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shigella infection induces cellular activation of t and b cells and distinct species-related changes in peripheral blood lymphocyte subsets during the course of the disease.immunophenotypic changes in peripheral blood lymphocytes (t, b, and nk cells) in patients during shigellosis was characterized by using triple-color flow cytometry. eleven shigella dysenteriae 1-infected adult patients (sdip), 11 shigella flexneri-infected adult patients (sfip), 15 age- and sex-matched healthy controls from bangladesh (c-b), and 15 healthy volunteers from sweden (v-s) were studied. in sdip and sfip, a significant increase in the cd45ro+ cells in both cd4+ and cd8+ t cells were s ...19957622216
the hrp gene locus of pseudomonas solanacearum, which controls the production of a type iii secretion system, encodes eight proteins related to components of the bacterial flagellar biogenesis complex.five transcription units of the pseudomonas solanacearum hrp gene cluster are required for the secretion of the hr-inducing popa1 protein. the nucleotide sequences of two of these, units 1 and 3, have been reported. here, we present the nucleotide sequence of the three other transcription units, units 2, 4 and 7, which are together predicted to code for 15 hrp genes. this brings the total number of hrp proteins encoded by these five transcription units to 20, including hrpb, the positive regulat ...19957623665
virg, a yersinia enterocolitica lipoprotein involved in ca2+ dependency, is related to exsb of pseudomonas aeruginosa.pathogenic yersiniae require ca2+ for growth at 37 degrees c. they harbor closely related plasmids of about 70 kb that are essential for virulence. at 37 degrees c and in the absence of ca2+ ions, these plasmids cause a decrease in growth rate and the release of large amounts of proteins called yops. here we describe the virg gene of yersinia enterocolitica; virg is located just upstream of the virf gene, which encodes the transcriptional activator of some plasmid virulence factors. analysis of ...19957635810
role of interleukin-1 in the pathogenesis of experimental shigellosis.the effect of human recombinant interleukin-1 receptor antagonist on intestinal inflammation, tissue destruction, and bacterial invasion during experimental shigellosis caused by shigella flexneri was studied in the rabbit-ligated loop infection model. intravenous infusion of the inhibitor at a dose of 2 mg/kg per h, was initiated 30 min before intestinal loops were ligated and infected, and continued during the 8-h period of infection. the animals treated with il-1 receptor antagonist showed a ...19957635983
evaluation of the safety, immunogenicity, and efficacy in healthy adults of four doses of live oral hybrid escherichia coli-shigella flexneri 2a vaccine strain ecsf2a-2.in previous trials, live invasive escherichia coli-shigella flexneri 2a hybrid vaccine candidate ecsf2a-2, administered to adult volunteers as 3 doses of ca. 2 x 10(9) colony forming units (c.f.u.) spaced over one week, induced fever and/or diarrhea in 11% of subjects and provided only limited protection (36% efficacy) against illness following challenge with virulent s. flexneri 2a. we sought to improve the clinical safety of this vaccine by administering a lower inoculum, and to enhance protec ...19957639017
h-ns regulation of virulence gene expression in enteroinvasive escherichia coli harboring the virulence plasmid integrated into the host chromosome.we have previously shown that integration of the virulence plasmid pinv into the chromosome of enteroinvasive escherichia coli and of shigella flexneri makes these strains noninvasive (c. zagaglia, m. casalino, b. colonna, c. conti, a. calconi, and m. nicoletti, infect. immun. 59:792-799, 1991). in this work, we have studied the transcription of the virulence regulatory genes virb, virf, and hns (virr) in wild-type enteroinvasive e. coli hn280 and in its pinv-integrated derivative hn280/32. whil ...19957642498
enteropathogenic escherichia coli contains a putative type iii secretion system necessary for the export of proteins involved in attaching and effacing lesion formation.enteropathogenic escherichia coli (epec) causes a characteristic histopathology in intestinal epithelial cells called the attaching and effacing lesion. although the histopathological lesion is well described the bacterial factors responsible for it are poorly characterized. we have identified four epec chromosomal genes whose predicted protein sequences are similar to components of a recently described secretory pathway (type iii) responsible for exporting proteins lacking a typical signal sequ ...19957644527
252cf-plasma desorption mass spectrometry analysis of lipids a obtained by an elimination reaction under mild conditions.lipids a are the hydrophobic domains of bacterial endotoxic lipopolysaccharides. since they are responsible for most of the biological activities (both pathogenic and beneficial) of endotoxins, the characterization of their structure is crucial to the understanding of their mode of action. however, the inadequacy of existing methods for preparing certain lipids a has prompted us to devise a new, mild procedure which gives intact products. use was made of the special features of 252cf-plasma deso ...19957647366
[the immunomodulating capacity of shigella flexneri 2a bacteria that have lost their invasiveness plasmid].an immunosuppressive effect produced by live microbial cells of s. flexneri virulent plasmid-carrying strain 2a 516 (psf 140-) was shown in relation to the formation of splenic cells producing antibodies to heterologous antigen (sheep red blood cells). this effect was most pronounced at an early period (days 4-7) after the infection of mice. on the contrary, avirulent plasmid-free variant (psf 140-), genetically related to s. flexneri strain 2a 516, produced an immunostimulating effect at this p ...19957653137
epidemiological, clinical and microbiological features of shigellosis among hospitalized children in northern israel.the epidemiological, clinical, and bacteriological aspects of shigellosis were studied in a population of hospitalized children in northern israel. during the 6-year period 1987-92, 262 children were hospitalized due to shigella infection. shigellosis represented 10% of pediatric admissions for diarrhea. admissions for the disease peaked during the summer and autumn. the median age of the patients was 3 years. shigella sonnei was isolated in 74% of patients and s. flexneri in 21%, compared with ...19957660077
pivmecillinam resistant shigella infections in rural bangladesh. 19957660498
identification of a global repressor gene, rsma, of erwinia carotovora subsp. carotovora that controls extracellular enzymes, n-(3-oxohexanoyl)-l-homoserine lactone, and pathogenicity in soft-rotting erwinia spp.the production of extracellular enzymes such as pectate lyase (pel), polygalacturonase (peh), cellulase (cel), and protease (prt) is activated by the cell density (quorum)-sensing signal, n-(3-oxohexanoyl)-l-homoserine lactone (hsl); plant signals; and aep genes during postexponential growth of erwinia carotovora subsp. carotovora 71. studies with mutants of e. carotovora subsp. carotovora 71 derepressed in exoenzyme production led to the identification of a negative regulator gene, rsma (rsm, r ...19957665490
1995 flemming lecture. dna topology and the global control of bacterial gene expression: implications for the regulation of virulence gene expression. 19957670631
the pho regulon of shigella flexneri.growth of escherichia coli k-12 in low-phosphate conditions results in the induction of the synthesis of many proteins, including the outer membrane porin phoe, alkaline phosphatase, and the pst system for the transport of phosphate (p1). this response is controlled by a two-component regulatory system of which phob and phor are the response-regulator and the sensor/kinase, respectively. when shigella flexneri was starved for p1, neither phoe nor alkaline phosphatase was produced. however, induc ...19957746146
acid tolerance of enterohemorrhagic escherichia coli.enterohemorrhagic escherichia coli (ehec) strains were tested for their ability to survive in acid ph at 37 degrees c. no loss of viability was observed in an o157:h7 ehec strain (atcc 43895) at ph levels of 3.0 and 2.5 for at least 5 h. the level of acid tolerance of most ehec isolates was very high, similar to that of shigella flexneri strains. the acid tolerance was dependent on the growth phase and ph of the growth medium.19957747983
actin-based bacterial motility.listeria monocytogenes and other bacterial pathogens move in the host cell cytoplasm, propelled by continuous actin assembly at one pole of the bacterium. this actin-based motility requires the presence of the bacterial proteins acta on l. monocytogenes and icsa on shigella flexneri. there have been several major discoveries in the past year: the discovery of the polar distribution of acta and icsa on the bacterial surface; the demonstration that bacterial acta is phosphorylated in infected host ...19957755995
potency of endotoxin from bicarbonate dialysate compared with endotoxins from escherichia coli and shigella flexneri.endotoxin is a potent activator of the complement system and other host immunoregulators, including the cytokines, tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6. in this study, the potency of an endotoxin from bicarbonate dialysate was compared with endotoxins from two enteric microorganisms, shigella flexneri and escherichia coli. endotoxin concentrations were standardized for the three endotoxins by use of the limulus amebocyte lysate turbidimetric assay. endotoxin potency ...19957756598
[the phagocytic activity of the blood neutrophils in monkeys undergoing multiple irradiation].the study of pathogenic activity of neutrophils under chronic low-dose irradiation (total doses were 0.84-24.99 gy) was carried out. the stage of phase changes was followed by a stable increase in neutrophil phagocytic activity, according to absorbing capacity, at relatively high total doses of irradiation. the data obtained were considered as a defence-compensatory reaction caused by decrease and depression of digestive capacity of phagocytes.19957757188
disulfide oxidoreductase activity of shigella flexneri is required for release of ipa proteins and invasion of epithelial cells.secretion of ipab, ipac, and ipad proteins of shigella flexneri, essential for the invasion of epithelial cells, requires a number of proteins encoded by the spa and mxi loci on the large plasmid. introduction of dsba::tn5 into s.flexneri from escherichia coli k-12 reduced invasiveness, which resulted from a decrease in the capacity to release ipab, ipac, and ipad proteins into the external medium. examination of the surface-presented ipa proteins of the dsba mutant, however, revealed ipa protei ...19957761426
safety and immunogenicity study of the auxotrophic shigella flexneri 2a vaccine sfl1070 with a deleted arod gene in adult swedish volunteers.the live auxotrophic shigella flexneri 2a vaccine strain sfl1070 with a deleted arod gene was given orally to 37 adult swedish volunteers who received three doses within 5 days. each dose comprised 1 x 10(5) (n = 9), 1 x 10(7) (n = 10), 1 x 10(8) (n = 9) or 1 x 10(9) (n = 9) c.f.u. s. flexneri sfl1070. one volunteer vaccinated with 1 x 10(7) and three vaccinated with 1 x 10(8) c.f.u. reported mild gastrointestinal symptoms after the first dose. vaccination with 1 x 10(9) c.f.u. caused abdominal ...19957762285
regulated underexpression and overexpression of the flin protein of escherichia coli and evidence for an interaction between flin and flim in the flagellar motor.the flin protein of escherichia coli is essential for the assembly and function of flagella. here, we report the effects of regulated underexpression and overexpression of flin in a flin null strain. cells that lack the flin protein do not make flagella. when flin is underexpressed, cells produce relatively few flagella and those made are defective, rotating at subnormal, rapidly varying speeds. these results are similar to what was seen previously when the flagellar protein flim was underexpres ...19957768859
shigella enterotoxin 1: an enterotoxin of shigella flexneri 2a active in rabbit small intestine in vivo and in vitro.culture filtrates of shigella flexneri 2a strain m4243 grown in iron-depleted medium, caused significant fluid accumulation in rabbit ileal loops. also, when tested in ussing chambers, a greater rise in potential difference and short circuit current was seen with such filtrates compared with the medium control. analogous filtrates from two m4243 derivatives lacking the 140-md invasiveness plasmid (either m4243avir or bs103) retained 60-65% of the wild-type enterotoxic activity. ultrafiltration a ...19957769126
identification of bacterial genes that contribute to survival and growth in an intracellular environment. 19957773592
[the role of the outer membrane proteins, determined by the shigella flexneri invasiveness plasmid, in inducing cellular immune reactions].fractions of s.flexneri 2a 516 outer membrane proteins determined by plasmid psf140 have been shown to possess immunomodulating activity and to be capable of influencing the intensity of hematopoiesis, manifested by the stimulation of endocolony formation, the increase of the amount of splenic colony-forming units in the marrow, the increase of the pool of proliferating splenic colony-forming units of the marrow and their intensive migration into the blood. outer membrane proteins have been show ...19957778372
[new methodological approaches to the use of the pha reaction in determining anti-shigella antibodies].pronounced correlation between the titers of hemagglutinating antibodies to different types of shigellae and other bacteria in healthy persons and in sick persons of control groups has been established. on the basis of this regularity a new approach to the use of the passive hemagglutination test in shigellosis, taking into account the ratio of antibody titers to different shigella types, has been developed. this essentially increases the sensitivity and specificity of the test, thus making it p ...19957778383
[bactericidal effect of hydrated lime in aqueous solution].this study determined the bactericidal effect of the supernatants of saturated solutions of common lime and of micronized calcium hydroxide (ca(oh)2) (1500 mg/l), which was used as a control, compared with disinfectants made of solutions of 0.33% colloidal silver (0.0016 mg/l), toluene sulfachloramine (41 mg/l) with sodium bicarbonate (9 mg/l), and sodium hypochlorite (5 mg/l). the test involved four strains of vibrio cholerae 01, v. parahaemolyticus, escherichia coli, salmonella typhimurium, sh ...19957779285
contact of shigella with host cells triggers release of ipa invasins and is an essential function of invasiveness.the invasion of colonic epithelial cells by shigella, an early essential step for causing bacillary dysentery, is mediated by the ipab, ipac and ipad proteins. secretion of the ipa proteins from shigella requires functions encoded by the mxi and spa loci. in this study, we show that contact between the bacteria and epithelial cell triggers release of the ipa proteins into the external medium, which results in a rapid decrease in levels of ipa proteins presented on the cell surface. when the bact ...19957781600
a common-source outbreak of shigellosis involving a piped public water supply in northern thai communities.we report an epidemiological investigation of an explosive common-source water-borne shigellosis outbreak traced to a piped public water system in northern thai communities. in august 1991, 242 cases of acute diarrhoeal illness occurred in sam ngao subdistrict, tak province. about 30% of the cases were culture-positive for multiresistant shigella flexneri 2a. the outbreak affected all age groups, with the highest attack rate (9.4%) in children < 5 years old. the first ten cases occurred during 1 ...19957783269
overexpression of the shigella flexneri genes coding for dna topoisomerase iv compensates for loss of dna topoisomerase i: effect on virulence gene expression.introducing the escherichia coli topa20::tn10 allele to shigella flexneri results in osmotic sensitivity, a reduced growth rate, an increase in reporter plasmid supercoiling (all common to the e. coli mutants), an inability to grow on macconkey agar and a loss of virulence gene expression. e. coli mutants harbouring this topa allele often compensate for the loss of dna topoisomerase i by amplifying the genes coding for topoisomerase iv. unlike the e. coli topa mutants, derivatives of s. flexneri ...19957783621
shigella flexneri-hela cell interactions: a putative role for host cell protein kinases.epithelial cell invasion has been shown to be a prerequisite for shigella flexneri virulence. recently, we have documented the induction of transcription factor dna binding activities as a result of s. flexneri challenge of hela cells. in this report, we show that hela cells challenged with s. flexneri display differences in phosphotyrosine-containing proteins. these changes are detected as early as 5 min post-challenge. challenge with a noninvasive ipab mutant strain resulted in the induction o ...19957719286
cytoskeletal rearrangements and the functional role of t-plastin during entry of shigella flexneri into hela cells.shigella flexneri is an enteroinvasive bacterium which causes bacillary dysentery in humans. a major feature of its pathogenic potential is the capacity to invade epithelial cells. shigella entry into epithelial cells is considered a parasite-induced internalization process requiring polymerization of actin. here we describe the cytoskeletal rearrangements during s. flexneri invasion of hela cells. after an initial contact of the bacterium with the cell surface, distinct nucleation zones of heav ...19957721941
a focal adhesion factor directly linking intracellularly motile listeria monocytogenes and listeria ivanovii to the actin-based cytoskeleton of mammalian cells.the surface-bound acta polypeptide of the intracellular bacterial pathogen listeria monocytogenes is the sole listerial factor needed for recruitment of host actin filaments by intracellularly motile bacteria. here we report that following listeria infection the host vasodilator-stimulated phosphoprotein (vasp), a microfilament- and focal adhesion-associated substrate of both the camp- and cgmp-dependent protein kinases, accumulates on the surface of intracytoplasmic bacteria prior to the detect ...19957729410
antibody and cytokine responses in a mouse pulmonary model of shigella flexneri serotype 2a infection.a murine pulmonary model was used to study the mucosal immune response to shigella flexneri serotype 2a infection. inoculation of balb/cj mice with shigellae via the intranasal route resulted in bacterial invasion of bronchial and alveolar epithelia with concomitant development of acute suppurative bronchiolitis and subsequent development of lethal pneumonia. the pathology of pulmonary lesions resembled the colitis that characterizes shigellosis in humans and primates. significant protection aga ...19957729907
[regarding the shigella flexneri 4 strains isolated in recent years].a total of 38 strains of shigella flexneri 4, 14 of which were subserotype 4a but 24 of which were of an undecided subserotype, isolated in recent years, were studied for their biochemical and serological characteristics, and drug susceptibility. among the biochemical characteristics examined, 21 of the 38 strains (55.3%) were mannitol negative biotype and utilized sodium acetate, meanwhile, 17 of the mannitol positive strains did not utilize sodium acetate. the results of serological tests show ...19957745304
genetic analysis of the rfbx gene of shigella flexneri.analysis of the nucleotide sequence of the rfbx gene of shigella flexneri revealed that it contained a high proportion of rare codons, as previously observed in the analysis of the o-antigen polymerase-encoding gene rfc [morona et al., j. bacteriol. 176 (1994) 733-747]. the rfbx gene encodes a hydrophobic, 46-kda protein, with 12 potential transmembrane-spanning domains, that shows structural homology with gene products encoded in many rfb regions, and with orf0416 of the rff region of escherich ...19957698674
a conformationally homogeneous combinatorial peptide library.in search for a rational way to convert the information encoded in peptide structures into peptidomimetics, major progress could be made by coupling the power of selection methods, now enormously increased in number as a result of the development of combinatorial peptide libraries, with the rational design of structure-inducing templates for the selectable sequences. the availability of libraries of peptides with predetermined structure would enable selection-driven peptidomimetic design, whereb ...19957707366
fecal excretion of leukotriene c4 during human disease due to shigella dysenteriae.fecal excretion of leukotriene c4 was determined in 26 individuals with dysentery and in 19 healthy controls. of the patients, five were infected with shigella dysenteriae type 1, 15 were infected with shigella flexneri, two were infected with shigella boydii, and four were infected with shigella sonnei. three of the healthy controls were infected with non-dysenteriae shigellae. all isolates of shigella dysenteriae type 1 produced shiga toxin; the other strains were not toxigenic. patients with ...19957714683
cell-to-cell spread of shigella flexneri: exploitation of the host cytoskeleton. 19957714693
high frequency of strains multiply resistant to ampicillin, trimethoprim-sulfamethoxazole, streptomycin, chloramphenicol, and tetracycline isolated from patients with shigellosis in northeastern brazil during the period 1988 to 1993.the occurrence and antimicrobial resistance pattern of shigella isolates obtained from persons in community and hospital-based studies of diarrhea and matched controls in northeastern brazil were studied. the isolation rate of shigella spp. from patients with diarrhea during 1988 to 1993 varied from 4.5% (26 of 575) for the urban community of gonçalves dias to 6.7% (12 of 179) and 5.9% (7 of 119) for hospital infantil and hospital universitário, respectively. of the 55 shigella isolates (45 from ...19957695319
cleavage of shigella surface protein virg occurs at a specific site, but the secretion is not essential for intracellular spreading.the large plasmid-encoded outer membrane protein virg (icsa) of shigella flexneri is essential for bacterial spreading by eliciting polar deposition of filamentous actin (f-actin) in the cytoplasm of epithelial cells. recent studies have indicated that virg is located at one pole on the surface of the bacterium and secreted into the culture supernatant and that in host cells it is localized along the length of the f-actin tail. the roles of these virg phenotypes in bacterial spreading still rema ...19957896693
the occurrence of duplicate lysyl-trna synthetase gene homologs in escherichia coli and other procaryotes.the lysyl-trna synthetase (lysrs) system of escherichia coli k-12 consists of two genes, lyss, which is constitutive, and lysu, which is inducible. it is of importance to know how extensively the two-gene lysrs system is distributed in procaryotes, in particular, among members of the family enterobacteriaceae. to this end, the enterics e. coli k-12 and b; e. coli reference collection (ecor) isolates ec2, ec49, ec65, and ec68; shigella flexneri; salmonella typhimurium; klebsiella pneumoniae; ente ...19957896714
persistence of local cytokine production in shigellosis in acute and convalescent stages.shigella infection is accompanied by an intestinal activation of epithelial cells, t cells, and macrophages within the inflamed colonic mucosa. a prospective study was carried out to elucidate the cytokine pattern in shigella infection linked to development of immunity and eradication of bacteria from the local site and also to correlate the cytokine profile with histological severity. an indirect immunohistochemical technique was used to determine the production and localization of various cyto ...19957806368
caulobacter fliq and flir membrane proteins, required for flagellar biogenesis and cell division, belong to a family of virulence factor export proteins.the caulobacter crescentus fliq and flir genes encode membrane proteins that have a role in an early step of flagellar biogenesis and belong to a family of proteins implicated in the export of virulence factors. these include the mopd and mope proteins from erwinia carotovora, the spa9 and spa29 proteins from shigella flexneri, and the yscs protein from yersinia pestis. inclusion in this family of proteins suggests that fliq and flir may participate in an export pathway required for flagellum as ...19957814323
functional conservation among members of the salmonella typhimurium inva family of proteins.inva, which is essential for salmonella spp. to enter cultured epithelial cells, is a member of a family of proteins involved in either flagellar biosynthesis or the secretion of virulence determinants by a number of plant and mammalian pathogens. the predicted overall secondary structures of these proteins show significant similarities and indicate a modular construction with a hydrophobic amino-terminal half, consisting of six to eight potential transmembrane domains, and a hydrophilic carboxy ...19957822051
thermoregulation of virb transcription in shigella flexneri by sensing of changes in local dna superhelicity.transcription of the virb gene, a transcriptional regulator of invasion genes on the large plasmid of shigella flexneri, is strictly regulated by growth temperature; when bacteria are grown at 37 degrees c, virb transcription is highly activated, while at 30 degrees c the level of virb transcription decreases to less than 5% of that at 37 degrees c. transcription from the virb promoter is activated by virf, which is encoded on the same plasmid, in a dna superhelicity-dependent manner (t. tobe, m ...19957860590
identification of two targets of the type iii protein secretion system encoded by the inv and spa loci of salmonella typhimurium that have homology to the shigella ipad and ipaa proteins.an important virulence factor of salmonella spp. is their ability to gain access to host cells. a type iii secretion system encoded in the inv and spa loci of these organisms is essential for this phenotype. we have identified two proteins, sipa and sipd, whose secretion from the bacterial cells is dependent on this system. the genes encoding these proteins are located at centisome 63 on the s. typhimurium chromosome, immediately downstream of the previously identified sipb and sipc genes (k. ka ...19958522512
use of plasma desorption mass spectrometry in structural analysis of endotoxins: effects on lipid a of different acid treatments. 19958524917
biological properties of yolk immunoglobulins. 19958526019
identification and sequences of the treponema pallidum flim', fliy, flip, fliq, flir and flhb' genes.information regarding the biology and virulence attributes of treponema pallidum (tp) is limited due to the lack of genetic exchange mechanisms and the inability to continuously cultivate this spirochete. we have utilized tnphoa mutagenesis of a tp genomic dna library in escherichia coli (ec) to identify genes encoding exported proteins, a subset of which are likely to be important in treponemal pathogenesis. we report here the identification and nucleotide (nt) sequence of a 5-kb treponemal dna ...19958529894
viral diarrhoea in a rural coastal region of karnataka india.a total of 106 children below 5 years of age admitted to the kasturba medical college hospital manipal karnataka (south india) were investigated over a period of 6 months to determine the aetiological role of viruses in acute diarrhoea. viral aetiological agents isolated were rotaviruses in 12 (11 per cent) cases, adenoviruses in 3 (3 per cent) cases, coronavirus and astroviruses in two (2 per cent) cases each. non-viral isolates were cryptosporidium and salmonella typhimurium in two cases each, ...19958531264
shigellosis in children from north india: a clinicopathological study.stool samples of 1488 children suffering from acute diarrhoea were studied for bacterial culture and sensitivity. shigella culture was positive in 143 (10 per cent) children and 53 hospitalized children could be studied in detail. thirty-six (68 per cent) children were under 2 years of age and peak prevalence was observed in summer months. fever and diarrhoea were universal features; 96 per cent had blood and mucus in the stools, but 32 per cent started with watery diarrhoea lasting 1-3 days fol ...19958531265
extracellular transport of virg protein in shigella.the ability of shigella to spread within and between epithelial cells is a prerequisite for causing bacillary dysentery and requires the function encoded by the virg gene on the large plasmid. the outer membrane virg (icsa) protein is essential for bacterial spreading by eliciting polar deposition of filamentous actin (f-actin) in the cytoplasm of epithelial cells. recent studies have indicated that an n-terminal 80-kda virg portion is exposed on the bacterial cell surface and released into the ...19958537341
partial dna sequence of a beta-lactamase produced by a shigella flexneri strain.a probe was constructed by radioactive labelling, and enzymatically a dna fragment of plasmid pmam-1, which codes for a beta-lactamase in shigella flexneri ucsm 129, was obtained by amplification of a small part of the gene using the polymerase chain reaction technique (pcr). since previous published work indicated that this beta-lactamase was of the tem type, the primers used to amplify the gene were two highly conserved dna regions in all tem beta-lactamases. a 500 bp dna probe was obtained wh ...19958538491
population dynamics in the co-culture of shigella flexneri 1b original strain and its antigenic 3b mutant carrying a prophage.the antigenic mutant shigella flexneri 3b showed selective prevalence when subcultured with the original strain 1b. mathematical analysis of such co-cultures showed that the dynamics of bacterial growth may be described by equations of the lotka-volterra type. the analysis of serial cultivations suggests that parameters of the equations may be realizations of random variables characterizing strains and media. the mutant carries a prophage lethal for the original strain. distinctive features of t ...19958538494
serological identification of shigella flexneri strains by the coagglutination reaction.several variants of reagents were prepared by coupling type (i, ii iii, iv, v and vi) and group (3, 4, 6 and 7, 8, 9) anti-shigella flexneri sera with protein a--containing staphylococcal suspension. for most serum lots coagglutination led to a 1/10 minimum dilution. however, different efficiencies were reported between serum lots and even within the same type or group. no improvement by the coagglutination reaction could be obtained for one lot from group 3, 4 and 7, 8, 9 sera and for both type ...19958993123
a transferable multiple drug resistance plasmid from vibrio cholerae o1.ten multiple antimicrobial-resistant isolates of vibrio cholerae o1 isolated from patients in uganda were characterized, and the transferability of resistance to bacteria of diverse origins was investigated. the isolates were toxigenic and belonged to biotype e1 tor, serotype ogawa, and ribotype 8, and possessed a 130-mda plasmid of incompatibility group 6-c. this plasmid, designated prvc1, was shown to confer resistance to trimethoprim (mediated by a dhfri gene), sulfonamides (a suii gene), tet ...19959158776
[the use of non-euclidean metrics in epidemiological classifications].a non-euclidean metric, stable to pollutions in sample data, for hierarchical cluster analysis in epidemiology is proposed. the simplicity of calculations permits its easy use in practice. on the basis of this metric the towns of tula province have been grouped according to morbidity rates in the shigellosis of flexner and sonne with the conjugated value of parameters.19959381873
[the selection of a virulent subpopulation of escherichia coli during shigella and salmonella infections in children]. 19958553728
[the antigenic and immunogenic properties of the bivalent strain shigella flexneri-shigella sonnei 1 no. 200]. 19958553752
mxig, a membrane protein required for secretion of shigella spp. ipa invasins: involvement in entry into epithelial cells and in intercellular dissemination.entry of shigella flexneri into epithelial cells involves secretory proteins, the ipa proteins, and their dedicated secretion apparatus, the mxi-spa translocon, which is encoded by the mxi and spa operons. we have characterized the mxig gene that is located at the proximal part of the mxi operon. inactivation of mxig abolished lpa secretion, which indicates that mxig is an essential component of the mxi-spa translocon. immunoblotting analysis of membrane fractions suggests that the 42 kda mxig p ...19958559065
microbiological investigation of diarrhoea epidemics among rwandan refugees in zaire. 19958560524
serotype distribution and antimicrobial susceptibility of shigellae isolated from diarrhoeal patients in yangon, myanmar.in myanmar there is a changing pattern in the prevalence of shigella strains with an increasing antimicrobial resistance, and, thus the serotype prevalence and antibiotic sensitivity pattern of shigellae were studied in 1993. dysenteric stool samples were collected from the laboratory of infectious diseases hospital, yangon during january-june 1993. the shigella isolates were identified by the standard bacteriologic procedures. four hundred and sixty stool samples containing blood and mucous wer ...19958568195
immunogenicity of the shigella flexneri serotype y (sfl 124) vaccine strain expressing cloned glucosyl transferase gene of converting bacteriophage sfx.the glucosyl transferase gene (gtr) from bacteriophage phage x (sfx) caused partial conversion of serotype y (group antigen 3, 4) to x (group antigen 7, 8) when introduced into a candidate vaccine strain of shigella flexneri serotype y (sfl124). the gtr gene caused conversion of o-antigens but did not eliminate the adsorption of the corresponding phage sfx. the hybrid strain expressing both group antigens 7, 8 and 3, 4 showed 75% protection when immunized guinea pigs were challenged with a wild- ...19958569531
adherence of helicobacter pylori to cultured human gastric carcinoma cells.to examine the binding activity of helicobacter pylori to cultured gastric epithelial cells using flow cytometry.19958574746
serum antibody to lipopolysaccharide antigens of shigella species among u.s. military personnel deployed to saudi arabia and kuwait during operations desert shield and desert storm.during operations desert shield and desert storm, u.s. troops were at high risk of diarrheal disease due to shigella spp., particularly shigella sonnei. in order to better understand the serologic response to shigella infection, 830 male u.s. combat troops were evaluated before and after the deployment to saudi arabia and kuwait for immunoglobulin a (iga) and igg anti-shigella lipopolysaccharide (lps) (antibody to s. sonnei form i and shigella flexneri serotypes 1a, 2a, and 3a) in serum. just be ...19958574833
construction and evaluation of a virg thya double mutant of shigella flexneri 2a as a candidate live-attenuated oral vaccine.a virg thya double mutant of shigella flexneri 2a was constructed as a candidate live-attenuated oral vaccine. in the keratoconjunctivitis model it did not provoke any adverse reaction by itself on guinea pigs' eyes and completely protected them from provoking keratoconjunctivitis. when (2.7-4.8) x 10(10) of the vaccine was inoculated intragastrically after 1 day fasting in cynomolgus monkeys three times at weekly intervals, a watery stool was observed at 40% as a side-effect. upon intragastric ...19958578822
a modified shigella volunteer challenge model in which the inoculum is administered with bicarbonate buffer: clinical experience and implications for shigella infectivity.in the absence of a definitive immunologic correlate of protection against shigellosis, promising shigella vaccine candidates have been selected based on their ability to confer resistance against experimental challenge with wild-type shigella in healthy adult volunteers. a limitation of this model has been the low and often variable attack rate of illness among controls, necessitating repeated inpatient studies to demonstrate statistically significant results. in this study, the shigella challe ...19958578831
shigella lipopolysaccharide antibodies in pediatric populations.shigellosis is the most common cause of bacterial dysentery. to study the specific immunity to the two major groups causing shigellosis, we assayed antibodies to lipopolysaccharide (lps) by enzyme-linked immunoadsorbent assay to both shigella sonnei and shigella flexneri 2a serotypes in the following populations: (1) women immediately after delivery and their infants to assess the transfer of passive immunity by placenta and the presence of secretory antibodies in breast milk; (2) children of di ...19958584312
evaluation of giardeia kit for giardiasis diagnosis.giardia lamblia is recognized as one of the most common agents for diarrhea world wide. to date, microscopical examination of stool samples is the gold standard for giardiasis diagnosis. however, intermittence of the giardia cycle and some medications may cause temporary disappearance of cysts from stools, thus giving false negative results. in the present study, we evaluated a commercially available enzyme immunoassay kit (giardeia) for the detection of giardia copro-antigens and compared the r ...19958586858
[species and serovar-distribution, and drug-resistance of shigella strains isolated from imported and domestic cases from 1990 through 1994 in tokyo].a total of 446 shigella strains consisting of 336 imported and 110 domestic strains isolated in tokyo from 1990 to 1994 were examined for their species and serovar-distribution, and their drug-resistance. in both imported and domestic strains, s. sonnei was found to be the most prevalent species, followed by s. flexneri. in imported strains, however, the isolation frequency of s. flexneri, s. boydii and s. dysenteriae were higher than that of domestic strains, and the serovar of each species was ...19958586884
the novel nuclear gene dss-1 of saccharomyces cerevisiae is necessary for mitochondrial biogenesis.a previously unknown nuclear gene dss-1 from saccharomyces cerevisiae was cloned and sequenced. the gene was isolated as a multicopy suppressor of a disruption of the suv-3 gene coding for a dead/h box protein involved in processing and turnover of mitochondrial transcripts. the dss-1 gene codes for a 970 amino-acid protein of molecular weight 111 kda and is necessary for mitochondrial biogenesis. amino-acid sequence analysis indicates the presence of motifs characteristic for escherichia coli r ...19958590460
expression of flagella and motility by shigella.since the discovery of shigella as the aetiologic agent of acute dysentery almost 100 years ago, this organism has been described as a non-motile and nonflagellated organism that invades the human colonic mucosa. in this study, the production of flagella by prototypic strains of all four shigella species and, moreover, by fresh clinical isolates was demonstrated by electron microscopy. the flagellum of shigella (flash) is approximately 10 microns long and 12-14 nm in diameter and is typically se ...19958596461
shigellosis in thai children: experience from a rural hospital 1985-1993.six hundred and ninety-four cases of shigellosis in nakhon nayok hospital from january 1985 to december 1993 were studied to determine epidemiologic and microbiological features. forty-five percent of cases were children under the age of 14 years. the majority of cases were in children under the age of four. the organism was found throughout the year, with peak incidence in june and july. the most common type isolated was shigella flexneri, about 74.43%. only 0.32% of organisms were shigella dys ...19958629073
sequence and expression analysis of the hrpb pathogenicity operon of xanthomonas campestris pv. vesicatoria which encodes eight proteins with similarity to components of the hrp, ysc, spa, and fli secretion systems.in this paper we describe the molecular characterization of hrpb, the largest operon in the xanthomonas campestris pv. vesicatoria hrp cluster. the hrpb region encompasses 6 kb and encodes eight putative proteins, seven of which were expressed in escherichia coli. the hrpb3 protein is the only one carrying a signal peptide sequence at the n-terminus and is a putative lipoprotein localized in the outer membrane of x. campestris pv. vesicatoria. the hrpb4 and hrpb8 proteins contain one and five pu ...19958664494
the cell biology of infection by intracellular bacterial pathogens.listeria monocytogenes and shigella flexneri are unrelated bacterial pathogens that have independently evolved similar strategies of survival within an infected host animal. bacteria coming into contact with the surface of an epithelial cell induce cytoskeletal rearrangements resulting in phagocytosis. they then secrete enzymes that degrade the phagosomal membrane, releasing the bacteria into the host cytoplasm. intracytoplasmic bacteria move rapidly, in association with a "comet tail" made up o ...19958689557
a role for bacteriophages in the evolution and transfer of bacterial virulence determinants.a virulence-associated region in the genome of dichelobacter nodosus has been shown to contain an integrase gene which is highly related to the integrases of shigella flexneri phage sf6 and coliphages p4 and phi r73, together with open reading frames (vapb, c and d) related to genes borne on plasmids in neisseria gonorrhoeae, escherichia coli, actinobacillus actinomycetemcomitans and treponema denticola. similar to p4 and phi r73, the vap region is bracketed by putative bacteriophage att sites a ...19958709840
lipopolysaccharide with an altered o-antigen produced in escherichia coli k-12 harbouring mutated, cloned shigella flexneri rfb genes.cloning of the rfb genes of shigella flexneri 2a into escherichia coli k-12 strain dh1 results in the synthesis of lipopolysaccharides (lps) with an o-antigen chain having type antigen iv and group antigens 3,4. during genetic studies of these rfb genes in e. coli k-12, we observed that strains harbouring plasmids with certain mutations (inversion and transposon insertions) which should have blocked o-antigen synthesis nevertheless still produced lps with o-antigen chains. these lps migrated dif ...19958709841
genetic polymorphism of the ipah multicopy antigen gene in shigella spps. and enteroinvasive escherichia coli.the ipah loci comprise a multicopy antigen gene family unique to shigella species and enteroinvasive escherichia coli (eiec). dna probes derived from the shigella flexneri serotype 5 ipah7.8 gene were used to compare the molecular arrangement of ipah alleles in a variety of shigella and eiec strains. multiple copies of ipah-homologous sequences were detected in all invasion plasmids examined. oligonucleotide probes covering discrete 24 bp segments of the ipah7.8 gene and sequences flanking the i ...19958778567
mechanism of antigenic variation in shigella flexneri bacilli. iii. complement sensitivity of s. flexneri 1b strains and their 3b variants selected either as lac+ recombinants or phage f2 resistant mutants.several s. flexneri 1b serotype strains of clinical isolation were compared with their 3b serotype variants isolated either as lac+ recombinants from crosses of s. flexneri x e. coli hfr c, or f2-resistant mutants. the studied variants 3b were deprived of type i antigen but acquired type iii antigen. they appeared to be less sensitive to killing action of complement present in normal bovine serum although kinetics of killing and its effectiveness differed between the strains.19958744688
brain edema: an underdiagnosed complication of shigella infection. 19958745030
gene transfer from bacteria to mammalian cells.transfer of genetic information between phylogenetically remote bacterial genera [1], from bacteria to yeast [2] and from bacteria to plants [3] by plasmid conjugation has been described. however, direct dna transfer from prokaryotes to mammalian cells has not yet been demonstrated. certain bacterial species have evolved the ability to enter mammalian cells by inducing their own internalization [4]. we show that invasive strains of shigella flexneri and escherichia coli, that undergo lysis upon ...19958745635
the unrelated surface proteins acta of listeria monocytogenes and icsa of shigella flexneri are sufficient to confer actin-based motility on listeria innocua and escherichia coli respectively.listeria monocytogenes and shigella flexneri are two unrelated facultative intracellular pathogens which spread from cell to cell by using a similar mode of intracellular movement based on continuous actin assembly at one pole of the bacterium. this process requires the asymmetrical expression of the acta surface protein in l. monocytogenes and the icsa (virg) surface protein in s. flexneri. acta and icsa share no sequence homology. to assess the role of the two proteins in the generation of act ...19958748026
salmonella typhimurium secreted invasion determinants are homologous to shigella ipa proteins.salmonella typhimurium secreted proteins (ssp) were previously implicated in epithelial cell invasion. here we describe four genes (sspb, sspc, sspd, and sspa), located between spat and prgh, which encode proteins of 63, 42, 36, and 87 kda, respectively. these ssp are homologous to shigella flexneri secreted proteins ipab, ipac, ipad and ipaa. a non-invasive mutant with a transposon insertion in sspc lacks ssp of 87, 42 and 36 kda. complementation and analyses show that sspc and sspd encode the ...19958748032
shigella isolates in stool.a total of 447 shigella strains were isolated from stool samples during 1989-1991. of these 270 (60%) were from children. among the different species and serotypes sh. flexneri 60 (13.4%) and sh. sonnei phage 139 (65%) were the most frequently isolated strains. 154 (34.4%) strains were resistant to three and 179 (40%) to more than three antibiotics. some strains of shigella were found to be resistant to furazolidine and neomycin.19958919104
shigellosis in children: clinical and laboratory features. 19958904140
a marker induction mechanism for the establishment of ordered neural mappings: its application to the retinotectal problem. 199541273
proceedings: developmental changes in the sensitivity of neurohormone-stimulated cyclic amp formation in chick cerebral hemispheres. 1995177142
drugging a defendant: arm-chair ethics? 199541820
the sleep of psychotic patients: does it all look alike? 1995176702
teicoplanin in open fractures: a preliminary report.the occurrence of infection following open fractures varies with the severity of the fracture and associated soft tissue damage. in order to study the effect of antibiotics given prophylactically, teicoplanin has been used in a prospective study. on admission, fractures were graded according to the severity of the tissue damage: type i--soft tissue injury less than 1 cm type ii--soft tissue injury more than 1 cm. type iii fractures characterized by extensive soft tissue and bone damage were not ...19951381635
[female hormonal disorders. diagnostic possibilities]. 1995394501
[is psoriasis an autoimmunologic disease?].dthe defective function of t-lymphocytes, which is a finding in active psoriasis, is transitional and reversible, whereas the immunological mechanism is mainly related to the formation of immune complexes consisting of stratum corneum antibodies and stratum corneum antigen, which through binding of complement and activation of chemotactic complement components is responsible for the phenomenon of "squirting papillae". the earliest lesions preceding pin point papules, called pre-pin-point papules ...1995398360
[clinical use of "flavitan" in some mucosal diseases of the mouth]. 1995295972
from inkblots to art therapy. 19952199910
[epr- and ir-spectroscopic study of the processes of carbonization of amino acid crystals].initial stages of "low temperature" carbonization in crystal amino acids have been studied by esr- and ir-spectroscopy. it was revealed that block polycondensation of amino acids with the formation of polypeptide chains took place. in the air oxygen also surface carbonization of crystals took place; it became stronger with the occurrence of radiation defects.1995173400
iliocaval thrombi in pulmonary thromboembolic disease.rational management of patients with pulmonary thromboembolic disease should include assessment of the risk of additional emboli. other authors have shown that the possibility of fatal pulmonary embolism is higher when the iliofemoral system contains thrombus, and it is recommended that vena caval interruption rather than simple anticoagulation is indicated. additional factors governing the therapeutic choice should include the magnitude of the original embolic occlusion as well as the presence ...1996178222
[treatment of painful sequelae of peripheral nerve lesions]. 1996174354
detection of complement (c3d) coated cells in a newborn due to maternal anti-i.a case of a positive direct antiglobulin test on a newborn's cord red blood cells caused by maternal anti-i is reported. the direct antiglobulin test was moderately positive using polyspecific antiglobulin reagent and monospecific anti-c3d, but negative using monospecific anti-igg. the infant showed no clinical signs of hemolytic disease of the newborn.1996452076
an attempt at a simulation of the end-plate current. 1996173931
[classification and metabolic patterns of hyperlipoproteinemia, with special reference to serum lipoprotein metabolism]. 1996173902
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