Infectious diarrhoeas: weakening of mucosa protection induced in rabbit ileal loops by a pathogenic Escherichia coli.

The histological, enzymatic, and electrolyte changes induced by a toxigenic strain of E. coli (0128B12) were studied in the rabbit. After 4 hours of contact with the bacteria, one-third of the goblet cells of the intestinal epithelium were totally degranulated, indicating an increase in the destruction of mucus and hence a weakening of mucosal protection through action of bacterial enzymes. The good histological conservation of the ileal mucosa at the end of the study period was confirmed by the stability of the disaccharidase of the glycocalyx and of the luminal surface membrane enzymes, alkaline phosphatase and leucine amino-peptidase. The observed water, sodium and bicarbonate losses were principally due to the action of the bacterial toxins on the ionic pumps of the epithelial cells.