A comparison of the susceptibilities of anaerobic bacteria to trimethoprim and sulfamethoxazole individually and in combination.

The activities of trimethoprim and sulfamethoxazole, singly and in combination, were compared with the activities of six other antimicrobial drugs against 50 anaerobic bacteria isolated from clinical specimens. Trimethoprim alone had little activity against the anaerobes tested, but sulfamethoxazole and the sulfamethoxazole/trimethoprim combination were active against most of the organisms. Results with the combination were slightly better than those with sulfamethoxazole alone.