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production of antimicrobial silver nanoparticles in water extracts of the fungus amylomyces rouxii strain ksu-09.a fungal strain, ksu-09, isolated from the roots of date palm (phoenix dactylifera), was identified as amylomyces rouxii based on sequence analysis of the internal transcribed spacer (its) region of its rrna genes. mycelia-free water extracts obtained from mycelium suspended in water for 72h facilitated the production of stable, predominantly monodispersed and spherical silver nanoparticles (agnps) in the size range of 5-27nm upon addition of 1mm silver nitrate, as determined by the xrd, afm and ...201020619641
synthesis, structure and in vitro antibacterial activities of new hybrid disinfectants quaternary ammonium compounds: pyridinium and quinolinium stilbene benzenesulfonates.the series of pyridinium (1-10) and quinolinium (11-20) stilbene benzenesulfonates have been synthesized and their structures were investigated by uv-vis, ft-ir and (1)h nmr spectroscopy. in addition, compound 5 was also determined by single crystal x-ray diffraction technique. the antibacterial activity of the synthesized compounds against both gram-positive and gram-negative bacteria has been determined. the quinolinium derivatives exhibited two very potent characteristic activities, namely, ( ...201020619939
comparison of 61 sequenced escherichia coli genomes.escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. sixty-one publically available e. coli and shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics trees, and to identify the pan- and core genomes of this set of sequenced strains. a hierarchical clustering of variable genes allowed clear separation of the strains into clusters, including known pathoty ...201020623278
reduced azithromycin susceptibility in shigella sonnei, united states.to investigate azithromycin susceptibility in shigella sonnei in the united states, we examined the azithromycin minimum inhibitory concentrations (mics) of outbreak and routine human s. sonnei isolates. isolate susceptibility clustered at 8 mg/l, but three isolates displayed higher mics (>64  mg/l) to azithromycin. all three isolates contained a plasmid-encoded mpha gene, known to encode a macrolide-2'-phosphotransferase enzyme. transformation of the mpha gene into escherichia coli dh10b allowe ...201020624094
evidence for alternative quaternary structure in a bacterial type iii secretion system chaperone.type iii secretion systems are a common virulence mechanism in many gram-negative bacterial pathogens. these systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. prior to translocation specialized chaperones maintain proper effector protein conformation. the class ii chaperone, invasion plasmid gene (ipg) c, stabilizes ...201020633281
prolonged episodes of acute diarrhea reduce growth and increase risk of persistent diarrhea in children.prolonged episodes of acute diarrhea (prod; duration 7-13 days) or persistent diarrhea (pd; duration ≥14 days) are important causes of undernutrition, yet the epidemiology and nutritional impact of prod are poorly understood.201020638937
the omptins of yersinia pestis and salmonella enterica cleave the reactive center loop of plasminogen activator inhibitor 1.plasminogen activator inhibitor 1 (pai-1) is a serine protease inhibitor (serpin) and a key molecule that regulates fibrinolysis by inactivating human plasminogen activators. here we show that two important human pathogens, the plague bacterium yersinia pestis and the enteropathogen salmonella enterica serovar typhimurium, inactivate pai-1 by cleaving the r346-m347 bait peptide bond in the reactive center loop. no cleavage of pai-1 was detected with yersinia pseudotuberculosis, an oral/fecal pat ...201020639337
shiga toxin b subunits induce vwf secretion by human endothelial cells and thrombotic microangiopathy in adamts13-deficient mice.diarrhea-associated hemolytic uremic syndrome (d+hus) is the most common cause of acute renal failure among children. renal damage in d+hus is caused by shiga toxin (stx), which is elaborated by shigella dysenteriae and certain strains of escherichia coli, in north america principally e coli o157:h7. recent studies demonstrate that stx also induces von willebrand factor (vwf) secretion by human endothelial cells and causes thrombotic thrombocytopenic purpura, a disease with similarities to d+hus ...201020644116
photodynamic antimicrobial chemotherapy by liposome-encapsulated water-soluble photosensitizers.photodynamic antimicrobial chemotherapy is an alternative method for killing bacterial cells in view of the increasing problem of multi-antibiotic resistance. we examined the effect of three water-soluble photosensitizers (phs): methylene blue (mb), neutral red (nr) and rose bengal (rb) on gram-positive and gram-negative bacteria. we compared the efficacy of phs in their free form and encapsulated in liposomal formulations against various bacterial strains, and determined conditions for the effe ...201020644595
[structure of the oligosaccharide region (core) of the lipopolysaccharides of shigella flexneri types 2a and 5b].the full structure of the lipopolysaccharide core of bacteria shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional nmr spectroscopy. the structure of the o-antigen repeating unit and the configuration and position of the linkage between the o-antigen and the core were determined in the lipopolysaccharide of s. flexneri type 2a.201020644600
antibacterial properties of essential oils and methanol extracts of sweet basil ocimum basilicum occurring in bangladesh.the antibacterial potential of essential oils and methanol extracts of sweet basil ocimum basilicum l. (lamiaceae) was evaluated for controlling the growth range of food-borne pathogenic bacteria. essential oils extracted by hydrodistillation from the leaves and stems were analyzed by gc-ms. fifty-seven compounds representing 94.9 and 96.1% of the total leaf and stem oils, respectively, were identified, of which methyl chavicol (36.7 and 29.9%), gitoxigenin (9.3 and 10.2%), trimethoquinol (10.3 ...201020645791
enteropathogenic escherichia coli, samonella, shigella and yersinia: cellular aspects of host-bacteria interactions in enteric diseases.abstract: a successful infection of the human intestine by enteropathogenic bacteria depends on the ability of bacteria to attach and colonize the intestinal epithelium and, in some cases, to invade the host cell, survive intracellularly and disseminate from cell to cell. to accomplish these processes bacteria have evolved an arsenal of molecules that are mostly secreted by dedicated type iii secretion systems, and that interact with the host, subverting normal cellular functions. here we overvi ...201020649986
in silico characterization of shikimate kinase of shigella flexneri: a potential drug target.shigella flexneri is a major pathogen responsible for shigellosis causing massive morbidity among young population and imposes huge socio-economic burden. in this study, shikimate kinase (sk) from s. flexneri was characterized in silico and disordered regions were predicted. motifs and domains were calculated using computational tools. a three dimensional model of shikimate kinase of s.flexneri was constructed using shikimate kinase of e.coli (pdbid: 1kag_a) as template by comparative modeling a ...201020658341
convalescent cultures for control of shigellosis outbreaks.a shigellosis outbreak in the st louis, missouri metropolitan area.201020661101
prevalence of integrons in shigella sonnei from brazil. 201020664608
synthesis and in vitro antibacterial activity of novel fluoroquinolone derivatives containing substituted piperidines.we report herein the synthesis of novel 7-(4-alkoxyimino-3-aminomethyl-3-methylpiperidin-1-yl) fluoroquinolone derivatives. the antibacterial activity of the newly synthesized compounds was evaluated and correlated with their physicochemical properties. results reveal that all of the target compounds have good potency in inhibiting the growth of staphylococcus aureus and staphylococcus epidermidis including mrse (mic: 0.125-4 microg/ml). compounds 12, 13 are more potent than or comparable to lev ...201020667731
glycan encapsulated gold nanoparticles selectively inhibit shiga toxins 1 and 2.shiga toxins (stx) released by escherichia coli o157:h7 and shigella dysentriae cause life-threatening conditions that include hemolytic uremic syndrome (hus), kidney failure, and neurological complications. cellular entry is mediated by the b-subunit of the ab(5) toxin, which recognizes cell surface glycolipids present in lipid raft-like structures. we developed gold glyconanoparticles that present a multivalent display similar to the cell surface glycolipids to compete for these toxins. these ...201020669970
control of coliform bacteria detected from diarrhea associated patients by extracts of moringa oleifera.the aims of this study were to determine the total population of coliform bacteria in the samples collected from diarrhea associated patients from the local area of bangladesh and to examine the antibacterial efficacy of leaf extracts of moringa oleifera (moringaceae) against the isolated coliform bacteria. the coliform bacteria detected in these samples by some microbial-biochemical tests such as escherichia coli, shigella dysenteriae, salmonella sp., enterobacter sp., klebsiella pneumoniae and ...201020677603
impact of diet in shaping gut microbiota revealed by a comparative study in children from europe and rural africa.gut microbial composition depends on different dietary habits just as health depends on microbial metabolism, but the association of microbiota with different diets in human populations has not yet been shown. in this work, we compared the fecal microbiota of european children (eu) and that of children from a rural african village of burkina faso (bf), where the diet, high in fiber content, is similar to that of early human settlements at the time of the birth of agriculture. by using high-throu ...201020679230
facile glycosylation strategy with two-stage activation of allyl glycosyl donors. application to concise synthesis of shigella flexneri serotype y o-antigen.a practical, useful glycosylation method employing only allyl glycoside building blocks has been developed. the donor's glycosylation reactivity is turned on via isomerization of its anomeric allyl protecting group into the corresponding prop-1-enyl moiety. subsequent chemoselective activation with nis/tfoh achieves high yields in glycosidic bond construction at room temperature. the efficacy and efficiency of this approach in carbohydrate synthesis is demonstrated in the concise synthesis of th ...201020683518
antimicrobial resistance and molecular analysis of non-typhoidal salmonella isolates from human in tunisia.during the period from 2006 to 2007, a total of 32 clinical isolates of salmonella enterica were isolated from diarrheagenic stool samples and further examined for their susceptibility to various antibiotics. sixteen of the human isolates were from the capital tunis, 11 were from sousse, four were from nabeul and one was from mahdia, tunisia. the isolates were serotyped and identified at the national centre of enteropathogenic bacteria, pasteur institute, tunis (centre national de salmonella, sh ...201020685046
plasmid-mediated streptomycin and sulfamethoxazole resistance in shigella flexneri 3a.shigellosis is a major cause of diarrhoea-related morbidity and mortality, especially in children in developing countries such as india. recently, it was estimated that 91 million individuals worldwide contract shigellosis each year. the emergence and dissemination of multidrug-resistant strains of shigella is now an emerging global health problem. during the past two decades, much attention was given to re-evaluation of treatment recommendations. in the present study, we investigated a clinical ...201020685089
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.201020687081
hemolysin e (hlye, clya, shea) and related toxins.certain strains of escherichia coli, salmonella enterica and shigella flexneri produce a pore-forming toxin hemolysin e (hlye), also known as cytolysin a (clya) and silent hemolysin, locus a (shea). hlye lyses erythrocytes and mammalian cells, forming transmembrane pores with a minimum internal diameter of-25 a. we review the current knowledge of hlye structure and function in its solution and pore forms, models for membrane insertion, its potential use in biotechnology applications and its rela ...201020687485
shigellosis update: advancing antibiotic resistance, investment empowered vaccine development, and green bananas.shigella is the principal cause of clinical dysentery and an important cause of morbidity and mortality among children in impoverished regions. the purpose of this review is to present key findings in the areas of epidemiology, disease control, and treatment of shigellosis.201020689423
etiology of diarrhea in older children, adolescents and adults: a systematic review.diarrhea is an important cause of morbidity and mortality in all regions of the world and among all ages, yet little is known about the fraction of diarrhea episodes and deaths due to each pathogen.201020689809
crystal structures of phd-doc, higa, and yeeu establish multiple evolutionary links between microbial growth-regulating toxin-antitoxin systems.bacterial toxin-antitoxin (ta) systems serve a variety of physiological functions including regulation of cell growth and maintenance of foreign genetic elements. sequence analyses suggest that ta families are linked by complex evolutionary relationships reflecting likely swapping of functional domains between different ta families. our crystal structures of phd-doc from bacteriophage p1, the higa antitoxin from escherichia coli cft073, and yeeu of the yeeuwv systems from e. coli k12 and shigell ...201020696400
pic, an autotransporter protein secreted by different pathogens in the enterobacteriaceae family, is a potent mucus secretagogue.a hallmark of enteroaggregative escherichia coli (eaec) infection is a formation of biofilm, which comprises a mucus layer with immersed bacteria in the intestines of patients. while studying the mucinolytic activity of pic in an in vivo system, rat ileal loops, we surprisingly found that eaec induced hypersecretion of mucus, which was accompanied by an increase in the number of mucus-containing goblet cells. interestingly, an isogenic pic mutant (eaec δpic) was unable to cause this mucus hypers ...201020696826
diverse pathways for salicin utilization in shigella sonnei and escherichia coli carrying an impaired bgl operon.utilization of the aryl-β-glucosides salicin or arbutin in most wild-type strains of e. coli is achieved by a single-step mutational activation of the bgl operon. shigella sonnei, a branch of the diverse e. coli strain tree, requires two sequential mutational steps for achieving salicin utilization as the bglb gene, encoding the phospho-β-glucosidase b, harbors an inactivating insertion. we show that in a natural isolate of s. sonnei, transcriptional activation of the gene sso1595, encoding a ph ...201020697693
[mucocutaneous abnormalities in chlamydia trachomatis-induced reactive arthritis].reactive arthritis (previously known as reiters syndrome) is an inflammatory arthritis that is a type of spondyloarthropathy. the disease consists of the classical triad of arthritis, urethritis and conjunctivitis, but mucocutaneous abnormalities also frequently appear: balanitis circinata, keratoderma blennorrhagicum, aphthous ulcers in the mouth and nail disorders. these skin lesions are mainly found in reactive arthritis induced by chlamydia trachomatis (ct). reactive arthritis is often trigg ...201020699017
production of glycoprotein vaccines in escherichia coli.conjugate vaccines in which polysaccharide antigens are covalently linked to carrier proteins belong to the most effective and safest vaccines against bacterial pathogens. state-of-the art production of conjugate vaccines using chemical methods is a laborious, multi-step process. in vivo enzymatic coupling using the general glycosylation pathway of campylobacter jejuni in recombinant escherichia coli has been suggested as a simpler method for producing conjugate vaccines. in this study we descri ...201020701771
comparative in vitro activity of tigecycline and other antimicrobial agents against shigella species from kuwait and the united arab of emirates.shigella species isolated from stool samples of symptomatic patients of all age groups at the mubarak al kabir hospital and infectious diseases hospital, kuwait and tawam hospital, uae during a 2-year period were investigated for their susceptibility to tigecycline and several other antibiotics by determining the minimum inhibitory concentrations (mics) using the e test method. a total of 100 and 42 strains were collected from uae and kuwait, respectively. the extent of drug resistance in the sh ...201020701889
foodborne proportion of gastrointestinal illness: estimates from a canadian expert elicitation survey.the study used a structured expert elicitation survey to derive estimates of the foodborne attributable proportion for nine illnesses caused by enteric pathogens in canada. it was based on a similar study conducted in the united states and focused on campylobacter, escherichia coli o157:h7, listeria monocytogenes, nontyphoidal salmonella enterica, shigella spp., vibrio spp., yersinia enterocolitica, cryptosporidium parvum, and norwalk-like virus. for each pathogen, experts were asked to provide ...201020704505
seasonal variation of enteropathogens in infants and preschoolers with acute diarrhea in western mexico.the present study estimates the prevalence of some enteropathogens in infants and preschoolers with acute diarrhea. from 2006 to 2007, 5459 consecutive stool samples were evaluated. cryptosporidium parvum was the parasite identified with the higher frequency (5.1%), followed by giardia lamblia (1.2%). campylobacter jejuni was isolated in 858 cases (15.7%) and was the most frequent enteropathogen overall. the rates of c parvum, shigella, and salmonella were higher in the summer. rotavirus had the ...201020706147
csra and cra influence shigella flexneri pathogenesis.shigella flexneri is a facultative intracellular pathogen that invades and disrupts the colonic epithelium. in order to thrive in the host, s. flexneri must adapt to environmental conditions in the gut and within the eukaryotic cytosol, including variability in the available carbon sources and other nutrients. we examined the roles of the carbon consumption regulators csra and cra in a cell culture model of s. flexneri virulence. csra is an activator of glycolysis and a repressor of gluconeogene ...201020713625
phenotypic and genotypic characterization of shigella spp. with reference to its virulence genes and antibiogram analysis from river narmada.water samples of the river narmada from origin to end were analyzed for the presence of shigellae. analysis of 40 water samples by biotyping, serotyping, and molecular typing were done. out of all 40 isolates, 23 were identified as shigella flexneri, 10 as shigella sonnei, and seven as shigella dysenteriae. serotyping was found to be a better identification method than biotyping since biotyping was not found to be very sharp. in the present investigation, amplified ribosomal dna restriction anal ...201019501495
lactobacilli inhibit shigella dysenteriae 1 induced pro-inflammatory response and cytotoxicity in host cells via impediment of shigella-host interactions.shigella dysenteriae type 1 dysentery is a major cause of morbidity and mortality in children from less developed and developing countries. the present study explores the hypothesis that lactobacilli protect the host cell during s. dysenteriae type 1 infection and its mechanism of action.201019535308
biennial hyperepidemic shigellosis in an observant jewish community.we aimed to study patterns of shigellosis in a large observant jewish community in israel and to describe local interventions during outbreaks. surveillance data from the ministry of health were used to calculate incidence rates in 1998-2006, both in the city of bene beraq and the tel aviv district. information on isolates was collected from the bacteriological laboratory of a community hospital. public notices and educational conferences conveyed a message to increase personal hygiene and keep ...201019602299
survey of bacterial populations present in us-produced linerboard with high recycle content.to survey paperboard products from 17 us mills for bacterial populations and for bacteria potentially harmful to human health.201019645765
differential expression of enteric neuroimmune-network in invasive and acute watery diarrhoea.we aimed to evaluate the changes of nerve morphology and distribution of neurotransmitters and neuropeptides in the rectum of shigella flexneri-infected patients and in the duodenum of vibrio cholerae o1-infected patients. nerve morphology was observed by transmission electron microscopy. immunoreactivity of nerve growth factor (ngf), neurotransmitters and neuropeptides in tissues were studied by immunohistochemistry. ultrastructural analysis of intestinal biopsy revealed persisting axons degene ...201019650770
diarrhea in children less than two years of age with known hiv status in kisumu, kenya.to compare the frequency and etiology of diarrhea in children aged less than 2 years with known hiv status.201019664950
the escherichia coli o149 rfb gene cluster and its use for the detection of porcine e. coli o149 by real-time pcr.pcr or hybridization assays are widely used for the identification and detection of various escherichia coli serogroups and serotypes. this study explored this approach for the detection of e. coli o149 in pigs, a dominant serogroup among those associated with porcine post-weaning diarrhea (pwd) worldwide. for this purpose, we sequenced the o antigen (rfb) gene cluster of a representative enterotoxigenic e. coli (etec) o149:h10 strain and identified a 2kbp region specific for the o149 rfb gene c ...201019733452
evaluation of isolation methods for pathogenic yersinia enterocolitica from pig intestinal content.the aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic yersinia enterocolitica from pig intestinal content.201019735331
clinical practice. today's understanding of the haemolytic uraemic syndrome.the haemolytic uraemic syndrome (hus) includes the triad of haemolytic anaemia, thrombocytopenia, and acute renal failure. the classical form [d(+) hus] is caused by infectious agents, and it is a common cause of acute renal failure in children. the enterohaemorrhagic escherichia coli-producing shiga toxin (stx) is the most common infectious agent causing hus. other infectious agents are shigella and streptococcus pneumoniae. infections by s. pneumoniae can be particularly severe and has a highe ...201019707787
structure of the heme/hemoglobin outer membrane receptor shua from shigella dysenteriae: heme binding by an induced fit mechanism.shigella dysentriae and other gram-negative human pathogens are able to use iron from heme bound to hemoglobin for growing. we solved at 2.6 a resolution the 3d structure of the tonb-dependent heme/hemoglobin outer membrane receptor shua from s. dysenteriae. shua binds to hemoglobin and transports heme across the outer membrane. the structure consists of a c-terminal domain that folds into a 22-stranded transmembrane beta-barrel, which is filled by the n-terminal plug domain. one distal histidin ...201019731368
a new multiplex pcr for differential identification of shigella flexneri and shigella sonnei and detection of shigella virulence determinants.most of the multiplex pcr (mpcr) used to identify shigella do not discriminate between shigella species or serotypes. we designed a mpcr to differentiate between s. flexneri and s. sonnei strains based on the detection of markers associated with the she pathogenicity island described in shigella. in addition, specific primers were included to detect the shigella virulence determinants shet-1 and shet-2 enterotoxin genes. the analysis of 304 shigella strains from chile and 79 shigella strains fro ...201019765332
automated use of whonet and satscan to detect outbreaks of shigella spp. using antimicrobial resistance phenotypes.antimicrobial resistance is a priority emerging public health threat, and the ability to detect promptly outbreaks caused by resistant pathogens is critical for resistance containment and disease control efforts. we describe and evaluate the use of an electronic laboratory data system (whonet) and a space-time permutation scan statistic for semi-automated disease outbreak detection. in collaboration with whonet-argentina, the national network for surveillance of antimicrobial resistance, we appl ...201019796449
immunomodulation using genetically engineered bacteria for type iii-mediated delivery of heterologous antigens and cytokines: potential application in vaccine and therapeutical developments.the rational design of new approaches aiming to improve antigen or drug delivery remains a major challenge in numerous vaccine and therapeutical strategies. studies on genetically engineered bacteria have led to significant progress in the delivery of heterologous proteins. yet, the efficiency of such recombinant bacteria relies particularly on their ability to deliver sufficient amount of the drug to intended cell tissues. gram-negative bacteria like salmonella, shigella, yersinia and pseudomon ...201019778176
requirement for formin-induced actin polymerization during spread of shigella flexneri.actin polymerization in the cytosol and at the plasma membrane is locally regulated by actin nucleators. several microbial pathogens exploit cellular actin polymerization to spread through tissue. the movement of the enteric pathogen shigella flexneri, both within the cell body and from cell to cell, depends on actin polymerization. during intercellular spread, actin polymerization at the bacterial surface generates protrusions of the plasma membrane, which are engulfed by adjacent cells. in the ...201019841078
genetic diversity of o157:h7 and non-o157 verocytotoxigenic escherichia coli from argentina inferred from multiple-locus variable-number tandem repeat analysis (mlva).although serotype o157:h7 has been implicated in most cases of haemolytic-uraemic syndrome (hus), there is growing concern about non-o157 serotypes of verocytotoxigenic escherichia coli (vtec). multiple-locus variable-number tandem repeat analysis (mlva) has been focused on the specific typing of o157:h7 isolates, but recently, a generic mlva assay for e. coli and shigella has been developed. we performed a study of the polymorphism in 7 generic vntr loci both in vtec o157:h7 and non-o157 isolat ...201019850517
pretreatment of epithelial cells with rifaximin alters bacterial attachment and internalization profiles.rifaximin is a poorly absorbed semisynthetic antibiotic derivative of rifampin licensed for use in the treatment of traveler's diarrhea. rifaximin reduces the symptoms of enteric infection, often without pathogen eradication and with limited effects on intestinal flora. epithelial cells (hep-2 [laryngeal], hct-8 [ileocecal], a549 [lung], and hela [cervical]) were pretreated with rifaximin (or control antibiotics) prior to the addition of enteroaggregative escherichia coli (eaec). eaec adherence ...201019858255
evaluation of new chromogenic substrates for the detection of coliforms.to evaluate a new range of chromogenic substrates for the detection of beta-galactosidase activity in coliforms and to compare their performance in agar media and broths.201019878523
virulence, inflammatory potential, and adaptive immunity induced by shigella flexneri msbb mutants.the ability of genetically detoxified lipopolysaccharide (lps) to stimulate adaptive immune responses is an ongoing area of investigation with significant consequences for the development of safe and effective bacterial vaccines and adjuvants. one approach to genetic detoxification is the deletion of genes whose products modify lps. the msbb1 and msbb2 genes, which encode late acyltransferases, were deleted in the shigella flexneri 2a human challenge strain 2457t to evaluate the virulence, infla ...201019884336
inactivation of escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves by x-ray.several recent foodborne disease outbreaks associated with leafy green vegetables, including spinach, have been reported. x-ray is a non-thermal technology that has shown promise for reducing pathogenic and spoilage bacteria on spinach leaves. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves using x-ray at different doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) was studied. the effect of x-ray on col ...201019913687
effects of x-ray radiation on escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri inoculated on shredded iceberg lettuce.the main goal of this investigation was to study the efficacy of x-ray doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) on inoculated escherichia coli o157: h7, listeria monocytogenes, salmonella enterica and shigella flexneri on shredded iceberg lettuce. the second goal was to study the effect of x-ray on the inherent microflora counts and visual color of shredded iceberg lettuce during storage at 4 degrees c for 30 days. treatment with 1.0 kgy x-ray significantly reduced the population o ...201019913700
yersinia enterocolitica in slaughter pig tonsils: enumeration and detection by enrichment versus direct plating culture.tonsil samples from 139 slaughter pigs were examined for the presence of pathogenic yersinia enterocolitica by enrichment procedures based on the standard method iso 10273:2003. in addition, samples were tested by direct plating method to evaluate its efficiency compared to the enrichment culture methods and to quantify the level of contamination in porcine tonsils. in total, 52 samples (37.4%) were positive for pathogenic y. enterocolitica, all belonging to bioserotype 4/o:3. fifty out of the 5 ...201019913707
adaptive immune responses during shigella dysenteriae type 1 infection: an in vitro stimulation with 57 kda major antigenic omp in the presence of anti-cd3 antibody.an effort was made to understand the role of the 57 kda major antigenic fraction of shigella outer membrane protein (omp) in the presence of t-cell antigen receptor in activation of adaptive immune responses of the cell mediated immune (cmi) restored patients. the expression of hla-dr/cd4 out of cd3(+) t-cells was significantly dominant over the hla-dr/cd8 and comparable to unstimulated cells of infected or healthy controls. cd4(+) t-cell activation together with hla-dr is associated with the ex ...201019915959
differentiation and identification of shigella spp. and enteroinvasive escherichia coli in environmental waters by a molecular method and biochemical test.both shigella spp. and enteroinvasive escherichia coli (eiec) are important human pathogens that are responsible for the majority of cases of endemic bacillary dysentery. however, they are difficult to identify and differentiate by biochemical tests or molecular methods alone. in this study, we developed a procedure to detect shigella spp. and eiec from environmental water samples using membrane filtration followed by nutrient broth enrichment, isolation using selective culture plates, and ident ...201019917511
the australian bush fly (musca vetustissima) as a potential vector in the transmission of foodborne pathogens at outdoor eateries.abstract australian outdoor activities are often accompanied by a barbeque (bbq) with family, friends, and guests, which are often interrupted by uninvited guests in the form of the australian bush fly, musca vetustissima. we investigated the bacterial loading associated with the australian bush in three different environments: on a cattle farm, in a typical urban area (shopping center car park), and at a bbq. the highest bacterial populations per fly were found to occur in a farm environment ( ...201019895260
caspase-8-mediated cleavage of bid and protein phosphatase 2a-mediated activation of bax are necessary for verotoxin-1-induced apoptosis in burkitt's lymphoma cells.verotoxin (vt-1) is a cytotoxin, produced by shigella dysenteriae type 1 or by shiga toxin-producing escherichia coli, which binds specifically to globotriaosylceramide (gb3). this glycosphingolipid is a b cell differentiation antigen (gb3/cd77) strongly expressed on burkitt's lymphoma cells. we have previously shown that, in these cells, vt-1 induces apoptosis via a caspase- and mitochondria-dependent pathway. in this report, we provide new insights into this signal transduction pathway. first, ...201019895884
solution nmr structures of proteins vpa0419 from vibrio parahaemolyticus and yiis from shigella flexneri provide structural coverage for protein domain family pfam 04175. 201019927321
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
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
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
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
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
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
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
antibodies against recombinant shiga toxin subunit b neutralize shiga toxin toxicity in hela cells.shigella dysenteriae type 1 and escherichia coli o157:h7 produce shiga toxin 1 (stx) and shiga toxin1 (stx1), respectively and these two toxins are almost identical. e. coli o157:h7 is the major cause of diarrhea-associated hemolytic uremic syndrome. stx and stx1 are ab5 type of toxin with a molecular weight of 70 kda, comprising an enzymaticaly-active a subunit (32 kda) and five receptor-binding b subunits (7.7 kda). in this study dna fragment (289 bp, gene bank accn no. ef685161) coding for b ...201020044923
rifaximin-induced alteration of virulence of diarrhoea-producing escherichia coli and shigella sonnei.rifaximin shortens the duration of travellers' diarrhoea without important alteration of colonic flora. this study investigated the expression of virulence factors [heat-stable (st) and heat-labile (lt) enterotoxins, surface adhesion factors (cs2/cs3, cs6) and matrix metalloproteinase-9 (mmp-9)] as well as the interleukin (il)-8 induction potential of diarrhoeagenic escherichia coli and shigella sonnei strains exposed to rifaximin (8, 32 and 64mg/l) for 4, 8, 18 and 24h. following exposure to ri ...201020045287
increased immunoendocrine cells in intestinal mucosa of postinfectious irritable bowel syndrome patients 3 years after acute shigella infection--an observation in a small case control study.postinfectiously irritable bowel syndrome (pi-ibs) develops in 3-30% of individuals with bacterial gastroenteritis. recent studies demonstrated increases in inflammatory components in gut mucosa of pi-ibs patients even after complete resolution of infection. we aimed to investigate histological changes in colon and rectum of pi-ibs subjects after long term period of infection.201020046513
osmoregulated periplasmic glucans synthesis gene family of shigella flexneri.osmoregulated periplasmic glucans (opgs) of food- and water-borne enteropathogen shigella flexneri were characterized. opgs were composed of 100% glucose with 2-linked glucose as the most abundant residue with terminal glucose, 2-linked and 2,6-linked glucose also present in high quantities. most dominant backbone polymer chain length was seven glucose residues. individual genes from the opg gene family comprising of a bicistronic operon opggh, opgb, opgc and opgd were mutagenized to study their ...201020062978
nlrc4/ipaf/clan/card12: more than a flagellin sensor.nlrc4 is a member of the nod-like receptors (nlrs), a family of cytosolic receptors involved in sensing bacterial molecules. nlrs are a group of proteins containing spans of leucine-rich repeats that senses bacterial factors within the eukaryotic cytosol. the recognition of bacterial factors provokes the formation of the inflammasome complex which includes specific nlrs. the inflammasome is responsible for caspase-1 activation which leads to the cleavage and maturation of inflammatory cytokines ...201020067841
tracking the dynamic interplay between bacterial and host factors during pathogen-induced vacuole rupture in real time.escape into the host cell cytosol following invasion of mammalian cells is a common strategy used by invasive pathogens. this requires membrane rupture of the vesicular or vacuolar compartment formed around the bacteria after uptake into the host cell. the mechanism of pathogen-induced disassembly of the vacuolar membrane is poorly understood. we established a novel, robust and sensitive fluorescence microscopy method that tracks the precise time point of vacuole rupture upon uptake of gram-nega ...201020070313
age-related efficacy of shigella o-specific polysaccharide conjugates in 1-4-year-old israeli children.despite its high worldwide morbidity and mortality, there is yet no licensed vaccine for shigellosis. we reported the safety and immunogenicity of shigella o-specific polysaccharide-protein conjugates in adults and young children and efficacy of shigella sonnei conjugate in young adults.201020056180
the structure of the salmonella typhimurium type iii secretion system needle shows divergence from the flagellar system.the type iii secretion system (t3ss) is essential for the infectivity of many pathogenic gram-negative bacteria. the t3ss contains proteins that form a channel in the inner and outer bacterial membranes, as well as an extracellular needle that is used for transporting and injecting effector proteins into a host cell. the homology between the t3ss and the bacterial flagellar system has been firmly established, based upon both sequence similarities between respective proteins in the two systems an ...201020060835
new enterovirulent escherichia coli serogroup 64474 showing antigenic and genotypic relationships to shigella boydii 16.studies based on the analysis of housekeeping genes indicate that escherichia coli and all shigella species, except for shigella boydii type 13, belong to a single species. this study analysed the phenotypic and genotypic characteristics of 23 e. coli strains isolated in different countries from faecal specimens taken from children with diarrhoea. strains were identified using the vitek system and typed with rabbit sera obtained against 186 somatic and 53 flagellar e. coli antigens and against 4 ...201020075111
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
structural and functional divergence of the newly identified gtric from its gtr family of conserved shigella flexneri serotype-converting glucosyltransferases.glucosyltransferases (gtrs) and o-acetyltransferase (oac) are integral membrane proteins embedded within the cytoplasmic membrane of shigella flexneri. gtrs and oac are responsible for unidirectional host serotype conversion by altering the epitopic properties of the bacterial surface lipopolysaccharide (lps) o-antigen. in this study, we present the membrane topology of a recently recognized gtr, gtric, which is known to mediate s. flenxeri serotype switching from 1a to 1c. the gtric topology is ...201020095950
a yersinia pestis guaba mutant is attenuated in virulence and provides protection against plague in a mouse model of infection.there is a need to develop effective countermeasures for yersinia pestis, the etiologic agent of plague and a potential bioterrorism agent. salmonella and shigella spp. deleted in the guaba genes involved in guanine biosynthesis have been shown to be attenuated in vivo. in this study, we sought to determine whether deletion of the guaba operon would render y. pestis auxotrophic for guanine and avirulent; such a strain could serve as a live attenuated plague vaccine candidate. a y. pestis guaba m ...201020096773
antibacterial activity of artemisia nilagirica leaf extracts against clinical and phytopathogenic bacteria.the six organic solvent extracts of artemisia nilagirica were screened for the potential antimicrobial activity against phytopathogens and clinically important standard reference bacterial strains.201020109237
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
a novel antisense rna regulates at transcriptional level the virulence gene icsa of shigella flexneri.the virulence gene icsa of shigella flexneri encodes an invasion protein crucial for host colonization by pathogenic bacteria. within the intergenic region vira-icsa, we have discovered a new gene that encodes a non-translated antisense rna (named rnag), transcribed in cis on the complementary strand of icsa. in vitro transcription assays show that rnag promotes premature termination of transcription of icsa mrna. transcriptional inhibition is also observed in vivo by monitoring the expression p ...201020129941
cesarean delivery and risk of intestinal bacterial infection.an individual's intestinal bacterial flora is established soon after birth. delivery by cesarean section (c-section) deprives the newborn of colonization with maternal vaginal bacteria. we determined whether delivery by c-section is associated with an altered risk of infection with intestinal bacterial pathogens.201020132034
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