Showing papers on "Shigella dysenteriae published in 1980"
TL;DR: Nucleotide sequences representing the fusion of trpG and trpD in Escherichia, Shigella and Salmonella are not more nor less divergent than other portions of the trp(G)D coding sequences.
117 citations
TL;DR: Data indicate that three of the known biological activities of Shiga toxin are associated with a 33,000-dalton substance which can be dissociated into 29,000 and 4,000 to 7,000 daltons components.
Abstract: Shigella dysenteriae 1 (Shiga) toxin was purified from whole-cell lysates by antitoxin affinity column chromatography, radioiodination, and Sephacryl S-200 gel filtration of 125I-labeled affinity column eluates. Two chromatographic peaks were observed. The percentage of radioactivity in peak I samples immunoprecipitated with antitoxin ranged from 95 to 100%. A pool of samples from this first peak contained over 90% of the HeLa-cell-cytotoxic units applied to the column and was enterotoxic for rabbit ileal loops and lethal for rabbits. This radiolabeled material migrated as a single cytotoxic band after nondenaturing polyacrylamide gel electrophoresis, but formed three bands, of 33,000, 29,000, and 4,000 to 7,000 daltons, after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In addition, material estimated as 7,000 daltons by Bio-Gel P-10 chromatography could be generated by treatment of S-200 peak I samples with 8 M urea. Pooled fractions from the second S-200 peak were separable into several low-molecular-weight peaks on a P-10 column. One of these P-10 peaks (7,000 daltons) was 27% immunoprecipitable with antitoxin. These data indicate that three of the known biological activities of Shiga toxin are associated with a 33,000-dalton substance which can be dissociated into 29,000- and 4,000- to 7,000-dalton components.
89 citations
TL;DR: The inhibitory effect of toxin was sensitive to heat inactivation and was prevented by antibody neutralization, and several cytotoxic components were separated by polyacrylamide gel electrophoresis of the purified toxin preparations; all inhibited protein and deoxyribonucleic acid syntheses equally.
Abstract: Shiga toxin purified to near homogeneity from cell lysates of Shigella dysenteriae 1 inhibited protein and deoxyribonucle acid syntheses in intact HeLa cells. Inhibition was dependent on toxin concentration and time of incubation. A minimal latent period of 30 min was observed with saturating doses of toxin. Ribonucleic acid synthesis, uptake of alpha-aminoisobutyric acid, and maintenance of intracellular K+ concentrations were not affected until well after maximal inhibition of protein and deoxyribonucleic acid syntheses. The inhibitory effect of toxin was sensitive to heat inactivation and was prevented by antibody neutralization. Several cytotoxic components were separated by polyacrylamide gel electrophoresis of the purified toxin preparations; all inhibited protein and deoxyribonucleic acid syntheses equally.
79 citations
TL;DR: Variations in the number and mobility of bands among Shigella strains defined different esterase patterns (zymotypes) which appeared to be distinct for each species.
Abstract: SUMMARY: Esterases of 57 strains of Shigella dysenteriae, Sh. flexneri, Sh. boydii and Sh. sonnei and 26 strains of Escherichia coli, including the Alkalescens Dispar group, were compared by polyacrylamide-agarose gel electrophoresis. Six types of esterase bands differing in their ability to hydrolyse synthetic substrates and in their sensitivity to heat and to di-isofluoropropyl phosphate were defined. Individual activities and sensitivities of these bands and the apparent molecular weight of the major esterase, estimated to be 58000 by polyacrylamide gradient gel electrophoresis, were identical for both Shigella species and E. coli. One esterase with a molecular weight of 104000 was found in some strains of E. coli. Variations in the number and mobility of bands among Shigella strains defined different esterase patterns (zymotypes) which appeared to be distinct for each species.
29 citations
TL;DR: An alteration in myoelectric activity of the small intestine in New Zealand White rabbits is demonstrated principally by RBAP activity indicative of invasion.
Abstract: Bacterial strains of Shigella dysenteriae I (3818-T and 3818-O) and Shigella enterotoxin altered myoelectric activity of the small intestine in New Zealand White rabbits. These agents were compared with activity caused by sterile culture broth or sterile saline. The altered myoelectric activity was characterized by two distinct complexes: repetitive bursts of action potentials (RBAP), characteristic of invasive strains of bacteria, and the migrating action potential complex (MAPC), characteristic of noninvasive bacteria. RBAP activity was the predominant myoelectric complex observed with S. dysenteriae strain 3818-T, an invader and toxin producer; S. dysenteriae strain 3818-O, a noninvader and toxin producer; and by Shigella enterotoxin. MAPC activity was present but was significantly less in all cases. These studies of the small intestine demonstrate an alteration in myoelectric activity characterized principally by RBAP activity indicative of invasion.
27 citations
TL;DR: Quantitative microassay of cytosol toxicity showed that Shiga toxin was produced intracellularly by strain 3818T, suggesting that cytolysis of infected mammalian cells is caused, at least in part, by intrace cellular Shiga toxins.
26 citations
TL;DR: Findings indicate that such a minicell-producing alteration in the cell division cycle of shigellae has not significantly affected their virulence.
Abstract: Minicells are small, anucleate cells resulting from aberrant cell divisions at the polar ends of bacilli. We have isolated minicell-producing mutant strains of Shigella flexneri 2a (MC-I) and Shigella dysenteriae 1 (MC-V) after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. Microscopically, broth cultures of MC-I and MC-V were found to contain free minicells, normal cells, and filamentous cells with polar, attached minicells. Both strains retained their ability to provoke keratoconjunctivitis in guinea pigs and to invade HeLa cells. Purified suspensions of minicells containing less than one whole cell per 10(6) minicells were obtained by a combination of differential sedimentation and density gradient centrifugation (5 to 30% [wt/vol] linear sucrose gradients). Each MC-I minicell contained about 0.005 times the amount of deoxyribonucleic acid of one normal S. flexneri. The MC-V minicell had about 0.003 times the amount of deoxyribonucleic acid of one whole S. dysenteriae cell. Purified MC-V minicells were treated with polymyxin B to release Shiga toxin. Shiga toxin was readily detected in MC-V minicells by means of a microtiter HeLa cell cytotoxicity assay. Our findings indicate that such a minicell-producing alteration in the cell division cycle of shigellae has not significantly affected their virulence.
18 citations
TL;DR: In each case, secondary infection rates were higher when the first cases of the families, were children aged below 10 or females aged 10 and over, than when the index cases were males 10 years old or more.
Abstract: To characterize the epidemiological contrast between Shigella dysenteriae type 1, Sh. flexneri and dysentery-like control families, a 10-day follow-up study has been conducted in Dacca areas where Sh. flexneri and Sh. dysenteriae type 1 were the two most prevalent types. In children (0–9), the secondary infection rates were 29·3% in Sh. dysenteriae type 1, 24% in Sh. flexneri and 10·6% in the control group. The overall secondary infection rates were 20·4, 21·2 and 6·1% and secondary case rates were 13·3, 4·3 and 2·0% respectively for the three groups. In the Sh. flexneri group, secondary cases in infected adults were nil, but 41·1% of the adults infected with Sh. dysenteriae type 1 developed symptoms. Over 2% of the contacts of Sh. dysenteriae type 1 and none from the Sh. flexneri needed to be kept in hospital. Mixed infection, in contacts of all the three types ranged from 4·6 to 6·4%. The undiagnosed diarrhoea (over 14%) exceeded the secondary cases in all groups. In each case, secondary infection rates were higher when the first cases of the families, were children aged below 10 or females aged 10 and over, than when the index cases were males 10 years old or more. In Sh. dysenteriae type 1, secondary spread continued up to the last day of follow-up. In Sh. flexneri , it stopped two days earlier. Users of water from both open and closed sources and users of open latrines had higher attack rates than did those who used closed water sources and closed latrines. In all cases the poorest group had higher secondary attack rates. Sh. dysenteriae type 1 was 98% resistant to tetracycline and 93·6% to streptomycin, while over 20% of Sh. flexneri were resistant to tetracycline and 50% to streptomycin. Both the strains were 100% sensitive to kanamycin and ampicillin at the time of this study 1973.
17 citations
Journal Article•
13 citations
TL;DR: Shigella toxin inhibits polyuridylic acid-directed polymerization of phenylalanine in ribosome-enzyme systems obtained from Escherichia coli or from Shigella dysenteriae.
Abstract: Shigella toxin inhibits polyuridylic acid-directed polymerization of phenylalanine in ribosome-enzyme systems obtained from Escherichia coli or from Shigella dysenteriae. The inhibition is the result of toxin acting on ribosomes to prevent polyuridylic acid attachment.
13 citations
TL;DR: Among children 3 years of age or under, bacteriological relapses tended to be more frequent in the low-dose group and were not related to serum levels of ampicillin, nutritional status, or the severity of colitis on admission, so it is recommended that younger children be treated with 100 mg/kg per day of oralAmpicillin.
Abstract: To establish optimal therapy for severe dysentery due to Shigella dysenteriae type 1 and Shigella flexneri, we compared in a prospective randomized trial two oral ampicillin doses (50 and 150 mg/kg per day) in 57 children and 39 adults in Dacca, Bangladesh. Clinical failure did not occur in either group, indicating that conventional doses need not be increased even in severe disease. Among children 3 years of age or under, bacteriological relapses tended to be more frequent in the low-dose group and were not related to serum levels of ampicillin, nutritional status, or the severity of colitis on admission. Therefore, we recommend that younger children be treated with 100 mg/kg per day of oral ampicillin.
TL;DR: A family outbreak of foodborne shigellosis caused by an unusual strain of Shigella dysenteriae and agglutinated in antiserum prepared against provisional serotype 3341-55 is described.
Abstract: A family outbreak of foodborne shigellosis caused by an unusual strain of Shigella is described. The strain was a mannitol-positive variant of Shigella dysenteriae and agglutinated in antiserum prepared against provisional serotype 3341-55.
Journal Article•
TL;DR: Mouse lung toxicity was compared to other pathogenicity tests, and strains isolated from healthy individuals were also toxic for mice, so a positive lung test cannot be considered a criterion of the aetiological role of the agent.
Abstract: Mouse lung toxicity of 439 strains (431 Escherichia coli, 1 Shigella dysenteriae 1, 1 Enterobacter cloacae, 5 Vibrio sp., 1 Klebsiella) was compared to other pathogenicity tests (mouse virulence, enterotoxicity, guinea pig eye test), to serogroup distribution, loss of virulence on storage, origin and haemolytic activity. Mouse lethality was highest in serogroup O4 (p 0.1, p = 0.05, p > 0.1). There was no significant difference between strains isolated from the stools of patients with enteritis and of healthy individuals (p = 0.1, p > 0.99) and between those isolated from all faecal specimens and from extraintestinal samples (p = 0.05, p > 0.3). There was no correlation between lung toxicity and other pathogenicity tests. Since strains isolated from healthy individuals were also toxic for mice, a positive lung test cannot be considered a criterion of the aetiological role of the agent.
01 Jan 1980
TL;DR: Variations in the number and mobility of bands among Shigella strains defined different esterase patterns (zymotypes) which appeared to be distinct for each species.
Abstract: Esterases of 57 strains of Shigella dysenteriue, Sh.JZexneri, Sh. boydii and Sh. sonnei and 26 strains of Escherichia coli, including the Alkalescens Dispar group, were compared by polyacrylamide-agarose gel electrophoresis. Six types of esterase bands differing in their ability to hydrolyse synthetic substrates and in their sensitivity to heat and to di-isofluoropropyl phosphate were defined. Individual activities and sensitivities of these bands and the apparent molecular weight of the major esterase, estimated to be 58 000 by polyacrylamide gradient gel electrophoresis, were identical for both Shigella species and E. coli. One esterase with a molecular weight of 104000 was found in some strains of E. coli. Variations in the number and mobility of bands among Shigella strains defined different esterase patterns (zymotypes) which appeared to be distinct for each species. INTRODU CTI ON Previous investigations have shown that Escherichia coli, Proteus and Providencia, Salmonella, Levinea, Serratia, Klebsiella and Enterobacter are characterized by distinct electrophoretic patterns of their esterases (Goullet, 1973, 1975, 1977, 1978, 1980; Goullet & Richard, 1977). In the present work, esterases of 57 strains of Shigella dysenteriae, Sh. Jlexneri, Sh. boydii and Sh. sonnei, and 26 new strains of E. coli, including the Alkalescens Dispar group, were analysed by polyacrylamide-agarose gel and polyacrylamide gradient gel electrophoresis. METHODS