Abstract
Nine strains of Fusobacterium necrophorum biovars A, B, and C were examined for the presence of plasmid by agarose gel electrophoresis. Although none of biovars A and B possessed extrachromosomal deoxyribonucleic acids, all the strains of biovar C examined so far contained a single plasmid with a molecular weight of 118 megadaltons. This suggests the presence of plasmid may link to the biological variation in the F.necrophorum species.
