Publications

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nlrc4/ipaf/clan/card12: more than a flagellin sensor.nlrc4 is a member of the nod-like receptors (nlrs), a family of cytosolic receptors involved in sensing bacterial molecules. nlrs are a group of proteins containing spans of leucine-rich repeats that senses bacterial factors within the eukaryotic cytosol. the recognition of bacterial factors provokes the formation of the inflammasome complex which includes specific nlrs. the inflammasome is responsible for caspase-1 activation which leads to the cleavage and maturation of inflammatory cytokines ...201020067841
tracking the dynamic interplay between bacterial and host factors during pathogen-induced vacuole rupture in real time.escape into the host cell cytosol following invasion of mammalian cells is a common strategy used by invasive pathogens. this requires membrane rupture of the vesicular or vacuolar compartment formed around the bacteria after uptake into the host cell. the mechanism of pathogen-induced disassembly of the vacuolar membrane is poorly understood. we established a novel, robust and sensitive fluorescence microscopy method that tracks the precise time point of vacuole rupture upon uptake of gram-nega ...201020070313
selective deletion of cd8(+) cells upregulated by caspases-1 via il-18 in mice immunized with major outer membrane protein of shigella dysenteriae 1 following infection.introduction: mucosal lymphoid changes were observed in cryopreserved rectal tissues obtained from balb/c mice infected with shigella dysenteriae 1, immunized with 57-kda major antigenic outer membrane protein, and infection after immunization. discussion: our data suggested that caspase-3 is downregulated in cd4(+) cells of immunized balb/c mice following infection with substantial increased expression of interleukin (il)-2 and interferon (ifn)-gamma, while caspase-1 is upregulated in cd8(+) ce ...201020084439
the extreme c terminus of shigella flexneri ipab is required for regulation of type iii secretion, needle tip composition, and binding.type iii secretion systems (t3sss) are widely distributed virulence determinants of gram-negative bacteria. they translocate bacterial proteins into host cells to manipulate them during infection. the shigella t3ss consists of a cytoplasmic bulb, a transmembrane region, and a hollow needle protruding from the bacterial surface. the distal tip of mature, quiescent needles is composed of ipad, which is topped by ipab. physical contact with host cells initiates secretion and leads to assembly of a ...201020086081
chaperonin activity modulates codon adaptation. 201020087337
groel dependency affects codon usage--support for a critical role of misfolding in gene evolution.it has recently been suggested that the use of optimal codons limits mistranslation-induced protein misfolding, yet evidence for this remains largely circumstantial. in contrast, molecular chaperones have long been recognized to play crucial roles in misfolding prevention and remedy. we propose that putative error limitation in cis can be elucidated by examining the interaction between codon usage and chaperoning processes. using escherichia coli as a model system, we find that codon optimality ...201020087338
th17 cells are the dominant t cell subtype primed by shigella flexneri mediating protective immunity.the t cell response to shigella, the causative agent of bacillary dysentery, remains poorly understood. using a murine model of infection, we report that shigella flexneri primes predominately il-17a- and il-22-producing th17 cells. shigella-specific th1 cells are only significantly induced on secondary infection, whereas specific th2 and cd8(+) t cells are undetectable. apart from th17 cells that are primed in a mhc class ii- and il-6-dependent, but il12/23p40-independent manner, we identified ...201020089698
antibiotic therapy for shigella dysentery.shigella dysentery is a relatively common illness and occasionally causes death, worldwide. mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. the antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.201020091606
emergence of resistance to third-generation cephalosporin in shigella--a case report.the emergence of ciprofloxacin resistance in shigella has shifted the attention to cephalosporins. the first occurrence of third generation cephalosporin-resistant shigella flexneri was from france. this article reports the first case of cephalosporin-resistant s. flexneri from india. a 12-month-old child was admitted for a 20-day episode of loose stools, non-fetid, with mucus and blood. the stool sample showed the presence of blood and mucus and s. flexneri which was resistant to ampicillin, na ...201019955258
emergence of a new multidrug-resistant serotype x variant in an epidemic clone of shigella flexneri.shigella spp. are the causative agent of shigellosis with shigella flexneri serotype 2a being the most prevalent in developing countries. epidemiological surveillance in china found that a new serotype of s. flexneri appeared in 2001 and replaced serotype 2a in 2003 as the most prevalent serotype in henan province. the new serotype also became the dominant serotype in 7 of the 10 other provinces under surveillance in china by 2007. the serotype was identified as a variant of serotype x. it diffe ...201019955273
antilisterial activity of a broad-spectrum bacteriocin, enterocin lr/6 from enterococcus faecium lr/6.enterocin lr/6, a purified bacteriocin, exhibited broad inhibitory spectrum both against related as well as some food-borne pathogens such as listeria monocytogenes, yersinia enterocolitica, aeromonas sp., shigella sp., and bacillus licheniformis. in this investigation, we have focused on l. monocytogenes as the target organism, as it is not only an important pathogen but can also survive over a wide range of environmental conditions such as refrigeration temperature, low ph, and high-salt conce ...201019957209
interference of the cadc regulator in the arginine-dependent acid resistance system of shigella and enteroinvasive e. coli.a typical pathoadaptive mutation of shigella and enteroinvasive escherichia coli (eiec) is the inactivation of the cad locus which comprises the genes necessary for lysine decarboxylation, an enzyme involved in ph homoeostasis. in e. coli, the cadba operon, encoding lysine decarboxylase (cada) and a lysine cadaverine antiporter (cadb), is submitted to the control of cadc, a positive activator whose gene maps upstream the operon, and is transcribed independently from the same strand. cadc is an i ...201019959396
combined effects of probiotic fermentation and high-pressure extraction on the antioxidant, antimicrobial, and antimutagenic activities of deodeok (codonopsis lanceolata).this study was designed to evaluate the combined effects of probiotic fermentation and high-pressure extraction (hpe) on the functional properties of codonopsis lanceolata. the ground c. lanceolata samples were anaerobically fermented with lactobacillus acidophilus adh, bifidobacterium longum b6, lactobacillus rhamnosus gg, or lactobacillus paracasei at 37 degrees c for 10 days and subjected to 500 mpa at 50 degrees c for 30 min. the extraction yields of c. lanceolata samples were noticeably inc ...201020000575
global analysis of a plasmid-cured shigella flexneri strain: new insights into the interaction between the chromosome and a virulence plasmid.shigella flexneri is an important human pathogen that causes dysentery, and remains a significant threat to public health, particularly in developing countries. the virulence of this pathogen is dependent on an acquired virulence plasmid. to investigate the crosstalk between the bacterial chromosome and the exogenous virulence plasmid, a virulence plasmid-cured strain was constructed using plasmid incompatibility. the global patterns of gene expression of this strain compared with the wild-type ...201020000779
characterization of wrss2 and wrss3, new second-generation virg(icsa)-based shigella sonnei vaccine candidates with the potential for reduced reactogenicity.live, attenuated shigella vaccine candidates, such as shigella sonnei strain wrss1, shigella flexneri 2a strain sc602, and shigella dysenteriae 1 strain wrsd1, are attenuated principally by the loss of the virg(icsa) protein. these candidates have proven to be safe and immunogenic in volunteer trials and in one study, efficacious against shigellosis. one drawback of these candidate vaccines has been the reactogenic symptoms of fever and diarrhea experienced by the volunteers, that increased in a ...201019932216
development of a serogroup-specific dna microarray for identification of escherichia coli strains associated with bovine septicemia and diarrhea.escherichia coli strains belonging to serogroups o8, o9, o15, o26, o35, o78, o86, o101, o115 and o119 are commonly associated with septicemia or diarrhea in calves and pose a significant threat to the cattle industry worldwide. in this study, a microarray detection system targeting o-antigen-specific genes was developed for the identification of those serogroups. by testing against 186 e. coli and shigella o-serogroup reference strains, 36 e. coli clinical isolates, and 9 representative strains ...201019932572
antimicrobial lipids from the hemolymph of brachyuran crabs.the potential of marine crabs as a source of biologically active products is largely unexplored. in the present study, antimicrobial activity of the hemolymph (plasma) and hemocytes (plasma cells) of six brachyuran crabs was investigated against 16 pathogenic strains. among the 16 strains tested maximum zone of inhibition was recorded in the hemolymph of hyas araneus against shigella flexineri. interestingly staphylococcus aureus and salmonella typhi were susceptible to all the hemolymph and hem ...201019937399
inactivation of escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves by x-ray.several recent foodborne disease outbreaks associated with leafy green vegetables, including spinach, have been reported. x-ray is a non-thermal technology that has shown promise for reducing pathogenic and spoilage bacteria on spinach leaves. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves using x-ray at different doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) was studied. the effect of x-ray on col ...201019913687
effects of x-ray radiation on escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri inoculated on shredded iceberg lettuce.the main goal of this investigation was to study the efficacy of x-ray doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) on inoculated escherichia coli o157: h7, listeria monocytogenes, salmonella enterica and shigella flexneri on shredded iceberg lettuce. the second goal was to study the effect of x-ray on the inherent microflora counts and visual color of shredded iceberg lettuce during storage at 4 degrees c for 30 days. treatment with 1.0 kgy x-ray significantly reduced the population o ...201019913700
yersinia enterocolitica in slaughter pig tonsils: enumeration and detection by enrichment versus direct plating culture.tonsil samples from 139 slaughter pigs were examined for the presence of pathogenic yersinia enterocolitica by enrichment procedures based on the standard method iso 10273:2003. in addition, samples were tested by direct plating method to evaluate its efficiency compared to the enrichment culture methods and to quantify the level of contamination in porcine tonsils. in total, 52 samples (37.4%) were positive for pathogenic y. enterocolitica, all belonging to bioserotype 4/o:3. fifty out of the 5 ...201019913707
adaptive immune responses during shigella dysenteriae type 1 infection: an in vitro stimulation with 57 kda major antigenic omp in the presence of anti-cd3 antibody.an effort was made to understand the role of the 57 kda major antigenic fraction of shigella outer membrane protein (omp) in the presence of t-cell antigen receptor in activation of adaptive immune responses of the cell mediated immune (cmi) restored patients. the expression of hla-dr/cd4 out of cd3(+) t-cells was significantly dominant over the hla-dr/cd8 and comparable to unstimulated cells of infected or healthy controls. cd4(+) t-cell activation together with hla-dr is associated with the ex ...201019915959
differentiation and identification of shigella spp. and enteroinvasive escherichia coli in environmental waters by a molecular method and biochemical test.both shigella spp. and enteroinvasive escherichia coli (eiec) are important human pathogens that are responsible for the majority of cases of endemic bacillary dysentery. however, they are difficult to identify and differentiate by biochemical tests or molecular methods alone. in this study, we developed a procedure to detect shigella spp. and eiec from environmental water samples using membrane filtration followed by nutrient broth enrichment, isolation using selective culture plates, and ident ...201019917511
identification of antibacterial and antifungal pharmacophore sites for potent bacteria and fungi inhibition: indolenyl sulfonamide derivatives.synthesis of seven new indolenyl sulfonamides, have been prepared by the condensation reaction of indole-3-carboxaldehyde with different sulfonamides such as, sulphanilamide, sulfaguanidine, sulfathiazole, sulfamethoxazole, sulfisoxazole, sulfadiazine and sulfamethazine. these synthesized compounds have been used as potential ligands for complexation with some selective divalent transition metal ions (cobalt, copper, nickel & zinc). structure of the synthesized ligands has been deduced from thei ...201020005022
solution nmr structures of proteins vpa0419 from vibrio parahaemolyticus and yiis from shigella flexneri provide structural coverage for protein domain family pfam 04175. 201019927321
immobilization of bacteriophages on modified silica particles.bacteriophages are selective anti-bacterial agents, which are receiving increasing acceptance by regulatory agencies for use both in the food industry and in clinical settings for biocontrol. while immobilized phage could be particularly useful to create antimicrobial surfaces, current immobilization strategies require chemical bioconjugation to surfaces or more difficult processes involving modification of their head proteins to express specific binding moieties, for example, biotin or cellulos ...201019945158
galectin-3, a marker for vacuole lysis by invasive pathogens.shigella bacteria invade macrophages and epithelial cells and following internalization lyse the phagosome and escape to the cytoplasm. galectin-3, an abundant protein in macrophages and epithelial cells, belongs to a family of beta-galactoside-binding proteins, the galectins, with many proposed functions in immune response, development, differentiation, cancer and infection. galectins are synthesized as cytosolic proteins and following non-classical secretion bind extracellular beta-galactoside ...201019951367
a bacterial e3 ubiquitin ligase ipah9.8 targets nemo/ikkgamma to dampen the host nf-kappab-mediated inflammatory response.nf-kappab (nuclear factor kappab) has a pivotal role in many cellular processes, including the inflammatory and immune responses and, therefore, its activation is tightly regulated by the ikk (ikappab kinase) complex and by ikappabalpha degradation. when shigella bacteria multiply within epithelial cells they release peptidoglycans, which are recognized by nod1 and stimulate the nf-kappab pathway, thus leading to a severe inflammatory response. here, we show that ipah9.8, a shigella effector pos ...201020010814
pivotal advance: bifidobacteria and gram-negative bacteria differentially influence immune responses in the proinflammatory milieu of celiac disease.cd is a chronic inflammatory disorder of the small intestine that presents in genetically predisposed individuals following gluten consumption. in this study, the effects of bifidobacterium (bifidobacterium bifidum iata-es2 and bifidobacterium longum atcc15707) and gram-negative bacteria (bacteroides fragilis dsm2451, escherichia coli cbl2, and shigella cbd8 isolated from cd patients), alone and in the presence of cd triggers (gliadins and/or ifn-gamma) on surface marker expression and cytokine ...201020007908
characteristics of children with shigella encephalopathy: experience from a large urban diarrhea treatment center in bangladesh.encephalopathy is a serious neurologic complication from shigellosis often with fatal outcome but data on simple clinical and sociodemographic predicting factors are limited. we sought to identify those factors in children.201020016394
cem-101, a novel fluoroketolide: antimicrobial activity against a diverse collection of gram-positive and gram-negative bacteria.cem-101 is a novel fluoroketolide with reported high potency against diverse groups of gram-positive (micrococcus spp., viridans group streptococci, corynebacterium spp. listeria monocytogenes, clostridium spp., etc.) and gram-negative bacteria (neisseria gonorrhoeae, campylobacter jejuni, helicobacter pylori, bacteroides fragilis, shigella spp., etc.), including mycoplasma and ureaplasma, as well as bacteria commonly associated with community-acquired respiratory tract infections and skin and s ...201020022192
reactive arthritis after enteric infections in the united states: the problem of definition.bacterial enteric infections cause substantial morbidity in the united states both from acute illness and sequelae that follow. reactive arthritis (rea) is a poorly defined term that is used to describe a variety of rheumatologic phenomena that may occur after salmonella, shigella, campylobacter, and yersinia infection, as well as other types of infections (eg, chlamydia). this review focuses on clinical and epidemiologic investigations of rea following bacterial enteric infection in the united ...201020025528
transcriptional profile of the shigella flexneri response to an alkaloid: berberine.berberine, a natural isoquinoline alkaloid found in many medicinal herbs, has been shown to be active against a variety of microbial infections. to examine the potential effects of berberine on shigella flexneri, a whole-genome dna microarray was constructed and a transcriptome analysis of the cellular responses of s. flexneri when exposed to berberine chloride (bc) was performed. our data revealed that bc upregulated a group of genes involved in dna replication, repair and division. intriguingl ...201020030725
metal based biologically active compounds: design, synthesis, and antibacterial/antifungal/cytotoxic properties of triazole-derived schiff bases and their oxovanadium(iv) complexes.a new series of oxovanadium(iv) complexes have been designed and synthesized with a new class of triazole schiff bases derived from the reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde and acetyl pyridine-2-carboxaldehyde, respectively. physical (magnetic susceptibility, molar conductance), spectral (ir, (1)h nmr, (13)c nmr, mass and electronic) and analytical data have established the structures of these synthesized schi ...201020338672
identification of active site residues in the shigella flexneri glucosyltransferase gtrv.the serotype-specific glucosyltransferase, gtrv, is responsible for glucosylation of the o-antigen repeating unit of shigella flexneri serotype 5a strains. gtrv is an integral inner membrane protein with two essential periplasmic loops: the large loop 2 and the c-terminal loop 10. in this study, the full length of the loop 2 was shown to be necessary for gtrv function. site-directed mutagenesis within this loop revealed that conserved aromatic and charged amino acids have a critical role in the ...201020334579
[preparation of a 96-microwell plate dna diagnostic chip for detection of foodborne bacteria and its application in an incident of food poisoning].to develop a 96-microwell plate dna diagnostic chip for simultaneous detection of 9 major foodborne bacteria.201020335099
isolation and selection of coliphages as potential biocontrol agents of enterohemorrhagic and shiga toxin-producing e. coli (ehec and stec) in cattle.to isolate, characterize and select phages as potential biocontrol agents of enterohemorrhagic and shiga toxin-producing escherichia coli (ehec and stec) in cattle.201020353429
molecular architecture of the mn2+-dependent lactonase ulag reveals an rnase-like metallo-beta-lactamase fold and a novel quaternary structure.the ulag gene, located in the ula regulon, is crucial for the catabolism of l-ascorbate under anaerobic conditions and it has been proposed to encode for the putative l-ascorbate-6-p lactonase. the ulag gene is widespread among eubacteria, including human commensal and pathogenic genera such as escherichia, shigella, klebsiella and salmonella. here, we report the three-dimensional structures of the apoenzyme and mn(2+) holoenzyme of ulag from e. coli to 2.6 a resolution, determined using single- ...201020359483
modeling fimbriae mediated parasite-host interactions.type 1 fimbriae are a known virulence factor in a number of pathogenic enterobacteriaceae, including salmonella, shigella and e. coli. yet, they are also expressed by some commensal strains, notably of e. coli. one hypothesis of the role of fimbriae in commensals is that they evoke a small but tolerable host immune response in order to have the host release sialic acid, which is a valuable nutrient. genetic evidence suggests that sialic acid down-regulates fimbriation. this has been believed to ...201020359486
a soluble form of the pilus protein fima targets the vdac-hexokinase complex at mitochondria to suppress host cell apoptosis.inhibition of apoptotic response of host cells during an early phase of infection is a strategy used by many enteroinvasive bacterial pathogens to enhance their survival. here, we report the identification of a soluble form of the pilus protein fima from the culture supernatants of e. coli k1, salmonella, and shigella that can potently inhibit bax-mediated release of cytochrome c from isolated mitochondria. similar to the infected cells, hct116 cells stably expressing fima display a delay in the ...201020347420
34 kda momp of shigella flexneri promotes tlr2 mediated macrophage activation with the engagement of nf-kappab and p38 map kinase signaling.the 34 kda major outer membrane protein (momp) of shigella flexneri 2a induces combinatorial expression of tlr2 and tlr6 on peritoneal macrophages of balb/c mice. between the two best-characterized tlrs, to date, tlr2 and tlr4, which are chiefly responsible for recognizing majority of bacterial products, tlr2 alone participates in recognition of 34 kda momp. in addition to tlrs, momp enhances the mrna expression of myd88 and traf6 and induces the nuclear translocation of nf-kappab as well as act ...201020347487
long-term downregulation of protease-activated receptor-2 expression in distal colon in rats following bacillary dysentery.the aim of this study was to determine changes of par-2 expression in distal colon and the sensitivity of colonic muscle to sligrl-nh2, the par-2-activating peptide (par-2-ap) following bacillary dysentery. shigella flexneri was administrated intragastrically in healthy male rats to induce bacillary dysentery. the effect of sligrl-nh2 on the motility of colonic muscle strips were examined. the expression of par-2 was determined by immunohistochemistry and western blotting. intragastric administr ...201020347884
antibiotics for the treatment of dysentery in children.ciprofloxacin, ceftriaxone and pivmecillinam are the antibiotics currently recommended by the world health organization (who) for the treatment of dysentery in children; yet there have been no reviews of the clinical effectiveness of these antibiotics in recent years.201020348130
global transcriptional response of macrophage-like thp-1 cells to shiga toxin type 1.shiga toxins (stxs) are bacterial cytotoxins produced by the enteric pathogens shigella dysenteriae serotype 1 and some serotypes of escherichia coli that cause bacillary dysentery and hemorrhagic colitis, respectively. to date, approaches to studying the capacity of stxs to alter gene expression in intoxicated cells have been limited to individual genes. however, it is known that many of the signaling pathways activated by stxs regulate the expression of multiple genes in mammalian cells. to ex ...201020351145
characterisation of multidrug-resistant salmonella typhimurium 4,[5],12:i:- dt193 strains carrying a novel genomic island adjacent to the thrw trna locus.in 2006, monophasic, multidrug-resistant salmonella enterica spp. enterica serovar 4,[5],12:i:- strains appeared as a novel serotype in germany, associated with large diffuse outbreaks and increased need for hospitalisation. the emerging 4,[5],12:i:- strains isolated from patients in germany belong mainly to phage type dt193 according to the anderson phage typing scheme for s. typhimurium (stm) and exhibit at least a tetra-drug resistance. the strains have been shown to harbour stm-specific gifs ...201020303825
neutrophil antimicrobial proteins enhance shigella flexneri adhesion and invasion.shigella flexneri is an enteric pathogen that causes massive inflammation and destruction of the human intestinal epithelium. neutrophils are the first cells of the innate immune system recruited to the site of infection. these cells can attack microbes by phagocytosis, neutrophil extracellular trap (net) formation and degranulation. here, we investigated how neutrophil degranulation affects virulence and show that exposure of shigella to granular proteins enhances infection of epithelial cells. ...201020331641
bacterial enteritis as a risk factor for childhood intussusception: a retrospective cohort study.to assess the relationship between bacterial enteritis and intussusception.201020138300
a repulsive electrostatic mechanism for protein export through the type iii secretion apparatus.many gram-negative bacteria initiate infections by injecting effector proteins into host cells through the type iii secretion apparatus, which is comprised of a basal body, a needle, and a tip. the needle channel is formed by the assembly of a single needle protein. to explore the export mechanisms of mxih needle protein through the needle of shigella flexneri, an essential step during needle assembly, we have performed steered molecular dynamics simulations in implicit solvent. the trajectories ...201020141759
risk factors for sporadic shigellosis, foodnet 2005.an estimated 450,000 cases of shigellosis occur annually in the united states. outbreaks have been associated with food, water, child daycare centers, and men who have sex with men. however, for sporadic infections, which account for the majority of cases, risk exposures are poorly characterized.201020113209
extended-spectrum beta-lactamase-producing escherichia coli in patients with travellers' diarrhoea.the identification of patients carrying extended-spectrum beta-lactamase (esbl)-producing bacteria is important, since these patients are at risk of receiving inappropriate empirical therapy if they become infected. the purpose of this study was to investigate the occurrence of esbl-producing bacteria in patients with travellers' diarrhoea. patients with travellers' diarrhoea (n = 242) having delivered stool samples for the diagnosis of salmonella, shigella, yersinia or campylobacter, were also ...201020121649
campylobacteriosis and other bacterial gastrointestinal diseases in sofia, bulgaria for the period 1987-2008.campylobacter is the most commonly reported enteric bacterial pathogen in humans. we still do not have any systematic data concerning campylobacteriosis in bulgaria. for that reason, we present data of the thermophilic campylobacter jejuni and campylobacter coli in the aetiology of diarrhoeal diseases in sofia, for the period from 1987 to 2008. the study included patients from 0 to over 65 years-old. a total of 51,607 faecal specimens were screened for campylobacter. c. jejuni and c. coli were d ...201020122383
bacterial guanine nucleotide exchange factors sope-like and wxxxe effectors.subversion of rho family small gtpases, which control actin dynamics, is a common infection strategy used by bacterial pathogens. in particular, salmonella enterica serovar typhimurium, shigella flexneri, enteropathogenic escherichia coli (epec), and enterohemorrhagic escherichia coli (ehec) translocate type iii secretion system (t3ss) effector proteins to modulate the rho gtpases rhoa, cdc42, and rac1, which trigger formation of stress fibers, filopodia, and lamellipodia/ruffles, respectively. ...201020123714
a versatile internal control for use as dna in real-time pcr and as rna in real-time reverse transcription pcr assays.to develop and evaluate a taqman-based internal amplification control (iac) that can be used as dna in real-time pcr (qpcr) or as rna in reverse transcription real-time pcr (qrt-pcr) to identify the presence of assay inhibition and to evaluate its incorporation into existing qpcr and qrt-pcr methods for bacterial detection.201020149084
characterisation of pathogenic bacteria in a uasb-polishing pond system using molecular techniques.molecular techniques have been commonly used to detect and quantify pathogenic bacteria in food, clinical and environmental samples, but in wastewater treatment plants few studies have been carried out. this work applied pcr with a specific set of primers to investigate pathogenic bacteria in a wastewater plant comprised of a uasb reactor followed by polishing ponds. in addition, in-situ hybridisation technique (fish) was used to estimate the abundance of escherichia coli in the system. accordin ...201020150719
food-borne diseases - the challenges of 20 years ago still persist while new ones continue to emerge.the burden of diseases caused by food-borne pathogens remains largely unknown. importantly data indicating trends in food-borne infectious intestinal disease is limited to a few industrialised countries, and even fewer pathogens. it has been predicted that the importance of diarrhoeal disease, mainly due to contaminated food and water, as a cause of death will decline worldwide. evidence for such a downward trend is limited. this prediction presumes that improvements in the production and retail ...201020153070
development of a multiplex real-time polymerase chain reaction for simultaneous detection of enterohemorrhagic escherichia coli and enteropathogenic escherichia coli strains.a multiplex real-time polymerase chain reaction (pcr) was developed for the simultaneous detection of genes encoding intimin (eae) and all variants of shiga toxins 1 and 2 (stx1 and stx2) in diagnostic samples. the uida gene encoding a beta-glucuronidase specific for escherichia coli and shigella spp. was included in the multiplex pcr assay as an internal amplification control. the multiplex pcr was tested on 30 e. coli reference strains and 174 diagnostic samples already characterized as harbor ...201020156086
a challenge model for shigella dysenteriae 1 in cynomolgus monkeys (macaca fascicularis).shigella dysenteriae type 1 can cause devastating pandemics with high case fatality rates; a vaccine for shigella is unavailable currently. because of the risks associated with performing challenge studies with wild-type s. dysenteriae 1 in human clinical trials to advance vaccine development, an improved nonhuman primate model is needed urgently. in the present study, cynomolgus macaques (macaca fascicularis) were challenged with various doses of s. dysenteriae 1 strain 1617 to establish a dose ...201020158950
the proteome of shigella flexneri 2a 2457t grown at 30 and 37 degrees c.to upgrade the proteome reference map of shigella flexneri 2a 2457t, the protein expression profiles of log phase and stationary phase cells grown at 30 and 37 degrees c were thoroughly analyzed using multiple overlapping narrow ph range (between ph 4.0 and 11.0) two-dimensional gel electrophoresis. a total of 723 spots representing 574 protein entries were identified by maldi-tof/tof ms, including the majority of known key virulence factors. 64 hypothetical proteins and six misannotated protein ...201020164057
influences of hydraulic loading rate on svoc removal and microbial community structure in drinking water treatment biofilters.six biofilters were used for advanced treatment of yangtze river source water to investigate the effects of hydraulic loading rate (hlr) on pollutant removal and microbial community. hlr was found to exert significant influences on the removal efficiency of the conventional pollutants and 24 detectable semivolatile organic compounds (svocs). more than 85% of chemical oxygen demand and assimilable organic carbon was removed at the optimal hlr of 3.0 m h(-1). with the increase of hlr, svoc removal ...201020189298
disruption of the rickettsia rickettsii sca2 autotransporter inhibits actin-based motility.rickettsii rickettsii, the etiologic agent of rocky mountain spotted fever, replicates within the cytosol of infected cells and uses actin-based motility to spread inter- and intracellularly. although the ultrastructure of the actin tail and host proteins associated with it are distinct from those of listeria or shigella, comparatively little is known regarding the rickettsial proteins involved in its organization. here, we have used random transposon mutagenesis of r. rickettsii to generate a s ...201020194597
specific igg activity against diarrheagenic bacteria in bovine immune milk and effect of ph on its antigen-binding activity upon heating.bovine colostrum and milk antibodies of calving and lactating cows immunized with a multivalent vaccine consisting of whole cells of three different species of pathogenic bacteria including four strains of enterotoxigenic escherischia coli, five strains of enteropathogenic esch. coli, three strains of enteroinvasive esch. coli, two strains of samonella typhi, and one strain each of shigellia dysenteriae, sh. sonnei and sh. flexneri were generated, respectively. a significantly elevated activity ...201020196896
mst (molecular serotyping tool): a program for computer-assisted molecular identification of escherichia coli and shigella o antigens.escherichia coli and shigella o antigens can be inferred using the rfb-restriction fragment length polymorphism (rflp) molecular test. we present herein a dynamic programming algorithm-based software to compare the rfb-rflp patterns of clinical isolates with those in a database containing the 171 previously published patterns corresponding to all known e. coli/shigella o antigens.201020200287
structure, biological functions and applications of the ab5 toxins.ab(5) toxins are important virulence factors for several major bacterial pathogens, including bordetella pertussis, vibrio cholerae, shigella dysenteriae and at least two distinct pathotypes of escherichia coli. the ab(5) toxins are so named because they comprise a catalytic a-subunit, which is responsible for disruption of essential host functions, and a pentameric b-subunit that binds to specific glycan receptors on the target cell surface. the molecular mechanisms by which the ab(5) toxins ca ...201020202851
prevalence of plasmid-mediated quinolone-resistance determinants in shigella flexneri isolates from anhui province, china.quinolones are used extensively to treat shigella flexneri infection, and plasmid-mediated quinolone resistance (pmqr) determinants were recently reported. a total of 26 s. flexneri isolates collected from anhui province, china, in 2005 were screened for pmqr determinants, bla gene, gyra and parc genes, by pcr and sequencing. pmqr determinants were present in 53.8% (14 of 26) of isolates and qnra(1), qnrs(1), qnrs(2), aac(6')-ib-cr and qepa were present in 30.8, 11.5, 3.8, 19.2 and 11.5% of thos ...201020203702
[rectal prolapse in a neonate with shigella diarrhea].a case of neonatal rectal prolapse during shigella diarrhea is described. a 10 days neonate exclusively breast fed, whose 2 years old brother has had the same process 2 weeks ago. medical treatment with intravenous ceftriaxone resolved rectal prolapse in 48 hours. stool cultures showed the presence of shigella flexneri ii resistant to amoxicillin; blood and cerebrospinal fluid, cultures were negative. conclusion: rectal prolapse is an uncommon complication seen in infants with shigella diarrhea. ...201020204227
synthesis, in-vitro antimicrobial and cytotoxic studies of novel azetidinone derivatives.developing novel antimicrobial drugs is increasingly important in the modern pharmaceutical industry. a series of novel 3-chloro-4-[4-(2-oxo-2h-chromen-4-ylmethoxy)phenyl]-1-phenylazetidin-2-ones 5a-o have been synthesized from 4-bromomethylcoumarins 1a-e and 4-aryliminomethyl-phenols 3a-c. these compounds were screened for their in-vitro antibacterial activity against two gram-positive (staphylococcus aureus and vancomycin resistant enteroccoccus) and two gram-negative (escherichia coli and shi ...201020205197
induction of apoptosis by shiga toxins.shiga toxins comprise a family of structurally and functionally related protein toxins expressed by shigella dysenteriae serotype 1 and multiple serotypes of escherichia coli. while the capacity of shiga toxins to inhibit protein synthesis by catalytic inactivation of eukaryotic ribosomes has been well described, it is also apparent that shiga toxins trigger apoptosis in many cell types. this review presents evidence that shiga toxins induce apoptosis of epithelial, endothelial, leukocytic, lymp ...201020210553
identification and characterization of ctx-m-producing shigella isolates in the united states. 201020211893
prolonged remission of chronic reactive arthritis treated with three infusions of infliximab.reactive arthritis is generally self-remitting but can be chronic. predictors of chronicity include hla b27 positivity and triggering infections with yersinia, salmonella, shigella, or chlamydia. nonsteroidal antiinflammatory drugs and local steroids are the mainstays, with some evidence for disease modifying antirheumatic drugs. limited evidence suggests effectiveness of tumor necrosis factor antagonists. we report the case of reactive arthritis following a chlamydia urinary tract infection pro ...201020216128
autotransporter passenger proteins: virulence factors with common structural themes.autotransporter proteins are virulence factors associated with a wide variety of diseases caused by pathogenic gram-negative bacteria, and they play a variety of roles in pathogenesis including disabling host defences and mediating colonization. pertactin, a key component of the whooping cough vaccine, is an autotransporter protein. a large sub-family of the autotransporters carries a trypsin-like protease domain, but these enzymes have different substrates and functions. the unique export proce ...201020217035
[role of galactose-specific receptor--lectin in bactericidal activity of hemolysin of vibrio cholerae non o1/o139].to study the role lectin galactose-specific receptor of vibrio cholerae hemolysin in receptor mechanisms of bacterial cells lysis.201020218337
shigella mediated depletion of macrophages in a murine breast cancer model is associated with tumor regression.a tumor promoting role of macrophages has been described for a transgenic murine breast cancer model. in this model tumor-associated macrophages (tams) represent a major component of the leukocytic infiltrate and are associated with tumor progression. shigella flexneri is a bacterial pathogen known to specificly induce apotosis in macrophages. to evaluate whether shigella-induced removal of macrophages may be sufficient for achieving tumor regression we have developed an attenuated strain of s. ...201020221397
disease burden of post-infectious irritable bowel syndrome in the netherlands.post-infectious irritable bowel syndrome (pi-ibs) has been established as a sequel of infectious intestinal disease (iid). the aim of this study was to estimate the burden of pi-ibs caused by the pathogens campylobacter, salmonella and shigella, and to compare this with other outcomes associated with these pathogens. the attributable risk of pi-ibs due to bacterial pathogens was calculated and linked to national data on gastroenteritis incidence and measures for severity and duration of illness ...201020223049
a new paradigm of bacteria-gut interplay brought through the study of shigella.bacteria-gut epithelial interplay and the mucosal immune response are the most critical issues in determining the fate of bacterial infection and the severity of diseases. shigella species (abbreviated here as shigella), the causative agent of bacillary dysentery (shigellosis), are highly adapted human pathogens that are capable of invading and colonizing the intestinal epithelium, which results in severe inflammatory colitis. shigella secrete a large and diverse number (more then 50) of effecto ...201020228623
[shigella bacteremia dysentery in an adult]. 201020232025
high-throughput screening of the virulence regulator virf: a novel antibacterial target for shigellosis.shigella flexneri is a human enteropathogen that infects about 165 million people and claims more than 1 million lives per year worldwide. although shigellosis has been considered a disease of the "third world," like many other contagious diseases, it does occur in developed countries. the emergence of drug and multidrug-resistant strains of shigella emphasizes the need for novel antibiotic development. virf, an arac-type transcriptional regulator, is responsible for the expression of all downst ...201020237205
[the evolution of the etiological structure of shigellosis]. 201020734730
plasmon-induced inactivation of enteric pathogenic microorganisms with ag-agi/al2o3 under visible-light irradiation.the plasmon-induced photocatalytic inactivation of enteric pathogenic microorganisms in water using ag-agi/al(2)o(3) under visible-light irradiation was investigated. the catalyst was found to be highly effective at killing shigella dysenteriae (s. dysenteriae), escherichia coli (e. coli), and human rotavirus type 2 wa (hrv-wa). its bactericidal efficiency was significantly enhanced by hco(3)(-) and so(4)(2-) ions, which are common in water, while phosphate had a slightly positive effect on the ...201020734989
detection of airborne bacteria in a german turkey house by cultivation-based and molecular methods.today's large-scale poultry production with densely stocked and enclosed production buildings is often accompanied by very high concentrations of airborne microorganisms leading to a clear health hazard for employees working in such environments. depending on the expected exposure to microorganisms, work has to be performed under occupational safety conditions. in this study, turkey houses bioaerosols were investigated by cultivation-based and molecular methods in parallel to determine the conce ...201020720091
uncivil engineers: chlamydia, salmonella and shigella alter cytoskeleton architecture to invade epithelial cells.the obligate intracellular bacterial pathogen chlamydia trachomatis is a major cause of blindness and sexually transmitted diseases. like the enteric pathogens salmonella and shigella, chlamydia injects effector proteins into epithelial cells to initiate extensive remodeling of the actin cytoskeleton at the bacterial attachment site, which culminates in the engulfment of the bacterium by plasma membrane extensions. numerous salmonella and shigella effectors promote this remodeling by activating ...201020722600
serum neopterin is elevated in patients infected with shigella.abstract:201020727206
lactoferrin increases both resistance to salmonella typhimurium infection and the production of antibodies in mice.lactoferrin (lf) is a multifunctional iron-binding glycoprotein with antibacterial and immunomodulatory activities. the antibacterial influence of orally administered bovine lf (blf) against murine infection caused by salmonella typhimurium (s. typhimurium) has scarcely been explored. in the current study, balb/c mice were treated orally for 7 days with either 5 or 100mg of bovine lactoferrin (blf). on day 7 of treatment, mice were intragastrically infected with a lethal or sublethal dose of col ...201020727369
medicinal potions used against infectious bowel diseases in mayan traditional medicine.since one of the main health problems of the indigenous population are infectious bowel diseases, we decided to test mayan medicinal potions used to treat these conditions against some of the causal agents.201020728517
[dysentery and amoebiasis in poland in 2008].the number as well as incidence rate of notified as shigellosis, bacillary dysentery cases in xxi century are every year lower. only 33 cases were notified in the year 2008 (incidence rate 0.09/100 000 population), while the 64 cases were notified in 2007 (incidence rate 0.17/100 000), but 35 (incidence rate 0.09) were notified in 2006 and median in the 2002-2006 years was 75 cases, incidence rate 0.2/100 000 population. since 2000 no one-death case was notified. several imported cases were noti ...201020731222
pad4 is essential for antibacterial innate immunity mediated by neutrophil extracellular traps.neutrophils trap and kill bacteria by forming highly decondensed chromatin structures, termed neutrophil extracellular traps (nets). we previously reported that histone hypercitrullination catalyzed by peptidylarginine deiminase 4 (pad4) correlates with chromatin decondensation during net formation. however, the role of pad4 in net-mediated bacterial trapping and killing has not been tested. here, we use pad4 knockout mice to show that pad4 is essential for net-mediated antibacterial function. u ...201020733033
mutagenesis and chemical cross-linking suggest that wzz dimer stability and oligomerization affect lipopolysaccharide o-antigen modal chain length control.in shigella flexneri, the polysaccharide copolymerase (pcp) protein wzz(sf) confers a modal length of 10 to 17 repeat units (rus) to the o-antigen (oag) component of lipopolysaccharide (lps). pcps form oligomeric structures believed to be related to their function. to identify functionally important regions within wzz(sf), random in-frame linker mutagenesis was used to create mutants with 5-amino-acid insertions (termed wzz(i) proteins), and dna sequencing was used to locate the insertions. anal ...201020453100
carbon metabolism of intracellular bacterial pathogens and possible links to virulence.new technologies such as high-throughput methods and 13c-isotopologue-profiling analysis are beginning to provide us with insight into the in vivo metabolism of microorganisms, especially in the host cell compartments that are colonized by intracellular bacterial pathogens. in this review, we discuss the recent progress made in determining the major carbon sources and metabolic pathways used by model intracellular bacterial pathogens that replicate either in the cytosol or in vacuoles of infecte ...201020453875
acid stress response in enteropathogenic gammaproteobacteria: an aptitude for survival.enteric bacteria such as escherichia coli have acquired a wide array of acid stress response systems to counteract the extreme acidity encountered when invading the host's digestive or urinary tracts. these acid stress response systems are both enzyme and chaperone based. the 3 main enzyme-based acid resistance pathways are glutamate-, arginine-, and lysine-decarboxylase pathways. they are under a complex regulatory network allowing the bacteria to fine tune its response to the external environm ...201020453931
antioxidant, antibacterial and antigiardial activities of walsura robusta roxb.walsura robusta roxb. (family: meliaceae) is a well-known multi-purpose medicinal plant, and has been employed for a wide range of disease conditions without documented scientific data. in the current study, four pure isolated compounds, 3,4,5-trimethoxyphenyl beta-d-glucopyranoside (1), turpinionoside a (2), (+)-lyoniresinol 3alpha-o-beta-d-glucopyranoside (3) and (-)-lyoniresinol 3alpha-o-beta-d-glucopyranoside (4), were isolated from the leaves and twigs of w. robusta. biological evaluation f ...201020461627
structures of the o-antigens of escherichia coli o13, o129, and o135 related to the o-antigens of shigella flexneri.o-polysaccharides (o-antigens) were isolated from escherichia coli o13, o129, and o135 and studied by chemical analyses along with 2d (1)h and (13)c nmr spectroscopy. they were found to possess a common -->2)-l-rha-(alpha1-->2)-l-rha-(alpha1-->3)-l-rha-(alpha1-->3)-d-glcnac-(beta1--> backbone, which is a characteristic structural motif of the o-polysaccharides of shigella flexneri types 1-5. in both the bacterial species, the backbone is decorated with lateral glucose residues or/and o-acetyl gr ...201020546712
agap2 regulates retrograde transport between early endosomes and the tgn.the retrograde transport route links early endosomes and the tgn. several endogenous and exogenous cargo proteins use this pathway, one of which is the well-explored bacterial shiga toxin. adp-ribosylation factors (arfs) are approximately 20 kda gtp-binding proteins that are required for protein traffic at the level of the golgi complex and early endosomes. in this study, we expressed mutants and protein fragments that bind to arf-gtp to show that arf1, but not arf6 is required for transport of ...201020551179
host factors required for modulation of phagosome biogenesis and proliferation of francisella tularensis within the cytosol.francisella tularensis is a highly infectious facultative intracellular bacterium that can be transmitted between mammals by arthropod vectors. similar to many other intracellular bacteria that replicate within the cytosol, such as listeria, shigella, burkholderia, and rickettsia, the virulence of f. tularensis depends on its ability to modulate biogenesis of its phagosome and to escape into the host cell cytosol where it proliferates. recent studies have identified the f. tularensis genes requi ...201020552012
generation of chitin-derived oligosaccharides toxic to pathogenic bacteria using chia74, an endochitinase native to bacillus thuringiensis.to demonstrate that an endochitinase (chia74) native to bacillus thuringiensis can be used to generate chitin-derived oligosaccharides (ogs) with antibacterial activity against a number of aetiological agents of disease, including bacteria that cause diarrhoeal and emetic syndromes in humans.201020557451
development of a serogroup-specific multiplex pcr assay to detect a set of escherichia coli serogroups based on the identification of their o-antigen gene clusters.the escherichia coli serogroups o115, o126, o137, o158, o165, and o173 are pathogenic strains associated with diarrhea. molecular approaches such as pcr have been proven to be rapid, inexpensive, and accurate. the sequences of the o-antigen-processing genes wzx and wzy are specific for different o antigens and are generally used as the target genes for the detection and identification of e. coli strains belonging to different o serogroups. in this report, the o-antigen gene clusters of these 6 o ...201020561581
frequency and antimicrobial susceptibility of shigella species isolated in children medical center hospital, tehran, iran, 2001-2006.appropriate antimicrobial treatment of shigellosis depends on identifying its changing resistance pattern over time. we evaluated 15,255 stool culture submitted from july 2001 to june 2006 to the laboratory of children medical center hospital. specimen culture, bacterial identification, and disk diffusion susceptibility testing were performed according to national committee for clinical laboratory standards guidelines. from 15,255 stool samples, 682 (4.5%) were positive for shigella species. the ...201020563441
comparison of chromogenic biolog rainbow agar shigella/aeromonas with xylose lysine desoxycholate agar for isolation and detection of shigella spp. from foods.shigella outbreaks are widely reported throughout the world. however, it remains a challenge to isolate shigella spp. from foods by using conventional microbiological media. the main objective of this study was to determine the effectiveness of a novel chromogenic medium, rainbow agar shigella/aeromonas (rainbow agar), for the isolation and detection of shigella spp. in foods. all four shigella species, s. sonnei, s. flexneri, s. dysenteriae, and s. boydii, were studied. rainbow agar was compare ...201020819355
cytoskeleton-modulating effectors of enteropathogenic and enterohemorrhagic escherichia coli: a case for espb as an intrinsically less-ordered effector.enterohemorrhagic and enteropathogenic escherichia coli produce various effector proteins that are directly injected into the host-cell cytosol through the type iii secretion system. e. coli secreted protein (esp)b is one such effector protein, and affects host-cell morphology by reorganizing actin networks. unlike most globular proteins that have well-ordered, rigid structures, the structures of type iii secretion system effectors from pathogenic gram-negative bacteria, including espb, are ofte ...201020477867
sensitization of microcin j25-resistant strains by a membrane-permeabilizing peptide.microcin j25 (mccj25) is a plasmid-encoded, 21-amino-acid, antibacterial peptide produced by escherichia coli. mccj25 inhibits rna polymerase and the membrane respiratory chain. mccj25 uptake into e. coli-sensitive strains is mediated by the outer membrane receptor fhua and the inner membrane proteins tonb, exbb, exbd, and sbma. this peptide is active on some e. coli, salmonella, and shigella species strains, while other gram-negative bacteria, such as clinical isolates of enterobacter cloacae, ...201020802073
an outbreak of shigellosis due to shigella flexneri serotype 3a in a prison in iran.on june 16 and 17, 2007, the medical clinic of a prison in isfahan, iran received multiple reports of gastrointestinal illness among prisoners. a cross-sectional study was therefore undertaken to determine the extent, causative agent and possible source of the outbreak.201020804308
near-atomic resolution analysis of bipd, a component of the type iii secretion system of burkholderia pseudomallei.burkholderia pseudomallei, the causative agent of melioidosis, possesses a type iii protein secretion apparatus that is similar to those found in salmonella and shigella. a major function of these secretion systems is to inject virulence-associated proteins into target cells of the host organism. the bipd gene of b. pseudomallei encodes a secreted virulence factor that is similar in sequence and is most likely to be functionally analogous to ipad from shigella and sipd from salmonella. proteins ...201020823511
molecular mechanisms of necroptosis: an ordered cellular explosion.for a long time, apoptosis was considered the sole form of programmed cell death during development, homeostasis and disease, whereas necrosis was regarded as an unregulated and uncontrollable process. evidence now reveals that necrosis can also occur in a regulated manner. the initiation of programmed necrosis, 'necroptosis', by death receptors (such as tumour necrosis factor receptor 1) requires the kinase activity of receptor-interacting protein 1 (rip1; also known as ripk1) and rip3 (also kn ...201020823910
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