Effect of hemorrhagic toxin produced by Clostridium sporogenes on rabbit ligated intestinal loop

In order to characterize the toxicity of the hemorrhagic toxin of Clostridium sporogenes isolated from the rabbit with antibiotic-associated hemorrhagic diarrhoea, we studied the toxin productivity of C. sporogenes cultured in various media and the toxic effect of the partially purified preparation of the culture supernatant in rabbit intestinal loops. The hemorrhagic activity, which was determined by rabbit skin test for assessment of the toxin production, of culture supernatant of C. sporogenes reached maximum in the early stationary phase of the bacterial growth in GAM or Trypticase soy broth that contained rich glucose, ammonia and peptide. The partially purified toxin prepared by hydroxyapatite, phenyl Toyopearl and Superdex 200 columns caused marked hemorrhage in rabbit ligated intestinal loops. Histological examination of the intestinal loops injected with the toxin revealed noticeable pathological alterations which seemed to be a characteristic of this toxin. Marked hemorrhage could be observed in the mucosa, submucosa, muscular layer and subserous spaces. There were various degrees of infiltration of inflammatory cells such as polymorphonuclear leukocytes and granulated leukocytes throughout the intestinal wall, but it was not associated with any necrotic changes of the tissue. These findings indicate that hemorrhagic toxin produced by C. sporogenes induces vascular changes in the intestine without any direct effects on the parenchymal cells. (C) 1997 Academic Press Limited