New medium selective for Fusobacterium species and differential for Fusobacterium necrophorum

Fusobacterium egg yolk agar is a new medium selective for Fusobacterium species and differential for Fusobacterium necrophorum. The medium is a Brucella Agar base (Difco Laboratories, Detroit, Mich.) containing vancomycin, neomycin, josamycin, and egg yolk. All species of fusobacteria grew with only minimal inhibition. The mean log difference in counts between Fusobacterium egg yolk agar and control media for 30 strains of seven species of fusobacteria was 0.1922. F. necrophorum typically showed a strong lipase reaction. Most other organisms were significantly inhibited by the medium.