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subunit interaction of monomeric alanine racemases from four shigella species in catalytic reaction.bacterial alanine racemases are classified into two types of subunit structure (monomer and homodimer). to clarify the catalytic unit of monomeric alanine racemases, we examined the apparent molecular mass of the monomeric alanine racemases from shigella dysenteriae, shigella boydii, shigella flexneri, and shigella sonnei by gel filtration in the presence of the substrate and inhibitor. the enzymes were eluted on gel filtration as a monomer of about 39,000 da at low protein concentration and in ...200312725937
helicobacter pylori: an invading microorganism? a review.in this review we evaluate the pros and cons of helicobacter pylori invasion of epithelial cells as part of the natural history of h. pylori infection. h. pylori is generally considered an extracellular microorganism. however, a growing body of evidence supports the controversial hypothesis that at least a subset of h. pylori microorganisms has an intracellular (intraepithelial) location. most significant is the fact that h. pylori invades cultured epithelial cells with invasion frequencies simi ...200312738380
icsb, secreted via the type iii secretion system, is chaperoned by ipga and required at the post-invasion stage of shigella pathogenicity.shigella deliver a subset of effector proteins such as ipaa, ipab and ipac via the type iii secretion system (ttss) into host cells during the infection of colonic epithelial cells. many bacterial effectors including some from shigella require specific chaperones for protection from degradation and targeting to the ttss. in this study, we have investigated the role of the icsb gene located upstream of the ipabcda operon in shigella infection because the role of icsb as a virulence factor remains ...200312753186
shigella flexneri bacteremia in a child.we report an unusual and lethal case of shigella flexneri septicemia in an 8-year-old saudi handicapped child from a social home presenting with severe toxic megacolon and acute abdomen secondary to fulminant necrotizing enterocolitis.200312754544
a method for allelic replacement in francisella tularensis.a vector for mutagenesis of francisella tularensis was constructed based on the puc19 plasmid. by inserting the sacb gene of bacillus subtilis, orit of plasmid rp4, and a chloramphenicol resistance gene of shigella flexneri, a vector, ppv, was obtained that allowed specific mutagenesis. a protocol was developed that allowed introduction of the vector into the live vaccine strain, lvs, of f. tularensis by conjugation. as a proof of principle, we aimed to develop a specific mutant defective in exp ...200312770718
seasonal variation in bacterial pathogens isolated from stool samples in karachi, pakistan.to determine the seasonal variation of the commonly isolated bacterial pathogens in stool samples.200312779031
patterns and properties of haemagglutinins expressed by shigella serogroups in lagos, nigeria.forty-five strains of shigella were screened for haemagglutinin production and broad-spectrum haemagglutination reaction. mannose-sensitive haemagglutinin (msha) was found in 22 strains [shigella flexneri (7), s. dysenteriae (7), s. sonnei (3), and s. boydii (5)]. eighteen strains harboured mannose-resistant haemagglutinin (mrha), and 8 strains were observed to be non-haemagglutinating to guinea pig erythrocyte. with the exception of human erythrocytes (o, a, b, and ab), the observed msha and mr ...200313677435
prevalence and pattern of antimicrobial resistance of shigella species among patients with acute diarrhoea in karaj, tehran, iran.the study was carried out to determine the prevalence and pattern of antimicrobial resistance of shigella species among patients with acute diarrhoea in karaj, tehran, iran. the study included all acute diarrhoea patients who visited the hospitals and treatment centres of karaj during november 2001-october 2002. of 734 stool samples collected from patients with acute diarrhoea and analyzed for shigella spp., 123 (16.8%) yielded shigella spp. (7.5% shigella flexneri, 5.2% s. sonnei, 2.6% s. dysen ...200313677436
adipokinetic hormone enhances laminarin and bacterial lipopolysaccharide-induced activation of the prophenoloxidase cascade in the african migratory locust, locusta migratoria.lom-akh-i enhances the activation in vivo of prophenoloxidase in the haemolymph of the african migratory locust, locusta migratoria, in response to challenge with laminarin. akh does not influence the speed or initial magnitude of the phenoloxidase response to laminarin, but prolongs the period of activation of the enzyme in a dose-dependent manner. injections of preparations of bacterial lipopolysaccharide (lps) do not activate prophenoloxidase in vivo, but co-injection of lom-akh-i with commer ...200212770071
electrophoretic analysis of salmonella typhi and other bacteria.a comparative study involving sds-page of salmonella typhi and other bacteria was conducted. protoplasmic antigens of salmonella typhi. salmonella paratyphi a, salmonella typhimurium, proteus sp, klebsiellas sp. pseudomonas aeruginosa, shigella flexneri, staphylococcus aureus were separated and compared on sds-page followed by checking of their cross reactivity by gel diffusion using antisera raised against whole cell and lysates of salmonella typhi. lines of identity between salmonella typhi, s ...200212649947
his-asp phosphorelay signal transduction in higher plants: receptors and response regulators for cytokinin signaling in arabidopsis thaliana.bacteria have devised phosphotransfer signaling mechanisms for eliciting a variety of adaptive responses to their environment. these mechanisms are collectively referred to as two-component regulatory systems. each system generally consists of a sensor protein histidine kinase, which is anchored in the cell membrane, and a cytoplasmic response regulator, whose activity is modulated by the sensor. most response regulators are transcription factors. in this review, we briefly introduce the establi ...200212589073
antimicrobial activity of feiii, cuii, agi, znii and hgii complexes of 2-(2-hydroxy-5-bromo/nitro-phenyl)-1h- and 2-(2-hydroxyphenyl)-5-methyl/chloro/nitro-1h-benzimidazoles.antimicrobial activity of 2-(2-hydroxyphenyl)-5-r5-1h-benzimidazoles, 2-(2-hydroxy-5-r5'-phenyl)-1h-benzimidazoles and their feiii, cuii, agi, znii and hgii nitrate complexes was tested toward staphylococcus aureus, staphylococcus epidermidis, escherichia coli, klebsiella pneumoniae, pseudomonas aeruginosa, salmonella typhi, shigella flexneri, and proteus mirabilis. antifungal activity was tested against candida albicans. benzimidazole benzene ring substituents increase the antimicrobial activit ...200212503391
molecular dissection of virb, a key regulator of the virulence cascade of shigella flexneri.the virb protein is a key regulator of virulence gene expression in the facultative enteroinvasive pathogen shigella flexneri. while genetic evidence has shown that it is required for activation of transcription of virulence genes located on a 230-kb plasmid in this bacterium, hitherto, evidence that virb is a dna-binding protein has been lacking. although virb shows extensive homology to proteins involved in plasmid partitioning, it does not resemble any known conventional transcription factor. ...200211850420
shigella flexneri interactions with the basolateral membrane domain of polarized model intestinal epithelium: role of lipopolysaccharide in cell invasion and in activation of the mitogen-activated protein kinase erk.an early step governing shigella flexneri pathogenesis is the invasion of the colonic epithelium from the basolateral surface followed by disruption of the colonic epithelial barrier. despite recent insight into s. flexneri-host interactions, much remains to be determined regarding the nature of the initial contact between s. flexneri and the host epithelial basolateral membrane domain. since the lipopolysaccharide (lps) is located at the outermost part of the bacterial membrane, we considered t ...200211854195
use of aflp, plasmid typing and phenotyping in a comparative study to assess genetic diversity of shigella flexneri strains.shigella flexneri infections are one of the main causes of acute diarrhoea in cuba. twenty strains isolated from sporadic cases in nine different cuban provinces were characterized. serotyping, antibiotic-resistance typing, plasmid-typing and aflp-typing were used to determine their suitability for use in epidemiological studies of s. flexneri. the predominant serotypes were serotype 6 (35%) and serotype 2 (35%). eleven different plasmid profiles were detected (diversity index = 0.92). aflp-typi ...200212558326
[comparison of shigella susceptibility to commonly used antimicrobials in the temuco regional hospital, chile 1990 - 2001].the permanent surveillance of antimicrobial susceptibility of shigella sp in the temuco regional hospital, allowed us to define the empirical use of antimicrobials in dysenteric syndrome.200212434650
evolution of multiresistance in nontyphoid salmonella serovars from 1984 to 1998 in argentina.molecular evolution of multiresistance in nontyphoid salmonella spp. was investigated with 155 isolates obtained in argentina from 1984 to 1998. in 74 isolates obtained from 1984 to 1988 resistance was associated with the presence of tn3, tn9, class i (in0) and ii (tn7) integrons, and the aac(3)-iia gene. extended-spectrum cephalosporin (esc) resistance in salmonella spp. emerged in 1989, and 81 isolates resistant to at least one esc and one aminoglycoside were collected thereafter. among these, ...200212435702
lactoferrin protects rabbits from shigella flexneri-induced inflammatory enteritis.shigella species cause bacillary dysentery in humans by invasion, intracellular multiplication, spread to adjacent cells, and induction of brisk inflammatory responses in the intestinal epithelium. in vitro data suggest that lactoferrin, a glycoprotein present in human mucosal secretions, has a role in protection from bacterial enteric infections. we sought to determine the activity of lactoferrin in vivo, using the concentration present in human colostrum, to investigate its effect on the devel ...200212438385
functional comparison of serine protease autotransporters of enterobacteriaceae.the plasmid-encoded toxin (pet) of enteroaggregative escherichia coli (eaec) belongs to a family of high-molecular-weight serine protease autotransporters of enterobacteriaceae (spates) which also includes pic from eaec and shigella flexneri, espc from enteropathogenic e. coli, espp from enterohemorrhagic e. coli, sat from uropathogenic e. coli, tsh from avian pathogenic e. coli, and sepa from s. flexneri. phylogenetic analysis shows the spate proteins to represent a distinct subfamily of autotr ...200212438392
identification of the cis-acting site involved in activation of promoters regulated by activity of the type iii secretion apparatus in shigella flexneri.bacteria of shigella spp. use a virulence plasmid-encoded type iii secretion (tts) system to invade the colonic epithelium in humans. the activity of the tts apparatus is tightly regulated in the wild-type strain and is induced upon contact of bacteria with epithelial cells, whereas it is deregulated, i.e., constitutively active, in some mutants. under conditions of deregulated secretion, approximately 20 proteins are secreted, including vira, ospb to ospg, and at least three members of the ipah ...200212446624
igg antibodies to enterobacteria 60 kda heat shock proteins in the sera of hla-b27 positive ankylosing spondylitis patients.to study the association of hla-b27 and the igg response to the 60 kda hsps of klebsiella pneumoniae, yersinia enterocolitica, shigella flexneri, escherichia coli and salmonella typhi.200212455814
purification and detection of shigella type iii secretion needle complex. 200212474402
surveillance of bacterial pathogens of diarrhea disease in indonesia.emerging or reemerging infections due to bacterial disease may be a local, regional or global problem. bacterial acute gastroenteritis is a potential cause of substantial morbidity in travelers and deployed u.s. military personnel. a surveillance study was conducted over a two-year period in indonesia among 6760 patients with debilitating diarrheal diseases. of the 6,760 patients, 587 (9%) of the patient stools were positive for bacteria. the proportions of bacteria isolated from the 587 patient ...200212493168
neutrophil elastase targets virulence factors of enterobacteria.shigellae cause bacillary dysentery, a bloody form of diarrhoea that affects almost 200 million people and causes nearly 2 million deaths per year. shigella invades the colonic mucosa, where it initiates an acute inflammation, rich in neutrophils, that initially contributes to tissue damage and eventually resolves the infection. neutrophils are phagocytic cells that kill microorganisms but it is unclear how neutrophils control pathogenic bacteria expressing virulence factors that manipulate host ...200212018205
distinct recent lineages of the stra- strb streptomycin-resistance genes in clinical and environmental bacteria.we report the linkage of the stra-strb streptomycin-resistance genes with class 1 integron sequences on pstr1, a 75-kb multiple antibiotic-resistance plasmid from shigella flexneri. stra-strb had previously been detected only within tn 5393, a tn 3-family transposon, and on small nonconjugative broad-host-range plasmids such as rsf1010. the geographic range of tn 5393 was also extended to pseudomonas spp. isolated from apple trees in new zealand and soil in the usa. comparative sequence analyses ...200212029529
the effect of nacl on survival of shigella flexneri in broth as affected by temperature and ph.shigella, a major foodborne pathogen, survives well in salt-containing environments. however, systematic data are scarce. we studied the behavior of shigella flexneri 5348 in brain heart infusion broth (ph 4 to 6) containing 0.5 to 8% nacl. stationary-phase cells were inoculated into sterile media at initial concentrations of 6 to 7 log10 cfu/ml and incubated at 12 to 37 degrees c. bacterial population sizes were determined periodically by plate counts. survivor curves were derived from plate co ...200212030287
inorganic polyphosphate is essential for long-term survival and virulence factors in shigella and salmonella spp.the importance of inorganic polyphosphate (poly p) and poly p kinase (ppk), the enzyme principally responsible for its synthesis, has been established previously for stationary-phase survival of escherichia coli and virulence in pseudomonas aeruginosa. the gene (ppk) that encodes ppk is highly conserved among many bacterial pathogens, including shigella and salmonella spp. in view of the phylogenetic similarity of the enteropathogens and the frequency with which virulence factors are expressed i ...200212032342
mucosal dna vaccination with highly attenuated shigella is superior to attenuated salmonella and comparable to intramuscular dna vaccination for t cells against hiv.an immunization strategy using attenuated bacteria to deliver dna vaccine plasmids to mucosal sites may induce protective t cell responses against sexual hiv transmission. in a murine intranasal (i.n.) immunization model, we demonstrate that transiently persistent deltaasd shigella flexneri strain 15d harboring dna vaccines induces hiv- and siv-specific gamma interferon (ifn-gamma) producing cd8+ t cells among splenocytes more efficiently than either a longer persisting deltaarod salmonella typh ...200212036602
[clinical and morphological aspects of shigellosis flexneri in patients with an aggravated premorbid state].the analysis of 10 fatal outcomes in patients with acute shigellosis during the period of 1999-2000 made it possible to find out that most of deceased shigellosis patients belonged to the group inclined to alcohol abuse and having initial alimentary disturbances. in 6 cases of acute shigellosis with fatal outcome the causative agent was s. flexneri 2a, in 2 cases--s. flexneri 3a, in 1--s. flexneri 4b. the main cause of fatal outcomes was accompanying double pneumonia. lesions of the intestinal t ...200212043161
[molecular characterization of resistance mechanisms to chloramphenicol in shigella flexneri strains isolated from chilean children with acute diarrhea].chloramphenicol is one of the therapeutic options for shigellosis, but resistance to this antimicrobial is increasing.200212043369
representational difference analysis uncovers a novel is10-like insertion element unique to pathogenic strains of yersinia enterocolitica.the method of suppressive subtractive hybridization was employed to map out genomic differences between the highly pathogenic yersinia enterocolitica (ye) biogroup 1b, serotype o:8 strain (wa-314) and the closely related apathogenic y. enterocolitica biogroup 1a, serotype o:5 strain (nf-o). a novel is10-like element, is1330, uncovered by this technique was found to be uniquely present in high copy numbers among the highly pathogenic y. enterocolitica 1b strains, while a single copy of the elemen ...200212044683
[studies on the actin-based spreading of shigella]. 200212048885
differential expression of inducible nitric oxide synthase is associated with differential toll-like receptor-4 expression in chicken macrophages from different genetic backgrounds.the purpose of this study was to examine inos gene expression and activity in macrophages from different chicken genetic lines against various bacterial lps. furthermore, the possible involvement of surface lps receptors as candidates for differential inos gene induction in these genetic lines of chicken was also examined. sephadex-elicited abdominal macrophages (1 x 10(6)) as well as inos hyper-responder macrophages from a transformed chicken macrophage cell line, mq-ncsu, were exposed to 5 mic ...200211777534
chronic vulvovaginitis caused by antibiotic-resistant shigella flexneri in a prepubertal child.a 7-year 8-month-old girl was diagnosed with a prolonged course of vulvovaginitis caused by shigella flexneri. the child was symptomatic with intermittent vaginal bleeding, dysuria and foul smelling vaginal discharge for a 3-year period. initial attempts to resolve the infection with successive courses of antibiotic therapy using ampicillin, trimethoprim-sulfamethoxazole, cefixime and amoxicillin/clavulanic acid failed. the child's infection was finally resolved by a 14-day course of ciprofloxac ...200211840089
shigella spa32 is an essential secretory protein for functional type iii secretion machinery and uniformity of its needle length.the shigella type iii secretion machinery is responsible for delivering to host cells the set of effectors required for invasion. the type iii secretion complex comprises a needle composed of mxih and mxii and a basal body made up of mxid, mxig, and mxij. in s. flexneri, the needle length has a narrow range, with a mean of approximately 45 nm, suggesting that it is strictly regulated. here we show that spa32, encoded by one of the spa genes, is an essential protein translocated via the type iii ...200211844752
cdc42 facilitates invasion but not the actin-based motility of shigella.the enteric pathogen shigella utilizes host-encoded proteins to invade the gastrointestinal tract. efficient invasion of host cells requires the stimulation of rho-family gtpases and cytoskeletal alterations by shigella-encoded ipac. following invasion and lysis of the phagosome, shigella exploits the host's actin-based polymerization machinery to assemble an actin tail that serves as the propulsive force required for spreading within and between cells. the shigella surface protein icsa stimulat ...200211864577
complete genomic sequence of sfv, a serotype-converting temperate bacteriophage of shigella flexneri.bacteriophage sfv is a temperate serotype-converting phage of shigella flexneri. sfv encodes the factors involved in type v o-antigen modification, and the serotype conversion and integration-excision modules of the phage have been isolated and characterized. we now report on the complete sequence of the sfv genome (37,074 bp). a total of 53 open reading frames were predicted from the nucleotide sequence, and analysis of the corresponding proteins was used to construct a functional map. the gene ...200211889106
genetic determinants of tetracycline resistance in vibrio harveyi.isolates of vibrio harveyi, a prawn pathogen, have demonstrated multiple antibiotic resistance to commonly used antimicrobial agents, such as oxytetracycline. in this paper, we describe the cloning and characterization of two tetracycline resistance determinants from v. harveyi strain m3.4l. the first resistance determinant, cloned as a 4,590-bp fragment, was identical to teta and flanking sequences encoded on transposon tn10 from shigella flexneri. the second determinant, cloned as a 3,358-bp f ...200211897587
wild-type intracellular bacteria deliver dna into mammalian cells.gene transfer in vitro from intracellular bacteria to mammalian phagocytic and non-phagocytic cells and in vivo in mice has been reported. the bacteria used as dna delivery vectors were engineered to lyze upon entry in the cell due to impaired cell wall synthesis for shigella flexneri and invasive escherichia coli, or production of a phage lysin for listeria mono- cytogenes. in vivo gene transfer was obtained with attenuated salmonella typhimurium and resulted in stimulation of mucosal immunity. ...200211906454
prevalence of the sat gene among clinical isolates of shigella spp. causing travelers' diarrhea: geographical and specific differences. 200211923399
development of a p1 phagemid system for the delivery of dna into gram-negative bacteria.the inability to transform many clinically important gram-negative bacteria has hampered genetic studies addressing the mechanism of bacterial pathogenesis. this report describes the development and construction of a delivery system utilizing the broad-host-range transducing bacteriophage p1. the phagemids used in this system contain a p1 pac initiation site to package the vector, a p1 lytic replicon to generate concatemeric dna, a broad-host-range origin of replication and an antibiotic-resista ...200211932441
[phenomenon of apoptosis in the survival of enterobacteria in the parasite-host system].data on the apoptosis phenomenon with enterobacteria used as a model are presented. one of the mechanisms regulating the vital activity of eukaryotic cells is, together with cell proliferation and differentiation, the phenomenon known as "apoptosis". this physiological process of the eukaryotic cells death is used by many parasites in parasite--host relationships in different epitopes. the system known to trigger programmed cell death, is the surface receptor fas, the receptor of tumor necrosis ...200211949266
neural wiskott-aldrich syndrome protein (n-wasp) is the specific ligand for shigella virg among the wasp family and determines the host cell type allowing actin-based spreading.shigella, the causative agent of bacillary dysentery, is capable of directing its movement within host cells by forming an actin comet tail. the virg (icsa) pro-tein expressed at one pole of the bacterium recruits neural wiskott-aldrich syndrome protein (n-wasp), a member of the wasp family, which in turn stimulates actin-related protein (arp) 2/3 complex-mediated actin polymerization. as all the wasp family proteins induce actin polymerization by recruiting arp2/3 complex, we investigated their ...200211952639
spa15 of shigella flexneri, a third type of chaperone in the type iii secretion pathway.the type iii secretion (tts) pathway is used by numerous gram-negative pathogens to inject virulence factors into eukaryotic cells. in addition to a functional tts apparatus, secretion of effector proteins depends upon specific chaperones. using a two-hybrid screen in yeast and a co-purification assay in shigella flexneri, we demonstrated that spa15, which is encoded by an operon for components of the tts apparatus, is associated in the cytoplasm with three proteins that are secreted by the tts ...200211952903
regulation of transcription by the activity of the shigella flexneri type iii secretion apparatus.the virulence plasmid-encoded type iii secretion system of shigella flexneri consists of the mxi-spa secretion apparatus, secreted proteins ipaa-d and ipgd involved in entry of bacteria into epithelial cells,cytoplasmic chaperones ipgc and ipge and 15 other secreted proteins of unknown function, including vira and members of the ipah family. the activity of the mxi-spa apparatus is regulated by external signals, and transcription of vira and ipah genes is specifically induced in conditions of ac ...200211971264
genomic subtraction to identify and characterize sequences of shiga toxin-producing escherichia coli o91:h21.to identify shiga toxin-producing escherichia coli genes associated with severe human disease, a genomic subtraction technique was used with hemolytic-uremic syndrome-associated o91:h21 strain ch014 and o6:h10 bovine strains. the method was adapted to the shiga toxin-producing e. coli genome: three rounds of subtraction were used to isolate dna fragments specific to strain ch014. the fragments were characterized by genetic support analysis, sequencing, and hybridization to the genome of a collec ...200211976103
characterization of pecl18 and pkpn2: a proposed pathway for the evolution of two plasmids that carry identical genes for a type ii restriction-modification system.the primary structures of the plasmids pecl18 (5571 bp) and pkpn2 (4196 bp) from escherichia coli and klebsiella pneumoniae, respectively, which carry genes for a type ii restriction-modification system (rms2) with the specificity 5'-ccngg-3', were determined in order to elucidate the structural relationship between them. the data suggest a possible role for recombination events at bom (basis of mobility) regions and the sites of resolution of multimer plasmid forms (so-called cer sequences) in ...200211976960
quantification of shigella icsa required for bacterial actin polymerization.shigella move through the cytoplasm of host cells by active polymerization of host actin to form an "actin tail." actin tail assembly is mediated by the shigella protein icsa. the process of shigella actin assembly has been studied extensively using icsa-expressing escherichia coli in cytoplasmic extracts of xenopus eggs. however, for reasons that have been unclear, wild type shigella does not assemble actin in these extracts. we show that the defect in actin assembly in xenopus extracts by shig ...200211977093
cytotoxicity and interleukin-1beta processing following shigella flexneri infection of human monocyte-derived dendritic cells.shigella flexneri infection of macrophages (mphi) leads to activation of caspase-1 by the ipab virulence factor, which induces rapid cell death and release of mature il-1beta. here we show that s. flexneri infection of human monocyte-derived dendritic cells (dc) also results in rapid ipab-dependent death. cytotoxicity is only partially blocked by the caspase-1 inhibitor yvad, but completely blocked by the pan-caspase inhibitor z-vad. cytotoxicity is also partially blocked by glycine without affe ...200211981835
development of an oral prime-boost strategy to elicit broadly neutralizing antibodies against hiv-1.given the increasing incidence of hiv-1 infection world-wide, an affordable, effective vaccine is probably the only way that this virus will be contained. accordingly, our group is developing an oral prime-boost strategy with the primary goal of eliciting broadly neutralizing antibodies against hiv-1 to provide sterilizing immunity for this virus. our secondary goal is to elicit broadly cross-reactive anti-viral cd8(+) t cells by this strategy to blunt any breakthrough infections that occur afte ...200211983256
bromoperoxidase activity of vanadate-substituted acid phosphatases from shigella flexneri and salmonella enterica ser. typhimurium.vanadium haloperoxidases and the bacterial class a nonspecific acid phosphatases have a conserved active site. it is shown that vanadate-substituted recombinant acid phosphatase from shigella flexneri (phon-sf) and salmonella enterica ser. typhimurium (phon-se) in the presence of h2o2 are able to oxidize bromide to hypobromous acid. vanadate is essential for this activity. the kinetic parameters for the artificial bromoperoxidases have been determined. the km value for h2o2 is about the same as ...200211985594
two msbb genes encoding maximal acylation of lipid a are required for invasive shigella flexneri to mediate inflammatory rupture and destruction of the intestinal epithelium.shigella flexneri is a gram-negative pathogen that invades and causes inflammatory destruction of the human colonic epithelium, thus leading to bloody diarrhea and dysentery. a type iii secretion system that delivers effector proteins into target eukaryotic cells is largely responsible for cell and tissue invasion. however, the respective role of this invasive phenotype and of lipid a, the endotoxin of the shigella lps, in eliciting the inflammatory cascade that leads to rupture and destruction ...200211994481
incidence and molecular analysis of vibrio cholerae associated with cholera outbreak subsequent to the super cyclone in orissa, india.an epidemiological study was carried out to find out the aetiological agent for diarrhoeal disorders in the cyclone and flood affected areas of orissa, india. rectal swabs collected from 107 hospitalized diarrhoea patients were bacteriologically analysed to isolate and identify the various enteropathogens. detection of toxic genes among e. coli and v. cholerae was carried out by polymerase chain reaction (pcr) assay. of the 107 rectal swabs analysed, 72.3% were positive for v. cholerae o1 ogawa, ...200212002529
rhamnose-binding lectins from steelhead trout (oncorhynchus mykiss) eggs recognize bacterial lipopolysaccharides and lipoteichoic acid.the interaction between bacteria and three l-rham-nose-binding lectins, named stl1, stl2, and stl3, from steelhead trout (oncorhynchus mykiss) eggs was investigated. although stls bound to most gram-negative and gram-positive bacteria, they agglutinated only escherichia coli k-12 and bacillus subtilis among the bacteria tested. the binding was inhibited by l-rhamnose. stls bound to distinct serotypes of lipopolysaccharides (lpss), and showed much higher binding activities to smooth-type lpss of ...200212005056
regulation of the overlapping pic/set locus in shigella flexneri and enteroaggregative escherichia coli.most strains of shigella flexneri 2a and enteroaggregative escherichia coli carry a highly conserved chromosomal locus which encodes a 109-kda secreted mucinase (called pic) and, on the opposite strand in overlapping fashion, an oligomeric enterotoxin called shet1, encoded by the seta and setb genes. here, we characterize the genetic regulation of these overlapping genes. our data suggest that pic and the setba loci are transcribed as complementary 4-kb mrna species. the major pic promoter is ma ...200212010980
construction, characterization, and animal testing of wrsd1, a shigella dysenteriae 1 vaccine.wrsd1 is a shigella dysenteriae 1 vaccine containing deletions of the virg(icsa) gene required for intercellular spreading and a 20-kb chromosomal region encompassing the shiga toxin genes (stxab). wrsd1 was constructed from s. dysenteriae 1 strain 1617 that was originally isolated during the 1968 to 1969 epidemic of shiga dysentery in guatemala. the virg(icsa) deletion was constructed from a streptomycin-resistant (str(r)) mutant of 1617 by a filter mating procedures using a virg(icsa) deletion ...200212010984
the dynamics of actin-based motility depend on surface parameters.in cells, actin polymerization at the plasma membrane is induced by the recruitment of proteins such as the arp2/3 complex, and the zyxin/vasp complex. the physical mechanism of force generation by actin polymerization has been described theoretically using various approaches, but lacks support from experimental data. by the use of reconstituted motility medium, we find that the wiskott aldrich syndrome protein (wasp) subdomain, known as vca, is sufficient to induce actin polymerization and move ...200212015607
spa32 regulates a switch in substrate specificity of the type iii secreton of shigella flexneri from needle components to ipa proteins.type iii secretion systems (ttss) are essential virulence determinants of many gram-negative bacteria and serve, upon physical contact with target cells, to translocate bacterial proteins directly across eukaryotic cell membranes. the shigella ttss is encoded by the mxi/spa loci located on its virulence plasmid. by electron microscopy secretons are visualized as tripartite with an external needle, a transmembrane domain, and a cytoplasmic bulb. in the present study, we generated a shigella spa32 ...200212057936
human monocytes kill shigella flexneri but then die by apoptosis associated with suppression of proinflammatory cytokine production.shigella flexneri infection of human macrophages is followed by rapid bacterial escape into the cytosol and secretion of ipab, which activates caspase-1 to mediate cell death and release of mature interleukin (il)-1 beta. here we report a different outcome following infection of human peripheral blood monocytes. s. flexneri infects monocytes inefficiently in the absence of complement and, following complement-dependent uptake, cannot escape the endosomal compartment. consequently, bacteria are k ...200212065527
shigella flexneri regulates tight junction-associated proteins in human intestinal epithelial cells.shigella spp. are a group of gram-negative enteric bacilli that cause acute dysentery in humans. we demonstrate that shigella flexneri has evolved the ability to regulate functional components of tight junctions after interaction at the apical and basolateral pole of model intestinal epithelia. in the regulation of tight junctional protein assemblies, s. flexneri can engage serotype-specific mechanisms, which targets not only expression, but also cellular distribution and membrane association of ...200212067320
[development of vaccine for enterohemorrhagic escherichia coli infection].efforts on the development of vaccines against enterohemorrhagic escherichia coli (ehec) infection has been described in this review. two kinds of vaccines were developed and these have been targeted for in humans and cattle. one vaccine candidate is toxoid, which uses an inactive form of shiga toxin(stx). a part of b subunit, each b or a subunit or one or two amino acid mutated holotoxin were developed as a toxoid vaccine candidate. the other candidate was bacterial surface antigen such as a li ...200212078077
phenotypic and genotypic characterization of serologically atypical strains of shigella flexneri type 4 isolated in dhaka, bangladesh.twenty-one atypical shigella flexneri type 4 strains isolated from patients attending the dhaka treatment center of the international centre for diarrhoeal disease research, bangladesh, were extensively characterized and compared with s. flexneri serotypes 4a and 4b. the atypical strains agglutinated only with the type antigen factor 4 and did not agglutinate with any group factors, thereby excluding their characterization into serotype 4a or 4b. of the 21 strains, 85.7% did not ferment mannitol ...200212089268
prevalence of the genes for shigella enterotoxins 1 and 2 among clinical isolates of shigella in israel.two enterotoxins, shigella enterotoxin 1 (shet1) and shigella enterotoxin 2 (shet2) have been recently characterized and are believed to play a role in the clinical manifestation of shigellosis. one hundred and twenty-one isolates of shigella spp. of 13 different serotypes and variants and 10 isolates of enteroinvasive escherichia coli (eiec) isolated in israel, were examined by polymerase chain reaction for the presence of shet1 and shet2 genes. shet1 was only prevalent among isolates of s. fle ...200212113500
identification of chromosomal shigella flexneri genes induced by the eukaryotic intracellular environment.upon entry into the eukaryotic cytosol, the facultative intracellular bacterium shigella flexneri is exposed to an environment that may necessitate the expression of particular genes for it to survive and grow intracellularly. to identify genes that are induced in response to the intracellular environment, we screened a library containing fragments of the s. flexneri chromosome fused to a promoterless green fluorescent protein gene (gfp). bacteria containing promoter fusions that had a higher le ...200212117948
[a fatal case of shigellosis in an elderly patient].a 71 year-old male, with no recent history of travelling abroad and a past history of lung cancer two years prior to presentation, which had been successfully treated, developed a sudden onset of watery diarrhea more than ten times a day on february 26, 2001, which gradually became bloody. the next day he visited the department of integrated medicine of the tokyo metropolitan komagome hospital by ambulance because his consciousness was deteriorating and he was hospitalized. he was hypotensive on ...200212136656
quadrupole ion-trap mass spectrometry to locate fatty acids on lipid a from gram-negative bacteria.the structure of lipid a released by mild acid hydrolysis from lipopolysaccharide from two strains of shigella flexneri with different degrees of acylation was characterized using electrospray ionization (esi) and ion-trap mass spectrometry. the lipid a was analyzed underivatized with esi in negative-ion mode. with multiple stages of fragmentation (ms(n)), both the degree of acylation and the positions of the fatty acids on the disaccharide backbone could be determined. it was possible to determ ...200212137789
mxie regulates intracellular expression of factors secreted by the shigella flexneri 2a type iii secretion system.the mxi-spa locus on the virulence plasmid of shigella flexneri encodes components of the type iii secretion system. mxie, a gene within this locus, encodes a protein that is homologous to the arac/xyls family of transcriptional regulators, but currently its role in pathogenesis remains undefined. we characterized the virulence phenotype of a nonpolar mxie mutant and found that this mutant retained the ability to invade mammalian cells in tissue culture and secrete ipas (type iii effectors requi ...200212142411
rapid detection of six types of bacterial pathogens in marine waters by multiplex pcr.a rapid multiplex pcr (m-pcr) method that allows the simultaneous detection, in a single tube, of six commonly encountered waterborne pathogens is developed. the target genes used were: the aerolysin (aero) gene of aeromonas hydrophila, the invasion plasmid antigen h (ipah) gene of shigella flexneri, the attachment invasion locus (ail) gene of yersinia enterocolitca, the invasion plasmid antigen b (ipab) gene of salmonella typhimurium, the enterotoxin extracellular secretion protein (epsm) gene ...200212146868
isolation of shigella dysenteriae type 1 and s. flexneri strains from surface waters in bangladesh: comparative molecular analysis of environmental shigella isolates versus clinical strains.bacillary dysentery caused by shigella species is a public health problem in developing countries including bangladesh. although, shigellae-contaminated food and drinks are often the source of the epidemic's spread, the possible presence of the pathogen and transmission of it through environmental waters have not been adequately examined. we analyzed surface waters collected in dhaka, bangladesh, for the presence of shigellae by a combination of pcr assays followed by concentration and culturing ...200212147489
bacterial inactivation by high-pressure homogenisation and high hydrostatic pressure.the resistance of five gram-positive bacteria, enterococcus faecalis, staphylococcus aureus, lactobacillus plantarum, listeria innocua and leuconostoc dextranicum, and six gram-negative bacteria, salmonella enterica serovar typhimurium, shigella flexneri, yersinia enterocolitica, pseudomonas fluorescens and two strains of escherichia coli, to high-pressure homogenisation (100-300 mpa) and to high hydrostatic pressure (200-400 mpa) was compared in this study. within the group of gram-positive bac ...200212160080
identification of a putative pathogenicity island in shigella flexneri using subtractive hybridisation of the s. flexneri and escherichia coli genomes.the genetic differences between the human pathogen, shigella flexneri, and the non-pathogenic escherichia coli were investigated in an attempt to identify pathogenicity islands (pais) in the s. flexneri genome. genomic subtraction identified a large unique region of dna which was present in s. flexneri serotype 2a but absent from e. coli k-12. this 42-kb dna segment was localised to the s. flexneri chromosome and was found to contain a number of elements often associated with pais including: ins ...200212167547
acid tolerance of shigella sonnei and shigella flexneri.determination of the behaviour of shigella sonnei and sh. flexneri under acid conditions.200212174047
enteroinvasive escherichia coli virulence-plasmid-carried apyrase (apy) and ospb genes are organized as a bicistronic operon and are subject to differential expression.in shigella flexneri and enteroinvasive escherichia coli (eiec) the expression of the virulence-plasmid(pinv)-carried potential pathogenesis-associated apy gene, which encodes apyrase (atp diphosphohydrolase), is regulated by the same regulators that govern the expression of virulence genes. to understand the transcriptional organization of the apy gene, the authors sequenced an 8023 bp psti fragment of the pinv of eiec strain hn280, which encompasses apy as well as its adjacent genes. the psti ...200212177345
initial steps of shigella infection depend on the cholesterol/sphingolipid raft-mediated cd44-ipab interaction.shigellosis is an acute inflammatory bowel disease caused by the enteroinvasive bacterium shigella: upon host cell-shigella interaction, major host cell signalling responses are activated. deciphering the initial molecular events is crucial to understanding the infectious process. we identified a molecular complex involving proteins of both the host, cd44 the hyaluronan receptor, and shigella, the invasin ipab, which partitions during infection within specialized membrane microdomains enriched i ...200212198147
sequence analysis and characterization of plasmid psfd10 from salmonella choleraesuis.the nucleotide sequence of a small plasmid, designated psfd10, is isolated from the vaccine strain salmonella choleraesuis c500 in china, has been determined. this plasmid is 4091 bp long with a total g+c content of 51.4%, which is in the range of salmonella genomic dna. analysis of the complete nucleotide sequence reveals that psfd10 has a high degree of similarity to cole1-type plasmid, having the possible cer and rom genes, and a putative mobilization origin of cole1-type. plasmid psfd10 poss ...200212206756
three modifications in the d and t arms of trna influence translation in escherichia coli and expression of virulence genes in shigella flexneri.the modified nucleosides 2'-o-methylguanosine, present at position 18 (gm18), 5-methyluridine, present at position 54 (m(5)u54), and pseudouridine, present at position 55 (psi55), are located in the d and t arms of trnas and are close in space in the three-dimensional (3d) structure of this molecule in the bacterium escherichia coli. the formation of these modified nucleosides is catalyzed by the products of genes trmh (gm18), trma (m(5)u54), and trub (psi55). the combination of trmh, trma, and ...200212218021
survival and growth of shigella flexneri, salmonella enterica serovar enteritidis, and vibrio cholerae o1 in reconstituted infant formula.formula feeding is an alternative method to prevent mother-to-child infection with human immunodeficiency virus through breast-feeding in developing countries. growth of bacterial pathogens in reconstituted infant formula has become a health hazard when contaminated water is used for rehydration. this study was conducted to assess bacterial safety risk of using contaminated water to reconstitute infant formula. survival and growth characteristics were determined for three bacterial pathogens, vi ...200212224592
effect of organic acids and temperature on survival of shigella flexneri in broth at ph 4.the survival of bacterial pathogens in acidified foods depends not only on the hydrogen ion concentration, but also on the type of acid and the storage temperature. shigella flexneri is a foodborne pathogen that is acid tolerant. the survival of s. flexneri 5348 in brain heart infusion broth supplemented with 0.04 m acetic, citric, lactic, malic, or tartaric acid and adjusted to ph 4 with hci or naoh was studied. the control medium was brain heart infusion broth adjusted to ph 4 with hci. statio ...200212233851
conversion of ptdins(4,5)p(2) into ptdins(5)p by the s.flexneri effector ipgd reorganizes host cell morphology.phosphoinositides play a central role in the control of several cellular events including actin cytoskeleton organization. here we show that, upon infection of epithelial cells with the gram-negative pathogen shigella flexneri, the virulence factor ipgd is translocated directly into eukaryotic cells and acts as a potent inositol 4-phosphatase that specifically dephosphorylates phosphatidylinositol 4,5-bisphosphate [ptdins(4,5)p(2)] into phosphatidylinositol 5-monophosphate [ptdins(5)p] that then ...200212356723
epithelial inflammation response induced by shigella flexneri depends on mucin gene expression.the protective effects of different mucin gene profiles on gut protection were assessed by the evaluation of tnfalpha production by intestinal epithelial cells infected by shigella flexneri. three ht-29 cell lines were used: ht29-g(-) (enterocyte-like cells, secreting no mucins), ht29-fu (highly expressing muc2 and muc4) and ht29-mtx (highly expressing muc3 and muc5ac). these cells were infected either by an invasive (m90t) or the control isogenic (bs176) strains of s. flexneri, and tnfalpha mrn ...200212361911
[dysentery in poland in 2000].the notified number of dysentery cases is still falling down since the year 1995 when bacteriological examination of feces for diagnostic purposes lost free of charge status obtained in 1928 under the legislation act of infectious disease investigation and obligatory registration. only 121 dysentery cases were notified in the year 2000 (incidence 0.31/100,000 population), while 292 cases were notified in 1999 (incidence 0.76/100,000). no one death case was notified. only 2 outbreaks (one due to ...200212371362
septic shock associated with shigella flexneri dysentery.septic shock is a very unusual presentation of shigella infection. we describe a 3-y-old child who developed severe septic shock and severe encephalopathy during an episode of dysentery caused by shigella flexneri.200212374365
shigella flexneri degp facilitates icsa surface expression and is required for efficient intercellular spread.a degp mutant of shigella flexneri was identified in a screen for insertion mutants that invaded cultured cells but did not form wild-type plaques in monolayers. the degp mutant sm1100 invaded henle cells at wild-type levels and induced apoptosis in macrophages but formed smaller plaques than those formed by wild-type s. flexneri in confluent monolayers of henle and caco-2 cells. the proportion of sm1100 bacteria with icsa localized to the bacterial pole, a process required for actin polymerizat ...200212379715
enteropathogens associated with acute diarrhea in community and hospital patients in jakarta, indonesia.the prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from march 1997 through august 1999 in jakarta, indonesia was determined using routine bacteriology and molecular assay techniques. bacterial pathogens isolated from hospital patients were, in decreasing frequency, vibrio cholerae o1, shigella flexneri, salmonella spp. and campylobacter jejuni, while s. flexneri, v. cholerae o1, salmonella spp. and c. jejuni were isolated fr ...200212381465
genetics of isoprenoid biosynthesis in paracoccus zeaxanthinifaciens.the genes coding for all the enzymes involved in the conversion of acetyl-coa to farnesyl diphosphate (fpp) in the zeaxanthin-producing bacterium paracoccus zeaxanthinifaciens were cloned and characterized. two genes encoding enzymes catalysing the condensation of two acetyl-coa molecules to acetoacetyl-coa were found. the six enzymes involved in the conversion of acetyl-coa and acetoacetyl-coa to isopentenyl diphosphate (ipp) and dimethylallyl diphosphate (dmapp) are grouped in an operon, desig ...200212384294
genome sequence of shigella flexneri 2a: insights into pathogenicity through comparison with genomes of escherichia coli k12 and o157.we have sequenced the genome of shigella flexneri serotype 2a, the most prevalent species and serotype that causes bacillary dysentery or shigellosis in man. the whole genome is composed of a 4 607 203 bp chromosome and a 221 618 bp virulence plasmid, designated pcp301. while the plasmid shows minor divergence from that sequenced in serotype 5a, striking characteristics of the chromosome have been revealed. the s.flexneri chromosome has, astonishingly, 314 is elements, more than 7-fold over thos ...200212384590
selection of shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm.we describe an in vivo expression technology (ivet)-like approach, which uses antibiotic resistance for selection, to identify shigella flexneri genes specifically activated in bacteria resident in host cell cytoplasm. this procedure required construction of a promoter-trap vector containing a synthetic operon between the promoterless chloramphenicol acetyl transferase (cat) and lacz genes and construction of a library of plasmids carrying transcriptional fusions between s. flexneri genomic frag ...200212390353
doc-mediated cell killing in shigella flexneri using a c1/laci controlled expression system.in this report we describe the development of a highly stringent and dually regulated promoter system for shigella flexneri. dual regulation was provided by utilizing a promoter susceptible to control by the bacteriophage p1 temperature-sensitive c1 repressor that in turn was under the transcriptional control of laci. the level of induction/repression ratios observed was up to 3700-fold in s. flexneri. the general utility of this promoter system was evaluated by demonstrating that the bacterioph ...200212399040
[the role of hla-b27 molecules in the pathogenesis of ankylosing spondylitis].ankylosing spondylitis (as) is characterised by the strongest association with an hla antigen ever described for any disease. it represents therefore the ideal model for the understanding of the link between immune-mediated diseases and the hla system. the role of hla-b27 in the pathogenesis of as will be discussed focusing on the recently described higher expression of these molecules in patients with as compared with healthy controls.200212404037
[acute diarrhea outbreak caused by shigella flexneri at a school in madrid, cundinamarca: phenotypic and genotypic characterization of the isolates].shigellosis is an acute diarrhoeal disease that is the main cause of morbidity and mortality in developing countries. in 1997, the colombian instituto nacional de salud microbiology group organized a network surveillance program with the country's public health laboratories (phls) to monitor the principal etiological agents responsible for acute diarrhoeal disease. in may, 2001, the phl of the state of cundinamarca reported a food poisoning outbreak involving an elementary school community. the ...200212404927
shigella flexneri bacteraemia in an immunocompetent male treated with oral ciprofloxacin. 200212423618
shigella isolation in vellore, south india (1997-2001).shigellosis has been a major cause of dysentery for many years at vellore, south india. in the last two years the number of shigella being isolated from samples of faeces from patients with diarrhoea has decreased (5% isolation rate in 1997 to 3.9% in 2001), although the microbiological methods and media used have not changed. also, the nalidixic acid (na) resistance has increased for s. sonnei (now 94%). this is noteworthy, since na has been recommended for the empirical treatment of patients s ...200212424931
molecular recognition of oligosaccharide epitopes by a monoclonal fab specific for shigella flexneri y lipopolysaccharide: x-ray structures and thermodynamics.the antigenic recognition of shigella flexneri o-polysaccharide, which consists of a repeating unit abcd [-->2)-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->], by the monoclonal antibody sya/j6 (igg3, kappa) has been investigated by crystallographic analysis of the fab domain and its two complexes with two antigen segments (a pentasaccharide rha a-rha b-rha c-glcnac d-rha a' and a modified trisaccharide rha b-rha c-glcnac d in which rha c* is missing a c2-oh ...200212427018
polymerase chain reaction detection of invasive shigella and salmonella enterica in food. 200211692869
antimicrobial and anti-lipase activity of quercetin and its c2-c16 3-o-acyl-esters.neither quercetin (q), nor 3-o-acylquercetines, up to 100 microg/ml, had any significant activity on selected gram-positive strains (staphylococcus aureus, bacillus subtilis, listeria ivanovi, listeria monocytogenes, listeria serligeri), gram-negative strains (escherichia coli, shigella flexneri, shigella sonnei, salmonella enteritidis, salmonella tiphymurium) and yeasts (candida albicans and candida glabrata). in addition, we confirmed the known anti-hiv activity of q (80% inhibition at 40 micr ...200211741775
in vivo dna-binding and oligomerization properties of the shigella flexneri arac-like transcriptional regulator virf as identified by random and site-specific mutagenesis.in shigella flexneri expression of the plasmid-encoded virulence genes is regulated via a complex mechanism involving both environmental signals and specific transactivators. the primary regulator protein, virf, is a member of the arac family of transcription factors and shares with other arac-like proteins a conserved carboxy-terminal domain thought to be important for dna binding. random and site-directed mutagenesis of the virf gene encoding virf yielded a number of mutations along the length ...200211751832
[papillary cystadenocarcinoma of the kidney. apropos of a case and review of the literature]. 20022732502
the time course of effects of cadmium and 3-methylcholanthrene on activities of enzymes of xenobiotic metabolism and metallothionein levels in the plaice, pleuronectes platessa.plaice were treated with an acute dose of a polyaromatic hydrocarbon (3-methylcholanthrene, 3-mc) or cadmium, or 3-mc and cadmium by i.p. injection. the effects on hepatic detoxication systems, cytochrome p-450 (ethoxyresorufin o-deethylase, erod), udp-glucuronyl transferase, glutathione s-transferase, glutathione peroxidase activities, total glutathione (gsh), metallothionein and cd and zn in the cytosol were studied over a 14 day period. 3-mc increased erod (7-18-fold), glucuronyl transferase ...20022869905
[suitable dwellings also for the disabled (author's transl)].(1) the construction and adaptation of dwelling which are supposed to provide a permanent focal point in the lives of the disabled are approved in purely residential areas. (2) von den verschiedenen möglichkeiten trägerschaftlicher zuordnung einer wohnstätte für behinderte erscheint der eingetragene verein als die geeignetste rechtsform. (3) wohnstätten mit mindestens sechs behinderten unterliegen den bestimmungen des heimgesetzes (heimvertrag, mitwirkung). (4) wünschenswert wäre es, dass die bu ...2002134435
[working conditions of technical engineering workers in factory management and shop work]. 2002133048
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