Abstract
In order to detect bovine serum antibody against Fusobacterium necrophorum, serological investigation was made on bovine isolates of this species by the agar gel double diffusion test. Precipitin lines were observed between most of the HC1-heat extracts prepared from these strains and four anti-F. necrophorum sera. Precipitin was developed in rabbits inoculated experimentally with the organism, in the late stage of infection. Precipitin lines appeared between concentrated antigen prepared from the VPI 2891 strain and 16 of 23 sera from cattle affected with hepatic abscess, and between this antigen and 4 of 88 sera from healthy cattle.
