Assay, characterization, and localization of an enterotoxin produced by Salmonella

Koupal, L R; Deibel, R. H.

doi:10.1128/iai.11.1.14-22.1975

Cited by 88 publications

(27 citation statements)

References 25 publications

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“…Salmonella typhimurium is an enteric pathogen that is known to cause fluid and electrolyte loss from epithelial cells of the small intestine. The heat-labile enterotoxic principle involved in salmonellosis also causes erythematous skin reac- tions in rabbits and elongation of ClIO cells [1,2]. These three biological activities were blocked both by cholera antitoxin and GM1 ganglioside [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Location of the enterotoxin gene from Salmonella typhimurium and characterization of the gene products

Chary

1993

FEMS Microbiology Letters

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The enterotoxin gene (stn) in Salmonella typhimurium (Q1 strain) was confined to an 800 bp ClaI-EcoRI genomic DNA fragment (pCE3) that coded for two polypeptides (25 and 12 kDa) under the control of the T7 RNA polymerase/promoter system. The appearance of the 25 kDa protein corresponded to the enterotoxic activity, as determined by elongation of Chinese hamster ovary (CHO) cells, fluid accumulation in rabbit intestinal loops, and altered vascular permeability in rabbit skin. The stn gene products (STN) caused an elevation of intracellular cAMP in CHO cells. These values were at control levels in stn mutants devoid of enterotoxicity, and the 25-kDa protein concurrently disappeared. The biological activity of the heat-labile enterotoxin was blocked by GM1 ganglioside and neutralized by affinity-purified antibodies made against cholera toxin. The 12 kDa protein however was not correlated with an enterotoxic response.

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Section: Introductionmentioning

confidence: 99%

Location of the enterotoxin gene from Salmonella typhimurium and characterization of the gene products

Chary

1993

FEMS Microbiology Letters

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“…Murine typhoid fever, however, does not mimic the acute gastroenteritis caused by S. typhimurium in humans (9). Instead, several cell culture and animal models have been used to study the various activities implicated in S. typhimurium-mediated diarrhea (10,13,23,24,28,29,31,32,(37)(38)(39)51). Since PE fimbriae mediate adhesion to the epithelial lining of the murine small intestine, we decided to undertake studies in mice.…”

Section: Resultsmentioning

confidence: 99%

Multiple host defense defects in failure of C57BL/6 ep/ep (pale ear) mice to resolve visceral Leishmania donovani infection

et al. 1996

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We investigated the role of the pef operon, containing the genes for plasmid-encoded (PE) fimbriae of Salmonella typhimurium, in adhesion to the murine small intestine. In an organ culture model, a mutant of S. typhimurium carrying a tetracycline resistance cassette inserted in pefC was found to be associated in lower numbers with murine small intestine than the wild type. Similarly, heterologous expression of PE fimbriae in Escherichia coli increased the bacterial numbers recovered from the intestine in the organ culture model. Adhesion to villous intestine mediated by PE fimbriae was further demonstrated by binding of an E. coli strain expressing PE fimbriae to thin sections of mouse small intestine. The contribution of pef-mediated adhesion on fluid accumulation was investigated in infant mice. Intragastric injection of S. typhimurium 14028 and SR-11 caused fluid accumulation in infant mice. In contrast, pefC mutants of S. typhimurium 14028 and SR-11 were negative in the infant mouse assay. Introduction of a plasmid containing pefBACD and orf5, the first five genes of the pef operon, into the pefC mutant complemented for fluid accumulation in the infant mouse assay. However, heterologous expression of PE fimbriae in E. coli did not result in fluid accumulation in the infant mouse, suggesting that factors other than fimbriae are involved in causing fluid accumulation.

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“…Several toxins of S. typhimurium have been reported [9][10][11], but these were all isolated from its bacillary forms. In contrast, the cytotoxin purified in the present study was isolated only from L-form S. typhimurium.…”

Section: Discussionmentioning

confidence: 99%

Isolation of a cytotoxin from L-form Salmonella typhimurium

Kita

Kamikaidou

Nakano

et al. 1993

FEMS Microbiology Letters

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A cytotoxin protein was isolated from the sodium dodecyl sulphate (SDS)‐solubilized extract of the stable L forms of Salmonella typhimurium by ion‐retardation chromatography, ion‐exchange chromatography, isoelectric focusing and gel filtration. The purified toxin, with a molecular mass of 32 kDa and with isoelectric point of 6.4, was thermolabile and trypsin‐sensitive. Against mouse macrophages, its cytolytic effect was detectable in vitro at concentrations higher than 0.7 μg/ml, with a complete lysis obtained at 5 μg/ml. In contrast, it stimulated C3H/HeJ macrophages in the dose range of 0.1–0.5 μg/ml to allow the cell to respond to endotoxin, resulting in the significant production of tumor necrosis factor α. By Northern blot analysis, this effect was detectable at a dose as low as 0.01 μg/ml. These findings suggest that the transformation of bacillary S. typhimurium into L forms in vivo may induce alterations in host resistance against murine typhoid.

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Assay, characterization, and localization of an enterotoxin produced by Salmonella

Cited by 88 publications

References 25 publications

Location of the enterotoxin gene from Salmonella typhimurium and characterization of the gene products

Location of the enterotoxin gene from Salmonella typhimurium and characterization of the gene products

Multiple host defense defects in failure of C57BL/6 ep/ep (pale ear) mice to resolve visceral Leishmania donovani infection

Isolation of a cytotoxin from L-form Salmonella typhimurium

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