Publications

case of shigella flexneri infection with treatment failure due to azithromycin resistance in an hiv-positive patient.		2014	24488332
the vps/vacj abc transporter is required for intercellular spread of shigella flexneri.	the vps/vacj abc transporter system is proposed to function in maintaining the lipid asymmetry of the outer membrane. mutations in vps or vacj in shigella flexneri resulted in increased sensitivity to lysis by the detergent sodium dodecyl sulfate (sds), and the vpsc mutant showed minor differences in its phospholipid profile compared to the wild type. vpsc mutants were unable to form plaques in cultured epithelial cells, but this was not due to a failure to invade, to replicate intracellularly, ...	2014	24478081
eata, an immunogenic protective antigen of enterotoxigenic escherichia coli, degrades intestinal mucin.	enterotoxigenic escherichia coli (etec) is a major cause of morbidity and mortality due to infectious diarrhea in developing countries for which there is presently no effective vaccine. a central challenge in etec vaccinology has been the identification of conserved surface antigens to formulate a broadly protective vaccine. here, we demonstrate that eata, an immunogenic secreted serine protease of etec, contributes to virulence by degrading muc2, the major protein present in the small intestina ...	2013	24478066
a gene knock-in method used to purify plasmid pspi12 from salmonella enterica serovar pullorum and characterization of ipaj.	a small plasmid with 4080 bp long, designated pspi12, was purified from salmonella enterica serovar pullorum using a gene knock-in method by inserting a kanamycin resistance cassette in the plasmid. the g+c content of the plasmid was 51.8%, which is in the range of salmonella genomic dna. a sequence analysis revealed that pspi12 had 99.1% homology to psfd10, which was first reported in the vaccine strain s. enterica serovar chloreaesuis c500, but not prevalent among other strains of s. chloreaes ...	2014	24468333
age-dependent association among helicobacter pylori infection, serum pepsinogen levels and immune response of children to live oral cholera vaccine cvd 103-hgr.	through its effects on gastric secretion, we hypothesized that helicobacter pylori infection may influence oral immunization. accordingly, we examined the association between h. pylori infection, serum pepsinogen (pg) (measures for h. pylori gastritis) and vibriocidal antibody (a correlate of protection) seroconversion following oral immunization with cvd 103-hgr live cholera vaccine among children of different ages.	2014	24454714
a substrate-fusion protein is trapped inside the type iii secretion system channel in shigella flexneri.	the type iii secretion system (t3ss) is a macromolecular complex used by gram-negative bacteria to secrete effector proteins from the cytoplasm across the bacterial envelope in a single step. for many pathogens, the t3ss is an essential virulence factor that enables the bacteria to interact with and manipulate their respective host. a characteristic structural feature of the t3ss is the needle complex (nc). the nc resembles a syringe with a basal body spanning both bacterial membranes and a long ...	2014	24453973
electron tomography and simulation of baculovirus actin comet tails support a tethered filament model of pathogen propulsion.	several pathogens induce propulsive actin comet tails in cells they invade to disseminate their infection. they achieve this by recruiting factors for actin nucleation, the arp2/3 complex, and polymerization regulators from the host cytoplasm. owing to limited information on the structural organization of actin comets and in particular the spatial arrangement of filaments engaged in propulsion, the underlying mechanism of pathogen movement is currently speculative and controversial. using electr ...	2014	24453943
intradermal delivery of shigella ipab and ipad type iii secretion proteins: kinetics of cell recruitment and antigen uptake, mucosal and systemic immunity, and protection across serotypes.	shigella is one of the leading pathogens contributing to the vast pediatric diarrheal disease burden in low-income countries. no licensed vaccine is available, and the existing candidates are only partially effective and serotype specific. shigella type iii secretion system proteins ipab and ipad, which are conserved across shigella spp., are candidates for a broadly protective, subunit-based vaccine. in this study, we investigated the immunogenicity and protective efficacy of ipab and ipad admi ...	2014	24453241
genomic portrait of the evolution and epidemic spread of a recently emerged multidrug-resistant shigella flexneri clone in china.	shigella flexneri is the major cause of shigellosis in developing countries. a new s. flexneri serotype, xv, appeared in 2000 and replaced serotype 2a as the most prevalent serotype in china. serotype xv is a variant of serotype x, with phosphoethanolamine modification of its o antigen mediated by a plasmid that contained the opt gene. serotype xv isolates belong to sequence type 91 (st91). in this study, whole-genome sequencing of 59 s. flexneri isolates of 14 serotypes (serotypes 1 to 4, y, yv ...	2014	24452172
relationship between o-antigen chain length and resistance to colicin e2 in shigella flexneri.	the shigella flexneri polysaccharide co-polymerase class 1a (pcp1a) protein, wzzbsf, regulates lps o-antigen (oag) chain length to confer short (s)-type oag chains of ~10-17 oag repeat units (rus). the s-type oag chains affect shigella flexneri virulence as they influence icsa-mediated actin-based motility. however, they do not confer resistance to complement; this is conferred by the very-long (vl)-type oag chains determined by wzzb(phs2). colicins are bacterial proteins produced by some escher ...	2014	24425769
inhibited growth of common enteropathogenic bacteria in lactic-fermented cereal gruels.	a natural lactic fermentation of mixtures of water and whole flour of either maize or high-tannin sorghum was obtained either before or after cooking to a weaning gruel: the preparations had a final ph of about 3.8 (range 3.67 to 4.00) and a ratio of lactic acid to acetic acid of 9∶1 (w/w). the growth of added (about 10(7) c.f.u./g gruel) gram-negative intestinal pathogenic bacteria, enterotoxigenicescherichia coli, campylobacter jejuni, shigella flexneri andsalmonella typhimurium, was strongly ...	1992	24425608
ph and acidity in lactic-fermenting cereal gruels: effects on viability of enteropathogenic microorganisms.	survival of bacillus cereus, campylobacter jejuni, enterotoxigenic escherichia coli, salmonella typhimurium and shigella flexneri during lactic acid fermentation of cereal gruels prepared from low-tannin (white) and high-tannin (red) sorghum varieties was studied. a previously fermented gruel (starter culture, sc) recycled daily or stored for 7, 14 or 28 days, germinated cereal flour (power flour, pf), or a combination of pf and sc (pf+sc) were used as starters. at 24 h, the ph of all gruels wit ...	1994	24421191
plasmid-mediated sulfamethoxazole resistance encoded by the sul2 gene in the multidrug-resistant shigella flexneri 2a isolated from patients with acute diarrhea in dhaka, bangladesh.	in this study, mechanisms of plasmid-mediated sulfamethoxazole resistances in the clinical strains of multi-drug resistant (mdr) shigella flexneri 2a were elucidated for the first time in bangladesh. from 2006 to 2011, a total of 200 s. flexneri 2a strains were randomly selected from the stock of the enteric and food microbiology laboratory of icddr,b. antimicrobial susceptibility of the strains showed 73%, 98%, 93%, 58%, 98%, 64% and 4% resistance to trimethoprim-sulfamethoxazole, nalidixic aci ...	2014	24416393
effect of wild-type shigella species and attenuated shigella vaccine candidates on small intestinal barrier function, antigen trafficking, and cytokine release.	bacterial dysentery due to shigella species is a major cause of morbidity and mortality worldwide. the pathogenesis of shigella is based on the bacteria's ability to invade and replicate within the colonic epithelium, resulting in severe intestinal inflammatory response and epithelial destruction. although the mechanisms of pathogenesis of shigella in the colon have been extensively studied, little is known on the effect of wild-type shigella on the small intestine and the role of the host respo ...	2014	24416363
development and preclinical evaluation of a trivalent, formalin-inactivated shigella whole-cell vaccine.	studies were undertaken to manufacture a multivalent shigella inactivated whole-cell vaccine that is safe, effective, and inexpensive. by using several formalin concentrations, temperatures, and incubation periods, an optimized set of inactivation conditions was established for shigella flexneri 2a, s. sonnei, and s. flexneri 3a to produce inactivated whole cells expressing a full repertoire of ipa proteins and lipopolysaccharide (lps). the inactivation conditions selected were treatment with 0. ...	2014	24403527
dissemination and serotype modification potential of psfxv_2, an o-antigen petn modification plasmid in shigella flexneri.	the o-antigens of all shigella flexneri serotypes, except serotype 6, share a linear tetrasaccharide repeat composed of one n-acetylglucosamine and three l-rhamnose residues, and differences between the serotypes are due to modification of various monosaccharide residues with glucosyl and/or o-acetyl and/or phosphoethanolamine (petn) groups. plasmid-borne opt (formerly lpt-o) gene encoding a petn transferase which modifies the o-antigens of s. flexneri serotype x, 4a and y strains and converts t ...	2014	24379081
cgtase-catalysed cis-glucosylation of l-rhamnosides for the preparation of shigella flexneri 2a and 3a haptens.	we report the enzymatic synthesis of α-d-glucopyranosyl-(1→4)-α-l-rhamnopyranoside and α-d-glucopyranosyl-(1→3)-α-l-rhamnopyranoside by using a wild-type transglucosidase in combination with glucoamylase and glucose oxidase. it was shown that bacillus circulans 251 cyclodextrin glucanotransferase (cgtase, ec 2.1.4.19) can efficiently couple an α-l-rhamnosyl acceptor to a maltodextrin molecule with an α-(1→4) linkage, albeit in mixture with the α-(1→3) regioisomer, thus giving two glucosylated ac ...	2014	24376024
impact of dynasore an inhibitor of dynamin ii on shigella flexneri infection.	shigella flexneri remains a significant human pathogen due to high morbidity among children < 5 years in developing countries. one of the key features of shigella infection is the ability of the bacterium to initiate actin tail polymerisation to disseminate into neighbouring cells. dynamin ii is associated with the old pole of the bacteria that is associated with f-actin tail formation. dynamin ii inhibition with dynasore as well as sirna knockdown significantly reduced shigella cell to cell spr ...	2013	24367704
a shigella effector dampens inflammation by regulating epithelial release of danger signal atp through production of the lipid mediator ptdins5p.	upon infection with shigella flexneri, epithelial cells release atp through connexin hemichannels. however, the pathophysiological consequence and the regulation of this process are unclear. here we showed that in intestinal epithelial cell atp release was an early alert response to infection with enteric pathogens that eventually promoted inflammation of the gut. shigella evolved to escape this inflammatory reaction by its type iii secretion effector ipgd, which blocked hemichannels via the pro ...	2013	24332032
temperature-regulated expression of outer membrane proteins in shigella flexneri.	bacteria exist widely in a diversity of natural environments. in order to survive adverse conditions such as nutrient depletion, biochemical and biological disturbances, and high temperature, bacteria have developed a wide variety of coping mechanisms. temperature is one of the most important factors that can enhance the expression of microbial proteins. this study was conducted to investigate how outer membrane proteins (omps) of the bacterium shigella flexneri respond to stress, especially dur ...	2013	24330657
subversion of inflammasome activation and pyroptosis by pathogenic bacteria.	activation of the inflammasome occurs in response to a notably high number of pathogenic microbes and is a broad innate immune response that effectively contributes to restriction of pathogen replication and generation of adaptive immunity. activation of these platforms leads to caspase-1- and/or caspase-11-dependent secretion of proteins, including cytokines, and induction of a specific form of cell death called pyroptosis, which directly or indirectly contribute for restriction of pathogen rep ...	2013	24324933
characterization of extended-spectrum beta-lactamase-producing clinical isolates of shigella flexneri.		2013	24288956
[o-antigen modification and serotype conversion of shigella flexneri].		2013	24257184
the host and the flora.	to prevent bacterial overgrowth, colonization of the epithelium and subsequent translocation, the gastrointestinal tract maintains an effective mucosal barrier. besides mucus the most important components of this protective system are epithelial antimicrobial peptides such as defensins, the cathelicidin ll-37, lysozyme, phospholipase a, and proteins with additional antimicrobial properties such as ubiquicidin, ribosomal proteins or histones. commensal species may tolerate intestinal antimicrobia ...	2013	24246976
isolation and molecular characterization of salmonella enterica, escherichia coli o157:h7 and shigella spp. from meat and dairy products in egypt.	foodborne pathogens are a major threat to food safety, especially in developing countries where hygiene and sanitation facilities are often poor. salmonella enterica, escherichia coli o157:h7 and shigella spp. are among the major causes of outbreaks of foodborne diseases. this large-scale study investigated the prevalence of these foodborne pathogens in meat (beef and chicken) and dairy products collected from street vendors, butchers, retail markets and slaughterhouses in egypt. a total of 1600 ...	2014	24239976
n-terminus of ipab provides a potential anchor to the shigella type iii secretion system tip complex protein ipad.	the type iii secretion system (t3ss) is an essential virulence factor for shigella flexneri , providing a conduit through which host-altering effectors are injected directly into a host cell to promote uptake. the type iii secretion apparatus (t3sa) is composed of a basal body, external needle, and regulatory tip complex. the nascent needle is a polymer of mxih capped by a pentamer of invasion plasmid antigen d (ipad). exposure to bile salts (e.g., deoxycholate) causes a conformational change in ...	2013	24236510
transposition of isecp1 modulates blactx-m-55-mediated shigella flexneri resistance to cefalothin.	the aim of this study was to uncover the mechanisms underlying shigella flexneri resistance to cefalothin. in this study, a resistance-related s. flexneri isolate, s. flexneri ydc, was obtained from s. flexneri mel-1998023/zz pre-incubated with cefalothin at a dose of 0.5 × the minimum inhibitory concentration. the isecp1 coding element was identified upstream of bla(ctx-m-55) in s. flexneri ydc. to further determine the role of isecp1 in s. flexneri resistance, plasmids containing bla(ctx-m-55) ...	2013	24207017
a creb3-arf4 signalling pathway mediates the response to golgi stress and susceptibility to pathogens.	treatment of cells with brefeldin a (bfa) blocks secretory vesicle transport and causes a collapse of the golgi apparatus. to gain more insight into the cellular mechanisms mediating bfa toxicity, we conducted a genome-wide haploid genetic screen that led to the identification of the small g protein adp-ribosylation factor 4 (arf4). arf4 depletion preserves viability, golgi integrity and cargo trafficking in the presence of bfa, and these effects depend on the guanine nucleotide exchange factor ...	2013	24185178
intracellular shigella remodels its lps to dampen the innate immune recognition and evade inflammasome activation.	lps is a potent bacterial effector triggering the activation of the innate immune system following binding with the complex cd14, myeloid differentiation protein 2, and toll-like receptor 4. the lps of the enteropathogen shigella flexneri is a hexa-acylated isoform possessing an optimal inflammatory activity. symptoms of shigellosis are produced by severe inflammation caused by the invasion process of shigella in colonic and rectal mucosa. here we addressed the question of the role played by the ...	2013	24167293
epidemiological characteristics of imported shigellosis in korea, 2010-2011.	shigellosis is a global disease as food poisoning by infection of shigella spp (s. dysenteriae, s. flexneri, s. boydii and s. sonnei). in korea, approximately 500 cases of shigellosis have reported every year since 2004, and imported shigellosis is increasing gradually from 2006 in particular. according to increase of numbers of overseas travelers, the numbers of patients diseased with imported shigellosis is also increasing. we need continuous surveillance studies network (ssn) for control of i ...	2013	24159548
enhanced type iii secretion system expression of atypical shigella flexneri ii:(3)4,7(8).	we aimed at evaluating the virulence of atypical shigella flexneri ii:(3)4,7(8) by dna microarray and invasion assay.	2012	24159518
a contribution of mdfa to resistance to fluoroquinolones in shigella flexneri.	in this study, we measured the drug resistance conferred by mdfa mutations in two shigella flexneri strains. a mutant in mdfa genes was constructed by polymerase chain reaction-based, one-step inactivation of chromosomal genes. the antimicrobial susceptibility of parent and mutant strains to fluoroquinolones was determined by minimal inhibitory concentration (mics). the △mdfa mutants were somewhat more susceptible to fluoroquinolones than the parent strains. the low level changes in mics of the ...	2011	24159476
mait cells detect and efficiently lyse bacterially-infected epithelial cells.	mucosal associated invariant t cells (mait) are innate t lymphocytes that detect a large variety of bacteria and yeasts. this recognition depends on the detection of microbial compounds presented by the evolutionarily conserved major-histocompatibility-complex (mhc) class i molecule, mr1. here we show that mait cells display cytotoxic activity towards mr1 overexpressing non-hematopoietic cells cocultured with bacteria. the nk receptor, cd161, highly expressed by mait cells, modulated the cytokin ...	2013	24130485
spa13 of shigella flexneri has a dual role: chaperone escort and export gate-activator switch of the type iii secretion system.	the type iii secretion apparatus (t3sa) is used by numerous gram-negative pathogens to inject virulence factors into eukaryotic cells. the shigella flexneri t3sa spans the bacterial envelope and its assembly requires the products of ~20 mxi and spa genes. despite progress made in understanding how the t3sa is assembled, the role of several predicted soluble components, such as spa13, remains elusive. here, we show that the secretion defect of the spa13 mutant is associated with lack of t3sa asse ...	2014	24126350
an alternative outer membrane secretion mechanism for an autotransporter protein lacking a c-terminal stable core.	autotransporter (at) proteins are a broad class of virulence factors from gram-negative pathogens. at outer membrane (om) secretion appears simple in many regards, yet the mechanism that enables transport of the central at 'passenger' across the om remains unclear. om secretion efficiency for two at passengers is enhanced by approximately 20 kda stable core at the c-terminus of the passenger, but studies on a broader range of at proteins are needed in order to determine whether a stability diffe ...	2013	24118465
analysis of the proteome of intracellular shigella flexneri reveals pathways important for intracellular growth.	global proteomic analysis was performed with shigella flexneri strain 2457t in association with three distinct growth environments: s. flexneri growing in broth (in vitro), s. flexneri growing within epithelial cell cytoplasm (intracellular), and s. flexneri that were cultured with, but did not invade, henle cells (extracellular). compared to in vitro and extracellular bacteria, intracellular bacteria had increased levels of proteins required for invasion and cell-to-cell spread, including ipa, ...	2013	24101689
[ctx-m-type extended-spectrum β-lactamase in shigella flexneri isolates from pediatric patients with acute diarrhea].		2013	24100837
isolation, characterization and comparative genomics of bacteriophage sfiv: a novel serotype converting phage from shigella flexneri.	shigella flexneri is the major cause of shigellosis in the developing countries. the o-antigen component of the lipopolysaccharide is one of the key virulence determinants required for the pathogenesis of s. flexneri. the glucosyltransferase and/or acetyltransferase genes responsible for the modification of the o-antigen are encoded by temperate serotype converting bacteriophage present in the s. flexneri genome. several serotype converting phages have previously been isolated and characterized, ...	2013	24090466
role of porin proteins in acquisition of transferrin iron by enteropathogens.	acquisition of iron from key innate immune defence proteins such as transferrin (tf) and lactoferrin is an important mechanism by which pathogenic bacteria obtain essential iron for growth within their host. bacterial species that do not produce siderophores often use specific tf-binding proteins, the best characterized being the neisseriaceae-type tf-binding proteins tbpa and tbpb. previous work from our laboratory has shown that siderophore-producing enteric species such as escherichia coli al ...	2013	24089578
production of microbial medium from defatted brebra (milletia ferruginea) seed flour to substitute commercial peptone agar.	to investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.	2013	24075344
impact of reclaimed water irrigation on antibiotic resistance in public parks, beijing, china.	the abundance and distribution of antibiotics and antibiotic resistance genes (args) in soils from six parks using reclaimed water in beijing, china, were characterized. three classes of commonly used antibiotics (tetracycles, quinolones, and sulfonamides) were analyzed by liquid chromatography-tandem mass spectrometry (lc-ms/ms). the highest concentrations of tetracyclines and quinolones were 145.2 μg kg(-1) and 79.2 μg kg(-1), respectively. detected tetg, tetw, suli, and sulii genes were quant ...	2014	24071635
synthesis of some novel bis[1, 2, 4]triazolo[3, 4-b][1, 3, 4]thiadiazine derivatives for antimicrobial evaluation.	a new series of novel bis[1, 2, 4]triazolo[3, 4-b][1, 3, 4]thiadiazines 7a-j has been synthesized by the reaction of [5, 5'-methylenebis(3-methylbenzofuran-7, 5-diyl)]bis[(4-amino-5-thioxo-4, 5-dihydro-1h-1, 2, 4-triazol-3-yl)methanone] (6) with a variety of phenacyl bromides in ethanol under reflux for 6 h. all the newly synthesized compounds were tested for in vitro activity against certain strains of bacteria such as escherichia coli, klebsiella pneumoniae, shigella dysenteriae and shigella f ...	2011	24062120
characterization of a novel fusion protein from ipab and ipad of shigella spp. and its potential as a pan-shigella vaccine.	shigellosis is an important disease in the developing world, where about 90 million people become infected with shigella spp. each year. we previously demonstrated that the type three secretion apparatus (t3sa) proteins ipab and ipad are protective antigens in the mouse lethal pulmonary model. in order to simplify vaccine formulation and process development, we have evaluated a vaccine design that incorporates both of these previously tested shigella antigens into a single polypeptide chain. to ...	2013	24060976
isolation and characterization of antimicrobial constituents of searsia chirindensis l. (anacardiaceae) leaf extracts.	searsia chirindensis is used in south african traditional medicine for management of bacterial infections such as diarrhoea. aim of the study was to examine the phytochemical composition from the leaves of searsia chirindensis that is responsible for the ethnomedicinal use of this plant.	2013	24060408
shigella flexneri enteritis in risk-taking hiv-infected msm.		2014	24055803
combination of extracts from aristolochia cymbifera with streptomycin as a potential antibacterial drug.	the appearance of new antibiotic-resistant bacteria is a societal problem that requires the development of new alternative treatments. therefore, this work evaluated the antibacterial activity of ethanolic (ehi), dichloromethanic (edi) and hexanic (ehe) extracts from aristolochia cymbifera stems and the combination of these extracts with an antimicrobial drug to develop a new antibacterial therapy. the edi, ehe and ehi extracts were obtained by maceration using three different solvents. the mini ...	2013	24040585
the zebrafish as a new model for the in vivo study of shigella flexneri interaction with phagocytes and bacterial autophagy.	autophagy, an ancient and highly conserved intracellular degradation process, is viewed as a critical component of innate immunity because of its ability to deliver cytosolic bacteria to the lysosome. however, the role of bacterial autophagy in vivo remains poorly understood. the zebrafish (danio rerio) has emerged as a vertebrate model for the study of infections because it is optically accessible at the larval stages when the innate immune system is already functional. here, we have characteri ...	2013	24039575
hypoxic stress, hepatocytes and caco-2 viability and susceptibility to shigella flexneri invasion.	inflammation due to shigella flexneri can cause damage to the colonic mucosa and cell death by necrosis and apoptosis. this bacteria can reach the bloodstream in this way, and the liver through portal veins. hypoxia is a condition present in many human diseases, and it may induce bacterial translocation from intestinal lumen. we studied the ability of s. flexneri to invade rat hepatocytes and caco-2 cells both in normoxic and hypoxic microenvironments, as well as morphological and physiological ...	2015	24037289
protective immunity by oral immunization with heat-killed shigella strains in a guinea pig colitis model.	the protective efficacy of and immune response to heat-killed cells of monovalent and hexavalent mixtures of six serogroups/serotypes of shigella strains (shigella dysenteriae 1, shigella flexneri 2a, s. flexneri 3a, s. flexneri 6, shigella boydii 4, and shigella sonnei) were examined in a guinea pig colitis model. a monovalent or hexavalent mixture containing 1 × 10(7) of each serogroup/serotype of heat-killed shigella cells was administered orally on days 0, 7, 14 and 21. on day 28, the immuni ...	2013	24033533
detection of shigella in lettuce by the use of a rapid molecular assay with increased sensitivity.	a multiplex polymerase chain reaction (pcr) assay to be used as an alternative to the conventional culture method in detecting shigella and enteroinvasive escherichia coli (eiec) virulence genes ipah and ial in lettuce was developed. efficacy and rapidity of the molecular method were determined as compared to the conventional culture. lettuce samples were inoculated with different shigella flexneri concentrations (from 10 cfu/ml to 10(7) cfu/ml). dna was extracted directly from lettuce after ino ...	2010	24031579
proinflammatory signal transduction pathway induced by shigella flexneri porins in caco-2 cells.	the recognition of bacterial components on the intestinal epithelial cells occurs through the toll-like receptors and is followed by the induction of an effective innate immune response. we analyzed receptor expression and signaling pathways involved in activation of human colon adenocarcinoma cells after stimulation with porins and lps of shigella flexneri. we also analyzed the expression and production of some cytokines, of intercellular adhesion molecule-1, of antimicrobial peptides human β-d ...	2009	24031417
molecular epidemiology of shigella spp strains isolated in two different metropolitam areas of southeast brazil.	shigella spp., the human pathogen responsible for shigellosis, is highly infectious even at low levels. the incidence rate of shigellosis varies with geographical distribution, location human development index, and age groups, being higher among children aged under 5 years. in brazil, a few works indicate that shigellosis cases are underestimated, with s. flexneri and s. sonnei strains being the major agents responsible for the shigellosis cases. the present study used pulsed field gel electroph ...	2009	24031415
complete genome sequence of sfii, a serotype-converting bacteriophage of the highly prevalent shigella flexneri serotype 2a.	sfii is a serotype-converting temperate bacteriophage of the highly prevalent shigella flexneri serotype 2a. we isolated the sfii phage from a wild-type strain of s. flexneri serotype 2a. here, we present the complete genome sequence of this phage.	2013	24029753
characterization and complete genome sequence of the shigella bacteriophage psf-1.	shigellosis is a global health problem, and shigella flexneri is the major cause of this disease. in this study, we isolated a virulent siphoviridae bacteriophage (phage), psf-1, that infects s. flexneri. this phage was isolated from the han river in korea and was found to infect s. flexneri, shigella boydii, and shigella sonnei. one-step growth analysis revealed that this phage has a short latent period (10 min) and a large burst size (86.86 pfu/cell), indicating that psf-1 has good host infect ...	2013	24012542
small-molecule inhibitor of the shigella flexneri master virulence regulator virf.	virf is an arac family transcriptional activator that is required for the expression of virulence genes associated with invasion and cell-to-cell spread by shigella flexneri, including multiple components of the type three secretion system (t3ss) machinery and effectors. we tested a small-molecule compound, se-1 (formerly designated ossl_051168), which we had identified as an effective inhibitor of the arac family proteins rhas and rhar, for its ability to inhibit virf. cell-based reporter gene ...	2013	24002059
analysis of different prognostic indicators for malnutrition and shigella flexneri infection among the children in bangladesh.	the present study investigates into some socio-economic, demographic, and nutritional features that can predispose bangladeshi children to malnutrition and shigella flexneri infection. significant prognostic indicators associated with malnutrition were mother's illiteracy (unadjusted odds ratio, or = 2.580; 95% confidence interval, ci = 1.134-5.867 and adjusted odds ratio, ora, 3.814; 95% ci = 1.124-12.943), low birth weight (or = 3.143; 95% ci = 1.2-8.232 and ora = 2.404; 95% ci = 0.870-6.644) ...	2012	23997331
structural insights into virb-dna complexes reveal mechanism of transcriptional activation of virulence genes.	virb activates transcription of virulence genes in shigella flexneri by alleviating heat-stable nucleoid-structuring protein-mediated promoter repression. virb is unrelated to the conventional transcriptional regulators, but homologous to the plasmid partitioning proteins. we determined the crystal structures of virb hth domain bound by the cis-acting site containing the inverted repeat, revealing that the virb-dna complex is related to parb-pars-like complexes, presenting an example that a parb ...	2013	23985969
o-antigen protects gram-negative bacteria from histone killing.	beyond their traditional role of wrapping dna, histones display antibacterial activity to gram-negative and -positive bacteria. to identify bacterial components that allow survival to a histone challenge, we selected resistant bacteria from homologous escherichia coli libraries that harbor plasmids carrying pieces of the chromosome in different sizes. we identified genes required for exopolysaccharide production and for the synthesis of the polysaccharide domain of the lipopolysaccharide, called ...	2013	23951089
shigella flexneri 3a outer membrane protein c epitope is recognized by human umbilical cord sera and associated with protective activity.	shigella flexneri 3a is one of the five major strains of the shigella genus responsible for dysentery, especially among children, in regions of high poverty and poor sanitation. the outer membrane proteins (omp) of this bacterium elicit immunological responses and are considered a prime target for vaccine development. when injected into mice they elicit a protective immunological response against a lethal dose of the pathogen. the omps from s. flexneri 3a were isolated and resolved by two-dimens ...	2013	23940590
human naip and mouse naip1 recognize bacterial type iii secretion needle protein for inflammasome activation.	inflammasome mediated by central nucleotide-binding and oligomerization domain (nod)-like receptor (nlr) protein is critical for defense against bacterial infection. here we show that type iii secretion system (t3ss) needle proteins from several bacterial pathogens, including salmonella typhimurium, enterohemorrhagic escherichia coli, shigella flexneri, and burkholderia spp., can induce robust inflammasome activation in both human monocyte-derived and mouse bone marrow macrophages. needle protei ...	2013	23940371
lps unmasking of shigella flexneri reveals preferential localisation of tagged outer membrane protease icsp to septa and new poles.	the shigella flexneri outer membrane (om) protease icsp (sopa) is a member of the enterobacterial omptin family of proteases which cleaves the polarly localised om protein icsa that is essential for shigella virulence. unlike icsa however, the specific localisation of icsp on the cell surface is unknown. to determine the distribution of icsp, a haemagglutinin (ha) epitope was inserted into the non-essential icsp om loop 5 using splicing by overlap extension (soe) pcr, and icsp(ha) was characteri ...	2013	23936222
identification and characterization of a novel shigella flexneri serotype yv in china.	shigella flexneri is the major cause of bacterial shigellosis in developing countries. s. flexneri is divided into at least 19 serotypes, the majority of which are modifications of the same basic o-antigen by glucosylation and/or o-acetylation of its sugar residues by phage encoded serotype-converting genes. recently, a plasmid encoded phosphoethanolamine (petn) modification of the o-antigen has been reported, which is responsible for the presence of the masf iv-1 determinant and results in conv ...	2013	23936172
modulators of antibiotic activity from ipomoea murucoides.	reinvestigation of the chcl3-soluble extract from the flowers of ipomoea murucoides, through preparative-scale recycling hplc, yielded three pentasaccharides of 11-hydroxyhexadecanoic acid, murucoidins xvii-xix, in addition to the known murucoidin iii and v, all of which were characterized by nmr spectroscopy and mass spectrometry. these compounds were found to be macrolactones of the known pentasaccharides simonic acid b and operculinic acid a. the acylating groups corresponded to acetic, (2s)- ...	2013	23920226
metal-based carboxamide-derived compounds endowed with antibacterial and antifungal activity.	a series of three bioactive thiourea (carboxamide) derivatives, n-(dipropylcarbamothioyl)-thiophene-2-carboxamide (l(1)), n-(dipropylcarbamothioyl)-5-methylthiophene-2-carboxamide (l(2)) and 5-bromo-n-(dipropylcarbamothioyl)furan-2-carboxamide (l(3)) and their cobalt(ii), copper(ii), nickel(ii) and zinc(ii) complexes (1)-(12) have been synthesized and characterized by their ir,(1)h-nmr spectroscopy, mass spectrometry and elemental analysis data. the crystal structure of one of the ligand, n-(dip ...	2014	23914928
oxalis corniculata (oxalidaceae) leaf extract exerts in vitro antimicrobial and in vivo anticolonizing activities against shigella dysenteriae 1 (nt4907) and shigella flexneri 2a (2457t) in induced diarrhea in suckling mice.	in this study, the extract of a green leafy vegetable oxalis corniculata (oxalidaceae) was evaluated for its in vitro antibacterial and in vivo anti colonizing effect against common intestinal pathogenic bacteria. methanolic extract (80%) of oxalis corniculata (oxalidaceae) leaf contained a polyphenol content of 910 mg gallic acid equivalent per gram of dry weight and the yield was 8%. the flavonoid content was 2.353 g quercetin equivalent per 100 g of the extract. in vitro studies indicated tha ...	2013	23909903
in situ structural analysis of the yersinia enterocolitica injectisome.	injectisomes are multi-protein transmembrane machines allowing pathogenic bacteria to inject effector proteins into eukaryotic host cells, a process called type iii secretion. here we present the first three-dimensional structure of yersinia enterocolitica and shigella flexneri injectisomes in situ and the first structural analysis of the yersinia injectisome. unexpectedly, basal bodies of injectisomes inside the bacterial cells showed length variations of 20%. the in situ structures of the y. e ...	2013	23908767
infrequent cross-transmission of shigella flexneri 2a strains among villages of a mountainous township in taiwan with endemic shigellosis.	shigellosis is rare in taiwan, with an average annual incidence rate of 1.68 cases per 100,000 persons in 2000-2007. however, the incidence rate for a mountainous township in eastern taiwan, zhuoxi, is 60.2 times the average rate for the entire country. traveling between zhuoxi's 6 villages (v1-v6) is inconvenient. disease transmission among the villages/tribes with endemic shigellosis was investigated in this study.	2013	23899288
noncanonical inflammasome activation by intracellular lps independent of tlr4.	gram-negative bacteria including escherichia coli, citrobacter rodentium, salmonella typhimurium, and shigella flexneri are sensed in an ill-defined manner by an intracellular inflammasome complex that activates caspase-11. we show that macrophages loaded with synthetic lipid a, e. coli lipopolysaccharide (lps), or s. typhimurium lps activate caspase-11 independently of the lps receptor toll-like receptor 4 (tlr4). consistent with lipid a triggering the noncanonical inflammasome, lps containing ...	2013	23887873
effects of subtherapeutic concentrations of antimicrobials on gene acquisition events in yersinia, proteus, shigella, and salmonella recipient organisms in isolated ligated intestinal loops of swine.	to assess antimicrobial resistance and transfer of virulence genes facilitated by subtherapeutic concentrations of antimicrobials in swine intestines.	2013	23879845
virulent shigella flexneri affects secretion, expression, and glycosylation of gel-forming mucins in mucus-producing cells.	mucin glycoproteins are secreted in large amounts by the intestinal epithelium and constitute an efficient component of innate immune defenses to promote homeostasis and protect against enteric pathogens. in this study, our objective was to investigate how the bacterial enteropathogen shigella flexneri, which causes bacillary dysentery, copes with the mucin defense barrier. we report that upon in vitro infection of mucin-producing polarized human intestinal epithelial cells, virulent s. flexneri ...	2013	23876800
molecular mechanisms of cell-cell spread of intracellular bacterial pathogens.	several bacterial pathogens, including listeria monocytogenes, shigella flexneri and rickettsia spp., have evolved mechanisms to actively spread within human tissues. spreading is initiated by the pathogen-induced recruitment of host filamentous (f)-actin. f-actin forms a tail behind the microbe, propelling it through the cytoplasm. the motile pathogen then encounters the host plasma membrane, forming a bacterium-containing protrusion that is engulfed by an adjacent cell. over the past two decad ...	2013	23864553
bacteremia in patients with acute pancreatitis as revealed by 16s ribosomal rna gene-based techniques*.	to define the characteristic of bacteremia in patients with acute pancreatitis and determine its possible association with the disease severity.	2013	23863226
self-adjuvanting bacterial vectors expressing pre-erythrocytic antigens induce sterile protection against malaria.	genetically inactivated, gram-negative bacteria that express malaria vaccine candidates represent a promising novel self-adjuvanting vaccine approach. antigens expressed on particulate bacterial carriers not only target directly to antigen-presenting cells but also provide a strong danger signal thus circumventing the requirement for potent extraneous adjuvants. e. coli expressing malarial antigens resulted in the induction of either th1 or th2 biased responses that were dependent on both antige ...	2013	23847617
¹³c, ¹⁵n and ¹h backbone and side chain chemical shift assignment of acid-stress bacterial chaperone hdea at ph 6.	hdea is a small chaperone found in the periplasm of several common pathogenic bacteria (escherichia coli, shigella flexneri and brucella abortus) which are the leading causes of dysentery worldwide, especially in developing countries. its job is to protect other periplasmic proteins from aggregating as the bacteria pass through the low ph environment of the human stomach on their way to infect the intestines. hdea is an inactive folded dimer at neutral ph, but becomes a disordered active monomer ...	2014	23835624
protein expression, crystallization and preliminary x-ray crystallographic analysis of the isolated shigella flexneri vapc toxin.	upon release from the stable complex formed with its antitoxin vapb, the toxin vapc (mvpt) of the gram-negative pathogen shigella flexneri is capable of globally down-regulating translation by specifically cleaving initiator trna(fmet) in the anticodon region. recombinant shigella flexneri vapc(d7a) harbouring an active-site mutation was overexpressed in escherichia coli, purified to homogeneity and crystallized by the vapour-diffusion technique. a preliminary x-ray crystallographic analysis sho ...	2013	23832203
synthesis, spectroscopic, molecular orbital calculation, cytotoxic, molecular docking of dna binding and dna cleavage studies of transition metal complexes with n-benzylidene-n'-salicylidene-1,1-diaminopropane.	eight mononuclear chromium(iii), manganese(ii), iron(iii), cobalt(ii), nickel(ii), copper(ii), zinc(ii) and cadmium(ii) complexes of schiff's base ligand were synthesized and determined by different physical techniques. the complexes are insoluble in common organic solvents but soluble in dmf and dmso. the measured molar conductance values in dmso indicate that the complexes are non-electrolytic in nature. all the eight metal complexes have been fully characterized with the help of elemental ana ...	2013	23831943
medicinal potential of morella serata (lam.) killick (myricaceae) root extracts: biological and pharmacological activities.	morella serata is a south african medicinal plant used in the treatment of microbial infections and to enhance male sexual performance. there is dearth of information in scientific literature on its efficacy and safety.	2013	23829770
systems-level overview of host protein phosphorylation during shigella flexneri infection revealed by phosphoproteomics.	the enteroinvasive bacterium shigella flexneri invades the intestinal epithelium of humans. during infection, several injected effector proteins promote bacterial internalization, and interfere with multiple host cell responses. to obtain a systems-level overview of host signaling during infection, we analyzed the global dynamics of protein phosphorylation by liquid chromatography-tandem ms and identified several hundred of proteins undergoing a phosphorylation change during the first hours of i ...	2013	23828894
synthesis, biological evaluation and molecular docking studies of some pyrimidine derivatives.	some novel pyrimidine-5-carbonitrile derivatives bearing various substituent have been synthesized. the structures of target compounds were confirmed by elemental analysis and spectral data. some selected members of the newly synthesized compounds were investigated for their cytotoxic potency against certain human tumor cell lines. five representative active anticancer compounds 6a, 6c, 6d, 17a and 18a were subjected to docking using moe program on the 3d structure of two enzymes, namely; thymid ...	2013	23811090
antimicrobial resistance and genetic characteristics of integron-carrier shigellae isolated in hungary (1998-2008).	antimicrobial susceptibility, integron carriage, genetic relationship and presence of some important virulence genes of the integron-carrier strains of shigella sonnei (n = 230) and shigella flexneri (n = 22) isolated from stool samples of patients in hungary between 1998 and 2008 were investigated. sixty-seven per cent (168/252) of the strains were resistant to sulfamethoxazole/trimethoprim (sxt) followed by streptomycin (s, 47%), ampicillin (a, 32%) and tetracycline (tc, 28%). thirty-six per c ...	2013	23800597
expression of shigella flexneri ipab gene in tobacco.	shigellosis is a leading cause of diarrhea in many developing countries and although the disease can be controlled and managed with antibiotics, the constant emergence of resistant species requiring ever newer antibacterial drugs make development of an effective vaccine necessary. the bacteria are highly contagious and since immunity to shigella is serotype-specific a multi-serotype vaccine is required for adequate protection. proteins encoded by shigella invasion plasmid, which are part of the ...	2013	23799180
single cell measurements of vacuolar rupture caused by intracellular pathogens.	shigella flexneri are pathogenic bacteria that invade host cells entering into an endocytic vacuole. subsequently, the rupture of this membrane-enclosed compartment allows bacteria to move within the cytosol, proliferate and further invade neighboring cells. mycobacterium tuberculosis is phagocytosed by immune cells, and has recently been shown to rupture phagosomal membrane in macrophages. we developed a robust assay for tracking phagosomal membrane disruption after host cell entry of shigella ...	2013	23792688
bacteremia in the patients with acute pancreatitis as revealed by 16s ribosomal rna gene-based techniques.	objectives:: to define the characteristic of bacteremia in the patients with acute pancreatitis and determine its possible association with the disease severity. design:: a prospective controlled study. setting:: icu of jinling hospital, china. patients:: a total of 48 patients with mild or severe acute pancreatitis were enrolled in this study. interventions:: none. measurements and main results:: samples of peripheral blood were collected from the patients at 4 or 5 and 9 or 10 days after acute ...	2013	23764972
outer membrane protein a (ompa) from shigella flexneri 2a: a promising subunit vaccine candidate.	shigellosis is the leading cause of childhood mortality and morbidity. despite many years of extensive research a practical vaccine is not yet available against the disease. recent studies illustrate that bacterial outer membrane proteins are budding target as vaccine antigen. outer membrane proteins a (ompa) are among the most immunodominant antigens in the outer membrane of gram negative bacteria and possess many characteristics desired of a vaccine candidate. we observe that ompa of shigella ...	2013	23764536
multidrug-resistant atypical variants of shigella flexneri in china.	we identified 3 atypical shigella flexneri varieties in china, including 92 strains with multidrug resistance, distinct pulse types, and a novel sequence type. atypical varieties were prevalent mainly in developed regions, and 1 variant has become the dominant shigella spp. serotype in china. improved surveillance will help guide the prevention and control of shigellosis.	2013	23763754
human single-chain urokinase is activated by the omptins pgte of salmonella enterica and pla of yersinia pestis despite mutations of active site residues.	fibrinolysis is important in cell migration and tightly regulated by specific inhibitors and activators; of the latter, urokinase (upa) associates with enhancement of cell migration. active upa is formed through cleavage of the single-chain upa (scupa). the salmonella enterica strain 14028r cleaved human scupa at the peptide bond lys158-ile159, the site cleaved also by the physiological activator human plasmin. the cleavage led to activation of scupa, while no cleavage or activation were detecte ...	2013	23763588
characterization of intracellular growth regulator icgr by utilizing transcriptomics to identify mediators of pathogenesis in shigella flexneri.	shigella species gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. with no vaccine available, shigellosis annually kills over 600,000 children in developing countries. this study demonstrates the utility of combining high-throughput bioinformatic methods with in vitro and in vivo assays to provide new insights into pathogenesis. comparisons of in vivo and in vitro gene expressio ...	2013	23753632
agglutinating secretory iga preserves intestinal epithelial cell integrity during apical infection by shigella flexneri.	shigella flexneri, by invading intestinal epithelial cells (iecs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. although m cells overlying peyer's patches are commonly considered the primary site of entry of s. flexneri, indirect evidence suggests that bacteria can also use iecs as a portal of entry to the lamina propria. passive delivery of secretory iga (siga), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from ...	2013	23753631
molecular cloning and biologically active production of ipad n-terminal region.	shigella is known as pathogenic intestinal bacteria in high dispersion and pathogenic bacteria due to invasive plasmid antigen (ipa). so far, a number of ipa proteins have been studied to introduce a new candidate vaccine. here, for the first time, we examined whether the n-terminal region of ipad(72-162) could be a proper candidate for shigella vaccine. initially, the dna sequence coding n-terminal region was isolated by pcr from shigella dysenteriae type i and cloned into pet-28a expression ve ...	2013	23731655
nanoparticle-based vaccine for mucosal protection against shigella flexneri in mice.	shigellosis is one of the leading causes of diarrhea worldwide with more than 130 million cases annually. hence, the research of an effective vaccine is still a priority. unfortunately, a safe and efficacious vaccine is not available yet. we have previously demonstrated the capacity of outer membrane vesicles (omvs) to protect mice against an experimental infection with shigella flexneri. now, we present results on the capacity of this antigenic complex to confer a longer-term protection by oral ...	2013	23727423
a role for the ankyrin repeat containing protein ankrd17 in nod1- and nod2-mediated inflammatory responses.	innate immune responses induced by the pattern-recognition receptors nod1 and nod2 play pivotal roles to combat infection and to instruct adaptive immunity. here we identify ankrd17 as a novel binding partner of nod2 and show that its n-terminal domain mediates nod2 binding. knock-down and overexpression analysis revealed that ankrd17 is functionally involved in nod2- and nod1-mediated responses in human myeloid and epithelial cells. in hela cells ankrd17 contributed to pro-inflammatory response ...	2013	23711367
providencia alcalifaciens causes barrier dysfunction and apoptosis in tissue cell culture: potent role of lipopolysaccharides on diarrheagenicity.	providencia alcalifaciens is a member of the enterobacteriaceae family that occasionally causes diarrheagenic illness in humans via the intake of contaminated foods. despite the epidemiological importance of p. alcalifaciens, little is known about its pathobiology. here we report that p. alcalifaciens causes barrier dysfunction in caco-2 cell monolayers and induces apoptosis in calf pulmonary artery endothelial cells. p. alcalifaciens infection caused a 30% reduction in transepithelial resistanc ...	2013	23710559
multi-serotype outer membrane vesicles of shigellae confer passive protection to the neonatal mice against shigellosis.	recently, we have demonstrated, immunization of adult female mice with outer membrane vesicles (omvs) of shigella boydii type 4 protected their offspring passively from shigellosis. in our present study, we have advanced our research by formulating multi-serotype outer membrane vesicles (momvs), mixing the omvs of shigella dysenteriae 1 δstx, shigella flexneri 2a, 3a and 6, s. boydii type 4 and shigella sonnei to achieve a broad spectrum protection against shigellosis. adult mice were immunized ...	2013	23684822
the shigella ospc3 effector inhibits caspase-4, antagonizes inflammatory cell death, and promotes epithelial infection.	caspase-mediated inflammatory cell death acts as an intrinsic defense mechanism against infection. bacterial pathogens deploy countermeasures against inflammatory cell death, but the mechanisms by which they do this remain largely unclear. in a screen for shigella flexneri effectors that regulate cell death during infection, we discovered that shigella infection induced acute inflammatory, caspase-4-dependent epithelial cell death, which is counteracted by the bacterial ospc3 effector. ospc3 int ...	2013	23684308
the antimicrobial effect of lactobacillus casei culture supernatant against multiple drug resistant clinical isolates of shigella sonnei and shigella flexneri in vitro.	shigellosis remains an important public health problem in developing countries with s. sonnei and s. flexneri in us, europe and in asian countries being of importance.	2013	23682323
shigella antigen-specific b memory cells are associated with decreased disease severity in subjects challenged with wild-type shigella flexneri 2a.	the role of shigella-specific b memory (bm) in protection has not been evaluated in human challenge studies. we utilized cryopreserved pre- and post-challenge peripheral blood mononuclear cells and sera from wild-type shigella flexneri 2a (wt-2457t) challenges. challenged volunteers were either naïve or subjects who had previously ingested wt-2457t or been immunized with hybrid escherichia coli-shigella live oral candidate vaccine (ecsf2a-2). bm and antibody titers were measured against lipopoly ...	2013	23649043
[virulence genes and pathogenicity of shigella flexneri xv isolated in beijing].	to understand the biochemical characteristics, virulence genes and pathogenicity of shigella flexneri xv isolated in beijing.	2013	23648252
genetic characterization of antimicrobial resistance of shigella flexneri 1c isolates from patients in egypt and pakistan.	shigella flexneri serotype 1c emerged as a critical isolate from children in egypt and pakistan. the pattern of antimicrobial susceptibility (ams) and resistance genes of this serotype have yet to be characterized.	2013	23638855
1,1-diphenyl,2-picrylhydrazyl free radical scavenging, bactericidal, fungicidal and leishmanicidal properties of teucrium stocksianum.	in the present study, we evaluated the pharmacological and toxicological effects of teucrium stocksianum. the crude extract of t. stocksianum (ts.cr) and its subsequent organic fractions: n-hexane (ts.hex), chloroform (ts.chcl3) and ethyl acetate (ts.etac) exhibited 1,1-diphenyl,2-picrylhydrazyl free radical scavenging activity with different potencies. ts.etac was found to be most potent. ts.cr, ts.hex, ts.chcl3 and ts.etac showed significant bactericidal activity against escherichia coli, stap ...	2015	23625908
structure of the o-antigen of a novel shigella flexneri serotype, 1d (i: 7,8).	recently, strains of a novel shigella flexneri serotype called 1d have been isolated from diarrheal patients in china. they are distinguished by the presence of a hitherto unknown combination of type o-factor i and group o-factor 7,8, both associated with lateral α-d-glucosyl groups on the basal linear o-polysaccharide. a serologically identical strain, 036_1d, has been constructed in the laboratory by sequential infection of serotype y by serotype-converting bacteriophages sfx and sfi. in this ...	2013	23603189