a global modulatory role for the yersinia enterocolitica h-ns protein.the h-ns protein plays a significant role in the modulation of gene expression in gram-negative bacteria. whereas isolation and characterization of hns mutants in escherichia coli, salmonella and shigella represented critical steps to gain insight into the modulatory role of h-ns, it has hitherto not been possible to isolate hns mutants in yersinia. the hns mutation is considered to be deleterious in this genus. to study the modulatory role of h-ns in yersinia we circumvented hns lethality by ex ...200818451036
mutagenesis of the shigella flexneri autotransporter icsa reveals novel functional regions involved in icsa biogenesis and recruitment of host neural wiscott-aldrich syndrome protein.the icsa (virg) protein of shigella flexneri is a polarly localized, outer membrane protein that is essential for virulence. within host cells, icsa activates the host actin regulatory protein, neural wiskott-aldrich syndrome protein (n-wasp), which in turn recruits the arp2/3 complex, which nucleates host actin to form f-actin comet tails and initiate bacterial motility. linker insertion mutagenesis was undertaken to randomly introduce 5-amino-acid in-frame insertions within icsa. forty-seven l ...200818456802
what's the point of the type iii secretion system needle?recent work by several groups has significantly expanded our knowledge of the structure, regulation of assembly, and function of components of the extracellular portion of the type iii secretion system (t3ss) of gram-negative bacteria. this perspective presents a structure-informed analysis of functional data and discusses three nonmutually exclusive models of how a key aspect of t3ss biology, the sensing of host cells, may be performed.200818458349
global epidemiology of infections due to shigella, salmonella serotype typhi, and enterotoxigenic escherichia coli. 200818461719
an intersubunit active site between supercoiled parallel beta helices in the trimeric tailspike endorhamnosidase of shigella flexneri phage sf6.sf6 belongs to the podoviridae family of temperate bacteriophages that infect gram-negative bacteria by insertion of their double-stranded dna. they attach to their hosts specifically via their tailspike proteins. the 1.25 a crystal structure of shigella phage sf6 tailspike protein (sf6 tsp) reveals a conserved architecture with a central, right-handed beta helix. in the trimer of sf6 tsp, the parallel beta helices form a left-handed, coiled-beta coil with a pitch of 340 a. the c-terminal domain ...200818462681
immunological evidence for functional rather than structural mimicry by a shigella flexneri y polysaccharide-mimetic approach to vaccine design is the use of molecules that mimic the immunogenic element of interest. in this context, the interaction of mdwnmhaa, a peptide mimic of the shigella flexneri y o polysaccharide (ps), with an anti-carbohydrate monoclonal antibody, as studied previously by x-ray crystallography, suggested the presence of functional rather than structural mimicry and a bound peptide conformation that was not represented significantly in the free-ligand ensemble. the antibody response ...200818463226
simple sequence repeats in different genome sequences of shigella and comparison with high gc and at-rich genomes.simple sequence repeats (ssrs) are omnipresent in prokaryotes and eukaryotes, and are found anywhere in the genome in both protein encoding and noncoding regions. in present study the whole genome sequences of seven chromosomes (shigella flexneri 2a str301 and 2457t, shigella sonnei, escherichia coli k12, mycobacterium tuberculosis, mycobacterium leprae and staphylococcus saprophyticus) have downloaded from the genbank database for identifying abundance, distribution and composition of ssrs and ...200818464038
identification of novel genomic islands associated with small rnas.genome evolution in prokaryotes is assisted by integration of gene pools from phages and plasmids. regions downstream of trnas and tmrnas are considered as hot spots for the integration of these gene pools or genomic islands. till date, genomic islands have been identified only at trna/tmrna genes in the enterobacterial genomes. present work reports 10 distinct small rnas as potent integration sites for genomic islands. a known tool trnacc 1.0 has been used to identify genomic islands associated ...200718467773
safety and immunogenicity of wrsd1, a live attenuated shigella dysenteriae type 1 vaccine candidate.among shigella serotypes shigella dysenteriae type 1 produces the most severe disease, including cases of hemolytic-uremic syndrome and pandemic outbreaks. wrsd1 is a live s. dysenteriae 1 strain attenuated by deletion of the virg(icsa) gene, which encodes a protein that mediates intercellular spread, and stxa and stxb, which encode the shiga toxin. in this phase i trial five groups of eight subjects ingested escalating doses of wrsd1 ranging from 10(3) to 10(7)cfu. no subject experienced fever ...200818468742
effect of lactoferrin on enteric pathogens.much has been learned in recent years about the mechanisms by which breastfeeding improves child health and survival. however, there has been little progress in using these insights to improve pediatric care. factors that are important for protecting the breast fed infant might be expected to decrease the adverse effects of weaning on diarrhea, growth, and development. lactoferrin, an iron-binding protein with multiple physiological functions (anti-microbial, anti-inflammatory, and immunomodulat ...200918472012
synthesis, characterization and antimicrobial activity of d metal complexes of some 2-substituted-1h-benzimidazoles.the metal complexes of nine 2-substituted-1h-benzimidazoles (i-ix) with ni(ii), pd(ii), cu(ii), ag(i), zn(ii) salts were synthesized. the compounds were characterized by melting point, analytical data, ir spectroscopy and magnetic susceptibility. the antimicrobial activity of the compounds was determined by the disk diffusion method in mueller-hinton agar on staphylococcus aureusatcc 6538, staphylococcus epidermidis atcc 12228, escherichia coli atcc 8739, klebsiella pneumoniae atcc 4352, pseudom ...199918472907
antimicrobial susceptibility of shigella isolates in eight asian countries, 2001-2004.shigellosis is a major health problem in developing countries, causing 91 million episodes and 414,000 deaths in asia annually. because of increasing trends towards drug resistance, this study was undertaken to monitor local resistance patterns of shigella isolates from 8 asian countries.200818473096
crystal structure of spa40, the specificity switch for the shigella flexneri type iii secretion system.the pathogenic bacterium shigella flexneri uses a type iii secretion system to inject virulence factors from the bacterial cytosol directly into host cells. the machinery that identifies secretion substrates and controls the export of extracellular components and effector proteins consists of several inner-membrane and cytoplasmic proteins. one of the inner membrane components, spa40, belongs to a family of proteins proposed to regulate the switching of substrate specificity of the export appara ...200818485071
specific detection of escherichia coli isolated from water samples using polymerase chain reaction targeting four genes: cytochrome bd complex, lactose permease, beta-d-glucuronidase, and develop a pcr-based method for reliable detection of escherichia coli that enables its differentiation from biochemically and phylogenetically related bacteria.200818489560
the response of type three secretion system needle proteins mxihdelta5, bsaldelta5, and prgidelta5 to temperature and ph.the type iii secretion system (ttss) is a specialized supramolecular injectisome composed of 25 or more proteins which form basal and extracellular domains and share gross architectural similarities with bacterial flagella. the extracellular component of the "needle complex" is primarily composed of a single monomeric subunit organized in a helical array surrounding a hollow pore and protrudes from the bacterial membrane. it is through this surface appendage that virulence factors are translocat ...200818491382
post-infectious functional gastrointestinal disorders in investigate the development of functional gastrointestinal disorders (fgids) after an episode of acute bacterial gastroenteritis (age) in children.200818492522
enterohaemorrhagic escherichia coli and shigella dysenteriae type 1-induced haemolytic uraemic syndrome.haemolytic uraemic syndrome (hus) can be classified according to the aetiology of the different disorders from which it is composed. the most prevalent form is that induced by shigatoxin producing escherichia coli (stec) and, in some tropical regions, by shigella dysenteriae type 1. stec cause a zoonosis, are widely distributed in nature, enter the food chain in different ways, and show regional differences. not all stec are human pathogens. enterohaemorrhagic e. coli usually cause attachment an ...200818493800
fast detection of salmonella infantis with carbon nanotube field effect this paper we report a fast, sensitive and label-free biosensor for the selective determination of salmonella infantis. it is based on a field effect transistor (fet) in which a network of single-walled carbon nantotubes (swcnts) acts as the conductor channel. anti-salmonella antibodies were adsorbed onto the swcnts and subsequently the swcnts were protected with tween 20 to prevent the non-specific binding of other bacteria or proteins. our fet devices were exposed to increasing concentratio ...200818495470
real-time pcrs and fingerprinting assays for the detection and characterization of salmonella genomic island-1 encoding multidrug resistance: application to 445 european isolates of salmonella, escherichia coli, shigella, and proteus.salmonella genomic island-1 (sgi-1) harbors a cluster of genes encoding multidrug resistance (mdr). sgi-1 is horizontally transmissible and is therefore of significant public health concern. this study presents two novel realtime pcrs detecting three sgi-1 protein-coding genes and a sgi-1 fingerprinting assay. these assays were applied to 445 european enterobacterial isolates. results from real-time pcrs were comparable to those obtained from gelbased pcrs used for the detection of sgi-1, but we ...200818500919
distinct isoforms of phospholipase a2 mediate the ability of salmonella enterica serotype typhimurium and shigella flexneri to induce the transepithelial migration of neutrophils.salmonella spp. and shigella spp. are responsible for millions of cases of enteric disease each year worldwide. while these pathogens have evolved distinct strategies for interacting with the human intestinal epithelium, they both induce significant proinflammatory responses that result in massive transepithelial migration of neutrophils across the intestinal mucosa. it has previously been shown with salmonella enterica serotype typhimurium that the process of neutrophil transmigration is mediat ...200818505810
etiology of childhood diarrhea in the northeast of brazil: significant emergent diarrheal a study conducted in joão pessoa, northeast of brazil, 2344 escherichia coli isolated from 290 infants with diarrhea and 290 healthy matched controls were analyzed for virulence traits. enteroaggregative e. coli (eaec) was the most prevalent pathogen associated to acute diarrhea. based on the results of colony blot hybridization, serotyping, and hep-2 cell adherence assays, strains were separated in categories as typical enteropathogenic e. coli (epec) (1.7%), atypical epec (a-epec) (9.3%), e ...201018508227
the epidemiological and clinical characteristics and nutritional development of infants with acute diarrhoea, in north-eastern order to assess the epidemiological and clinical characteristics and changing nutritional status of infants suffering from acute diarrhoea, 103 infants with such diarrhoea and the same number of age-matched controls were investigated at the universidade federal do rio grande do norte's paediatric hospital, in north-eastern brazil. each child with diarrhoea was given oral rehydration or, in the severe cases, intravenous rehydration. each subject was checked for enteropathogens and his or her w ...200818510816
a hierarchical model for studying risk factors for childhood diarrhoea: a case-control study in a middle-income identify factors associated with diarrhoea occurrence in children in a city in a middle-income country, with high access to water and sanitation.200818515864
viral, bacterial and parasitic etiology of pediatric diarrhea in gaza, determine the etiology of acute diarrhea in palestinian children under 5 years of age and to improve knowledge of the etiology of gastrointestinal pathogens using traditional and molecular diagnostic techniques.200818523397
the serine protease motif of pic mediates a dose-dependent mucolytic activity after binding to sugar constituents of the mucin substrate.the pic gene is harbored on the chromosomes of three important pathogens: enteroaggregative escherichia coli (eaec), uropathogenic e. coli (upec), and shigella flexneri. since pic is secreted into the intestinal lumen during eaec infection, we sought to identify intestinal-mucosal substrates for pic. pic did not damage epithelial cells, cleave fodrin, or degrade host defense proteins embedded in the mucus layer (siga, lactoferrin and lysozyme). however, by using a solid-phase assay to evaluate t ...200818538533
prevalence of different virulence factors and biofilm production in enteroaggregative escherichia coli isolates causing diarrhea in children in ifakara (tanzania).this study investigated the prevalence of 19 virulence factors and biofilm production in 86 eaec isolates causing diarrhea in children less than 5 years of age from ifakara, tanzania. virulence factors were detected by pcr, whereas biofilm production was determined using a microtiter plate assay. no virulence factor, with the exception of the aat gene used to identify eaec, was detected in 11/86 isolates (12.8%). the most frequently detected virulence factor was the aggr gene in 53 (61.6%) eaec, ...200818541781
crystal structure of escherichia coli phage hk620 tailspike: podoviral tailspike endoglycosidase modules are evolutionarily related.bacteriophage hk620 infects escherichia coli h and is closely related to shigella phage sf6 and salmonella phage p22. all three podoviridae recognize and cleave their respective host cell receptor polysaccharide by homotrimeric tailspike proteins. the three proteins exhibit high sequence identity in the 110 residues of their n-terminal particle-binding domains, but no apparent sequence similarity in their major, receptor-binding parts. we have biochemically characterized the receptor-binding par ...200818547389
shigella bacteraemia over a decade in soweto, south africa.shigella infection rarely penetrates beyond the intestinal mucosa to cause bacteraemia. aids patients may be at increased risk. we investigated shigella bacteraemia rates over a decade in a south african population with a high hiv prevalence and analysed presentation and outcome. a retrospective cohort analysis was performed for hospitalized patients for 2003-2006. the rates were compared to those for 1996-1998. adult medical rates decreased from 0.195/1000 in 1996-1998 to 0.087/1000 admissions ...200818550134
[shigella spp. infections in getafe hospital between 2001 and 2006].shigella spp. is a bacterium that frequently causes diarrhoea in underdeveloped countries, but not so much in spain, where it has been published that its incidence has decreased in the last few years.200818559201
a food borne outbreak of gastroenteritis due to shigella and possibly salmonella in a school.on august 5, 2005, a private hospital reported a large number of students with gastrointestinal illness from the same school in bangkok, thailand. the bureau of epidemiology along with the bangkok metropolitan administration investigated this outbreak, to determine risk factors, identify the source of infection and possible causative organism, and recommend prevention and control strategies. a case was defined as a person who was studying or working at school a and who developed abdominal pain, ...200818564716
reactive arthritis with conjunctivitis, urethritis and diarrhea in a child: immunological study of potential bacterial trigger. 200818565268
description of an unusual class 2 integron in shigella sonnei isolates in senegal (sub-saharan africa). 200818565971
molecular characterization of multidrug-resistant shigella species isolated from epidemic and endemic cases of shigellosis in india.shigella species represent one of the growing numbers of antimicrobial-resistant bacteria in developing countries. fluoroquinolone-resistant strains of shigella dysenteriae type 1 and shigella flexneri type 2a emerged in india during 2002 and 2003, respectively. sixty strains of shigella from different parts of india were analysed for antimicrobial susceptibility, the presence of the qnr plasmid, mutations in the quinolone resistance determining regions (qrdrs), fluoroquinolone accumulation, and ...200818566144
design, synthesis, characterization, antibacterial and antifungal activities of a novel class of 5,7-diaryl-4,4-dimethyl-4,5,6,7-tetrahydropyridino[3,4-d]-1,2,3-selenadiazoles.compound 26 is more potent against escherichia coli. and 24 is more active against staphylococcus aureus, beta-heamolytic streptococcus, vibreo cholerae, salmonella typhii, and shigella flexneri than the standard drug ciprofloxacin. moreover, of all the compounds tested, 26 is more effective against aspergillus flavus and mucor, than the standard drug fluconazole.200818569338
bacterial triggers and autoimmune rheumatic diseases.autoimmune rheumatic diseases are generally considered as a multifactorial aetiology, mainly genetic susceptibility combined with environmental triggers of which bacteria are considered one of the most prominent. among the rheumatic diseases where bacterial agents are more clearly involved as triggers are: reactive arthritis (rea), rheumatic fever (rf) and lyme disease. the role of bacterial infections in inducing other seronegative spondyloarthritis and antiphospholipid antibody syndrome has be ...200818570749
combined physico-chemical treatments based on enterocin as-48 for inactivation of gram-negative bacteria in soybean sprouts.enterocin as-48 was tested for decontamination of soybean sprouts against gram-negative bacteria. although treatment with bacteriocin alone had no effect on salmonella enterica, a synergistic antimicrobial effect was detected at ph 9.0 and in combination with moderate heat treatment. greatest inactivation was achieved for sprouts heated for 5 min at 65 degrees c in an alkaline (ph 9.0) enterocin as-48 solution of 25 microg/ml. bactericidal activity against s. enterica increased greatly when ente ...200818577412
vibrio cholerae vcib promotes iron uptake via ferrous iron transporters.vibrio cholerae uses a variety of strategies for obtaining iron in its diverse environments. in this study we report the identification of a novel iron utilization protein in v. cholerae, vcib. the vcib gene and its linked gene, vcia, were isolated in a screen for v. cholerae genes that permitted growth of an escherichia coli siderophore mutant in low-iron medium. the vciab operon encodes a predicted tonb-dependent outer membrane receptor, vcia, and a putative inner membrane protein, vcib. vcib, ...200818586940
anti-infectious effect of s-benzylisothiourea compound a22, which inhibits the actin-like protein, mreb, in shigella flexneri.s-benzylisothiourea compound a22 induces coccoid forms in escherichia coli by inhibiting the function of the actin-like cytoskeletal protein, mreb. the minimum inhibitory concentration of a22 and the minimum concentration to induce coccoid forms for various pathogenic bacteria were determined. at 10 microg/ml, a22 induced coccoid forms in shigella flexneri but did not inhibit the growth. no alteration of coccoid forms in the gram-positive bacteria and anaerobic bacteria tested were observed foll ...200818591769
[epidemic strains of different plasmidovars of bacteria from shigella genus].plasmid analysis of 46 strains of shigella species confirmed the view about heterogeneity and variability of plasmids composition in these microorganisms. on the other hand,the presence of low-molecular, multiplicated extrachromosomal replicons, which were stable, was shown. using them, it was possible to divide the shigella isolates into two major plasmidovars, characterize them according to repertoire of the most stable plasmids and determine epidemically significant variants during sporadic a ...200818595459
[sonnei dysentery--the next in stage of the shigelloses' evolution]. 200818595478
[electrical resistance of bacterial culture suspension as indicator of epidemic and sporadic variants of shigella].for the first time method of measurement of electric resistance of bacterial suspension was used for differentiation of "epidemic" and "sporadic" (further used without quotes) variants of shigella species. study of 40 strains of s. flexneri and s. sonnei revealed significant differences in electric resistance of cultures isolated during epidemic outbreaks after the growth during 1 or 6 hours - 18.1+/-8.3 kohm and 84.6+/-7.8 kohm respectively (increase in 4.9-fold; p<0.01), while non significant ...200818597992
shigella isolates of nepal: changes in the incidence of shigella subgroups and trends of antimicrobial susceptibility pattern.shigellosis is an important cause of bloody diarrhoea in all age groups, especially in children. a retrospective study was done to analyse the pattern of shigella isolates and the antimicrobial susceptibility trend of these shigella isolated at different hospitals of nepal from jan, 2003- dec, 2005.200718603983
clinico-laboratory profile of haemolytic uremic study the clinical profile, the spectrum of functional abnormalities, prognostic factors and outcome of children with haemolytic uremic syndrome (hus).200718604077
enteric bacteria isolated from acute diarrheal patients in the republic of korea between the year 2004 and an epidemiological survey of human enterobacterial infections in the republic of korea during three years from 2004 to 2006, we isolated 1,784 (6.2%, isolation rate of enteropathogens from stool samples) in 2004, 2,547 (9.5%) in 2005 and 3,506 bacteria (12.3%) from people who visited clinics. among the isolated bacteria, pathogenic escherichia coli, especially, eaec was the most frequently identified pathogen in both urban and rural regions followed by staphylococcus aureus, salmonella specie ...200818604503
intracellular bacteriolysis triggers a massive apoptotic cell death in shigella-infected epithelial cells.infected epithelial cells, which act as a first barrier against pathogens, seldom undergo apoptosis. rather, infected epithelial cells undergo a slow cell death that displays hallmarks of necrosis. here, we demonstrate that rapid intracellular lysis of shigella flexneri, provoked by either the use of a diaminopimelic acid auxotroph mutant or treatment of infected cells with antibiotics of the beta-lactam family, resulted in a massive and rapid induction of apoptotic cell death. this intracellula ...200818606244
selective activation of human intestinal mast cells by escherichia coli hemolysin.mast cells (mcs) are recognized to play an important role in bacterial host defense in the murine system. in this study, we studied the interaction of human mcs, isolated from the intestine and purified to homogeneity, with different escherichia coli and shigella flexneri strains. we show that alpha-hemolysin (hly)-producing e. coli strains induce the release of histamine, leukotrienes, and proinflammatory cytokines in intestinal mcs. in contrast, mcs were virtually unresponsive to s. flexneri a ...200818606698
antibiotic sensitivity of enteric pathogens in vietnam.the in vitro antimicrobial susceptibilities of 675 common enteropathogenic isolates from faecal specimens of patients with diarrhea (e. coli, shigella, salmonella and v. cholerae), and 568 e. coli isolates from faecal flora of healthy persons, which were collected as part of a national antibiotic resistance surveillance in vietnam, were determined. the agar dilution method was used for the following nine antibiotics: ampicillin, doxycycline, chloramphenicol, gentamicin, nalidixic acid, kanamycin ...199118611498
lomefloxacin versus trimethoprim/sulfamethoxazole in the treatment of adults with acute bacterial diarrhea.this study compared the efficacy and safety of lomefloxacin with that of trimethoprim/sulfamethoxazole (tmp/smx) in the treatment of adult patients with acute diarrhea of bacterial etiology. two centers enrolled a total of 133 patients; 99 (74%) presented with severe symptoms. the patients were randomized to receive either lomefloxacin 400 mg once daily (n=68) or tmp/smx 160/800 mg twice daily (n=65) for five days. bacteriologic success was achieved in 89.5% of evaluation lomefloxacin-treated pa ...199218611521
cefuroxime axetil.cefuroxime is the first commercially-available second-generation cephalosporine to be widely used in therapy; it is a semi-synthetic cephalosporin obtained from the 7-cephalosporanic acid nucleus of cephalosporin c. cefuroxime axetil is the acetoxyethyl ester of cefuroxime. the majority of micro-organisms associated with respiratory infections are highly sensitive to cefuroxime. these include haemophilus influenzae, streptococcus pneumoniae, streptococcus pyogenes and the other streptococci (exc ...199418611587
multiplication in serratia of a bacteriophage originating from escherichia coli: lysogenization and host-controlled variation.temperate bacteriophage p2, originally obtained from escherichia coli strain lisbonne, and usually grown on e. coli or shigella strains, is also able to multiply in some serratia strains. one of these has been shown to give stable lysogenic derivatives upon p2 infection. in passing from e. coli to serratia and vice versa, p2 undergoes host-controlled variation. the base ratio in the dna of the serratia strain used is typical of serratia strains (59% gc content) whereas that of p2 dna (50% gc con ...196718614062
microcalorimetric studies of the action on four organic acids in radix isatidis on the growth of microorganisms.the actions of four organic acids in radix isatidis, a traditional chinese medicinal (tcm) herb, on escherichia coli, staphylococcus aureus and shigella dysenteriae growth were investigated by microcalorimetry. the four organic acids were syringic acid, 2-amino-benzoic acid, salicylic acid and benzoic acid. the power-time curves of escherichia coli, staphylococcus aureus and shigella dysenteriae growth with and without organic acids were acquired, meanwhile the extent and duration of inhibitory ...200818616177
functional characterization of the shigella dysenteriae heme abc transporter.the heme atp binding cassette (abc) transporter, shuuv, of shigella dysenteriae has been incorporated into proteoliposomes. functional characterization of shuuv revealed that atp hydrolysis and transport of heme from the periplasmic binding protein, shut, to the cytoplasmic binding protein, shus, are coupled. site-directed mutagenesis of shut residues proposed to be required for stabilization of the complex abolished heme transport. furthermore, residues his-252 and his-262, located in the trans ...200818616281
structures of synthetic o-antigen fragments from serotype 2a shigella flexneri in complex with a protective monoclonal antibody.the anti-lps igg mab f22-4, raised against shigella flexneri serotype 2a bacteria, protects against homologous, but not heterologous, challenge in an experimental animal model. we report the crystal structures of complexes formed between fab f22-4 and two synthetic oligosaccharides, a decasaccharide and a pentadecasaccharide that were previously shown to be both immunogenic and antigenic mimics of the s. flexneri serotype 2a o-antigen. f22-4 binds to an epitope contained within two consecutive 2 ...200818621718
first italian case of cyclosporiasis in an immunocompetent woman: local acquired infection.cyclospora cayetanensis is a coccidian agent of chronic diarrhea in humans with a worldwide distribution. we report the first documented case of acquired cyclosporiasis in italy. the patient was an immunocompetent woman with no recent history of travel outside the country. microscopy detected cyclospora oocysts in a feces sample. pcr detected the pathogen in a second sample, which had tested negative by microscopy. the patient was investigated to detect other microorganisms in feces, such as sal ...200818623995
[detection of enteric pathogenic bacteria from surface waters by quantitative polymerase chain reaction (qpcr)].a rapid quantitative polymerase chain reaction (qpcr) analysis method with universal primers was developed to detect cell densities of the enteric pathogenic bacteria from 5 surface water of xi'an city for 4 months continuously. and the detection results by qpcr method were compared with counts of coliforms colony-forming units (cfu) determined by membrane filter (mf) analysis. the results showed that qpcr method had an estimated 94% confidence, and detection limit was 2.7 escherichia coli cells ...200818624175
overview of the inactivation by 254 nm ultraviolet radiation of bacteria with particular relevance to biodefense.our goal was to ultimately predict the sensitivity of untested bacteria (including those of biodefense interest) to ultraviolet (uv) radiation. in this study, we present an overview and analysis of the relevant 254 nm data previously reported and available in the literature. the amount of variability in this data prevented us from determining an "average" response for any bacterium. therefore, we developed particular selection criteria to include the data in our analysis and suggested future gui ...200818627518
is irritable bowel syndrome an inflammatory disorder?histopathologic data demonstrate low-grade mucosal inflammation in a subset of patients with irritable bowel syndrome (ibs). this inflammatory infiltrate is mainly represented by increased numbers of t lymphocytes and mast cells lying in the lamina propria. the close apposition of immunocytes to gut nerves supplying the mucosa provides a basis for neuroimmune cross-talk, which may explain gut sensorimotor dysfunction and related symptoms in patients with ibs. a previous gastroenteritis (due to c ...200818627650
a single-tube screen for salmonella and shigella.salmonella and shigella species are routinely sought in stool specimens submitted for culture. it is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and christensen urea agar to determine if further identification is necessary. we designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent salmonella or shigella. we tested this media combination with 106 sa ...200818628099
haemolytic uraemic syndrome in children admitted to a rural district hospital in kenya.we studied children admitted to kilifi district hospital, kenya, between 1997 and 2005 with haemolytic uraemic syndrome (hus) and reviewed their records in order to determine the clinical features and outcomes of the disease. thirty-one children fulfilled the criteria: 21 (68%) had diarrhoea-associated hus (d + hus), the remainder did not (d-hus); five had involvement of the central nervous system. those with d-hus had lower haemoglobin and platelet counts when compared with those with d + hus. ...200818628547
[investigation on species composition of cockroaches and bacteria-carrying on their bodies in five cities of hainan]."za-type" cages were used to capture cockroaches in 267 sites of 5 cities in hainan. species were identified and bacteria were isolated by routine method. 441 cockroaches were collected and identified as five species belonging to two genera, 75.3% being periplaneta americana. more cockroaches were found in sewerage. bacteria were detected from 82.4% of cockroaches, including escherichia coli, pseudomonas aeruginosa, salmonella sp, staphylococcus aureus, shigella sp, bacillus proteus and sort of ...200818637594
crystal structure of a glutamate/aspartate binding protein complexed with a glutamate molecule: structural basis of ligand specificity at atomic resolution.the crystal structure of a periplasmic l-aspartate/l-glutamate binding protein (debp) from shigella flexneri complexed with an l-glutamate molecule has been determined and refined to an atomic resolution of 1.0 a. there are two debp molecules in the asymmetric unit. the refined model contains 4462 non-hydrogen protein atoms, 730 water molecules, 2 bound glutamate molecules, and 2 tris molecules from the buffer used in crystallization. the final r(cryst) and r(free) factors are 13.61% and 16.89%, ...200818640128
mitracarpus frigidus aerial parts exhibited potent antimicrobial, antileishmanial, and antioxidant effects.the crude extract and the hexane, ch(2)cl(2), etoac, n-buoh, and hydromethanolic fractions of the aerial parts of mitracarpus frigidus were evaluated against promastigote forms of two species of leishmania (l. chagasi and l. amazonensis), 11 strains of bacteria (staphylococcus aureus, pseudomonas aeruginosa, salmonella enterica sorovar tythimurium, shigella sonnei, klebsiella pneumoniae, escherichia coli, micrococcus luteus, enterococcus faecalis, enterobacter cloacae, streptococcus pyogenes and ...200918644325
the interplay between entamoeba and enteropathogenic bacteria modulates epithelial cell damage.mixed intestinal infections with entamoeba histolytica, entamoeba dispar and bacteria with exacerbated manifestations of disease are common in regions where amoebiasis is endemic. however, amoeba-bacteria interactions remain largely unexamined.200818648517
acute diarrhea due to enteropathogenic bacteria in patients at hospitals in tehran.during a study examining causes of diarrhea from may 2004 to may 2005, 808 stool specimens were collected from patients with acute diarrhea in tehran. fecal samples were cultured and identified according to the standard biochemical methods. molecular identification of enteropathogens was carried out by amplification of their virulence genes by polymerase chain reaction. a total of 369 (45.6%) bacterial pathogens were recovered from 808 patients as follows: shigella spp., 155 (45.6%); diarrheagen ...200818653967
antimicrobial resistance in shigella species isolated in dakar, senegal (2004-2006).from may 2004 to october 2006, a prospective study was carried out in dakar, senegal, to update information about the antimicrobial susceptibility of shigella spp. isolated from stool specimens. among the 165 non-duplicate strains collected, 81 (49%) were identified as shigella flexneri, 75 (45%) as shigella sonnei, 5 (3%) as shigella boydii, and 4 (2%) as shigella dysenteriae. disk diffusion testing revealed that the majority of isolates were resistant to sulphonamides, trimethoprim-sulfamethox ...200818653976
simultaneous detection of six human diarrheal pathogens by using dna microarray combined with tyramide signal amplification.multiplex pcr and dna microarray were combined with tyramide signal amplification (tsa) to develop a reliable method suitable for simultaneous detection of six species of human diarrheal pathogens (yersinia enterocolitica, shigella spp, salmonella typhi, brucella spp, vibrio cholera and escherichia coli o157:h7). meanwhile, our method could distinguish v. cholera serotype o1 from o139, and o157:h7 from o157: non-h7. this assay conferred a specificity of 100% for target pathogens. the limit of de ...200818655810
the c-terminus of ipac is required for effector activities related to shigella invasion of host cells.invasion plasmid antigen c (ipac) is secreted by the shigella flexneri type iii secretion system (ttss) as an essential trigger of epithelial cell invasion. at the molecular level, ipac possesses a distinct functional organization. the ipac c-terminal region between amino acids 319 and 345 is predicted to form a coiled-coil structure. such alpha-helical motifs appear to be a recurring structural theme among ttss components. together with ipab, this ipac region is also required for the formation ...200818656530
characterization of soluble complexes of the shigella flexneri type iii secretion system atpase.the conserved atpase of type iii secretion systems is critical to the export of substrates through the apparatus. we present a characterization of the native t3ss atpase, spa47, from the cytoplasm of shigella flexneri, demonstrating it to be in two distinct high-molecular-weight complexes with spa33: mxin and mxik.200818657109
use of mchi encoding immunity to the antimicrobial peptide microcin h47 as a plasmid selection marker in attenuated bacterial live attenuated bacterial strains expressing heterologous antigens represent an attractive vaccine development strategy. however, the use of drug resistance genes for the selection of expression plasmids introduced into live vectors poses theoretical health risks. therefore, we developed a novel approach for plasmid selection based on immunity to the antimicrobial peptide microcin h47 (mcch47). two expression plasmids encoding the reporter green fluorescent protein (gfpuv) were constructed; sele ...200818663003
antimicrobial activity of broth fermented with kefir grains.kefir grains originate from the caucasus region and are used for preparing beverages using sugar solution, milk, and fruit juice. as long as they are formed by a microbial consortium useful in the intestine, the produced drinks can be called probiotics. the aim of this study was to determine the antimicrobial activity during kefir fermentation in sugar broth. fermentations with three kinds of carbohydrates (molasses, demerara sugar, and brown sugar) as carbon source were carried out. brown sugar ...200918663417
variable length tandem repeat polyglutamine sequences in the flexible tether region of the tsr chemotaxis receptor of escherichia coli.methyl-accepting chemotaxis proteins (mcps) are receptors that play an important role in bacterial chemotaxis. methylation of tsr, the mcp that mediates chemotaxis towards serine in escherichia coli, is thought to be facilitated by binding of the methyltransferase to a flexible tether region at the c-terminal end of tsr. this study analysed natural length variants of the tether that occur in e. coli due to genetic instability in tandem repeat dna sequences that code for glutaminyl (q) residues, ...200818667570
vaccination against shigellosis: is it the path that is difficult or is it the difficult that is the path?following several decades of research, there is not yet a convincing vaccine against shigellosis. it is still difficult, in spite of the breadth of strategies (i.e. live attenuated oral, killed oral, subunit parenteral) to select an optimal option. two approaches are clearly emerging: (i) live attenuated deletion mutants based on rational selection of genes that are key in the pathogenic process, and (ii) conjugated detoxified polysaccharide parenteral vaccines, or more recently conjugated synth ...200818672087
macrolide-resistant shigella sonnei.shigella sonnei ucn59, isolated during an outbreak of s. sonnei in january 2007, was resistant to azithromycin (mic 64 mg/l). the isolate contained a plasmid-borne mph(a) gene encoding a macrolide 2 -phosphotransferase that inactivates macrolides. emergence of the mph(a) gene in s. sonnei may limit usefulness of azithromycin for treatment of shigellosis.200818680661
bacterial biosensors for rapid and effective monitoring of biodegradation of organic pollutants in wastewater effluents.significant amounts of toxic substances which are hazardous to animals, plants, microorganisms, and other living organisms including humans are released annually into aquatic and terrestrial environments, mostly from improper wastewater discharges. early detection of such pollutants in wastewater effluents and proper monitoring before their final release into the environment is therefore necessary. in this study, two whole-cell bacterial biosensors were constructed by transforming competent cell ...200818688458
liquid chromatography/mass spectrometry characterization of escherichia coli and shigella species.liquid chromatography/quadrupole time of flight mass spectrometry (lc/qtof ms) utilizing electrospray ionization was employed to monitor protein expression in escherichia coli and shigella organisms. comparison with maldi/tof-ms revealed more proteins, particularly above 15 kda. a combination of automated charge state deconvolution, spectral mirroring, and spectral subtraction was used to reveal subtle differences in the lc/ms data. reproducible intact protein biomarker candidates were discovere ...200818692404
[antigenic polysaccharides of bacteria: 41. structures of the o-specific polysaccharides of shigella dysenteriae types 4 and 5 revised by nmr spectroscopy].the earlier established structures of the acidic o-specific polysaccharides from two typical strains of the shigella dysenteriae bacterium were revised using modern nmr spectroscopy techniques. in particular, the configurations of the glycosidic linkages of glcnac (s. dysenteriae type 4) and mannose (s. dysenteriae type 5) residues were corrected. in addition, the location of the sites of nonstoichiometric o-acetylation in s. dysenteriae type 4 was determined: the lateral fucose residue was show ...200818695724
epidemiological evidence of multidrug-resistant shigella sonnei colonization in india by sentinel surveillance in a japanese quarantine station.we applied a previously reported method to clarify whether a multidrug-resistant shigella colonizes in a south asian country. at kansai airport quarantine station, stool samples were collected from overseas travelers who reported a history of diarrhea. shigella strains were isolated, ranging from 53 to 106 (average, 82.4) isolates/year (2001-2005), and almost 80% of the isolates were shigella sonnei. the most frequent country of origin was india. strains from the country of the most frequent ori ...200818697484
identification and functional characterization of gene components of type vi secretion system in bacterial genomes.a new secretion system, called the type vi secretion system (t6ss), was recently reported in vibrio cholerae, pseudomonas aeruginosa and burkholderia mallei. a total of 18 genes have been identified to be belonging to this secretion system in v. cholerae. here we attempt to identify presence of t6ss in other bacterial genomes. this includes identification of orthologous sequences, conserved motifs, domains, families, 3d folds, genomic islands containing t6ss components, phylogenetic profiles and ...200818698408
structural and functional characterization of human iba proteins.iba2 is a homolog of ionized calcium-binding adapter molecule 1 (iba1), a 17-kda protein that binds and cross-links filamentous actin (f-actin) and localizes to membrane ruffles and phagocytic cups. here, we present the crystal structure of human iba2 and its homodimerization properties, f-actin cross-linking activity, cellular localization and recruitment upon bacterial invasion in comparison with iba1. the iba2 structure comprises two central ef-hand motifs lacking bound ca2+. iba2 crystallize ...200818699778
use of flow cytometry in an apoptosis assay to determine ph and temperature stability of shiga-like toxin 1.shiga toxins and shiga-like toxins (stx) are a relatively large group of cytotoxins produced by certain serotypes of shigella and e. coli (stec). these toxins are responsible for diarrhea, hemorrhagic colitis and may induce hemolytic uremic syndrome (hus) with serious consequences in young children. the toxins are proteins made up of 5 small b subunits responsible for binding to an outer membrane ligand on host cells and surround the larger, biologically active a subunit. for shiga-like toxin 1 ...200818710788
epidemiology of highly endemic multiply antibiotic-resistant shigellosis in children in the peruvian amazon.our goal was to estimate the impact of a shigella vaccine in an area where shigellosis is endemic by characterizing the disease burden and antibiotic-resistance profiles of isolates and by determining the prevalence of shigella flexneri serotypes.200818710884
invitro antibacterial activity of crude preparation of myrtle (myrtus communis) on common human pathogens.myrtle "addus" (myrtus communis) has long history as a traditional medicine/or different infectious disease by many peoples of the world and in ethiopia too.200818711991
acanthamoeba castellanii an environmental host for shigella dysenteriae and shigella sonnei.the interaction between shigella dysenteriae or shigella sonnei and acanthamoeba castellanii was studied by viable counts, gentamicin assay and electron microscopy. the result showed that shigella dysenteriae or shigella sonnei grew and survived in the presence of amoebae for more than 3 weeks. gentamicin assay showed that the shigella were viable inside the acanthamoeba castellanii which was confirmed by electron microscopy that showed the shigella localized in the cytoplasm of the acanthamoeba ...200918712360
methods and tools for comparative genomics of foodborne pathogens.a comparison of genome sequences and of encoded proteins with the database of existing annotated sequences is a useful approach to understand the information at the genome level. here we demonstrate the utility of several dna and protein sequence comparison tools to interpret the information obtained from several genome projects. comparisons are presented between closely related strains of escherichia coli commensal isolates, different isolates of o157:h7, and shigella spp. it is expected that c ...200818713064
all blood, no stool: enterohemorrhagic escherichia coli o157:h7 infection.enterohemorrhagic escherichia coli serotype o157:h7 is a pathotype of diarrheagenic e. coli that produces one or more shiga toxins, forms a characteristic histopathology described as attaching and effacing lesions, and possesses the large virulence plasmid po157. the bacterium is recognized worldwide, especially in developed countries, as an emerging food-borne bacterial pathogen, which causes disease in humans and in some animals. healthy cattle are the principal and natural reservoir of e. col ...200818716441
a potential plasmid-curing agent, 8-epidiosbulbin e acetate, from dioscorea bulbifera l. against multidrug-resistant bacteria.bioassay-guided fractionation of an aqueous methanolic extract of dioscorea bulbifera l. bulbs was performed using organic solvents. a novel plasmid-curing compound was identified as 8-epidiosbulbin e acetate (eea) (norditerpene) on the basis of modern spectroscopic analysis and x-ray crystallography. eea exhibited broad-spectrum plasmid-curing activity against multidrug-resistant (mdr) bacteria, including vancomycin-resistant enterococci. eea cured antibiotic resistance plasmids (r-plasmids) fr ...200818718743
factors associated with acute diarrhoea in children in dhahira, oman: a hospital-based elucidate the bacterial etiology of childhood diarrhoea in dhahira, 856 children < 12 years admitted for diarrhoea to ibri regional referral hospital from 2000 to 2002 were studied. the mean age was 2.4 (sd 2.3) years; the majority (92.9%) were < 5 years. bacterial etiology was found in 15.2% of cases; 10.6% due to shigella and 2.1% to salmonella. sh. sonnei was the commonest shigella serogroup isolated. salmonella infection was significantly associated with cramps, while shigella infection w ...200818720621
antimicrobial activity of extracts of edible wild and cultivated mushrooms against foodborne bacterial strains.the antimicrobial activity of aqueous, methanol, hexane, and ethyl acetate extracts from edible wild and cultivated mushrooms against nine foodborne pathogenic bacterial strains (escherichia coli o157:h7, salmonella enteritidis, shigella sonnei, vibrio parahaemolyticus, yersinia enterocolitica, bacillus cereus, clostridium perfringens, listeria monocytogenes, and staphylococcus aureus) was screened with a disk diffusion assay. twenty-nine of the 48 species tested had antimicrobial activity. meth ...200818724768
role of nleh, a type iii secreted effector from attaching and effacing pathogens, in colonization of the bovine, ovine, and murine gut.the human pathogen enterohemorrhagic escherichia coli (ehec) o157:h7 colonizes human and animal gut via formation of attaching and effacing lesions. ehec strains use a type iii secretion system to translocate a battery of effector proteins into the mammalian host cell, which subvert diverse signal transduction pathways implicated in actin dynamics, phagocytosis, and innate immunity. the genomes of sequenced ehec o157:h7 strains contain two copies of the effector protein gene nleh, which share 49 ...200818725419
resistance to fluoroquinolones by the combination of target site mutations and enhanced expression of genes for efflux pumps in shigella flexneri and shigella sonnei strains isolated in korea.among 5938 clinical shigella spp. isolates, two s. flexneri strains were isolated as those resistant to fluoroquinolones based on the mics of the following antibiotics: ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin and levofloxacin. s. flexneri 021787 had three substitutions, one in gyra (ser83leu) and two in parc (ser80ile and arg91gln). s. flexneri 021895 had four substitutions, two in gyra (ser83leu and asp87gly) and two in parc (ser80ile and arg91gln). the increased susceptibility of s ...200818727800
an outbreak of shigella newcastle dysentery. 194418746833
the relationship between genetics and environment in the pathogenesis of rheumatic diseases.major developments have taken place to further our understanding of the relationship between genetics and the environment in the pathogenesis of rheumatic disorders. the association between hla markers and human disease is becoming clearer. for instance, hla-drw4 frequently occurs in patients with rheumatoid disease, and penicillamine and gold toxicity are seen most often in patients with hla-drw2 or drw3. antisera to b alloantigens help define the genetic differences between systemic lupus eryt ...197918748470
occurrence and characteristics of the cytolysin a gene in shigella strains and other members of the family enterobacteriaceae.cytolysin a (clya, hlye, shea) is a hemolytic pore-forming toxin found in escherichia coli and salmonella enterica serovars typhi and paratyphi a. in the present study, analysis of several shigella strains revealed that they harbor only nonfunctional clya gene copies that have been inactivated either by the integration of insertion sequence (is) elements (shigella dysenteriae, shigella boydii, and shigella sonnei strains) or by a frameshift mutation (shigella flexneri). shigella dysenteriae and ...200818754791
characterization of endemic shigella boydii strains isolated in iran by serotyping, antimicrobial resistance, plasmid profile, ribotyping and pulsed-field gel electrophoresis.shigellosis is one of the major causes of morbidity in children with diarrhea in iran. the present study was undertaken to characterize apparently sporadic shigella boydii strains isolated from pediatric patients in iran.200818755045
topology and identification of critical residues of the o-acetyltransferase of serotype-converting bacteriophage, sf6, of shigella flexneri.the modification of the lps o-antigen, seen in the diverse serotypes of shigella flexneri is brought about by the glucosyltransferases (gtr) and the o-acetyltransferase (oac). in this study, we establish the membrane topology of oac using the dual reporter phoa-laczalpha. we have determined that oac is an integral membrane protein with 10 transmembrane regions. the hydrophilic n- and c-termini are oriented in the cytoplasm. functionally important cytoplasmic and periplasmic loops have also been ...200818755141
construction of a trivalent candidate vaccine against shigella species with dna this work asd gene of shigella flexneri 2a strain t32 was replaced by vibrio cholerae toxin b subunit (ctxb) gene with dna recombination in vivo and in vitro. the resulting derivative of t32, designed as fwl01, could stably express ctxb, but its growth in lb medium depended on the presence of diaminopimelic acid (dap). then form i plasmid of shigella sonnei strain s7 was labeled with strain t32 asd gene and mobilized into fwl01. thus a trivalent candidate oral vaccine strain, designed as fsw0 ...200218763059
structural and functional studies indicate that shigella vira is not a protease and does not directly destabilize microtubules.vira, an essential virulence factor in shigella disease pathogenesis, is involved in the uptake, motility, and cell-to-cell spread of shigella organisms within the human host. these functions have been attributed to a vira protease activity and a mechanism of microtubule destruction via tubulin degradation [yoshida, s., et al. (2006) science 314, 985-989]. we report functional and crystallographic data indicating a novel vira structure that lacks these activities but highlights the homology to t ...200818763811
bacterial conjugation in the cytoplasm of mouse cells.intracellular pathogenic organisms such as salmonellae and shigellae are able to evade the effects of many antibiotics because the drugs are not able to penetrate the plasma membrane. in addition, these bacteria may be able to transfer genes within cells while protected from the action of drugs. the primary mode by which virulence and antibiotic resistance genes are spread is bacterial conjugation. salmonellae have been shown to be competent for conjugation in the vacuoles of cultured mammalian ...200818765719
shigellosis in puducherry. 200818765885
the in vitro anti-pathogenic activity of immunoglobulin concentrates extracted from ovine immunoglobulin-rich fraction has been prepared from ovine blood in our laboratory. we have investigated its antibacterial activity and binding activity to pathogenic whole cell antigens, lipopolysaccharide (lps) and staphylococcal enterotoxin b. ovine immunoglobulin concentrate (oic) comprised about 73 +/- 2% of igg and 11 +/- 1% of igm on a protein basis. it inhibited the growth of all 13 strains of pathogens tested, but the inhibitory activity varied according to bacterial strain. the inhib ...200918769875
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