Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 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 ... | 1995 | 7814323 |
| 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 ... | 1995 | 7822051 |
| 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 ... | 1995 | 7860590 |
| 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 ... | 1995 | 7896693 |
| 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 ... | 1995 | 7896714 |
| serogroup prevalence of shigellae in bombay. | prevalence of shigellae serotypes in bombay was studied from june 1988 to may 1991. a total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs) with acute gastroenteritis. a total of 90 shigella were isolated giving the isolation rate of 3.2%. shigella flexneri was the predominant serogroup (73.3%) followed by shigella dysenteriae (16.6%). all the isolates were sensitive to nalidixic acid. eighty percent of the shigellae were multidrug resistant. present data were compare ... | 1995 | 10707731 |
| polymorphonuclear leukocyte transmigration promotes invasion of colonic epithelial monolayer by shigella flexneri. | in vivo and in vitro, shigella flexneri, an invasive pathogen of the human colon, cannot invade epithelial cells through their apical pole. to identify ways by which it may reach the cellular basolateral domain in order to invade, we have established an assay using the human colonic t-84 cell line grown on permeable filters. human pmn were added to the basal pole of the cells, and invasive shigellae to their apical pole. apical addition of bacteria induced strong transmigration of pmn, reaching ... | 1994 | 7906696 |
| is protection against shigellosis induced by natural infection with plesiomonas shigelloides? | shigellosis due to shigella sonnei is rare among people growing up and living in developing countries; however, infections due to s sonnei becomes more common than those due to s flexneri as societies develop economically. the relation between risk of s sonnei infection and economic development may be explained by the exposure of developing-country populations to plesiomonas shigelloides. p shigelloides is often found in surface water, and one serotype (serotype 17) possesses a cell-wall lipopol ... | 1994 | 7910890 |
| construction and characterization of attenuated delta aroa delta virg shigella flexneri 2a strain cvd 1203, a prototype live oral vaccine. | we engineered an oral shigella vaccine prototype that can invade intestinal epithelial cells but cannot undergo extensive intracellular replication or extend to adjacent epithelial cells. strain cvd 1203, derived from wild-type shigella flexneri 2a by introducing deletions in chromosomal aroa and invasion plasmid virg, was highly attenuated in the sereny test. two 10(9)-cfu orogastric doses (2 weeks apart) stimulated production of secretory immunoglobulin a antibodies to s. flexneri 2a and prote ... | 1994 | 7927802 |
| enhancement of anti-shigella lipopolysaccharide (lps) response by addition of the cholera toxin b subunit to oral and intranasal proteosome-shigella flexneri 2a lps vaccines. | addition of the cholera toxin b subunit to oral and intranasal proteosome-shigella flexneri 2a lipopolysaccharide vaccines improved their immunogenicities. enhancement of anti-o-shigella immunoglobulin a levels was most evident in lung lavages following oral immunization and in lung and intestinal fluids when suboptimal doses were used with either immunization route. | 1994 | 7927807 |
| involvement of escherichia coli dna polymerase ii in response to oxidative damage and adaptive mutation. | dna polymerase ii (pol ii) is regulated as part of the sos response to dna damage in escherichia coli. we examined the participation of pol ii in the response to oxidative damage, adaptive mutation, and recombination. cells lacking pol ii activity (polb delta 1 mutants) exhibited 5- to 10-fold-greater sensitivity to mode 1 killing by h2o2 compared with isogenic polb+ cells. survival decreased by about 15-fold when polb mutants containing defective superoxide dismutase genes, soda and sodb, were ... | 1994 | 7928992 |
| acute inflammation causes epithelial invasion and mucosal destruction in experimental shigellosis. | the gram-negative pathogen shigella flexneri causes bacillary dysentery, an invasive disease of the human colonic mucosa. a major characteristic of the infectious process is the occurrence of an acute inflammatory reaction of mucosal tissues which is generally consequence of primary invasion and destruction of colonic epithelial cells by the pathogen. confirming in vitro demonstration that s. flexneri is unable to invade the apical pole of colonic cells and that polymorphonuclear (pmn) cells may ... | 1994 | 7931064 |
| effect of subinhibitory concentrations of antimicrobial agents on virulence factors of shigella flexneri 2a and escherichia coli o124. | the effect of subinhibitory concentrations of rifampicin, chloramphenicol, tetracycline and nalidixic acid on the interaction of shigella flexneri 2a and escherichia coli o124 with hela cells was examined. antimicrobial agents altered adhesion, penetration and intracellular multiplication of the bacteria, as well as re-infection of adjacent cells. chloramphenicol increased the virulence of the bacterial strains whereas nalidixic acid, tetracycline and rifampicin diminished it. | 1994 | 7932621 |
| dna rearrangement of the shufflon determines recipient specificity in liquid mating of inci1 plasmid r64. | the shufflon is a unique dna rearrangement found in plasmid r64. r64 shufflon consists of four dna segments, which are flanked and separated by seven 19-bp repeat sequences. site-specific recombination between any inverted repeats results in a complex dna rearrangement where four dna segments invert independently or in groups. the shufflon is a biological switch to select one of the seven c-terminal segments of the pilv gene. to examine the biological significance of the shufflon, r64 derivative ... | 1994 | 7932741 |
| from the centers for disease control and prevention. outbreak of shigella flexneri 2a infections on a cruise ship. | 1994 | 7933412 | |
| molecular cloning of the wild-type and mutant thya gene from shigella flexneri y. | the thya gene which codes for thymidylate synthase has been cloned and sequenced from the wild-type shigella flexneri y strain sh4 and a thya mutant tsf21 after amplifying the gene by polymerase chain reaction (pcr). the nucleotide sequence revealed 98% homology to the e. coli k-12 thya gene. the sequence of the wild-type thya gene of shigella flexneri y was identical with that of the thya mutant except that the residue t at position 345 was replaced by residue a in the thya mutant. this change ... | 1994 | 7935051 |
| [the effect of shigellae on delayed hypersensitivity in mice infected by different routes]. | the influence of virulent and avirulent shigellae on delayed hypersensitivity in the case of infection by different methods has been examined. it was found that the stimulating effect of avirulent shigellae and suppressive effect of virulent shigellae were displayed after intranasal infection. intraperitoneal and intravenous infection was accompanied by only immunosuppressive influence, which was displayed by the virulent bacteria. the discrimination of t-suppressors by low doses of cyclophospha ... | 1994 | 7952228 |
| lps injected into the pregnant rat late in gestation does not induce fetal endotoxemia. | endotoxin is abortifacient. abortion may be due to maternal, fetal or combined endotoxemia. the present study was performed to evaluate if fetal rat endotoxemia was induced by maternal endotoxemia in late gestation. an intraperitoneal injection of smooth lipopolysaccharide (escherichia coli lps and shigella flexneri lps) or rough lps (rc mutant escherichia coli lps) induced limulus activity in maternal plasma, but not fetal plasma. these results suggest that fetal rat endotoxemia is not induced ... | 1994 | 7953189 |
| extracellular association and cytoplasmic partitioning of the ipab and ipac invasins of s. flexneri. | shigella species cause bacillary dysentery in humans by invading colonic epithelial cells. ipab and ipac, two major invasins of these pathogens, are secreted into the extracellular milieu. we show here that ipab and ipac form a complex in the extracellular medium and that each binds independently to a 17 kda polypeptide, ipgc, in the bacterial cytoplasm. the ipgc polypeptide was found to be necessary for bacterial entry into epithelial cells, to stabilize the otherwise unstable ipab protein, and ... | 1994 | 7954817 |
| the secretion of the shigella flexneri ipa invasins is activated by epithelial cells and controlled by ipab and ipad. | shigella species are enteropathogens that invade epithelial cells of the human colon. entry into epithelial cells is triggered by the ipab, ipac and ipad proteins which are translocated into the medium through the specific mxi-spa machinery. in vitro, shigella cells secrete only a small fraction of the ipa proteins, the majority of which remains in the cytoplasm. we show here that upon interaction with cultured epithelial cells or in the presence of fetal bovine serum, s.flexneri release pre-syn ... | 1994 | 7957095 |
| shigella flexneri: from in vitro invasion of epithelial cells to infection of the intestinal barrier. | 1994 | 7958310 | |
| regulation of surface presentation of icsa, a shigella protein essential to intracellular movement and spread, is growth phase dependent. | after lysing the phagocytic vacuole, shigella spp. accumulate filaments of polymerized actin on their surface at one pole, leading to the formation of actin tails that enable them to move through the cytoplasm. we have recently demonstrated that the shigella protein icsa is located at the pole that is adjacent to the growing end of the actin tail (m. b. goldberg, o. barzu, c. parsot, and p. j. sansonetti, j. bacteriol. 175:2189-2196, 1993). not every bacterium that is observed within the cytopla ... | 1994 | 7960150 |
| mutational analysis of the transcriptional activator virg of agrobacterium tumefaciens. | to find virg proteins with altered properties, the virg gene was mutagenized. random chemical mutagenesis of single-stranded dna containing the agrobacterium tumefaciens virg gene led with high frequency to the inactivation of the gene. sequence analysis showed that 29% of the mutants contained a virg gene with one single-base-pair substitution somewhere in the open reading frame. thirty-nine different mutations that rendered the virg protein inactive were mapped. besides these inactive mutants, ... | 1994 | 7961391 |
| [diarrheal disease in hospitalized patients during the first year of the war]. | during the period from april 1992 to april 1993 at the clinic for infectious disease in sarajevo were hospitalized 213 patients. the major causative agents were different kinds of shigella. shigella sonnei with 159 (74.6%) was the most frequent isolated organism, then subsequent shigella species with 38 (23.9%) and shigella flexneri 3 with 23 (14.5%). bacillary dysentery (shigellosis) was manifested as acute gastroenteritis with 60 patients (37.7%). this disease was manifested in the form of acu ... | 1994 | 7967796 |
| measurement of invasion by gentamicin resistance. | 1994 | 7968625 | |
| shigella flexneri: isolation of noninvasive mutants of gram-negative pathogens. | 1994 | 7968634 | |
| asymptomatic shigella infections in a cohort of mexican children younger than two years of age. | the proportion of shigella infections that occur asymptomatically in young children has not been established. a community-based cohort study of 367 infants was followed prospectively by weekly home visits from january, 1990, through december, 1991. stool samples were collected weekly and when diarrhea occurred and were tested for shigella and other enteropathogens. there were 2925 child months of observation and 65 episodes of shigella infection. there were 3.1 episodes/100 child months during t ... | 1994 | 7970946 |
| the n-terminal domain of virg of agrobacterium tumefaciens: modelling and analysis of mutant phenotypes. | fourteen mutants in the n-terminal domain of virulence factor g (virg) were obtained by random mutagenesis. two mutants showed an altered phenotype, all others were non-functional. all mutants can still be phosphorylated and bind to dna. a 3-d model was built based on the coordinates of chemotaxis protein y (chey). many of the observed phenotypic changes of virg are explained qualitatively. combination of model building and biochemical information leads to the conclusion that the active sites of ... | 1994 | 7971952 |
| [triple shigellosis in the same patient contracted during operation "turquoise" in rwanda]. | we report a case of shigellosis observed in a young french sanitary assistant, returning from a refugees camp in goma after a 5-week stay. three different species were isolated from stool samples: shigella flexneri, s. boydii and s. sonnei. this observation raises the matter of a chemical prophylaxis during a short stay in developing countries where sanitary conditions are poor. | 1994 | 7866040 |
| antimicrobial resistance of shigella isolates causing traveler's diarrhea. | shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in spain. ampicillin and chloramphenicol resistance was more frequent in shigella flexneri (60 and 46%, respectively) than in shigella sonnei (32 and 18%, respectively) and in travel-related isolates (p < 0.05 and 0.04, respectively). of s. sonnei isolates from patients with tr ... | 1994 | 7872767 |
| model for the combined effects of temperature, initial ph, sodium chloride and sodium nitrite concentrations on anaerobic growth of shigella flexneri. | a fractional factorial design was used to measure the effects and interactions of temperature (12-37 degrees c), initial ph (5.5-7.5), nacl (0.5-4.0%) and nano2 (0-1000 ppm) on the anaerobic growth kinetics of shigella flexneri in brain-heart infusion broth. anaerobic conditions were established by flushing the culture flasks with n2. a total of 375 cultures representing 124 variable combinations were analyzed, with growth curves being generated using the gompertz equation. growth rates decrease ... | 1994 | 7873336 |
| [the role of the activity of pathogenic enterobacteria in inactivating the antibacterial constituent of interferon during phagocytosis]. | 1994 | 7879491 | |
| [an evaluation of the efficacy of measures to limit the activity of the water factor in the transmission of shigellosis in the city of blagoveshchensk]. | 1994 | 7879538 | |
| [an analysis of the plasmid profile of shigella flexneri strains used for obtaining vaccinal preparations]. | 1994 | 7879547 | |
| [the etiological structure of shigellosis in monkeys of the adler nursery]. | 1994 | 7879549 | |
| safety and immunogenicity of the oral e. coli k12-s. flexneri 2a vaccine (ecsf2a-2) among israeli soldiers. | a double-blind placebo-controlled study was carried out on the safety and immunogenicity of the oral shigella flexneri (ecsf2a-2) vaccine among israeli soldiers. sixty volunteers received the vaccine and 59 received placebo. fifty-three were given the full vaccine regimen (four doses). doses ranged between 4.1 x 10(8) and 1.1 x 10(9) c.f.u. visits to the unit clinic for mild gastrointestinal symptoms were common after the first dose in vaccinees (13%) as compared with placebo recipients (5%), bu ... | 1994 | 7887022 |
| [epidemics and history: the berlin 1962 dysentery epidemic]. | 1994 | 7825366 | |
| [the blood circulation of the rectal mucosa and the functional status of the rectal sphincter in acute infectious enterocolitis]. | significant decrease in the tone of the rectal mucosa venules was to be seen at the climax of acute proteus and klebsiella enterocolitis, as evidenced by examinations with the aid of rheorectograph and an analyzer of intracavitary motor activity, general blood supply to the intestinal segment under study being not compromised. the tone of the rectal mucous membrane arterioles is raised at the climax of acute dysentery caused by a flexner type of organism in erosive and haemorrhagic proctosigmoid ... | 1994 | 7831889 |
| [diarrhea, dysentery, cholera, new frontiers?]. | 1994 | 7746137 | |
| acute bacterial diarrhoea in the emergency room: therapeutic implications of stool culture results. | empiric treatment with ciprofloxacin and norfloxacin has been recommended recently for patients with acute diarrhoeal disease. in a retrospective 6-month study period the results of stool cultures from 209 patients with acute diarrhoea admitted to the emergency room were analysed. seventy-eight cultures (37%) were positive for one or more bacteria. shigella was the most commonly isolated pathogen (68%). shigella sonnei comprised 72% and shigella flexneri 19% of all the bacterial isolates. while ... | 1994 | 7804582 |
| [bacteriostasis of rhizoma coptidis combined with trimethoprim (tmpo)]. | the agar-dilution method was adopted to study contrastively the bacteriostasis of rhizoma coptidis and tmp, and also of the two drugs in combination. the results indicate that the combination works in good cooperation against escherichia coli, bacillus pyocyaneus, staphylococcus aureus, shigella flexneri and s. dysenteriae. | 1994 | 7718141 |
| [the epithelial proliferative activity of the mucosa of the large intestine in dysentery patients at the acute period of the disease depending on the expression of morphological changes]. | the dependence of proliferative activity on the degree of histomorphological changes in colonic mucosa of patients with dysentery was studied histoautoradiographically in colonic biopsies. morphological changes were evaluated according to n. b. shalygina's schema (catarrhal, exudative, erosive or ulcerous inflammation) a 2.5-3-fold increase of the labelled nuclei index (lni) and label intensity (li) was found in the catarrhal inflammation. lni was increased 1.2-fold and li 1.5-fold in cases of o ... | 1994 | 7695494 |
| reiter's syndrome and reactive arthritis: a current view. | this paper reviews advances in the understanding of the pathogenesis of reactive arthritis that have occurred over the last decade. inflammatory aseptic joint disease has been linked with prior infection initiated by many different species of microorganisms. the presence of intra-articular bacterial antigens has now been firmly established with the demonstration of bacteria, bacterial fragments, dna, rna, and bacterial lipopolysaccharide in joints of patients with reactive arthritis. chlamydia t ... | 1994 | 7534942 |
| mechanism of antigenic variation in shigella flexneri. ii. sensitivity to complement as a selection factor for antigenic mutant 3b in 1b serotype. | in the first report we stated that the antigenic mutant of shigella flexneri 6713 3b serovar with antigenic formula iii: 3, 4, 6 was less sensitive to bactericidal action of normal calf serum in comparison to its parent strain s. flexneri 6713 1b with antigenic formula iii: 3, 4, 6. in this paper we show that the phenomenon is rather a general one; the difference in sensitivity was observed in three other strains s. flexneri 1b of independent clinical origin and its antigenic mutants 3b respecti ... | 1994 | 7503650 |
| local immune response and protection in the guinea pig keratoconjunctivitis model following immunization with shigella vaccines. | this study used the guinea pig keratoconjunctivitis model to examine the importance of route of administration (mucosal versus parenteral), frequency and timing of immunization (primary versus boosting immunization), and form of antigen given (live attenuated vaccine strain versus o-antigen-protein conjugate) on the production of protective immunity against shigella infection. since local immune response to the lipopolysaccharide (lps) o-antigen of shigella spp. is thought to be important for pr ... | 1994 | 7507892 |
| characterization of the rfc region of shigella flexneri. | the o antigen of the shigella flexneri lipopolysaccharide (lps) is an important virulence determinant and immunogen. we have isolated s. flexneri mutants which produce a semi-rough lps by using an o-antigen-specific phage, sf6c. western immunoblotting was used to show that the lps produced by the semi-rough mutants contained only one o-antigen repeat unit. thus, the mutants are deficient in production of the o-antigen polymerase and were termed rfc mutants. complementation experiments were used ... | 1994 | 7507920 |
| division inhibition gene dicf of escherichia coli reveals a widespread group of prophage sequences in bacterial genomes. | the genomes of various eubacteria were analyzed by southern blot hybridization to detect sequences related to the segment of the defective lambdoid prophage kim which encodes dicf rna, an antisense inhibitor of cell division gene ftsz in escherichia coli k-12. among the homologous sequences found, one fragment from e. coli b, similar to a piece of rac prophage, and two fragments from shigella flexneri were cloned and sequenced. dicf-like elements similar to transcriptional terminators were found ... | 1994 | 7508908 |
| genetic analysis of the o-specific lipopolysaccharide biosynthesis region (rfb) of escherichia coli k-12 w3110: identification of genes that confer group 6 specificity to shigella flexneri serotypes y and 4a. | we recently reported a novel genetic locus located in the sbcb-his region of the chromosomal map of escherichia coli k-12 which directs the expression of group 6-positive phenotype in shigella flexneri lipopolysaccharide, presumably due to the transfer of o-acetyl groups onto rhamnose residues of the s. flexneri o-specific polysaccharide (z. yao, h. liu, and m. a. valvano, j. bacteriol. 174:7500-7508, 1992). in this study, we identified the genetic region encoding group 6 specificity as part of ... | 1994 | 7517390 |
| some structures and processes of human epithelial cells involved in uptake of enterohemorrhagic escherichia coli o157:h7 strains. | several enterohemorrhagic escherichia coli (ehec) strains of serotype o157:h7 isolated from patients with hemorrhagic colitis, ischemic colitis, or hemolytic uremic syndrome were all found to be able to invade certain human epithelial cell lines in vitro. their ability to gain entry into epithelial cells was compared with those of known invasive shigella flexneri and salmonella typhi strains and the noninvasive e. coli strain hb101 in invasion assays utilizing gentamicin to kill extracellular ba ... | 1994 | 7523304 |
| polymicrobial and recurrent bacteremia with shigella in a patient with aids. | shigella gastroenteritis is uncommon among hiv seropositive patients and may be complicated in some patients by bacteremia; s. flexneri being the most frequently detected serogroup. while recurrent salmonella bacteremia is common among hiv-seropositive patients, recurrent shigella bacteremia is not. we report here an hiv-seropositive patient with shigella gastroenteritis, polymicrobial bacteremia due to s. flexneri and s. boydii, and recurrent gastroenteritis and bacteremia with s. boydii. relap ... | 1994 | 7984973 |
| serum igg antibody responses to shigella invasion plasmid-coded antigens detected by immunoblot. | serum igg antibody responses to shigella invasion plasmid-coded antigens (ipa) from 58 shigella flexneri, s. sonnei, and s. dysenteriae infected swedish patients were investigated by immunoblot technique. intense responses to most components of ipa (ipas a, b, c, d, and virg-virulence determinant on sali fragment g of the plasmid) were evident in sera from s. flexneri infected patients. the strongest response was to ipa b and the weakest, to ipa d. in contrast, there were weaker responses to ipa ... | 1994 | 7984976 |
| [a rapid specific reaction of the blood phagocytes to bacteria and the new possibilities for its diagnostic determination in infections]. | materials on the study of specific reaction of phagocytes, rapidly appearing after the contact of the body with soluble microbial substances, are presented. the study has established that of the reaction-inducing stimulus has a non-antigenic character and it acts directly on phagocytes. the method for the determination of phagocytic reaction by the ratio of the phagocytosis levels in the specific and control objects has been developed, which makes it possible to use a common diagnostic criterion ... | 1994 | 7992518 |
| cloning and sequencing of sara of staphylococcus aureus, a gene required for the expression of agr. | to evaluate the effect of a sar mutation on the agr locus, northern (rna) blotting was performed to determine the levels of rnaiii, the agr regulatory molecule, in two isogenic pairs of staphylococcus aureus strains. our results demonstrated that rnaiii was either significantly diminished or absent in both sar mutants compared with the parents. the rnaiii level was partially restored in sar mutants complemented with an intact sar gene (designated sara). additionally, we were able to complement s ... | 1994 | 8021198 |
| a role for h-ns in the thermo-osmotic regulation of virulence gene expression in shigella flexneri. | the role of the hns gene (coding for the curved-dna-binding protein h-ns) in the thermo-osmotic regulation of shigella flexneri virulence gene transcription was investigated. two structural genes, mxic and icsb, which are transcribed divergently on the high-molecular-weight virulence plasmid, were found to be transcriptionally inhibited in cultures grown in a low-osmolarity medium, even at the inducing temperature. this repression was relieved by inactivation of the hns gene, establishing a role ... | 1994 | 8021202 |
| shigellosis in neonates and young infants. | to determine the clinical features and outcome of shigellosis in young infants, we reviewed the hospital records of 159 infants < or = 3 months of age (including 30 neonates) and 159 children 1 to 10 years of age with shigellosis who were admitted to the diarrhoea treatment centre in dacca, bangladesh. infants more commonly had a history of nonbloody diarrhea (82.8% vs 42.7%; p < 0.001), moderate or severe dehydration (59.9% vs 32.1%; p < 0.001), or bacteremia (12.0% vs 5.0%; p = 0.027) and less ... | 1994 | 8021764 |
| immunopathological patterns in the rectal mucosa of patients with shigellosis: expression of hla-dr antigens and t-lymphocyte subsets. | expression of hla-dr antigens and infiltration of t-lymphocyte subsets (cd4, cd8), cell activation marker (cd25), b cells (cd20), macrophages (cd68 and ber-mac 3) and natural killer cells (cd56) in the rectal mucosa of patients with bacillary dysentery and in healthy controls were studied in an effort to interpret the immunopathological changes taking place in the rectal mucosa during the acute phase of shigellosis. the epithelium of the rectal mucosa from 21 of 32 patients was hla-dr+. conventi ... | 1994 | 8024739 |
| yscu, a yersinia enterocolitica inner membrane protein involved in yop secretion. | pathogenic yersiniae secrete antihost yop proteins by a recently discovered secretion pathway which is also encountered in several animal and plant pathogens. the components of the export machinery are encoded by the vira (lcra), virb (lcrb), and virc (lcrc) loci of the 70-kb pyv plasmid. in the present paper we describe yscu, the last gene of the virb locus. we determined the dna sequence and mutated the gene on the pyv plasmid. after inactivation of yscu, the mutant strain was unable to secret ... | 1994 | 8045883 |
| vacc, a virulence-associated chromosomal locus of shigella flexneri, is homologous to tgt, a gene encoding trna-guanine transglycosylase (tgt) of escherichia coli k-12. | the genetic determinants required for invasion of epithelial cells by shigella flexneri and for the subsequent bacterial spreading are encoded by the large virulence plasmid. expression of the virulence genes is under the control of various genes on the large plasmid as well as on the chromosome. we previously identified one of the virulence-associated loci near phobr in the noti-c fragment of the chromosome of s. flexneri 2a ysh6000 and designated the locus vacc. the vacc mutant showed decrease ... | 1994 | 8045893 |
| characterization of endemic shigella flexneri strains in somalia: antimicrobial resistance, plasmid profiles, and serotype correlation. | one hundred twelve shigella flexneri strain isolated from children with diarrheal disease in somalia in 1983, 1984, 1988, and 1989 were analyzed for serotype, plasmid profile, and genetic location of antimicrobial resistance determinants. the prevalent serotypes were 4 (46% of the isolates), 1b (16%), 2a (16%), 3a (12%), and 6 (8%). each serotype was associated with a characteristic predominant plasmid profile, whereas no specific correlation between antimicrobial resistance patterns and single ... | 1994 | 8051242 |
| constitutive expression of the virulence genes improves the efficiency of plant transformation by agrobacterium. | inducible virulence (vir) genes of the agrobacterium tumefaciens tumor-inducing (ti) plasmid are under control of a two-component regulatory system. in response to environmental factors (phenolic compounds, sugars, ph) vira protein phosphorylates virg, which in turn interacts with the promoters of other vir genes, causing induction. a mutation of virg, virgn54d (which codes for a asn-54-->asp amino acid change in the product), causes constitutive expression of other vir genes independent of vira ... | 1994 | 8052627 |
| detailed structural characterization of lipid a: electrospray ionization coupled with tandem mass spectrometry. | previous studies have defined specific functional relationships within monophosphoryl lipid a (mla) preparations. to extend this understanding to all contributing entities, mla samples have been structurally characterized using electrospray ionization, collision-induced dissociation (cid), and tandem mass spectrometry (ms/ms). mla profiles of salmonella minnesota re595 have been compared with shigella flexneri for sample type and component distribution. in excess of 20 individual structures comp ... | 1994 | 8053569 |
| a mutation in the receiver domain of the agrobacterium tumefaciens transcriptional regulator virg increases its affinity for operator dna. | we fused the wild-type agrobacterium tumefaciens virg gene and the constitutive virgn54d allele to the male gene of escherichia coli, and studied the binding of mbp-virg fusions to the autoregulated virg promoter. mbp-virgn54d protein bound this promoter with 10-fold higher affinity than mbp-virg, and bound to vir box i with eightfold higher affinity than to vir box iii. disruption of vir box iii did not alter the affinity for vir box i, suggesting a lack of cooperativity between these sites. we ... | 1994 | 8057837 |
| deregulation of temperature-dependent transcription of the invasion regulatory gene, virb, in shigella by rho mutation. | expression of the virb gene, the transcriptional regulator for the invasion genes encoded by the large plasmid of shigella flexneri, is temperature-regulated. virb transcription is under the control of virf and h-ns, which act as positive and negative regulators, respectively, and is highly responsive to changes in dna superhelicity. to further investigate the molecular mechanisms underlying the thermoregulation of virb transcription, a mutant which expressed an invasion phenotype at both 30 deg ... | 1994 | 8057851 |
| molecular characterization of intact, but cryptic, flagellin genes in the genus shigella. | flagellin genes (flic) were detected in two species of the genus shigella. the flicsf gene cloned from shigella flexneri produced normal-type flagella in an escherichia coli delta flic strain while the flicss genes from two shigella sonnei strains produced curly-type flagella and their expression is repressible by salmonella flja repressor. the flicsf gene (1650 bp) shared high similarity with the e. coli flice gene not only in the 5' and 3' constant sequences but also in the upstream and downst ... | 1994 | 8057852 |
| shigellosis in jordanian children: a clinico-epidemiologic prospective study and susceptibility to antibiotics. | during a 2-year prospective study of children hospitalized with gastroenteritis, shigellosis was detected in 66 cases (9 per cent of 726 admissions). the age group for peak shigella incidence was 1-4 years. the incidence increased from 8 per cent in 1991, to 11 per cent in 1992. shigella flexneri was the most common isolate (65 per cent), followed by shigella sonnei (17 per cent), shigella boydi (11 per cent), and shigella dysenteriae (7 per cent). at presentation, 44 per cent had watery diarrho ... | 1994 | 7853441 |
| shigella flexneri: genetics of entry and intercellular dissemination in epithelial cells. | 1994 | 7859507 | |
| outpatient studies of the safety and immunogenicity of an auxotrophic escherichia coli k-12-shigella flexneri 2a hybrid vaccine candidate, ecsf2a-2. | a phase ii study was conducted in 244 volunteers at fort ord, ca, to determine the safety and immunogenicity of ecsf2a-2, a live, oral shigella vaccine constructed by transfer of genes from shigella flexneri to escherichia coli k-12. in this placebo-controlled study, four doses of vaccine ranging from 2.3 to 9.0 x 10(8) colony-forming units were given on days 0, 3, 14 and 17. vaccine shedding occurred from 1 to 3 days after each dose. the vaccine was well tolerated at every dose tested. signific ... | 1994 | 8036831 |
| identification and characterization of a salmonella typhimurium oxygen-regulated gene required for bacterial internalization. | growth of salmonella typhimurium in a low-oxygen environment induces the ability of these bacteria to enter mammalian cells. we have carried out a search for invasion genes that are expressed under low-oxygen conditions by using tn5laczy transcriptional fusions. several noninvasive oxygen-regulated laczy insertion strains have been identified. the invasion defect in one of these noninvasive s. typhimurium strains, bj66, has been complemented by introduction of a cosmid (pbdj125) from an s. typhi ... | 1994 | 8063389 |
| [the characteristics of the antibiotic therapy of acute dysentery in an immunodeficiency body state in children with leukopenia]. | course of the disease and some indices of immunity were studied in 100 children with sonne's and flexner's dysentery. parameters of immunity in 32 children (the 1st group) were normal. 68 patients (the 2-nd group) had secondary immune deficiency and leukopenia. recovery of immunodeficient children in use of antibiotics and prodigiosan was slowed down by 5.2 days as compared to that of children without immunodeficiency. antibiotics used in combination with lysozyme in patients of the 1st group re ... | 1994 | 8067000 |
| epidemiology of shigella infections in two ethnic groups in a geographic region in southern israel. | the epidemiology of shigellosis in the jewish and bedouin populations that coexist in the same geographic region in southern israel and share the same medical facilities but live separately under different socioeconomic conditions was examined in a retrospective, culture-based study. the average annual attack rate for the four-year period 1989-1992 was 368/100,000 inhabitants. the average annual attack rate among the jews, who enjoy western socioeconomic conditions, was 413/100,000 and the disea ... | 1994 | 8070448 |
| outbreak of shigella flexneri 2a infections on a cruise ship. | 1994 | 8072477 | |
| [bacterial dysentery in 1992]. | 1994 | 8073150 | |
| molecular and cellular mechanisms of tissue invasion by shigella flexneri. | shigella flexneri, a member of the family of enterobacteriaceae, causes bacillary dysentery by invading the human colonic mucosa and provoking a very intense inflammation. recent in vitro data allow us to integrate different phenomena into a model of the infectious process during shigellosis. in vivo, bacteria appear to enter the submucosa via the m cells, specialized cells that cover the follicular structures of the intestinal mucosa. once inside the submucosa, shigellae encounter resident tiss ... | 1994 | 8080171 |
| protection against invasion of the mouse pulmonary epithelium by a monoclonal iga directed against shigella flexneri lipopolysaccharide. | 1994 | 8080209 | |
| immunogenicity of two types of shigella flexneri 2a o-specific polysaccharide-tetanus toxoid conjugates. | 1994 | 8080210 | |
| cadherin expression is required for the spread of shigella flexneri between epithelial cells. | shigella flexneri, a gram-negative pathogen, invades the human colonic epithelium. after entering epithelial cells, bacteria escape into the cytoplasm, move intracellularly, and pass from cell to cell. the bacterium diverts actin and associated actin-binding proteins to generate a cytoskeleton-based motor that pushes forward the bacterium. as the moving bacterium reaches the inner face of the host-cell cytoplasmic membrane, a protrusion forms that allows passage of this bacterium into a neighbor ... | 1994 | 8124719 |
| invasiveness of shigella flexneri in poliovirus infected ht-29 cells. | in this paper we report the effect in ht-29 cells of mixed infections with poliovirus type 1 and shigella flexneri serotype 5 strain m90t and derivative strains differing in adhesive as well as invasive properties. ht-29 epithelial intestinal cells derived from a human colon adenocarcinoma are a good model for coinfection studies because they are susceptible both to poliovirus replication and to s. flexneri invasion. the results show that 48 h after infection by poliovirus the invasiveness of wi ... | 1994 | 8127227 |
| acid and base resistance in escherichia coli and shigella flexneri: role of rpos and growth ph. | escherichia coli k-12 strains and shigella flexneri grown to stationary phase can survive several hours at ph 2 to 3, which is considerably lower than the acid limit for growth (about ph 4.5). a 1.3-kb fragment cloned from s. flexneri conferred acid resistance on acid-sensitive e. coli hb101; sequence data identified the fragment as a homolog of rpos, the growth phase-dependent sigma factor sigma 38. the clone also conferred acid resistance on s. flexneri rpos::tn10 but not on salmonella typhimu ... | 1994 | 8132468 |
| a chromosome map of shigella flexneri with the loci related to pathogenicity. | 1994 | 8133848 | |
| cleavage of the shigella surface protein icsa (virg): intention or accident? | 1994 | 8162437 | |
| immune responses in vietnamese children after a single dose of the auxotrophic, live shigella flexneri y vaccine strain sfl124. | the live, auxotrophic shigella flexneri vaccine strain sfl124 was given in a single dose of 10(7), 10(8) or 10(9) colony forming units (cfu), respectively, to each of three groups of 10 vietnamese children aged 9-14 years. the vaccine was well tolerated by all the children without any severe side effects such as diarrhoea or fever being observed. mild symptoms were reported by five children. only five children were found by culture to excrete sfl124 but, by pcr, 28 of 30 children were found to e ... | 1994 | 8163828 |
| the lcrb (yscn/u) gene cluster of yersinia pseudotuberculosis is involved in yop secretion and shows high homology to the spa gene clusters of shigella flexneri and salmonella typhimurium. | virulent bacteria of the genus yersinia secrete a number of virulence determinants called yops. these proteins lack typical signal sequences and are not posttranslationally processed. two gene loci have been identified as being involved in the specific yop secretion system (g. cornelis, p. 231-265, in c. e. hormache, c. w. penn, and c. j. smythe, ed., molecular biology of bacterial infection, 1992; s. c. straley, g. v. plano, e. skrzypek, p. l. haddix, and k. a. fields, mol. microbiol. 8:1005-10 ... | 1994 | 8169210 |
| characterization of a 3-dehydroquinase gene from actinobacillus pleuropneumoniae with homology to the eukaryotic genes qa-2 and qute. | a gene was cloned from actinobacillus pleuropneumoniae strain 4074 by complementation of an arod strain of escherichia coli. the e. coli gene arod codes for a 3-dehydroquinase enzyme of type i, active in the aromatic biosynthesis pathway. the a. pleuropneumoniae gene, termed aroq, displays no base or amino acid sequence homology to arod of e. coli. it is instead homologous to the qute and qa-2 genes, respectively of aspergillus nidulans and neurospora crassa. these genes code for 3-dehydroquinas ... | 1994 | 8170389 |
| characterization of the dtdp-rhamnose biosynthetic genes encoded in the rfb locus of shigella flexneri. | the nucleotide sequence of the proximal half of the rfb region of shigella flexneri has been determined, and the genes encoding enzymes involved in the biosynthesis of dtdp-rhamnose have been identified. these genes show strong homology to the rfb genes encoding dtdp-rhamnose biosynthesis in salmonella enterica serovar typhimurium (strain lt2) and s. enterica serovar anatum (strain m32) (jiang et al., 1991; wang et al., 1992). an open reading frame upstream of rfbb was also identified which enco ... | 1994 | 8170390 |
| identification and characterization of a chromosomal virulence gene, vacj, required for intercellular spreading of shigella flexneri. | intercellular spreading of shigellae is a prerequisite for shigellosis, although the molecular mechanisms underlying the phenomenon are still largely obscure. to elucidate some of these mechanisms, we performed random tn10 insertion mutagenesis in shigella flexneri ysh6000t and found a chromosomal locus in the noti-j segment responsible for bacterial spreading. the locus affected in the mutant, designated vacj, was neither involved in the invasion of epithelial cells nor in intracellular movemen ... | 1994 | 8145644 |
| a new class of proteins regulating gene expression in enterobacteria. | ymoa and hha are highly similar bacterial proteins downregulating gene expression in yersinia enterocolitica and escherichia coli, respectively. the phenotype of ymoa mutants evokes that of mutants affected in some histone-like proteins. this paper describes complementation of a ymoa mutation in y. enterocolitica by the hha gene from e. coli. we show that ymoa and hha are not only very similar proteins but that they are functionally interchangeable. genetic experiments indicate that hha can also ... | 1994 | 8145648 |
| in vivo r-plasmid transfer in a patient with a mixed infection of shigella dysentery. | transfer of shigella r-plasmids in vivo has seldom been demonstrated. strains of shigella dysenteriae type 1 and shigella flexneri type 5b were isolated from a bulgarian traveller who visited vietnam and developed dysentery, which was treated with trimethoprim/sulfamethoxazole (tmp/smz) for a short time. both species of shigellae are unusual in bulgaria where strains of s. sonnei predominate. both shigella strains were multiresistant to the same antimicrobial agents. each strain contained a 48-k ... | 1994 | 8149999 |
| nucleotide sequence of the rhamnose biosynthetic operon of shigella flexneri 2a and role of lipopolysaccharide in virulence. | n1308, a chromosomal tn5 mutant of shigella flexneri 2a, was described previously as a lipopolysaccharide (lps) mutant with a short o side chain. n1308 formed foci, but not plaques, in llc-mk2 cell monolayers and was negative in the serény test. in this study, the wild-type locus inactivated in n1308 was cloned and further defined by means of complementation analysis. a 4.3-kb bsteii-xhoi fragment of s. flexneri 2a ysh6200 dna was sufficient to restore both normal lps and virulence phenotype to ... | 1994 | 8157605 |
| infection, diarrhea, and dysentery caused by shigella species and campylobacter jejuni among guatemalan rural children. | to examine the factors that may influence the outcome of infections by shigella spp. and campylobacter jejuni we followed for 24 consecutive months 321 rural guatemala children 0 to 35 months old. home visits were made to determine child morbidity patterns with emphasis on diarrhea and dysentery. fecal samples for microbiologic studies were obtained from the participants when they were ill and during healthy periods. shigella spp. were isolated from 9.8 and 4.0% of ill and healthy children, resp ... | 1994 | 8177630 |
| [vaccination against the enterobacteria responsible for enteric infections]. | development of vaccines against enterobacterial species responsible for enteric infections sounds like an unrealistic project. on the other hand, based on our growing understanding of the pathogenesis of infections caused by the major species (i.e. salmonella typhi, shigella flexneri and shigella dysenteriae 1, enterotoxigenic escherichia coli) and on our better characterization of the immunological parameters of mucosal protection, it is likely that a limited number of vaccines controlling dise ... | 1994 | 8210205 |
| effect of outer membrane proteins (omp) of shigella on interleukin 2 (il-2) production by spleen cells of mice. | the kinetics of interleukin (il-2) release from mouse spleen cells incubated with different doses of outer membrane proteins (omp) from shigella was investigated. omp induced very low activity of il-2 after 2 and 4 h, and only a slightly higher level of the cytokine was detected after 6 h. however, il-2 activity increased markedly after 20 and 24 h of incubation, and doses of 5 and 10 micrograms of omp were found to be the most effective. spleen cells cultured with omp for 48 h contained reduced ... | 1994 | 7487346 |
| [ampicillin resistance mediated by the r plasmid in strains of shigella flexneri]. | forty shigella flexneri strains isolated from children attended to at the children's hospital of camagüey during an outbreak of acute diarrheal disease were studied; the minimal inhibitory concentration of ampicillin was determined. 33 strains (82.5%) were resistant to higher concentrations: 8 to 16 micrograms/ml, and 7 were susceptible to 4 micrograms/ml concentrations. resistance plasmid (r) extraction was carried out in all the isolated strains and a common plasmid was found this plasmid was ... | 1994 | 9768253 |
| inhibition of agrobacterium tumefaciens oncogenicity by the osa gene of psa. | the incw plasmid psa originally derived from shigella flexneri completely inhibits the tumor-inducing ability of agrobacterium tumefaciens when it is resident in this organism. oncogenic inhibition is mediated through the expression of the osa gene on psa. this gene is part of a 3.1-kb dna segment of psa that contains four open reading frames revealed by sequencing. specific deletions and tncat insertions within this segment localized the oncogenic inhibitory activity to the last open reading fr ... | 1994 | 8083162 |
| interleukin 1 is released by murine macrophages during apoptosis induced by shigella flexneri. | peritoneal macrophages undergoing apoptosis induced by shigella flexneri infection release the inflammatory cytokine interleukin 1 (il-1), but not il-6 or tumor necrosis factor alpha (tnf alpha). wild type shigella causes a very fast and significant release of il-1 from prestimulated peritoneal macrophages, before the cell's integrity is compromised. both il-1 alpha and il-1 beta are released, il-1 beta in its mature processed form. il-1 is released from presynthesized cytoplasmic pools. these r ... | 1994 | 8083373 |
| ipab mediates macrophage apoptosis induced by shigella flexneri. | shigella flexneri kills macrophages through apoptosis, involving the induction of host cell dna fragmentation and characteristic morphological changes. shigella can only cause damage if it escapes from the phagolysosome into the cytoplasm. the s. flexneri cytotoxic genes have been localized to the ipa operon of shigella's virulence plasmid. ipab, c and d deletion mutants are not invasive and therefore not cytotoxic. in order to distinguish genes involved in the escape from the phagolysosome as d ... | 1994 | 8196540 |
| molecular characterization, nucleotide sequence, and expression of the flio, flip, fliq, and flir genes of escherichia coli. | the flil operon of escherichia coli contains seven genes that are involved in the biosynthesis and functioning of the flagellar organelle. dna sequences for the first three genes of this operon have been reported previously. a 2.2-kb psti restriction fragment was shown to complement known mutant alleles of the flio, flip, fliq, and flir genes, the four remaining genes of the flil operon. four open reading frames were identified by dna sequence analysis and correlated to their corresponding genes ... | 1994 | 8282695 |
| comparison of conjugates composed of lipopolysaccharide from shigella flexneri type 2a detoxified by two methods and bound to tetanus toxoid. | shigella flexneri type 2a lipopolysaccharide (lps) was detoxified with acetic acid (o-sp) or with hydrazine (dealps). dealps, but not o-sp, retained part of its lipid a. both gave an identical line of precipitation with typing antiserum by double immunodiffusion, and both had low levels of lps activity by the limulus amoebocyte lysate assay. o-sp had an m(r) of approximately 17,000. dealps had two components of m(r)s approximately 30,00 (major and approximately 10,000 (minor). adipic acid hydraz ... | 1994 | 8262629 |
| mutants of agrobacterium vira that activate vir gene expression in the absence of the inducer acetosyringone. | in the presence of inducer molecules produced by wounded plants, the vira/virg two-component positive regulatory system of agrobacterium tumefaciens initiates transcription of virulence genes required for crown gall tumor formation. exactly how this system enables the bacterium to respond to an environmental signal is not known, but phosphorylation of vira and virg plays a role. to analyze further the function of vira, we chemically mutagenized the vira gene. two mutants that activate vir transc ... | 1994 | 8300595 |
| the binding site of the transcriptional activator virg from agrobacterium comprises both conserved and specific nonconserved sequences. | virulence genes of agrobacterium tumefaciens are transcriptionally activated in response to phenolic compounds and certain sugars. the transcription activator virg specifically binds to fragments containing the conserved vir box sequence present in the promoter region of all vir genes. this study shows that both the vir box as well as specific nonconserved sequences downstream of the vir box are required for virg binding and transcriptional activation. insertion of the identified virg binding si ... | 1994 | 8307169 |
| [determination of free and protein bound cortisol, transcortin binding capacity and adrenocorticotropic hormone in the plasma of patients with hypertension]. | the total non-conjugated plasma cortisol in 60 patients with hypertension disease (hd)is 17.5 mkg/ml. the free non-conjugated cortisol represents 8.45 per cent of the total - 1,5 mkg%, considerably (p less than 0.0001) higher than that in healthy subjects. protein conjugated cortisol is 16.0 mkg%. the bounding capacity of transcortin the plasma of hypertonics is considerably decreased (p less than 0.0001) - 15.8 mkg (in healthy - 18.5 mkg) per 100 ml. acth level in the plasma of patients with hd ... | 1994 | 188262 |