Passive bacteriocin typing of strains of Clostridium perfringens type A causing food poisoning for epidemiologic studies.

A passive bacteriocin typing system was developed for use as an epidemiologic tool to study outbreaks of food poisoning caused by Clostridium perfringens type A. The 90 strains tested were from England, the United States, India, Japan, France, and Canada. Forty of 74 strains produced bacteriocin when irradiated with ultraviolet light for 40-90 sec. Eight bacteriocins were concentrated with ammonium sulfate and titrated on a common indicator strain. These bacteriocins were found to be specific for C. perfringens type A. All of the 90 strains were typable, with 16 distinct bacteriocin types. Most (85.56%) of the strains were types 1-6. Strains of C. perfringens type A clustered into certain patterns of bacteriocin types according to their country of origin and source of isolation.