Bacteriological Studies of Fatal Clostridium perfringens Type-A Infection in Chickens

SUMMARY Heat-sensitive Clostridium perfringens type-A isolated from an outbreak of fatal infection in 6-14-day-old chicks were studied in detail. The source of infection was traced to contaminated fish meal and mash. This was confirmed by conducting a feeding trial with these ingredients. The condition was also experimentally reproduced in day-old chicks by feeding the intestinal contents of the dead birds and 8-hour-old cultures of the strain in cooked meat medium. Culture filtrates were nontoxic when fed. The washed bacilli were found to be pathogenic for guinea pigs and chickens inoculated intramuscularly. Analysis of the strain for soluble antigens revealed the production of alpha and kappa fractions only. Pathogenicity was due to the high 'invasiveness' of the strain and probably to an unidentified factor which is known to enhance the virulence of certain strains of Cl. perfringens type-A.