Cytotoxic activity ofEscherichia coli O157:H7 culture filtrate on the mouse colon and kidney

Escherichia coli O157:H7 culture filtrate (O157CF) produced colonic and renal lesions in mice following intraperitoneal or intravenous injection. Colonic lesions were characterized by death and sloughing of both surface and crypt epithelial cells, leading to loss of the mucous membrane and subsequent occult colonic hemorrhage. Several areas of severe colonic damage existed where loss of the epithelium and lamina propria was complete, leaving only the submucosal and smooth muscle layers intact. The colon was the only portion of the gastrointestinal tract affected by O157CF. Renal lesions were characterized by marked vacuolation and general necrosis of proximal convoluted tubular cells, and the presence of numerous exfoliated renal epithelial cells in the lumina of distal convoluted and collecting tubules. A neurogenic response was demonstrated by paralysis of the animals' rear extremities. The mouse was a useful model for detecting and studying in vivo the toxic properties of O157CF.