Enteric infection of swine with Clostridium perfringens types A and C

We were recently asked to examine a large group of isolates of C. perfringens obtained from piglets with classical hemorrhagic, necrotic enteritis to confirm that they were type C. In fact, 95% were type A, and considering that true type-C cases yield pure cultures of type C, it seems unlikely that these were “normal flora” type-A strains picked inadvertently from a background of disease-causing type-C strains. Elucidation of the role of type-A strains will require amassing epidemiologic and microbiologic data, as well as genotyping and phenotyping the isolates. For the present, the differential diagnosis for swine enteric disease should include both type A and type C. Summary