Showing papers on "Shigella dysenteriae published in 1979"

Shigella dysenteriae 1-like cytotoxic enterotoxins produced by Salmonella strains.

Abstract: A Salmonella enteritidis strain produced a cytotoxin in addition to heat-labile (LT) and heat-stable (ST) enterotoxins. Two strains of serotypes Salmonella kapemba and Salmonella thompson were LT and ST negative, but exhibited a cytotoxic effect. After Sephadex G-100 fractionation of the crude S. enteritidis material, some high and low molecular fractions had both cytotonic and cytotoxic activities. Of the two other salmonellae, only some high molecular fractions contained the cytotoxic substance. Neutralization experiments revealed an antigenic relationship between the cytotoxins studied and Shigella dysenteriae 1 enterotoxin. On the basis of cross neutralization and other data, it seems that cytotoxic and LT-like characters are carried by the same molecule. In S. thompson and S. kapemba the LT fails to exert a biological effect, although it is antigenically related to the LT of Escherichia coli.

Epidemiology of Shigella dysenteriae, type 1 infections, in Dacca urban area.

Abstract: A prospective study of 47 families with an index case of Shigella dysenteriae type 1 was conducted in the urban areas of Dacca. The subsequent infection rates in contacts type 1 were 30.6% and 28.3% in the age groups 0--4 and 5--9. Total secondary infection rate was 20.4% with rates in males higher than in females. Among the contacts 12.5% developed diarrhoea caused by the same serotype, but 22.1% developed diarrhoea with undiagnosed causes. For one hospitalised case there were seven symptomatic cases and 10 infections. All the infected infants age 0--4 developed diarrhoea and one fourth needed hospitalisation; but none aged over 9 needed it. Of these families 19% coincidentally had infections with other shigela types. Many factors were related with the higher infection rate. Use of open source of water was a significant factor. Multiple resistance to antibiotic was found, however, Shigella shiga was sensitive to Ampicillin, Kanamycin, Colistin and Furazolidone.

Mitomycin C stimulates production of a toxin in Shigella species that causes morphological changes in Chinese hamster ovary cells.

Abstract: Shigella dysenteriae produced a toxin that caused morphological changes in Chinese hamster ovary cells which was different from the neurotoxin (Y. Takeda, K. Okamoto, and T. Miwatani, Infect. Immun. 18:546--548, 1977). It was found that the toxin was produced not only by S. dysenteriae but also by S. flexneri, S. boydii, and S. sonnei. The production of the toxin was stimulated by the addition of 1 microgram of mitomycin C per ml to the culture in the early logarithmic growth phase.

Characteristics of lipid A-protein complex from endotoxin of Shigella dysenteriae type 1 (S and R strains).

Abstract: Mild acetic acid hydrolysis of endotoxin (lipopolysaccharide-protein complex) of Shigella dysenteriae type 1 (S and R forms) yielded a lipid A-protein complex that consisted of amino acids, fatty acids, and sugar and, in terms of chemical composition, displayed no marked differences between the S and R forms. Its protein portion (53 to 56%) consisted of at least 16 amino acids. In the fatty acid portion (14 to 18%), myristic, 3-hydroxymyristic, palmitic, and stearic acids accounted for 50%. The sugar portion (10 to 12%) consisted solely of glucosamine. The remainder was unidentified substances, most of which contained phosphorus. Lipid A-protein complexes derived from both S and R forms were not toxic for mice in doses up to 1,000 microgram/mouse, but their Linulus test activity had increased considerably as compared with the starting lipopolysaccharide-protein complex material: from 10(-6) to 10(-10--10(-12) mg/ml. The lipid A-protein complexes were readily soluble in a water solution of triethylamine, in dimethyl sulfoxide, and in pyridine.

Chapter V Bacteriophage Typing of Shigella

Abstract: Publisher Summary This chapter discusses bacteriophage typing of Shigella . Shigellosis constitutes a very significant problem on a world scale. In many countries—for example, in Scandinavia, shigellosis is now infrequent and usually not endemic but reflects imported cases. Shigella sonnei ( S. sonnei ) dominates with only rare isolates of Shigella Flexneri ( S. flexneri ). In non-industrialized countries, Shigella dysenteriae is more frequent than in industrialized nations, where S. sonnei and S. flexneri are the dominating species. Elucidating the source of a Shigella infection may present a considerable problem. Phage typing of the isolates may be an essential tool in both endemic and epidemic situations. Typing may be the only way to determine the source of infection of persons who have been exposed to several possible sources. Shigella is typed by a number of procedures, such as serological typing, biotyping, and bacteriocin typing, in addition to phage typing. Serotyping is not sufficiently distinctive in an epidemiological context but is invaluable for species diagnosis in this genus ( vide infra ).

Studies on the inhibitory effects of zinc heptanoate on microorganisms.

Abstract: Inhibitory effect of zinc heptanoate was observed on different cultures of bacteria and fungi. Growth of all the bacteria was inhibited by the compound. Greatest inhibition was seen in the case of Staphylococcus albus, Streptococcus pyogenes, Shigella dysenteriae, Shigella sonnei, Shigella flexneri, Salmonella typhi, S. paratyphi A, S. paratyphi B, Vibrio cholerae, Corynebacterium diphtheriae, and E. coli whereas least inhibition was found in the case of Staphylococcus aureus. In triethanolamine: water (1:1) solution minimum inhibitory concentration (MIC) was least for Klebsiella pneumoniae (800 p.p.m.) while in the case of Staph. aureus and Bacillus subtilis it was 200 p.p.m. Among yeasts and fungi greatest inhibition was found with Trichophyton schoenleini, T. rubrum, T. gourvili, Microsporum adouini, M. vanbreuseghemi and least in the case of Candida albicans. In triethanolamine: water (1:1) solution the MIC for T. schoenleini and T. gourvili and T. violaceum was as low as 900 p.p.m. whereas in the case of Aspergillus oryzae it was highest--3500 p.p.m. The effect of the compound on glucose consumption of Aspergillus niger and Bacillus subtilis was also seen.