CLOSTRIDIUM-PERFRINGENS NECROTIZING ENTERITIS OF THE FOWL - A LIGHT-MICROSCOPIC, IMMUNOHISTOCHEMICAL AND ULTRASTRUCTURAL-STUDY OF SPONTANEOUS DISEASE

Moderate lesions of spontaneous necrotic enteritis were investigated b y light microscopy, immunoperoxidase staining, and electron microscopy . Concurrent coccidial infection was detected in the intestinal mucosa of the majority of diseased birds. Electron microscopy of intestinal epithelium revealed vesiculation and blebbing of the luminal cell memb rane, as well as degenerative changes of cytoplasmic organelles. Using immunoperoxidase staining, Clostridium perfringens was identified and shown to constitute the majority of organisms in necrotic tissues, wh ereas bacteria were never seen in viable tissue. Thus, Clostridium per fringens always appeared to be present in the lesions and to act local ly, causing a coagulative type of necrosis. The observed vesiculation of epithelial cell membranes indicates that the hydrolysis of membrane components by bacterial toxins could be important in the pathogenesis of necrotic enteritis.