necessary for virb-dependent derepression. the atypical location of this cis-acting site is discussed.200919363111
a genome-scale proteomic screen identifies a role for dnak in chaperoning of polar autotransporters in shigella.autotransporters are outer membrane proteins that are widely distributed among gram-negative bacteria. like other autotransporters, the shigella autotransporter icsa, which is required for actin assembly during infection, is secreted at the bacterial pole. in the bacterial cytoplasm, icsa localizes to poles and potential cell division sites independent of the cell division protein ftsz. to identify bacterial proteins involved in the targeting of icsa to the pole in the bacterial cytoplasm, we sc ...200919684128
antibiotic resistance among shigella serogroups isolated in tehran, iran (2002-2004). 200919801811
autophagy in immunity against intracellular bacteria.autophagy is an innate immune defense mechanism against various intracellular bacterial pathogens, such as salmonella enterica serovar typhimurium (s. typhimurium), listeria monocytogenes and shigella flexneri. s. typhimurium uses type three secretion systems (t3sss) to invade mammalian cells and replicate in salmonella-containing vacuoles (scvs). a small population of intracellular s. typhimurium is targeted by autophagy shortly after infection. evidence suggests that these bacteria are present ...200919802566
enterohaemorrhagic escherichia coli serogroup o111 inhibits nf-(kappa)b-dependent innate responses in a manner independent of a type iii secreted ospg orthologue.enterohaemorrhagic and enteropathogenic escherichia coli (ehec and epec) inject a repertoire of effector proteins into host cells via a type iii secretion system (t3ss) encoded by the locus of enterocyte effacement (lee). ospg is an effector protein initially identified in shigella that was shown to inhibit the host innate immune response. in this study, we found ospg homologues in ehec (mainly of serogroup o111) and in yersinia enterocolitica. the t3ss encoded by the lee was able to inject thes ...200919628559
comparative study of pathogenicity tests for shigella spp. and enteroinvasive escherichia coli strains.the purpose of this study was to optimize an in vitro pathogenicity model, as an alternative to sereny test (on guinea pigs). the study was performed on 13 shigella spp. and 3 enteroinvasive escherichia coli (eiec) strains isolated in romania between 2005 and 2007. the investigation implied the comparative evaluation between the sereny test and cravioto's adapted method for the assessment of the adherence and invasion capacity of the studied bacterial strains on hela cells, as well as the pcr de ...200919507627
screening, purification, and identification of the enzyme producing n-(l-alpha-l-aspartyl)-l-phenylalanine methyl ester from l-isoasparagine and l-phenylalanine methyl ester.screening was carried out for microorganisms able to produce n-(l-alpha-l-aspartyl)-l-phenylalanine methyl ester [apm] from l-isoasparagine and l-phenylalanine methyl ester hydrochloride. of the 422 strains examined, 44 strains belonging to the family enterobacteriaceae were found to produce apm. the enzyme catalyzing apm production was purified and identified as dipeptidase e.200919664550
bacterial type iii effectors inhibit cell lifting by targeting integrin-linked kinase.many pathogenic bacteria are able to surmount exfoliation and colonize the host epithelium efficiently. in a recent article in nature, kim et al. (2009) show that shigella flexneri ospe, a conserved type iii effector, reinforces host cell adherence and prevents detachment of the infected cells by interacting with integrin-linked kinase.200919527878
bacterial jailbreak sounds cellular alarm: phagosome membrane remnants trigger signaling.shigella flexneri and other invasive bacteria rupture the phagosome membrane and escape to the host cytoplasm. now, dupont et al. address the fate and signaling functions of pathogen vacuole remnants and show that these membrane fragments trigger host-cell-signaling responses, including polyubiquitination, autophagy, and pyroptosis.200919683675
shigella phagocytic vacuolar membrane remnants participate in the cellular response to pathogen invasion and are regulated by autophagy.intracellular pathogens like shigella flexneri enter host cells by phagocytosis. once inside, the pathogen breaks the vacuolar membrane for cytosolic access. the fate and function of the vacuolar membrane remnants are not clear. examining shigella-infected nonmyeloid cells, we observed that proteins associated with vacuolar membrane remnants are polyubiquinated, recruit the autophagy marker lc3 and adaptor p62, and are targeted to autophagic degradation. further, inflammasome components and casp ...200919683680
sarcosaprophagous flies in suez governorate, egypt iv--persistence of human pathogenic bacteria in the developmental stages.the persistence of three species of human pathogenic bacteria (escherichia coli, shigella sonnei and staphylococcus epidermidis) in sterile artificially fed larvae was examined till adult emergence after ingestion by three species of sarcosaprophagous flies (house fly, musca domestica, oriental latrine blow fly, chrysomya megacephala and australian cheep blow fly, lucilia cuprina). the number of bacteria present in mature maggots, pupae and emerging adults declined significantly (p < 0.05). each ...200919530618
hospital-based surveillance of enteric parasites in kolkata.diarrhoea is the second leading cause of illness and death in developing countries and the second commonest cause of death due to infectious diseases among children under five in such countries. parasites, as well as bacterial and viral pathogens, are important causes of diarrhoea. however, parasitic infections are sometimes overlooked, leading after a period of time to an uncertain aetiology. in this paper we report the prevalence of giardia lamblia, entamoeba histolytica and cryptosporidium sp ...200919545355
multiplexed bead-based mesofluidic system for detection of food-borne pathogenic bacteria.in the present study, a simple and rapid multiplexed bead-based mesofluidic system (bms) was developed for simultaneous detection of food-borne pathogenic bacteria, including staphylococcus aureus, vibrio parahaemolyticus, listeria monocytogenes, salmonella, enterobacter sakazakii, shigella, escherichia coli o157:h7, and campylobacter jejuni. this system is based on utilization of isothiocyanate-modified microbeads that are 250 mum in diameter, which were immobilized with specific amino-modified ...200919717622
when shigella tells the cell to hang on.ospe, a shigella type iii effector binds to integrin-like kinase and enhances cell adhesion to better disseminate and colonize the intestinal epithelium. because of the existence of ospe orthologues in other enteropathogens such as enteropathogenic escherichia coli or salmonella sp., maintenance of cell adhesion appears as a widespread strategy for bacteria that interact with the intestinal epithelium.200919720630
assessment of cell surface properties and adhesion potential of selected probiotic strains.to evaluate the physicochemical cell surface and adhesive properties of selected probiotic strains for human use.200919725886
comparison of the entericbio multiplex pcr system with routine culture for detection of bacterial enteric pathogens.the entericbio system uses a multiplex pcr assay for the simultaneous detection of campylobacter spp., salmonella enterica, shigella spp., and escherichia coli o157 from feces. it combines overnight broth enrichment with pcr amplification and detection by hybridization. an evaluation of this system was conducted by comparing the results obtained with the system with those obtained by routine culture, supplemented with alternative pcr detection methods. in a study of 773 samples, routine culture ...200919726596
comparison of two label-free global quantitation methods, apex and 2d gel electrophoresis, applied to the shigella dysenteriae proteome.the in vitro stationary phase proteome of the human pathogen shigella dysenteriae serotype 1 (sd1) was quantitatively analyzed in coomassie blue g250 (cbb)-stained 2d gels. more than four hundred and fifty proteins, of which 271 were associated with distinct gel spots, were identified. in parallel, we employed 2d-lc-ms/ms followed by the label-free computationally modified spectral counting method apex for absolute protein expression measurements. of the 4502 genome-predicted sd1 proteins, 1148 ...200919563668
oxidative and antibacterial activity of mn3o4.mn(3)o(4) nanoparticles with diameter ca. 10nm were synthesized by the forced hydrolysis of mn(ii) acetate at 80 degrees c. the x-ray diffraction (xrd), fourier transform infra red (ft-ir) spectroscopy, scanning electron microscopy (sem) and energy dispersive x-ray (edx) techniques were employed to study structural features and chemical composition of the nanoparticles. the unique oxidative activity of the mn(3)o(4) nanoparticles was demonstrated in the polymerization and dye degradation reactio ...200919733434
nitric oxide production in acute gastroenteritis in indian children.this study compared nitric oxide (no) levels in 110 children with, and 110 children without, infectious gastroenteritis. post-infection intestinal function was assessed in a subset. at least one pathogen was identified in 47.2% of cases. the most common diarrhoeal pathogens were rotavirus (22.7%) and norovirus genogroup ii (11.8%). the levels of no measured by median urinary nitrite:creatinine ratio were significantly higher in children with diarrhoea [23.6; interquartile range (iqr) 12.3-46.7] ...200919552932
porin of shigella dysenteriae directly promotes toll-like receptor 2-mediated cd4+ t cell survival and effector function.porin of shigella dysenteriae type 1 up-regulated toll-like receptor (tlr)2 on cd3-stimulated cd4(+) t cells but could not induce the expression of other tlrs. tlr2 in association with myeloid differentiating factor 88 (myd88) triggered the downstream signal transduction pathway leading to activation of mitogen-activated protein kinase (mapk) and nuclear factor kappab (nf-kappab), and degradation of ikappab, the nf-kappab inhibitor. tlr2 co-stimulation by porin resulted in t cell expansion by in ...200919576636
aetiology of acute gastro-enteritis in children at saint camille medical centre, ouagadougou, burkina faso.the present study aims at identifying the infectious agents responsible for child acute gastroenteritis (age) in ouagadougou. from may 5 2006 to june 22 2008, 648 children aged from 2 to 41 months, with at least an average of 3 loose stools per day have been enrolled for coproculture, parasitology and virology test. among them, 34 (5.25%) were hiv seropositive. a single sample of faeces from each child was used to identify enteropathogens. an infectious aetiology was identified in 41.20% of case ...200919579955
influence of long-term consumption of a lactococcus lactis strain on the intestinal immunity and intestinal flora of the senescence-accelerated mouse.the senescence-accelerated mouse develops normally until 5-6 months of age and then displays rapid and irreversible advancement of senescence manifesting as clinical signs and gross lesions. to clarify the effect of lactic acid bacteria on the physiological changes with increasing age, heat-killed lactococcus lactis g50 was administered to 1-month-old senescence-accelerated-prone mouse (samp)6 mice for 11 months, a senescence-accelerated mouse strain that develops senile osteoporosis. mice fed g ...200919586567
involvement of rna-binding protein hfq in the osmotic-response regulation of inve gene expression in shigella sonnei.the expression of type iii secretion system (ttss) in shigella is regulated in response to changes in environmental osmolarity and temperature. temperature-dependent regulation of virf, the master regulator of ttss synthesis, is believed to occur at the transcriptional level. we recently demonstrated, however, that ttss synthesis also involves post-transcriptional regulation of the synthesis of inve, a target of virf and key regulator of ttss synthesis. the mrna levels of inve (virb) are stable ...200919476612
potential applicability of chymotrypsin-susceptible microcin j25 derivatives to food preservation.microcin j25 (mccj25) is a 21-residue ribosomally synthesized lariat peptide antibiotic. mccj25 is active against such food-borne disease-causing pathogens as salmonella spp., shigella spp., and escherichia coli, including e. coli o157:h7 and non-o157 strains. mccj25 is highly resistant to digestion by proteolytic enzymes present in the stomach and intestinal contents. mccj25 would therefore remain active in the gastrointestinal tract, affecting normal intestinal microbiota, and this limits the ...200919592527
ipab-ipgc interaction defines binding motif for type iii secretion translocator.the delivery of virulence factors into host cells through type iii secretion systems is essential for enterobacterial pathogenesis. molecular chaperones bind specifically to virulence factors in the bacterial cytosol before secretion. invasion plasmid gene c (ipgc) is a chaperone that binds 2 essential virulence factors of shigella: invasion plasmid antigens (ipa) b and c. here, we report the crystal structure of ipgc alone and in complex with the chaperone binding domain (cbd) of ipab. the chap ...200919478065
go4genome: a prokaryotic phylogeny based on genome organization.determining the phylogeny of closely related prokaryotes may fail in an analysis of rrna or a small set of sequences. whole-genome phylogeny utilizes the maximally available sample space. for a precise determination of genome similarity, two aspects have to be considered when developing an algorithm of whole-genome phylogeny: (1) gene order conservation is a more precise signal than gene content; and (2) when using sequence similarity, failures in identifying orthologues or the in situ replaceme ...200919436929
nonculturable response of animal enteropathogens in the agricultural environment and implications for food safety.concerns about animal enteropathogen contamination of fresh horticultural products have,increased worldwide and are mainly due to the ability of bacteria to survive under stress conditions in the agricultural environment and during raw-vegetable processing. this review challenges the idea that the viable but nonculturable phenomenon that has been proven to occur in plant-associated environments contributes to human pathogen survival and might be correlated with foodborne infection. factors assoc ...200919610353
metabolic control through ornithine and uracil of epithelial cell invasion by shigella flexneri.this paper shows that compounds in defined growth media strongly influence the expression of the effectors of virulence in the human invasive pathogen shigella flexneri. ornithine in conjunction with uracil reduces the haemolytic ability of wild-type cultures more than 20-fold and the expression of the type iii secretion system more than 8-fold, as monitored by an mxic : : lacz transcriptional reporter. mxic gene expression is further decreased by the presence of methionine or branched-chain ami ...200919460819
structural insights into host gtpase isoform selection by a family of bacterial gef mimics.the escherichia coli type iii effector map belongs to a large family of bacterial virulence factors that activate host rho gtpase signaling pathways through an unknown molecular mechanism. here we report direct evidence that map functions as a potent and selective guanine-nucleotide exchange factor (gef) for cdc42. the 2.3-a structure of the map-cdc42 complex revealed that map mimics the gef strategy of the mammalian dbl family but has a three-dimensional architecture that is nearly identical to ...200919620963
[virulence factors and in vitro susceptibility of plesiomonas shigelloides isolated from diarrhea episodes in cuba].acute diarrhea is still one of the main causes of disease in developing countries. at the national reference laboratory for acute diarrhoeal diseases, of the "pedro kourí" tropical medicine institute, 54 plesiomonas shigelloides strains were serotyped. as a result, the circulation of four new serotypes (o20:h2, 056:h18, 071 :h31,081 :h22) was detected. the most common antigenic variant was 094:h3. in addition, the susceptibility pattern to 21 antimicrobial agents (aa) was studied. highest percen ...200919621156
improvement of an acid phosphatase/dhap-dependent aldolase cascade reaction by using directed evolution.to enhance the phosphorylating activity of the bacterial nonspecific acid phosphatase from salmonella enterica ser. typhimurium lt2 towards dihydroxyacetone (dha), a mutant library was generated from the native enzyme. three different variants that showed enhanced activity were identified after one round of eppcr. the single mutant v78l was the most active and showed an increase in the maximal dhap concentration to 25 % higher than that of the wild-type enzyme at ph 6.0. this variant is 17 times ...200919623595
[isolation and study of perspective probiotic strain of spore-forming bacteria from bacillus genus].to study physiologic, biochemical as well as antagonistic characteristics of isolated strain of bacillus pumilus in comparison with known spore-forming bacteria from b. subtilis species.200919623717
[etiology of acute enteric infection in children with arid zone and effect of probiotics].to study etiologic structure of acute enteric infections (aei) with isolation of hemolytic and enteropathogenic escherichia and to assess the efficacy of probiotic therapy during infections caused by e. coli.200919623719
[rapid detection of salmonella in food by using fluorescently labeled phage o-i].to develop a rapid detection method for salmonella in food by using specific salmonella-phage o-i.200919623962
mechanism of unusual formation of 3-(5-phenyl-3h-[1,2,4]dithiazol-3-yl)chromen-4-ones and 4-oxo-4h-chromene-3-carbothioic acid n-phenylamides and their antimicrobial evaluation.6/6,7-substituted 3-formylchromones (9a-e) react with 2 equivalents of 2-phenyl-4-dimethylamino-1-thia-3-azabuta-1,3-diene (10) or thiobenzamide (11) in refluxing toluene to furnish novel substituted 3-(5-phenyl-3h-[1,2,4]dithiazol-3-yl)chromen-4-ones (12a-e). however, reactions of substituted 2-anilino-3-formylchromones (15a-d) with thiobenzamide (11, 2 equivalents) in refluxing xylene furnish 4-oxo-4h-chromene-3-carbothioic acid n-phenylamide (17a-d) in high yields. a mechanistic rationalizati ...200919375826
analytical comparison of nine pcr primer sets designed to detect the presence of escherichia coli/shigella in water samples.the analytical performance of 9 different pcr primer sets designed to detect escherichia coli and shigella in water has been evaluated in terms of ubiquity, specificity, and analytical detection limit. of the 9 pcr primer sets tested, only 3 of the 5 primer sets targeting uida gene and the primer set targeting tuf gene amplified dna from all e. coli strains tested. however, of those 4 primer sets, only the primer set targeting the tuf gene also amplified dna from all shigella strains tested. for ...200919482328
differentiation of whole bacterial cells based on high-throughput microarray chip printing and infrared microspectroscopic readout.using robotic automation, a microarray printing protocol for whole bacterial cells was developed for subsequent label-free and nondestructive infrared microspectroscopic detection. using this contact microspotting system, 24 microorganisms were printed on zinc selenide slides; these were 6 species of listeria, 10 species of vibrio, 2 strains of photobacterium damselae, yersinia enterocolitica 289, bacillus cereus atcc 14529, staphylococcus aureus, atcc 19075 (serotype 104 b), shigella sonnei 201 ...200919630511
[development of single base extension-tags microarray for the detection of food-borne pathogens].we developed single base extension-tags (sbe-tags) microarray to detect eight common food-borne pathogens, including staphylococcus aureus, vibrio parahaemolyticus, listeria monocytogenes, salmonella, enterobacter sakazaki, shigella, escherichia coli o157:h7 and campylobacter jejuni. with specific pcr primers identified and integrated for eight food-borne pathogens, target sequences were amplified and purified as template dna of single base extension-tags reaction. the products were hybridized t ...200919637631
design, synthesis, and immunochemical characterization of a chimeric glycopeptide corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic mdwnmhaa.two glycopeptide chimeras corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic were designed in an attempt to improve the binding affinity by increasing the entropy of binding relative to the original octapeptide mimic of the o-polysaccharide. the design was based on the x-ray crystal structures of a monoclonal antibody sya/j6 in complex with its cognate ligands, a pentasaccharide corresponding to the s. flexneri y o-polysaccharide and the octapeptide mimic, mdwnmhaa. ...200919467535
utility of multilocus variable-number tandem-repeat analysis as a molecular tool for phylogenetic analysis of shigella sonnei.a panel of 916 isolates, including 703 closely related ist1 isolates, were characterized by inter-is1 spacer typing (ist), pulsed-field gel electrophoresis (pfge), and multilocus variable-number tandem-repeat (vntr) analysis (mlva) to evaluate the utility of mlva as a molecular tool for the phylogenetic analysis of shigella sonnei. the global phylogenetic patterns determined by ist, pfge, and mlva were concordant. mlva was carried out using 26 vntr loci with a range of degrees of variability. ml ...200919225095
rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method.to develop a new, rapid and accurate reverse dot blot (rdb) method for the detection of intestinal pathogens in fecal samples.200919469006
incidence of multiple antibiotic resistant gram-negative bacteria isolated from surface and underground water sources in south western region of nigeria.in most rural and urban settlements, particularly in nigeria, wells, spring, streams or rivers and lakes serves as major sources of water supply for drinking and other domestic purposes. unfortunately, many of the available water sources are not potable without some form of treatment which is seldom available in most settings. the use of untreated surface water sources for drinking and for domestic purposes remains a major threat to public health as these could serve as reservoirs the for transf ...200919474486
structural mimicry of o-antigen by a peptide revealed in a complex with an antibody raised against shigella flexneri serotype 2a.the use of carbohydrate-mimicking peptides to induce immune responses against surface polysaccharides of pathogenic bacteria offers a novel approach to vaccine development. factors governing antigenic and immunogenic mimicry, however, are complex and poorly understood. we have addressed this question using the anti-lipopolysaccharide monoclonal antibody f22-4, which was raised against shigella flexneri serotype 2a and shown to protect against homologous infection in a mouse model. in a previous ...200919328810
expression, purification, crystallization and preliminary x-ray diffraction analysis of the tonb-dependent haem outer membrane transporter shua from shigella dysenteriae.as part of efforts towards understanding the crystallization of membrane proteins and membrane transport across the outer membrane of gram-negative bacteria, the tonb-dependent haem outer membrane transporter shua of shigella dysenteriae bound to heavy atoms was crystallized in several crystallization conditions using detergents. the insertion of a his(6) tag into an extracellular loop of shua, instead of downstream of the escherichia coli peptide signal, allowed efficient targeting to the outer ...200919342792
comparison of acute bloody and watery diarrhea: a case control study.the clinical and laboratory findings of 290 cases of bloody diarrhea who presented to the department of diarrhea training and treatment between june 1998 and may 2002 were investigated, and compared to those of two consecutive cases who had watery diarrhea. the bloody diarrhea group had higher mean age, higher frequencies of diarrhea, lower frequencies of vomiting, and shorter durations of diarrhea at the time of admission as compared to the watery diarrhea group. the number of cases using antib ...200919480324
laboratory-acquired infections.laboratory-acquired infections due to a wide variety of bacteria, viruses, fungi, and parasites have been described. although the precise risk of infection after an exposure remains poorly defined, surveys of laboratory-acquired infections suggest that brucella species, shigella species, salmonella species, mycobacterium tuberculosis, and neisseria meningitidis are the most common causes. infections due to the bloodborne pathogens (hepatitis b virus, hepatitis c virus, and human immunodeficiency ...200919480580
reactive arthritis: clinical aspects and medical management.reactive arthritis (rea) is an inflammatory arthritis that arises after certain gastrointestinal or genitourinary infections, representing a classic interplay between host and environment. it belongs to the group of arthritidies known as the spondyloarthropathies. the classic syndrome is a triad of symptoms, including the urethra, conjunctiva, and synovium; however, the majority of patients do not present with this triad. diagnostic criteria for rea exist, but data suggest new criteria are neede ...200919480995
synthesis, characterization, and immunogenicity in mice of shigella sonnei o-specific oligosaccharide-core-protein conjugates.shigellosis, an enteric disease, is on the world health organization's priority prevention list. in one study, the shigella sonnei o-specific polysaccharide (o-sp)-protein conjugate showed 72% protection against disease in israeli army recruits exposed to high rates (8-14%) of infection. the protection was related to vaccine-induced igg anti-o-sp levels. synthetic oligosaccharides of shigella dysenteriae type 1, bound by their reducing ends to a carrier protein ("sun"-type configuration), induce ...200919346477
protein interaction platforms: visualization of interacting proteins in yeast.here we describe the protein interaction platform assay, a method for identifying interacting proteins in saccharomyces cerevisiae. this assay relies on the reovirus scaffolding protein microns, which forms large focal inclusions in living cells. when a query protein is fused to microns and potential interaction partners are fused to a fluorescent reporter, interactors can be identified by screening for yeast that display fluorescent foci.200919483691
lack of antimicrobial activity by the antiretroviral drug nevirapine against common bacterial pathogens. 200919487448
bacteria hijack integrin-linked kinase to stabilize focal adhesions and block cell detachment.the rapid turnover and exfoliation of mucosal epithelial cells provides an innate defence system against bacterial infection. nevertheless, many pathogenic bacteria, including shigella, are able to surmount exfoliation and colonize the epithelium efficiently. here we show that the shigella flexneri effector ospe (consisting of ospe1 and ospe2 proteins), which is highly conserved among enteropathogenic escherichia coli, enterohaemorrhagic e. coli, citrobacter rodentium and salmonella strains, rei ...200919489119
molecular characterisation of the reca locus in clinical isolates of verocytotoxigenic e. coli o157:h7.molecular epidemiology of verocytoxigenic escherichia coli o157:h7 is important to help elucidate reservoirs and modes of transmission, particularly between animals and humans. as the reca gene locus is now beginning to gain application in bacterial genotyping schemes, and as it has not been examined previously in e. coli o157 isolates, this study aims to examine potential polymorphic variation as a possible epidemiological marker for the subspecies characterisation of clinically significant ver ...200919348125
life on the inside: the intracellular lifestyle of cytosolic bacteria.bacterial pathogens exploit a huge range of niches within their hosts. many pathogens can invade non-phagocytic cells and survive within a membrane-bound compartment. however, only a small number of bacteria, including listeria monocytogenes, shigella flexneri, burkholderia pseudomallei, francisella tularensis and rickettsia spp., can gain access to and proliferate within the host cell cytosol. here, we discuss the mechanisms by which these cytosolic pathogens escape into the cytosol, obtain nut ...200919369949
[norovirus infection in general hospitals for adults].to determine the role of noroviruses in the rise of hospital outbreaks of acute intestinal infections (aii), to study clinical and epidemiological aspects of hospital noroviral infection.200919514424
pulsed-field gel electrophoresis for molecular epidemiology of food pathogens.foodborne diseases due to well-recognized pathogens have emerged as an important and growing public health problem with a significant impact on health. molecular methods for subtyping these microorganisms have become a valid adjunct to the traditional techniques employed in most laboratories. one such molecular technique for the detection and identification of food pathogens is pulsed-field gel electrophoresis (pfge). this method separates large dna molecules by the use of an alternating electri ...200919521867
[complete structure of the o-polysaccharide from shigella dysenteriae type 10].the structure of the o-specific polysaccharide from shigella dysenteriae type 10, which has been reported previously in bioorg. khim. (1977, vol. 3, pp. 1219-1225), was refined: [formula: see text].200919377533
design of alpha-transglucosidases of controlled specificity for programmed chemoenzymatic synthesis of antigenic oligosaccharides.combined with chemical synthesis, the use of biocatalysts holds great potential to open the way to novel molecular diversity. we report in vitro chemoenzymatic pathways that, for the first time, take advantage of enzyme engineering to produce complex microbial cell-surface oligosaccharides and circumvent the chemical boundaries of glycochemistry. glycoenzymes were designed to act on nonnatural conveniently protected substrates to produce intermediates compatible with a programmed chemical elonga ...200919432472
bulging fontanelle in febrile infants: is lumbar puncture mandatory?to determine the aetiologies and clinical characteristics of infants with fever and a bulging fontanelle.200919531528
[multiplex pcr assay for dissemination and diversity of extended-spectrum beta-lactamase genes in shigella isolates].to develop a rapid and simple multiplex polymerase chain reaction (pcr) method which discriminates extended-spectrum beta-lactamases (esbls) genes in sporadic shigella isolates from 1998 to 2007 in hangzhou city, china.200919534925
the pic protease of enteroaggregative escherichia coli promotes intestinal colonization and growth in the presence of mucin.enteroaggregative escherichia coli (eaec) is increasingly being recognized as a cause of diarrheal disease in diverse populations. no small animal model is currently available to study this pathogen. we report here that conventional mice orally inoculated with prototype eaec strain 042 generally became colonized, though the abundance of organisms cultured from their stool varied substantially among individual animals. in contrast, mice whose water contained 5 g/liter streptomycin consistently be ...200919349428
physicochemical, nutritional and antibacterial characteristics of the fruit of bromelia pinguin l.bromelia pinguin l. is a plant native to sinaloa, mexico, where its fruit is used as food or as a phytotherapeutic agent. the fruits of b. pinguin were characterized and they could be considered as a functional food. these fruits show an average weight of 13.7 g and a yellow color of high luminosity (b* = 43.2, l* = 74.5). the values for acidity (4.6%, as citric acid) and ph (3.7) of b. pinguin fruit are similar to those of citrics. the edible portion is characterized by a high content of vitami ...200919536651
antibiotic resistance among bacterial pathogens in central africa: a review of the published literature between 1955 and 2008.a systematic review of the published literature on bacterial resistance in central africa between 1955 and 2008 was performed. eighty-three publications from seven countries were retrieved, the majority presenting data on enteric and other gram-negative pathogens. despite methodological limitations in many studies, alarming resistance rates are noted in nearly all pathogens. of special concern are multidrug resistance in shigella and salmonella spp. and the emergence of meticillin-resistant stap ...200919540725
activating mutations of n-wasp alter shigella pathogenesis.the pathogenesis of shigella requires binding to the host protein n-wasp. to examine the roles of structural conformation and phospho-regulation of n-wasp during shigella pathogenesis, mutant n-wasp constructs predicted to result in a constitutively open conformation (l229p and l232p) or either a phospho-mimicking (y253e) or phospho-disruptive (y253f) structure were constructed. pyrene actin assays demonstrated that the n-wasp l229p and l232p constructs are constitutively active. despite the inc ...200919379711
altered expression of inflammatory cytokine receptors in response to lps challenge through interaction between intestinal epithelial cells and lymphocytes of peyer's patch.the intense innate immunological activities occurring at the enteric mucosal surface involve interactions between intestinal epithelial cells and immune cells. our previous studies have indicated that peyer's patch lymphocytes may modulate intestinal epithelial barrier and ion transport function in homeostasis and host defense via cell-cell contact as well as cytokine signaling. the present study was undertaken using the established co-culture system of caco-2 epithelial cells with lymphocytes o ...200919385035
three-dimensional reconstruction of the shigella t3ss transmembrane regions reveals 12-fold symmetry and novel features throughout.type iii secretion systems (t3sss) mediate bacterial protein translocation into eukaryotic cells, a process essential for virulence of many gram-negative pathogens. they are composed of a cytoplasmic secretion machinery and a base that bridges both bacterial membranes, into which a hollow, external needle is embedded. when isolated, the latter two parts are termed the 'needle complex'. an incomplete understanding of the structure of the needle complex has hampered studies of t3ss function. to es ...200919396171
evaluation of antibacterial activity, phenol and flavonoid contents of thespesia populnea flower extracts.flavonoids which were reported as having many pharmacological activities, antimicrobial, antioxidant, cytotoxic, chemoprevention activities and they possess strong antiproliferative effects related to inhibition of cell cycle progression and apoptosis induction. on the basis of this thespesia populnea (l.) sol. ex correa (family-malvaceae) was selected and it is having the major composition of flavonoids and the antibacterial activity of methanolic extract of thespesia populnea flowers was inves ...200919553175
rapidly fatal bacteremia caused by shigella sonnei without preceding gastrointestinal symptoms in an adult patient with lung cancer. 200919416029
synthesis, spectral characterization, in-vitro microbiological evaluation and cytotoxic activities of novel macrocyclic bis hydrazone.a macrocyclic hydrazone schiff base was synthesized by reacting 1,4-dicarbonyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol and a series of metal complexes with this new schiff base were synthesized by reaction with co(ii), ni(ii) and cu(ii) metal salts. the schiff base and its complexes have been characterized by elemental analyses, ir, (1)h nmr, uv-vis, fab mass, esr spectra, fluorescence, thermal, magnetic and molar conductance data. the analytical data reveal that the co(ii), ni(ii) ...200919419802
a new ethanolamine phosphate-containing variant of the o-antigen of shigella flexneri type 4a.the o-specific polysaccharide (o-antigen) structure of a shigella flexneri type 4a strain from the dysentery reference laboratory (london, uk) was elucidated in 1978 and its characteristic feature was found to be alpha-d-glucosylation of glcnac at position 6, which defines o-factor iv. our nmr spectroscopic studies of the o-specific polysaccharides of two other strains belonging to s. flexneri type 4a (g1668 from adelaide, australia, and 1359 from moscow, russia) confirmed the carbohydrate backb ...200919376498
rational design and immunogenicity of liposome-based diepitope constructs: application to synthetic oligosaccharides mimicking the shigella flexneri 2a o-antigen.we have designed chemically defined diepitope constructs consisting of liposomes displaying at their surface synthetic oligosaccharides mimicking the o-antigen of the shigella flexneri 2a lipopolysaccharide (b-cell epitope) and influenza hemagglutinin peptide ha 307-319 (th epitope). using well controlled and high-yielding covalent bioconjugation reactions, the two structurally independent epitopes were coupled to the lipopeptide pam(3)cag, i.e. a tlr2 ligand known for its adjuvant properties, a ...200919559116
unc119 protects from shigella infection by inhibiting the abl family kinases.bacteria engage cell surface receptors and intracellular signaling molecules to enter the cell. unc119 is an adaptor protein, which interacts with receptors and tyrosine kinases. its role in bacterial invasion of cells is unknown.200919381274
antimicrobial activity of endemic digitalis lamarckii ivan from turkey.antimicrobial activity of the methanolic extracts of leaves and flowers of d. lamarckii ivan, (scophulariaceae), an endemic plant species of turkey, was tested on ten bacterial and four yeast strains. effective antibacterial activity was observed in four bacterial strains. minimum inhibitory concentration (mic) was calculated by use of liquid culture tests and in all the four effective bacterial strains, the mic was found to be > or = 199.5 mg/ml. the minimum bactericidal concentration (mbc) of ...200919405389
liposomes recruit ipac to the shigella flexneri type iii secretion apparatus needle as a final step in secretion induction.shigella flexneri contact with enterocytes induces a burst of protein secretion via its type iii secretion apparatus (ttsa) as an initial step in cellular invasion. we have previously reported that ipad is positioned at the ttsa needle tip (m. espina et al., infect. immuno. 74:4391-4400, 2006). from this position, ipad senses small molecules in the environment to control the presentation of ipab to the needle tip. this step occurs without type iii secretion induction or ipac recruitment to the s ...200919433542
the rho gtpase inactivation domain in vibrio cholerae martx toxin has a circularly permuted papain-like thiol protease fold.a rho gtpase inactivation domain (rid) has been discovered in the multifunctional, autoprocessing rtx toxin rtxa from vibrio cholerae. the rid domain causes actin depolymerization and rounding of host cells through inactivation of the small rho gtpases rho, rac, and cdc42. with only a few toxin proteins containing rid domains in the current sequence database, the structure and molecular mechanisms of this domain are unknown. using comparative sequence and structural analyses, we report homology ...200919434753
listeria monocytogenes membrane trafficking and lifestyle: the exception or the rule?listeria monocytogenes is an intracellular bacterial pathogen that promotes its internalization within nonprofessional phagocytes by interacting with specific host cell receptors. l. monocytogenes resides transiently in a membrane-bound compartment before escaping into the host cell cytosol where bacterial proliferation takes place. actin-based motility then promotes cell-to-cell pathogen spread. extensive studies on cytoskeleton rearrangements, membrane trafficking, and other events have establ ...200919575658
functions and pathologies of bip and its interaction partners.the endoplasmic reticulum (er) is involved in a variety of essential and interconnected processes in human cells, including protein biogenesis, signal transduction, and calcium homeostasis. the central player in all these processes is the er-lumenal polypeptide chain binding protein bip that acts as a molecular chaperone. bip belongs to the heat shock protein 70 (hsp70) family and crucially depends on a number of interaction partners, including co-chaperones, nucleotide exchange factors, and sig ...200919151922
overexpression, purification, characterization and preliminary crystallographic study of phosphoglycolate phosphatase from shigella flexneri 2a strain 301.phosphoglycolate phosphatase has a salvage function in the metabolism of the 2-phosphoglycolate formed during bacterial dna repair. in order to better understand its dimerization behaviour, the influence of metal ions on its activity and its catalytic mechanism at the molecular level, recombinant phosphoglycolate phosphatase from shigella flexneri was overexpressed, purified, characterized and crystallized by the hanging-drop vapour-diffusion method at 291 k using polyethylene glycol 3500 as a p ...200919153451
foodborne outbreaks, austria 2007.in 2007 austria reported a total of 438 foodborne outbreaks affecting 1715 people, including 286 hospitalized patients and one death. salmonella spp. and campylobacter spp. accounted for 95% of all reported outbreaks. forty-eight (11%) of the 438 austrian outbreaks were acquired abroad. of the 390 domestically acquired foodborne outbreaks, bacterial infection caused 376, viruses (norovirus and 1-time hepatitis a virus) caused 11, and intoxications (staphylococcus aureus enterotoxins, alkaloid to ...200919280130
organised genome dynamics in the escherichia coli species results in highly diverse adaptive paths.the escherichia coli species represents one of the best-studied model organisms, but also encompasses a variety of commensal and pathogenic strains that diversify by high rates of genetic change. we uniformly (re-) annotated the genomes of 20 commensal and pathogenic e. coli strains and one strain of e. fergusonii (the closest e. coli related species), including seven that we sequenced to completion. within the approximately 18,000 families of orthologous genes, we found approximately 2,000 comm ...200919165319
tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children.the aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (rei) caused by bacteria, specifically campylobacter, salmonella, escherichia coli o157, or shigella (rei-b).200919281302
the ipac carboxyterminal effector domain mediates src-dependent actin polymerization during shigella invasion of epithelial cells.shigella, the causative agent of bacillary dysentery, invades epithelial cells by locally reorganizing the actin cytoskeleton. shigella invasion requires actin polymerization dependent on the src tyrosine kinase and a functional bacterial type iii secretion (t3s) apparatus. using dynamic as well as immunofluorescence microscopy, we show that the t3s translocon component ipac allows the recruitment of the src kinase required for actin polymerization at bacterial entry sites during the initial sta ...200919165331
rapid emergence of third generation cephalosporin resistant shigella spp. in southern vietnam. 200919141753
survey of bacterial populations present in us-produced linerboard with high recycle content.to survey paperboard products from 17 us mills for bacterial populations and for bacteria potentially harmful to human health.201019645765
phenotypic and genotypic characterization of shigella spp. with reference to its virulence genes and antibiogram analysis from river narmada.water samples of the river narmada from origin to end were analyzed for the presence of shigellae. analysis of 40 water samples by biotyping, serotyping, and molecular typing were done. out of all 40 isolates, 23 were identified as shigella flexneri, 10 as shigella sonnei, and seven as shigella dysenteriae. serotyping was found to be a better identification method than biotyping since biotyping was not found to be very sharp. in the present investigation, amplified ribosomal dna restriction anal ...201019501495
evaluation of isolation methods for pathogenic yersinia enterocolitica from pig intestinal content.the aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic yersinia enterocolitica from pig intestinal content.201019735331
lactobacilli inhibit shigella dysenteriae 1 induced pro-inflammatory response and cytotoxicity in host cells via impediment of shigella-host interactions.shigella dysenteriae type 1 dysentery is a major cause of morbidity and mortality in children from less developed and developing countries. the present study explores the hypothesis that lactobacilli protect the host cell during s. dysenteriae type 1 infection and its mechanism of action.201019535308
diarrhea in children less than two years of age with known hiv status in kisumu, kenya.to compare the frequency and etiology of diarrhea in children aged less than 2 years with known hiv status.201019664950
differential expression of enteric neuroimmune-network in invasive and acute watery diarrhoea.we aimed to evaluate the changes of nerve morphology and distribution of neurotransmitters and neuropeptides in the rectum of shigella flexneri-infected patients and in the duodenum of vibrio cholerae o1-infected patients. nerve morphology was observed by transmission electron microscopy. immunoreactivity of nerve growth factor (ngf), neurotransmitters and neuropeptides in tissues were studied by immunohistochemistry. ultrastructural analysis of intestinal biopsy revealed persisting axons degene ...201019650770
immunomodulation using genetically engineered bacteria for type iii-mediated delivery of heterologous antigens and cytokines: potential application in vaccine and therapeutical developments.the rational design of new approaches aiming to improve antigen or drug delivery remains a major challenge in numerous vaccine and therapeutical strategies. studies on genetically engineered bacteria have led to significant progress in the delivery of heterologous proteins. yet, the efficiency of such recombinant bacteria relies particularly on their ability to deliver sufficient amount of the drug to intended cell tissues. gram-negative bacteria like salmonella, shigella, yersinia and pseudomon ...201019778176
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