Demonstration of synergism between trimethoprim and sulfamethoxazole against 10 Nocardia isolates was found to be critically dependent upon the isolate, the duration of incubation, and the trimethoprim-sulfamethoxazole ratio. Inoculum effect was not significant. The trimethoprim-sulfamethoxazole ratio in the commercial, fixed-dose combination was found to contain too little trimethoprim to be o...

It was observed that 10% of urine culture isolates of enterococci tested for antimicrobial susceptibility failed to grow on commercially prepared Mueller-Hinton agar with low levels of thymidine and thymine. All strains could utilize exogenous thymidine and thymine and required only low levels (0.4-microgram disk) to support growth. All thymidine-thymine-requiring strains were resistant to trim...

We compared susceptibility tests of 47 Pseudomonas aeruginosa isolates and 40 Pseudomonas species to carbenicillin and trimethoprim-sulfamethoxazole by the MS-2 and Sceptor systems and agar dilution. The major and very major errors encountered in these tests in the MS-2 and Sceptor systems raise doubts about the accuracy of these methods for testing P. aeruginosa and confirm that they should no...

Two types of transmissible plasmids which encode resistance to trimethoprim-sulfamethoxazole were found among five animal isolates of Salmonella krefeld. This is the first report of plasmid-mediated resistance to trimethoprim-sulfamethoxazole in Salmonella strains isolated in the United States.

Treatment with a combination of trimethoprim and sulfamethoxazole proved lifesaving in a patient with pulmonary melioidosis after therapeutic failure occurred with other antibiotics to which the organisms were sensitive in vitro. Antagonistic interaction of drugs occurred when the combination of trimethoprim and sulfamethoxazole was given along with other antibiotics. The combination of trimeth...

The combination trimethoprim-sulfamethoxazole had no greater activity in a murine model of toxoplasmosis than did sulfamethoxazole alone.

Urinary tract infections caused by staphylococci are usually attributed to Staphylococcus epidermidis or S. saprophyticus. The case study reported here describes a persistent urinary tract infection caused by S. haemolyticus in a 38-year-old male whose infection was ultimately resolved through the use of the antibiotic trimethoprim-sulfamethoxazole.