A total of twenty Strains of Escherichia coli isolated from pigs was examined for sensitivity in vitro of Carbadox and other antibacterial drugs under aerobic and anaerobic conditions. The results obtained are summarized as follows (Table 1):
With aerobic condition, it was shown that the growth of E. coli was inhibited with Carbadox at 25-100 µ,g/ml. The activity of the drug, however, was extremely enhanced due to the anaerobic incubation: minimum inhibitory concentration (MIC) of the drug were<l.56µ,g/ml against 5 strains (25 %), 1.56µ,g/ml against 4 (20%), and 3.13µ,g/ml against 11 (55%).
On the other hand, the sensitivity of the other antibacterial drugs as aminobenzyl penicillin and furatrizin were about as same results in both aerobic and anaerobic conditions. .