Experimental cecitis in gnotoxenic chickens monoassociated with Clostridium butyricum strains isolated from patients with neonatal necrotizing enterocolitis.

An animal model for Clostridium butyricum necrotizing cecitis has been developed in axenic chickens inoculated orally between 2 and 50 days of life. Cecitis was obtained with two C. butyricum strains isolated from neonatal necrotizing enterocolitis and not with a Clostridium beijerinckii strain from dairy products; the rate of colonization of the intestinal tract by this strain was lower than that obtained with C. butyricum strains. The clinical findings showed a slow gain in body weight. The cecitis lesions were well developed 3 and 4 weeks after oral inoculation, including enlargement with an increase of the cecum weight-body weight ratio, a marked hyperplasia, congestion, inflammatory infiltrate and pneumatosis of the cecal wall and mesentery, hemorrhage in the lamina propria and submucosa, and ulcerations and necrotic areas in the mucosa. By immunofluorescence and electron microscopy, the bacterial cells were located in the cecal lumen and in necrotic areas of the mucosa. The presence of 4% lactose in the diet seemed to be a prerequisite for the development of cecitis in chickens. A gradual rise of fluorescent antibodies in the sera was observed.