Susceptibilities of anaerobic bacteria isolated from animals with ovine foot rot to 28 antimicrobial agents.

The agar dilution method was used to determine the inhibitory activities of 28 antimicrobial agents against 35 strains of the genus Peptostreptococcus, 4 strains of the species Peptococcus niger, 20 strains of the species Megasphaera elsdenii, 7 strains from the species Acidaminococcus fermentans, 8 strains of the genus Clostridium, 11 strains of the genus Eubacterium, and 1 strain of the species Propionibacterium acidipropionici, all of which were isolated from 125 clinical cases of ovine foot rot between January 1987 and December 1988. The three unreidopenicillins studied proved to be the most active antimicrobial agents, with a high percentage of strains being susceptible at a concentration of 64 micrograms/ml. Penicillin G, ampicillin, and the three cephalosporins studied also had good activity. Fosfomycin showed a high degree of activity among the 116 anaerobic bacteria tested.