| morphologic homogeneity of bacteriophages and their biological activity. | lytic activity of morphologically homogeneous phage lysates, obtained from lysates containing morphologically inhomogeneous virions, was studied. five series of phage lysates found to contain morphologically inhomogeneous virions were investigated. by selecting suitable hosts from each series, two or three lines were obtained which reproduced morphologically homogeneous virions. morphologic homogeneity of these phage lines was determined by electron microscopy. in the course of this study it was ... | 1976 | 1259534 |
| a previously undescribed gram-negative bacillus causing septicemia and meningitis. | this report describes a case of septicemia and meningitis secondary to dog bites by two different dogs on two consecutive days. the case is noteworthy because of the unusual characteristics of the etiologic agent and the inability to place the etiologic agent into any currently defined genus or to identify it by the existing systems of classification. the organism is a small, thin, gram-negative bacillus after 24 hours of incubation on blood agar; after prolonged incubation, it becomes filamento ... | 1976 | 1266816 |
| antimicrobial susceptibilities of shigellae isolated in houston, texas, in 1974. | one hundred seventy-three strains of shigellae (113 shigella sonnei, 56 s. flexneri, and four others) isolated in houston during 1974 were tested for susceptibility to commonly used and newer antimicrobial agents. forty-five percent of s. sonnei strains were susceptible to ampicillin, whereas 93% of s. flexneri strains were susceptible to that agent. s. sonnei and s. flexneri strains were equally susceptible to tetracycline (35 and 33%, respectively). all 173 strains were uniformly susceptible t ... | 1976 | 1267426 |
| an "experimental" epidemic of reiter's syndrome revisited. follow-up evidence on genetic and environmental factors. | the relation between a specific infective event (shigellosis), a specific disease entity (reiter's syndrome), and a specific histocompatibility antigen (hl-a b27) is documented by follow-up study of an epidemic of post-shigella reiter's syndrome. five of the original 10 patients have been traced, hl-a typed, and clinically assessed 13 years after the initial episode. one of the 5 has minimal disease, remains symptom-free, and is hl-a b27-negative. the remaining 4 have followed a chronic course, ... | 1976 | 1275358 |
| absolute configuration of 3-hydroxy fatty acids present in lipopolysaccharides from various bacterial groups. | the absolute configuration of 3-hydroxy fatty acids has been studied, which are present in the lipopolysaccharides of the following bacteria: phodopseudomonas gelatinosa, rh. viridis, rhodospirillum tenue, chromobacterium violaceum, pseudomonas aeruginosa, bordetella pertussis, vibrio metchnikovii, vibrio cholerae, salmonella spp., escherichia coli, shigella flexneri, proteus mirabilis, yersinia enterocolitica and fusobacterium nucleatum. the 3-hydroxy acids were liberated by strong alkaline hyd ... | 1976 | 1278168 |
| [detection and identification of pathogenic bacteria by polymerase chain reaction with primers from dna sequence of ribosomal rna]. | applicability of the polymerase chain reaction method for identification of pathogenic bacteria was examined with the primers synthesized from the ribosomal rna gene sequence containing both homologous and species-specific regions of bacterial species from mycoplasma to mycobacteria. two out of the nine sets of promoters prepared, each covering about 650 nucleotides spanning from 16s rna to 23s rna regions, produced the corresponding dna fragments from all the strains tested, and another set did ... | 1992 | 1279233 |
| [the effect of shigella sonnei strains opposite in their virulence on different links in the immune system]. | for the first time different action of s. sonnei strains, opposite in their virulence, on hematopoiesis and the functional activity of t- and b-lymphocytes has been shown. the hematopoiesis-disturbing action of virulent shigellae is manifested by their capacity, more pronounced than similar capacity of an avirulent (vaccine) strain, for stimulating the processes of endo- and exocolony formation, the proliferation of hematopoietic stem cells and their migration to the blood. the effect produced b ... | 1992 | 1279912 |
| effect of natural and synthetic immunomodulators on the synthesis of interferon by peritoneal cells of mice. | the effect of different natural and synthetic immunomodulators on the spontaneous interferon (ifn) synthesis by freshly isolated resident peritoneal cells of balb/c, nzb and c3h mice was investigated. actinomycetal glycolipids isolated from curtobacterium betae, faenia rectivirgula, rothia dentocariosa and saccharopolyspora hirsuta at the concentration 1-20 micrograms/ml were found to potentiate the ifn synthesis by the peritoneal cells of balb/c mice. similar results were obtained when dsrna, l ... | 1992 | 1279963 |
| monoclonal antibodies against salmonella porins: generation and characterization. | monoclonal antibodies (mabs) were generated against porins, one of the major outer membrane proteins of salmonella typhi. six clones, designated mp1, mp2, mp3 (igg2ak), mpn4, mpn6 (igg1k) and mpn5 (igg2bk) were characterized by enzyme immunoassay (elisa) for their reactivity to porins from s. typhi, salmonella paratyphi a, s. paratyphi b, s. paratyphi c, salmonella choleraesuis, salmonella enteritidis, salmonella krefeld, salmonella panama, salmonella typhimurium, escherichia coli b, shigella fl ... | 1992 | 1280248 |
| acetylation of o-specific lipopolysaccharides from shigella flexneri 3a and 2a occurs in escherichia coli k-12 carrying cloned s. flexneri 3a and 2a rfb genes. | most of the shigella flexneri o-specific serotypes result from o-acetyl and/or glucosyl groups added to a common o-repeating unit of the lipopolysaccharide (lps) molecule. the genes involved in acetylation and/or glucosylation of s. flexneri lps are physically located on lysogenic bacteriophages, whereas the rfb cluster contains the biosynthesis genes for the common o-repeating unit (d.a.r. simmons and e. romanowska, j. med. microbiol. 23:289-302, 1987). using a cosmid cloning strategy, we have ... | 1992 | 1280255 |
| differentiation of shigella flexneri strains by rrna gene restriction patterns. | we studied the restriction endonuclease cleavage patterns of rrna genes (ribotypes) of 72 clinical isolates of shigella flexneri representing eight serotypes to determine whether ribotyping could be used to distinguish s. flexneri strains and to compare the discriminating ability of the method with that of serotyping. by using a cloned escherichia coli rrna operon as the probe, southern blot hybridization of restriction endonuclease-digested total dna was carried out. ribotyping of the isolates ... | 1992 | 1280647 |
| computer-assisted analysis of the structure of regular branched polysaccharides containing 2,3-disubstituted rhamnopyranose and mannopyranose residues on the basis of 13c nmr data. | a computer-assisted approach to the analysis of the structure of branched polysaccharides that contain 2,3-di-o-glycosylated alpha-rhamnopyranose and alpha-mannopyranose residues is based on evaluation of the 13c nmr spectra, using glycosylation effects and their deviations from additivity (delta delta values) at the branch points. this approach, in combination with monosaccharide and methylation analysis data, has been verified on a series of bacterial polysaccharides of known structure. | 1992 | 1284111 |
| characterization of a lipopolysaccharide encoded by a recombinant shigella sonnei plasmid in escherichia coli k-12. | the genetic information to synthesize the s-specific region of shigella sonnei phase i lipopolysaccharide (lps) is localized on a 180 kb plasmid which is lost quite readily. a recombinant plasmid derivative remaining stable in the bacteria was shown to determine the s-specific region of the lps which is completely identical with that of a s. sonnei phase i strain following transfer in escherichia coli k-12. however, the length control in polysaccharide biosynthesis is lost at least partially. | 1992 | 1284653 |
| dysentery due to shigella infection. | | 1992 | 1285156 |
| an outbreak of foodborne shigella sonnei infection. | | 1992 | 1285187 |
| multiresistant shigella species from african aids patients: antibacterial resistance patterns and application of the e-test for determination of minimum inhibitory concentration. | the antibacterial resistance pattern and minimum inhibitory concentrations (mic) of 25 shigella flexneri, 5 s. boydii, 8 s. sonnei, and 3 strains of s. dysenteriae type 2 isolated from kenyan prostitutes with bacillary dysentery and aids were determined, and the applicability of the e-test for mic determination evaluated. all strains were resistant to > or = 3 of 9 different antibacterial agents tested. all strains were resistant to tetracycline and erythromycin, 95% to trimethoprim/sulfonamide, ... | 1992 | 1287807 |
| persistent diarrhea in children: epidemiology, risk factors, pathophysiology, nutritional impact, and management. | a review of data on the morbidity and mortality caused by persistent diarrhea (more than 14 days' duration) was undertaken from studies in several geographic areas, including bangladesh, brazil, ethiopia, india, indonesia, and peru, over the last 3 decades. an estimated 3-5 billion diarrheal illnesses and 5-10 million diarrhea-related deaths occur annually among 3 billion people in africa, asia, and latin america. mostly the 338 million to 1 billion episodes and 4.6 million deaths annually. a ... | 1992 | 1289113 |
| [bacteriological study of traveller's diarrhoea. 4) isolation of enteropathogenic bacteria from patients with traveller's diarrhoea at osaka airport quarantine station during 1984-1991]. | during the last 8 years (1984 to 1991), 16,639,233 overseas travellers were quarantined at osaka airport quarantine station and 38,326 travellers reported that they were (or had been) suffering from diarrhoea. bacteriological examination of stools from 12,573 persons revealed the following results. 1) various enteropathogenic bacteria were isolated from 3,669 cases (29.2%) examined. the predominant species of bacteria isolated were as follows: salmonella, 1049 cases; plesiomonas shigelloides, 10 ... | 1992 | 1293222 |
| [the intoxication syndrome in acute dysentery]. | | 1992 | 1293830 |
| [research on sterilization of pathogens by high electrostatic voltage method]. | an experimental research has been carried out on the sterilization of four kinds of pathogens by high electrostatic method along with an inquiry into the influence of voltage waveform and the treated time on sterilization. it is concluded that pathogens can be killed efficiently by corona discharge field. | 1992 | 1294177 |
| [shigella flexneri strains having a new type antigen 89-141]. | two shigella strains (89-141 and 89-11) isolated from the stool of patients returning from abroad (both from india) in tokyo in 1989 showed an atypical serologic reaction of agglutination with only polyvalent antiserum to s. flexneri prepared commercially. these strains had the typical biochemical characteristics of s. flexneri and were biochemically identical. both strains were positive for serény test in guinea pig eye and cell-invasion test in hela cells. the strains also had virulence-plasmi ... | 1992 | 1294667 |
| campylobacter jejuni in acute diarrhoea in infancy and its relation to faecal leucocytic count. | a prospective study was carried out to identify the relative risk of campylobacter jejuni infection in 50 infants with acute diarrhoea, 24 infants with acute resistant diarrhoea and 25 healthy normal infants as a matching control group. faecal samples were collected from the three groups and were cultured on both selective media for campylobacter and other media for isolation of other organisms. direct stool smears, stained with methylene blue, were examined for detection of faecal leucocyte in ... | 1992 | 1295942 |
| prevalence of plesiomonas shigelloides among diarrhoeal patients in bangladesh. | the incidence of plesiomonas shigelloides among diarrhoeal patients attending the dhaka treatment centre of the international centre for diarrhoeal disease research, bangladesh (icddr, b) from january through december 1987, has been reported. using bile peptone broth (ph 8.8) as an enrichment medium and salmonella-shigella agar to isolate the organism, p. shigelloides was isolated from 838 (6.4%) of 13,142 patients, 523 (4.0%) of whom had no other pathogen isolated. the percentage of isolation w ... | 1992 | 1296610 |
| bacterial endotoxins as potential antitumor agents. tumor mass loss in mice treated with bacterial lipopolysaccharides of shigella dysenteriae serovar 1. | natural and modified preparations of lipopolysaccharides and lipopolysaccharide-protein complexes isolated from the s- and r-form of shigella dysenteriae serovar 1 were found to markedly inhibit the initial growth of mouse solid tumors derived from németh-kellner lymphoma, gardner 6c3hed lymphoma, an ill-defined syngeneic lymphoma of dba mice (skalsky lymphoma) and lp-2 plasmacytoma. the biopreparations were given intraperitoneally, most frequently at a dose range from 50 to 200 micrograms per m ... | 1992 | 1296928 |
| study of strains agglutinable with enteroinvasive anti e. coli polyvalent sera isolated from ill and healthy subjects for optimizing the laboratory diagnosis of diarrhoea. | 369 e. coli strains that are agglutinated in a or b anti e. coli enteroinvasive (eiec) polyvalent sera and inducing no keratoconjunctivitis in the guinea pig's eye have been selected. the biochemical reactions of e. coli strains that can be agglutinated in a or b eiec polyvalent sera occupy an intermediary position between those of shigella genus and the classical features of escherichia, i.e.; 87% are motile bacteria, 88%--ferment lactose, 81% form acid from sodium mucate and lysine is not deca ... | 1992 | 1297466 |
| effect of outer membrane proteins from shigella on humoral immunity induced in mice by srbc. | shigella flexneri outer membrane proteins (omp) which had been earlier found to exert immunomodulatory effect on cell mediated immune response were also found to act as immunomodulator of the humoral immune response. effects of omp were investigated in the experiments in vitro and in vivo, where the level of humoral immune response, measured as the number of plaque-forming cells (pfc) to srbc in the spleen was evaluated. we demonstrate that small doses of omp (1-5 micrograms) stimulate, whereas ... | 1992 | 1299171 |
| fraction of spleen cells responsible for suppression of cellular immune response to srbc in mice treated with outer membrane proteins of shigella. | effect of splenocytes isolated from mice immunized with suppressive dose of omp from shigella on delayed hypersensitivity, induced in mice with sheep red blood cells was investigated. only the population of t lymphocytes was found to suppress the delayed hypersensitivity, as measured by the footpad reaction. the results suggest that omp of shigella are able to induce in the spleens of animals active t cells which are responsible for the suppression of cellular response induced by srbc. | 1992 | 1299172 |
| [the clinical assessment of macrophage functional activity in patients with protracted dysentery and its correction with lysozyme and vitamin e]. | prospects for the correction of disturbances in the macrophagal system with a combination of lysozyme and vitamin e in patients with a protracted course of dysentery caused by shigella flexneri 1b were studied. the phagocytic activity of macrophages (pam) was found to be suppressed as early as at the beginning of the disease. out of 38 persons repeatedly found to release shigellae 24 were administered polychemotherapy. pam indices in patients treated with lysozyme and tocopherol acetate were lik ... | 1992 | 1301666 |
| extracellular export of shiga toxin b-subunit/haemolysin a (c-terminus) fusion protein expressed in salmonella typhimurium aroa-mutant and stimulation of b-subunit specific antibody responses in mice. | the shiga toxin b-subunit has been fused to the 23-kd c-terminus of escherichia coli haemolysin a (hlya) and exported from attenuated antigen carrier strain of salmonella typhimurium aroa (sl3261). the expression of the gene fusion under the control of a synthetic modified beta-lactamase promoter (constitutive expression) and under the iron-regulated aerobactin promoter showed that the fusion protein could be stably expressed and exported out of the bacterial cell in significant amounts so long ... | 1992 | 1302285 |
| a critical appraisal of 98.6 degrees f, the upper limit of the normal body temperature, and other legacies of carl reinhold august wunderlich. | to evaluate critically carl wunderlich's axioms on clinical thermometry. | 1992 | 1302471 |
| composition of lipid a in the s and r forms of shigella dysenteriae serovar 1. | a chemical analysis was performed of lipid a, isolated by acid hydrolysis of the lipopolysaccharide from the s and r forms of shigella dysenteriae serovar 1. differences in the moiety of both lipids and sugars were compared. the lipid portion consisted of a homologous series of fatty acids ranging from c12:0 to c18:0 (predominant homologues, c12:0, c14:0 and c16:0) and the homologous series of 3-hydroxy acids ranging from c12:0 to c16:0 (predominant homologue, 3-oh-c14:0). the major sugar portio ... | 1992 | 1303686 |
| hygiene habits and carriers in families with a child who has had typhoid fever. | the relationship between asymptomatic shedding of bacterial enteropathogens and the hygiene habits of families who have had a child with typhoid fever (tf) are investigated. the sample was made up of 80 families: 40 families in which one child had had tf (group a) and 40 in which no children or either of the parents had had a history of tf (group b). in each group 20 families belonged to a low socioeconomic status (ses) and 20 to a high ses. a structured interview was used to evaluate the ses an ... | 1992 | 1307431 |
| a 4-kilobase congo red binding plasmid dna fragment of shigella dysenteriae 1 suppresses the growth and cell differentiation in escherichia coli. | a 4-kilobase congo red binding plasmid dna fragment of pcat 120 of shigella dysenteriae 1 was transferred to an escherichia coli k12 strain by transformation. transformants were unable to grow in any liquid broth medium. electron microscopic studies revealed that the transformants grown on tryptic soy agar were associated in clusters after cell division. normal cell separation among the transformants in comparison with recipient e. coli k12 was only observed when the growth medium was supplement ... | 1992 | 1307443 |
| antimicrobial resistance of 100 serial gram-negative isolates in two intensive care units. | to determine antimicrobial resistance pattern among gram-negative bacteria isolated from suspected sources of infections in patients hospitalized in two intensive care units (icus) at siriraj hospital from september 1991 to december 1991, minimal inhibitory concentrations of one-hundred consecutive gram-negative isolates for various antimicrobials were performed using the microbroth dilution method. of all gram-negative bacterial isolates, 25 per cent were pseudomonas aeruginosa, 22 per cent aci ... | 1992 | 1308536 |
| [comparative activities in vitro of 4 quinolones (nalidixic acid, pefloxacin, norfloxacin, ofloxacin) on 13 bacterial species]. | nalidixic acid and three fluoroquinolones were tested on 389 strains belonging to 13 bacterial species, all isolated in algeria. ofloxacin, norfloxacin and pefloxacin have the same activities on e. coli, acinetobacter and s. aureus. norfloxacin has the best activity on proteus, enterobacter, shigella and klebsiella. norfloxacin and ofloxacin have the same activities on s. typhi, salmonella and choleric vibrio. norfloxacin has the same activity than pefloxacin on p. aeruginosa. it is necessary to ... | 1992 | 1309146 |
| spontaneous insertion of an is1-like element into the virf gene is responsible for avirulence in opaque colonial variants of shigella flexneri 2a. | colonial variation of shigella flexneri serotype 2a from the translucent (2457t) to the opaque form (2457o) occurs spontaneously once in 10(4) cell divisions, with concomitant loss of ipa gene expression and virulence. the appearance of 2457o was associated with the insertional inactivation of virf, an invasion plasmid-encoded positive regulator of ipa gene expression. plasmid pwr110, a tn5-tagged invasion plasmid that restores the invasive phenotype to plasmid-cured shigella derivatives, was co ... | 1992 | 1309511 |
| in vitro repair of double-strand breaks accompanied by recombination in bacteriophage t7 dna. | a double-strand break in a bacteriophage t7 genome significantly reduced the ability of that dna to produce viable phage when the dna was incubated in an in vitro dna replication and packaging system. when a homologous piece of t7 dna (either a restriction fragment or t7 dna cloned into a plasmid) that was by itself unable to form a complete phage was included in the reaction, the break was repaired to the extent that many more viable phage were produced. moreover, repair could be completed even ... | 1992 | 1309515 |
| surface presentation of shigella flexneri invasion plasmid antigens requires the products of the spa locus. | an avirulent, invasion plasmid insertion mutant of shigella flexneri 5 (phs1059) was restored to the virulence phenotype by transformation with a partial hindiii library of the wild-type invasion plasmid constructed in pbr322. western immunoblot analysis of phs1059 whole-cell lysates revealed that the synthesis of the invasion plasmid antigens virg, ipaa, ipab, ipac, and ipad was similar to that seen in the corresponding isogenic s. flexneri 5 virulent strain, m90t. ipab and ipac, however, were ... | 1992 | 1312536 |
| outbreaks of human enteric adenovirus types 40 and 41 in houston day care centers. | human enteric adenovirus (ead) types 40 and 41 cause diarrhea in young children, but little is known about their association with outbreaks of diarrhea in the child care setting. this study evaluated ead as a cause of outbreaks of diarrhea among infants and toddlers in day care centers. | 1992 | 1313095 |
| correlation between coxsackie b1 virus replication and enhanced invasiveness of shigella flexneri. | coxsackie b1 virus infection enhances the susceptibility of cultured hep-2 cells to shigella flexneri invasiveness. this can be reproduced partially with uv-inactivated virus, particularly the effect observed shortly after viral inoculation. the following phases of viral multiplication were correlated with the enhancing effect: uncoating of viral particles, synthesis of viral rna and proteins, and assembly of newly produced virus particles. uncoating of virus particles was completed within 60 mi ... | 1992 | 1314061 |
| detection of porin antigen in serum for early diagnosis of mouse infections with salmonella typhimurium. | the monoclonal antibodies to porin, an outer membrane protein isolated from salmonella typhimurium and sandwich enzyme linked immunosorbent assay (elisa) has made possible the detection of porin from sera of s. typhimurium-infected mice. the specificity of the monoclonal antibodies was ascertained based on their cross-reactivity with porins isolated from s. typhi, shigella flexneri and escherichia coli and lipopolysaccharide (lps) of s. typhimurium and e. coli. serum samples were found to be pos ... | 1992 | 1315558 |
| the evolution of insertion sequences within enteric bacteria. | to identify mechanisms that influence the evolution of bacterial transposons, dna sequence variation was evaluated among homologs of insertion sequences is1, is3 and is30 from natural strains of escherichia coli and related enteric bacteria. the nucleotide sequences within each class of is were highly conserved among e. coli strains, over 99.7% similar to a consensus sequence. when compared to the range of nucleotide divergence among chromosomal genes, these data indicate high turnover and rapid ... | 1992 | 1317318 |
| coxsackie b1 virus-induced changes in cell membrane-associated functions are not responsible for altered sensitivity to bacterial invasiveness. | to analyze the possible mechanisms by which coxsackie b1 virus infection affects the invasiveness of shigella flexneri, we have studied the influence of intracellular levels of na+ and k+, atpase activity, cytoplasmic membrane potential, camp level and cell communication through gap junctions. 3h after adsorption of viable or uv-inactivated coxsackie b1 virus the na(+)-k+ gradient of the cell collapsed, atpase activity decreased, the cytoplasmic membranic potential-dependent tetraphosphonium ion ... | 1992 | 1318709 |
| in vitro activity of lomefloxacin and other antimicrobials against bacterial enteritis pathogens. | lomefloxacin is a new, difluoroquinolone. in this study, the in vitro activity of lomefloxacin against clinical isolates of a variety of bacterial species associated with acute diarrheal disease was determined and compared with that of ciprofloxacin, ofloxacin, amoxicillin, sulphamethoxazole, trimethoprim, tetracycline, and chloramphenicol. bacterial isolates were obtained from different geographical areas, including western europe and the united kingdom, southern europe, africa, the middle east ... | 1992 | 1319301 |
| lactoferrin-binding proteins in shigella flexneri. | the ability of shigella flexneri to interact with lactoferrin (lf) was examined with a 125i-labeled protein-binding assay. the percent binding of human lactoferrin (hlf) and bovine lactoferrin (blf) to 45 s. flexneri strains was 19 +/- 3 and 21 +/- 3 (mean +/- standard error of the mean), respectively. 125i-labeled hlf and blf binding to strain m90t reached an equilibrium within 2 h. unlabeled hlf and blf displaced the 125i-hlf-bacteria interaction in a dose-dependent manner. the lf-bacterium co ... | 1992 | 1319403 |
| enrofloxacin treatment of long-tailed macaques with acute bacillary dysentery due to multiresistant shigella flexneri iv. | thirty-four cases of acute bacillary dysentery occurred within 90 days among macaques housed at the california regional primate research center. cases were identified by depression, diarrhea with blood and leukocytic exudate, and/or leukocytosis with a left shift. antimicrobial susceptibility testing of enteric isolates and plasmid profile analyses established an etiologic diagnosis of multiple antibiotic resistant shigella flexneri iv infection. when standard therapies were invalidated by high ... | 1992 | 1320152 |
| shiga toxin: biochemistry, genetics, mode of action, and role in pathogenesis. | | 1992 | 1324134 |
| environmental regulation of shigella virulence. | | 1992 | 1324135 |
| distribution of insertion sequence is1 in multiple-antibiotic resistant clinical enterobacteriaceae strains. | the presence of insertion sequence is1 in 70 multiple-antibiotic resistant clinical strains was determined. this 70-strain collection comprised 46 escherichia coli, 18 salmonella and 6 shigella strains. the presence of is1 was detected in the chromosome and plasmids of 73% and 63% of the strains, respectively, and 51% of the strains carried is1 in both. the frequency of is1 was higher in salmonella than in e. coli and shigella strains. a total of 31 strains carried large plasmids with is1; 10 of ... | 1992 | 1324200 |
| [microbial ecology of the digestive tract in patients with acute intestinal infections]. | | 1992 | 1324548 |
| [epidemiological investigation on pathogens of acute infectious diarrhea in ning xia]. | an epidemiological investigation on pathogens of diarrhoeal diseases in ning xia was reported. eight genus of agents were found in all stool specimens of persons with detectable rate of 41.16%. moreover, the most prevalent pathogens were shigella (19.59%), followed by rotaviruses (10.07%), salmonella (4.76%), and entero-pathogenic escherichia coli (4.20%). four of them accounted for 93.85% of detectable agents. in addition, in shigella b group made up 80.44%, and 2a was the predominant agent. si ... | 1992 | 1327534 |
| interferon treatment reduced adherence, invasiveness and intracellular multiplication of shigella flexneri in coxsackie b1 virus-infected cells. | the effect of interferon treatment on interaction of shigella flexneri with in vitro cultured cells was investigated. pretreatment of hep-2 cells with human interferons had no effect on the susceptibility of cells to s. flexneri, measured by invasiveness and adhesiveness. human leukocyte interferon and human recombinant interferon-alpha-a reduced adhesiveness, intracellular multiplication and invasiveness of s. flexneri in hep-2 cells preinfected with coxsackie b1 virus. also non-receptor mediat ... | 1992 | 1329437 |
| regulation of virulence-associated plasmid genes in enteroinvasive escherichia coli. | the transposon tnphoa was used for construction of gene fusions and for studies of gene regulation in an enteroinvasive strain of escherichia coli. several plasmid-encoded virulence genes (e.g., the ipab and virg operons) of such enteroinvasive strains are subject to coordinated thermoregulation involving both operon-specific (the virb and virf activators) and global regulators. the nucleoid-associated e. coli protein h-ns was shown to be a negative regulator as judged by studies using h-ns gene ... | 1992 | 1332938 |
| mxij, a lipoprotein involved in secretion of shigella ipa invasins, is homologous to yscj, a secretion factor of the yersinia yop proteins. | shigella flexneri causes bacillary dysentery by invading epithelial cells of the colonic mucosa. the invasion process requires the synthesis and secretion of the virulence plasmid-encoded ipa proteins. using tnphoa mutagenesis, we have identified two virulence plasmid genes, mxij and mxim, that encode proteins exported by the general export pathway. analysis of the mxij and mxim deduced amino acid sequences suggested that mxij and mxim might encode lipoproteins, which was confirmed by [3h]palmit ... | 1992 | 1332940 |
| susceptibility of recent clinical isolates to temafloxacin (a-63004) and other antimicrobial agents. | in vitro susceptibility of 1008 strains of recent clinical isolates was determined against the new aryl fluoroquinolone temafloxacin (t-167, a-63004) ciprofloxacin, norfloxacin, ampicillin, piperacillin, cephalothin, cefoxitin, ceftazidime, gentamicin, amikacin, oxacillin and vancomycin. the minimum inhibitory concentrations (mics) of temafloxacin in micrograms/ml required for > or = 90% isolates were 0.13-0.5 for enterobacter, 0.03-0.25 for escherichia coli, 0.12-0.5 for klebsiella, 0.5-1.0 for ... | 1992 | 1338041 |
| [survey of bacterial resistance in shanghai district]. | the data on bacterial resistance monitoring of 5,457 clinical isolates in 1990 against 21 antimicrobial agents showed that most isolates were highly resistant to commonly used antimicrobial agents, such as penicillin, ampicillin, erythromycin, chloramphenicol, tetracycline and gentamicin, with a resistant rate of around 50% or more. strains resistant to some newer agents, such as cefotaxime, ceftazidime, amikacin and norfloxacin, have appeared and are increasing in number. multi-resistant strain ... | 1992 | 1338505 |
| [toxic megacolon due to shigella: a report of a new case]. | a new case of shigella-caused megacolon is described in detailed form. some considerations are made about frequency, pathology, clinic and prognostic features. | 1992 | 1340679 |
| [shigellosis in children of the ix region of chile: clinical and epidemiologic aspects and antibiotic sensitivity]. | ninety four children with diarrhea and a positive stool culture for shigella, hospitalized at the hospital regional de temuco, were studied. forty six percent of patients were less than two years old. forty two percent of microorganisms were resistant to ampicillin, 45% to trimethoprim/sulfamethoxazole, 8% to tetracycline and none to chloramphenicol. isolated species were shigella flexneri 83% and shigella sonnei 17%. seventy nine percent of patients had fever, 60% dysentery and 21.3% seizures. ... | 1992 | 1340946 |
| antibodies against invasion plasmid coded antigens of shigellae in human colostrum and milk. | colostral and milk samples of swedish, vietnamese and costa rican mothers living under various socioeconomic conditions were tested for the presence of shigella invasion plasmid coded antigen (ipa) specific antibodies. iga antibodies of this specificity were found in significantly higher titres in samples of vietnamese (600 +/- 338) than in samples of swedish or high income costa rican mothers (190 +/- 224 and 290 +/- 241, respectively; p < 0.05). specific iga titres in the low income group of c ... | 1992 | 1343940 |
| [bacteriology of shigella isolated in a tropical zone chu]. | from 1981 to 1991, five hundred eighty one shigella's strains were isolated in the laboratories of the chu fann of dakar. they represent 24.8 per cent of enteropathogen agents and 4.3 per cent of diarrhoeae causative agents. shigella flexneri was predominant (71%), following by shigella dysenteriae (14.5%), shigella sonnei (11.4%) and shigella boydii (2.5%). in pediatric hospital 90 per cent of strains were isolated between 1 and 5 years age; in adults, the pic was found from 20 to 30 years. fiv ... | 1992 | 1345084 |
| identification of enteropathogens in infantile diarrhea in a study performed in the city of posadas, misiones, república argentina]. | the following work informs of the results of isolation, frequency and distribution of enteropathogens in children under five years old, without previous antibiotic treatment, less than seven days with diarrhoea, ambulatory or in hospital "dr. ramón madariaga" de posadas, misiones, república argentina, from june 1986 to may 1989. from a total of 972 children with diarrhoea, 78% required to be hospitalized. the greatest number of cases were found during spring and summer in children from 1 to 11 m ... | 1992 | 1345313 |
| molecular probe analysis of shigella dysenteriae type 1 isolates from 1940 to 1987. | fourteen strains of shigella dysenteriae type 1 (shiga bacillus) isolated from people in diverse locations from 1940 to 1987 were studied. southern hybridization with three cloned escherichia coli genes, shiga-like toxin i (slti), frd, and ompf, was used to determine restriction fragment length polymorphism (rflp) of the genomic dna of these strains. digestion with each of four restriction endonucleases generated fragments of identical size to which the frd and ompf hybridized for each of the 14 ... | 1992 | 1353066 |
| a model of interaction between entamoeba histolytica and shigella flexneri. | the establishment of a relationship between entamoeba histolytica and certain bacteria may contribute to the expression and/or enhancement of the pathogenicity of this parasite. recent experiments have shown that bacteria expressing mannose-binding lectins on their surface could attach to mannose-containing molecules on the surface of amoebae. in this study, we established a model of interaction between. e. histolytica and shigella flexneri. using well-characterized mutants of s. flexneri, we st ... | 1992 | 1353632 |
| molecular epidemiology of shigella infections in israel. | the dnas of shigella sonnei or shigella dysenteriae type 1 strains isolated in outbreaks of shigellosis or in sporadic cases were analysed by restriction fragment length polymorphism (rflp). southern blots of the dnas of 36 s. sonnei isolates digested by 8 restriction enzymes were hybridized with an escherichia coli rrna probe. the s. sonnei strains were unexpectedly diverse in their rflp. antibiotypes of the same isolates showed clusters of strains corresponding to the various outbreaks. on the ... | 1992 | 1356821 |
| pyrizinostatin: a new inhibitor of pyroglutamyl peptidase. | | 1992 | 1361487 |
| studies on novel pili from shigella flexneri. i. detection of pili and hemagglutination activity. | pili were detected using electron microscopy in clinical isolates of shigella flexneri which had been continuously subcultivated in liquid media. morphologically, the pili appeared as thin, flexible, cylindrical structures of up to 2-5 microns in length and about 3-5 nm in diameter. two strains showed mannose-resistant (mr) hemagglutination to fresh fowl erythrocytes (type 4), and one to tannic acid-treated horse erythrocyte (type 3) pili. these pili are novel and different from the mannose-sens ... | 1992 | 1361958 |
| salmonella, campylobacter and shigella in hiv-seropositive patients. | to study the incidence, clinical features, treatment and outcome of patients with salmonella, shigella or campylobacter infection. | 1992 | 1362879 |
| [occurrence of p.fimbrii in strains from selected genera of enterobacteriaceae]. | this study was aimed at recognition of frequency of occurrence of p fimbriae in strains of escherichia coli isolated from samples of feces of children with symptoms of diarrhoea and at search of these adhesions in strains representing other than escherichia genera of enterobacteriaceae strains. one hundred forty laboratory strains were investigated. they belonged to genus citrobacter, enterobacter, hafnia, klebsiella, morganella, proteus, providencia, salmonella, shigella, and yersinia. also wer ... | 1992 | 1363960 |
| effect of enterovirus infection on susceptibility of hela cells to shigella flexneri invasivity. | invasiveness of shigella flexneri m90t in hela cells was significantly increased when cells were preinfected with poliovirus 1, coxsackievirus b3 and echovirus 6. this effect was dependent on the dose of virus used, evident at early stages of viral infection and lasted hours before the appearance of a cytopathic effect. an increase of bacterial invasion ability was also noticed when hela cells were incubated with uv-inactivated enteroviruses. this enhancing effect obtained with both viable and u ... | 1992 | 1364020 |
| [effects of nifuroxazide (ercefuryl), trimethoprim-sulfamethoxazole and bactisubtil in acute diarrhea]. | the clinical effects of nifuroxasid (n), trimetoprim sulphametoxasol (ts) and bactisubtil (b) on bacillar dysentery and alimentary toxicoinfections in the patients treated at the clinic from january 1984 to the end of december 1989 have been analysed. according to the clinical signs, patients have been divided in ten categories of light, mild and heavy forms. in total, 329 cases of bacillar dysentery and 89 cases of alimentary toxicoinfections have been analysed. the following was established: a ... | 1991 | 1366328 |
| dna sequence of a salmonella-specific dna fragment and the use of oligonucleotide probes for salmonella detection. | hybridization specificity of a 1.8-kb hindiii dna fragment isolated from salmonella typhimurium by a molecular cloning technique was confirmed by colony hybridization with 327 salmonella isolates of various serotypes and 56 non-salmonella isolates including enterobacteriaceae closely related to salmonella, such as escherichia coli, klebsiella, citrobacter and shigella. it was found that this 1.8-kb dna fragment was highly specific for all the salmonella isolates tested. the dna sequence of this ... | 1991 | 1367316 |
| myosin-cross-reactive epitope of shigella flexneri invasion plasmid antigen b. | ipab, invasion plasmid antigen b, of shigella flexneri is a 62-kda protein required for invasion of intestinal epithelial cells. ipab is also one of several major protein antigens recognized by the humoral immune systems of most humans and monkeys after infection with shigellae. computer analysis of the deduced ipab amino acid sequence indicates that an alpha-helical structure is likely through much of the molecule. homology searches with protein data banks show that one alpha-helical domain bet ... | 1992 | 1370431 |
| identification and characterization of b-cell epitopes of ipac, an invasion-associated protein of shigella flexneri. | invasion plasmid antigen c (ipac) is a 43-kda plasmid-encoded protein associated with the ability of shigellae to invade epithelial cells. this protein is consistently strongly recognized by sera from convalescent patients and monkeys experimentally infected with shigellae. the strong immunogenicity of ipac in the course of natural infection makes it a good candidate as a potentially protective antigen. to map the b-cell epitopes of this protein, the gene encoding ipac was cloned and expressed a ... | 1992 | 1373401 |
| immunochemical characterization of citrobacter strain pcm 1487 o-specific polysaccharide- and core oligosaccharide-protein conjugates. | o-specific-polysaccharide and core oligosaccharide were isolated from citrobacter strain pcm 1487 lipopolysaccharide and purified. the polysaccharide was selectively devoid of 4-deoxy-d-arabinohexose residues. covalent conjugates of the modified o-specific polysaccharide and of the core oligosaccharide with tetanus toxoid were prepared. immunochemical characterization of these conjugates proved that they are strong immunogens. using monospecific rabbit antisera raised against the conjugates, the ... | 1992 | 1376131 |
| pathogenesis and immunology in shigellosis: applications for vaccine development. | | 1992 | 1380415 |
| shigella lipopolysaccharide: structure, genetics, and vaccine development. | | 1992 | 1380416 |
| immunoblot analysis of antibody responses to shigella dysenteriae type 1 infection. | immunoblot analysis was used to identify the antigenic components of the outer membrane protein (omp) extract from sh. dysenteriae type 1 that may be relevant in protection against infection. the omps were extracted by ultrasonic disruption followed by sarkosyl extraction. the macromolecular bands were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (sds-page), electroeluted to a nitrocellulose matrix and complexed with peroxidase conjugated antibodies in human convalesce ... | 1992 | 1380491 |
| stereoselective syntheses of a di-, tri-, and tetra-saccharide fragment of shigella dysenteriae type 1 o-antigen using 3,4,6-tri-o-acetyl-2-azido-2-deoxy-alpha-d-glucopyranosyl chloride as a glycosyl donor. | methyl 2,4-di-o-benzoyl-alpha-l-rhamnopyranoside (1) furnished a crystalline 3-o-bromoacetyl derivative that was treated with the dichloromethyl methyl ether-zncl2 reagent to give 2,4-di-o-benzoyl-3-o-bromoacetyl-alpha-l-rhamnopyranosyl chloride (3). compounds 1 and 3 were condensed under the conditions of base-deficient, silver trifluoromethanesulfonate-mediated glycosylation to give a fully protected rhamnobioside, which on o-debromoacetylation afforded the disaccharide nucleophile 10. similar ... | 1992 | 1381283 |
| hypothesis for vaccine development: protective immunity to enteric diseases caused by nontyphoidal salmonellae and shigellae may be conferred by serum igg antibodies to the o-specific polysaccharide of their lipopolysaccharides. | immunoprophylaxis for bacterial enteric diseases is hindered because the protective immune mechanism(s) against nontyphoidal salmonellae or shigellae in humans are not established. on the basis of the similarities between the clinical signs, epidemiology, pathogenesis, and pathology of as well as protective immunity to salmonellae and shigellae, we propose that serum igg antibodies to the o-specific polysaccharide (o-sp) of their lipopolysaccharides (lpss) will confer protective immunity to thes ... | 1992 | 1381621 |
| induction of a humoral immune response to a shiga toxin b subunit epitope expressed as a chimeric lamb protein in a shigella flexneri live vaccine strain. | shigella flexneri vaccine strain (sfl124) given orally, evokes humoral immune response in human volunteers. such a strain, expressing antigenic epitope of b subunit of shiga toxin, would also provide immunity to the toxin produced by some species of shigella. a synthetic oligonucleotide, specifying an epitope [13-26 amino acids (aa)] of the b subunit of shiga toxin, was inserted into the lamb gene of escherichia coli and expressed in the s. flexneri vaccine strain. the chimeric lamb protein func ... | 1992 | 1381804 |
| structural basis of antigenic specificity and design of new vaccines. | this manuscript describes the design of new vaccines based on synthetic peptides. to this end, we first analyze the structural basis of antigenic reactivity and specificity and the various types of epitopes that form the mosaics of macromolecular antigens, as well as the regulatory mechanisms involved in immune recognition. a distinction is made between sequential or continuous epitopes, and discontinuous or conformational ones, which are the majority of epitopes in globular proteins. in this co ... | 1992 | 1385242 |
| role of escherichia coli k-12 rfa genes and the rfp gene of shigella dysenteriae 1 in generation of lipopolysaccharide core heterogeneity and attachment of o antigen. | the rfp gene of shigella dysenteriae 1 and the rfa genes of escherichia coli k-12 and salmonella typhimurium lt2 have been studied to determine their relationship to lipopolysaccharide (lps) core heterogeneity and their role in the attachment of o antigen to lps. it has been inferred from the nucleotide sequence that the rfp gene encodes a protein of 41,864 da which has a structure similar to that of rfag protein. expression of this gene in e. coli k-12 results in the loss of one of the three ba ... | 1992 | 1385388 |
| comparative aetiology of childhood diarrhoea in kakamega and kiambu districts, kenya. | two hundred diarrhoea specimens collected during january to february 1988, from rural children aged 0 to 60 months in kakamega district were examined for bacteria, parasites and rotavirus. the results were compared with a sample of 184 diarrhoea specimens matched for month of collection, taken from data collected in the same manner from children in kiambu district. the mean ages of children in the 2 samples did not differ significantly. there were significant differences in the prevalence of spe ... | 1992 | 1396210 |
| monitoring of antibiotic resistance in shigellae isolated in the netherlands 1984-1989. | during surveillance of antimicrobial resistance in shigella strains isolated in the netherlands from 1984 to 1989 and forwarded to the national institute of public health and environmental protection for typing, sensitivity to twelve antimicrobial agents was assessed. high rates of resistance to the older drugs of choice in treating shigellosis were found, i.e. ampicillin and trimethoprim-sulfamethoxazole. ampicillin resistance varied from 33 to 53% among shigella flexneri strains and from 10 to ... | 1992 | 1396730 |
| [changes in specific reaction of erythrocytes to the antigen after administration of methylene blue and sodium azide]. | | 1992 | 1398187 |
| [plasmid analysis and antibiotic resistance pattern measurement of shigella in chengdu]. | a total of 81 strains of shigella isolated from sporadic cases and cases in an outbreak of shigella sonnei infection was analysed by plasmid profiles and antibiotic resistance patterns. the strains had a high resistance patterns. the strains had a high resistance of ampicillin, tetracycline, trimethoprim-sulfamethoxazole and chloramphenicol; while 97.2% of the strains were susceptible to gentamicin, kanamycin. the results showed that 50% of the strains harbored plasmid patterns within each speci ... | 1992 | 1398620 |
| unipolar reorganization of f-actin layer at bacterial division and bundling of actin filaments by plastin correlate with movement of shigella flexneri within hela cells. | shigella flexneri causes bacillary dysentery, an invasive disease of colonic epithelial cells in humans. the capacity of bacteria, once they have entered into a cell and escaped the phagocytic vacuole, to spread intracellularly and directly to adjacent cells without further extracellular passage is a key factor in invasion of the epithelial layer. movement of intracellular bacteria is dependent upon the polymerization of actin; concentration of the formed filaments to one end of the bacterium is ... | 1992 | 1398922 |
| specific lung mucosal and systemic immune responses after oral immunization of mice with salmonella typhimurium aroa, salmonella typhi ty21a, and invasive escherichia coli expressing recombinant pertussis toxin s1 subunit. | pertussis toxin (pt) is considered an essential protective component for incorporation into new generation vaccines against bordetella pertussis, the causative agent of whooping cough. traditionally, antipertussis vaccination has employed an intramuscular route. an alternative to this approach is to stimulate mucosal and systemic immune responses by oral immunization with live vaccine carrier strains of salmonella spp. or escherichia coli. recombinant s1 subunit of pertussis toxin was expressed ... | 1992 | 1398937 |
| vacb, a novel chromosomal gene required for expression of virulence genes on the large plasmid of shigella flexneri. | shigellae, the causative agents of bacillary dysentery, are capable of adhering to and invading epithelial cells and spreading into adjacent cells. a chromosomal mutant of shigella flexneri 2a ysh6000 with reduced invasive capacity was isolated by tn5 insertion mutagenesis. the linkage of the mutant phenotype to the tn5 insertion was determined by p1 phage transduction. the site of the tn5 insertion was assigned to a noti chromosomal restriction map, confirming that the virulence-associated locu ... | 1992 | 1400189 |
| identification of a b subunit gene promoter in the shiga toxin operon of shigella dysenteriae 1. | the shiga toxin operon (stx) is composed of a and b subunit genes which are transcribed as a bicistronic mrna from a promoter which lies 5' to the stxa gene. northern (rna) blot and primer extension analyses revealed the existence of a second stxb gene transcript. recombinant plasmids which carried the stxb gene without the stx operon promoter and with the influence of a vector promoter abrogated produced stx b polypeptides, suggesting that the stxb gene mrna was transcribed from an independent ... | 1992 | 1400202 |
| molecular analysis of the glpfkx regions of escherichia coli and shigella flexneri. | we have identified a new gene, glpx, belonging to the glp regulon of escherichia coli, located directly downstream of the glpk gene. the transcription of glpx is inducible with glycerol and sn-glycerol-3-phosphate and is constitutive in a glpr mutant. glpx is the third gene in the glpfkx operon. the function of glpx remains unknown. glpx has an apparent molecular weight of 40,000 on sodium dodecyl sulfate-polyacrylamide gels. in addition to determining the e. coli glpx sequence, we also sequence ... | 1992 | 1400248 |
| functional roles assigned to the periplasmic, linker, and receiver domains of the agrobacterium tumefaciens vira protein. | vira and virg activate the agrobacterium tumefaciens vir regulon in response to phenolic compounds, monosaccharides, and acidity released from plant wound sites. vira contains an amino-terminal periplasmic domain and three cytoplasmic domains: a linker, a protein kinase, and a phosphoryl receiver. we constructed internal deletions of vira that truncate one or more domains and tested the ability of the resulting proteins to mediate environmentally responsive vir gene activation in vivo. the perip ... | 1992 | 1400253 |
| altered-function mutations of the transcriptional regulatory gene virg of agrobacterium tumefaciens. | three point mutations were isolated in the agrobacterium tumefaciens virg gene by screening for vir gene expression in the absence of added phenolic inducing compounds. all three mutations were localized in the predicted amino-terminal phosphoryl receiver domain of the protein. one mutant (n54d) bypasses the requirement for vira and phenolic inducers both for transcriptional activation of all tested vir promoters and for plant tumorigenesis. this mutant also activates vir gene expression efficie ... | 1992 | 1400254 |
| specific detection of campylobacter jejuni and campylobacter coli by using polymerase chain reaction. | development of a routine detection assay for campylobacter jejuni and campylobacter coli in clinical specimens was undertaken by using the polymerase chain reaction (pcr). an oligonucleotide primer pair from a conserved 5' region of the flaa gene of c. coli vc167 was used to amplify a 450-bp region by pcr. the primer pair specifically detected 4 strains of c. coli and 47 strains of c. jejuni; but it did not detect strains of campylobacter fetus, campylobacter lari, campylobacter upsaliensis, cam ... | 1992 | 1400961 |
| selective criteria for the microbiological examination of faecal specimens. | to assess the effectiveness of predetermined investigation criteria for the examination of faecal samples from inpatients, cultured stool specimens were prospectively examined for salmonella spp, shigella spp, campylobacter spp and clostridium difficile, and screened microscopically for intestinal parasites. out of a total of 505 specimens, 421 (83%) fulfilled the criteria for examination for c difficile, 254 (50%) for salmonella spp, shigella spp, and campylobacter spp, and 87 (17%) for intesti ... | 1992 | 1401225 |
| an analysis of the quantitative relationship between oral temperature and severity of illness in experimental shigellosis. | the relationship between oral temperature and other parameters of illness was examined in 139 adult volunteers infected experimentally with shigella sonnei. in subjects developing clinical disease, peak temperature correlated positively with total number of signs and symptoms other than fever (rxy = .71, p < .001), stool volume (rxy = .41, p < .001) and number of stools produced during the illness (rxy = .46, p < .001). peak temperature correlated negatively with incubation period (rxy = -.34, p ... | 1992 | 1402032 |
| [in vitro antimicrobial activity of dr-3355, a new quinolone antibacterial agent, against clinical isolates of enteritis-causing bacteria]. | we determined the minimum inhibitory concentration (mic) of dr-3355, a newly developed quinolone-derivative antibacterial agent, against clinical isolates of various bacterial species from enteritis patients, and compared them with those of ofloxacin (oflx), ciprofloxacin (cpfx), nalidixic acid (na), ampicillin (abpc), kanamycin (km). mic90 of dr-3355 against 94 strains of shigella spp. and 5 strains of escherichia coli, 36 strains of salmonella spp., 22 strains of vibrio cholerae, 5 strains of ... | 1992 | 1402063 |
| [genetic analysis of shigella pathogenesis and rapid detection method of shigella virulence gene by the polymerase chain reaction]. | | 1992 | 1404924 |
| temperature regulation of shigella virulence: identification of the repressor gene virr, an analogue of hns, and partial complementation by tyrosyl transfer rna (trna1(tyr)). | virr is the central regulatory locus required for coordinate temperature-regulated virulence gene expression in the human enteric pathogens of shigella species. detailed characterization of virr+ clones revealed that virr consisted of a 411 bp open reading frame (orf) that mapped to a chromosomally located 1.8kb ecori-acci dna fragment from shigella flexneri. insertional inactivation of the virr orf at a unique hpai restriction site resulted in a loss of virr+ activity. the virr orf nucleotide s ... | 1992 | 1406252 |
| identification and characterization of virk, a virulence-associated large plasmid gene essential for intercellular spreading of shigella flexneri. | seven virulence loci have been identified by tn5 insertion mutagenesis on the large 230 kb plasmid (pmysh6000) of shigella flexneri 2a. in this study, we used tn10 insertion mutagenesis and identified a novel virulence locus on pmysh6000 responsible for bacterial spread. characterization of the invading bacteria of the tn10 insertion mutants in the epithelial cells revealed that the bacteria were capable of at least some intracellular spreading but not intercellular spreading. immunoblot analysi ... | 1992 | 1406277 |