Abstract
Serological typing was used as an epidemiological tool in the investigation of 524 outbreaks of Clostridium perfringens food poisoning in the United Kingdom and 37 outbreaks in other countries. Five thousand five hundred and fifty-four (77%) of 7245 strains of C. perfringens associated with the 561 outbreaks were typable with the 75 Food Hygiene Laboratory antisera; in 354 (63%) of these outbreaks a specific serotype was established as being responsible for the outbreak. An assessment is made of the ability of two additional sets of antisera, prepared against 34 American and 34 Japanese strains of C. perfringens, to increase the number of strains which can be typed. The extent of cross-reaction between the three sets of antisera was determined and the results are discussed in relation to the source and history of the type strains.