Intraepithelial Vibrio Associated with Acute Typhlitis of Young Rabbits

A retrospective morphologic study was conducted on tissues from weanling laboratory rabbits with diarrheal disease of unknown cause. The consistent lesion was in the cecum and consisted of exaggerated degeneration and loss and replacement of surface absorptive cells. This was accompanied by hyperplasia of crypt epithelial cells and acute diffuse inflammation of the lamina propria and submucosa. Numerous bacteria, identified morphologically as vibrio sp., were in surface epithelial cells in the cecum of affected rabbits. This was demonstrated in 10 of 12 affected rabbits via light microscopic examination of Levaditi-stained histologic sections. The occurrence, intraepithelial location, and identification of the vibrio, as well as the associated cytopathology, was confirmed in four of the six ceca from affected rabbits examined by electron microscopy. Lesions were not seen in cecal mucosa of six healthy weanlings from the colony. Vibrio was seen in the intestinal and cecal lumina of one control by both Levaditi and electron microscopic methods; none had invaded the mucosa, however. The possibilities that vibrio had either a primary or secondary causal association with acute typhlitis and that the disease had a pathogenesis similar to that of primate shigellosis are discussed.