Activity of sulfa drugs and dihydrofolate reductase inhibitors against Candida albicans.

Growth of Candida albicans can be inhibited by sulfa drugs which prevent biosynthesis of folic acid. The dihydrofolate reductase (E.C. 1.5.1.3) inhibitors aminopterin and methotrexate also exhibit anticandidal activity, but trimethoprim does not. Kinetic evaluations with C. albicans dihydrofolate reductase indicate that methotrexate and aminopterin are tight-binding inhibitors whereas trimethoprim binds poorly.