Antibiotic sensitivity and biochemical characterization of Fusobacterium spp. and Arcanobacterium pyogenes isolated from farmed white-tailed deer (Odocoileus virginianus) with necrobacillosis.

Bacterial cultures from 32 living and dead farmed white-tailed deer (Odocoileus virginianus) with necrobacillosis yielded Fusobacterium necrophorum from nine individuals, F. varium from six individuals, and Arcanobacterium pyogenes from 16 individuals. The isolates were characterized biochemically using automated identification systems. Gram-stained smears suggested the presence of Fusobacterium spp. in eight cases from which organisms were not cultured. Minimum inhibitory concentration determinations in 23 strains of gram-negative anaerobic bacteria detected resistance to enrofloxacin and clindamycin. Enrofloxacin resistance was detected in A. pyogenes isolates, and although biochemical profiling indicated that the deer strains of A. pyogenes could be grouped, it is uncertain whether these biochemical characteristics correlate with antigenic or virulence factors. Deer-specific or autogenous vaccines may provide a useful alternative to generic vaccines.