Ulcerative enteritis in broiler chickens caused by Clostridium colinum and in vitro activity of 19 antimicrobial agents in tests on isolates.

Ulcerative enteritis in broiler chickens occurred at five poultry farms in Kagoshima Prefecture, southern Japan, in February and March, 1987. This is the first incidence of this disease reported for chickens in Japan. The mortality rate was estimated to be 1 to 5%. Ulcerative enteritis in the intestines, and necrosis in the liver and spleen, were observed mainly in autopsied broilers. Identification involving tests of biochemical properties and production of metabolic endproducts using gas-liquid chromatography were consistent with an identification of Clostridium colinum. Antimicrobial agent susceptibility tests on the isolates showed that all were highly sensitive to the agents, with the exception of aminoglycoside antibiotics. Minimum inhibitory concentrations of penicillin-G and ampicillin ranged from .025 microgram/mL to .05 microgram/mL. No resistant strains were isolated.