In vitro sensitivity to 5-fluorocytosine of strains isolated from patients under treatment for chromomycosis.

In vitro 5-fluorocytosine sensitivity tests of strains were isolated from chromomycosis patients undergoing therapy. Tests were rountinely performed for 0.1, 1.0, 5.0 and 10.0 mug/ml 5-fluorocytosine concentrations. In two cases resistance could be demonstrated up to 60.0 and 100.0 mug/ml. Fungistatic activity of 5-fluorocytosine against the agents of chromomycosis was confirmed. Sensitivity tests are useful to detect resistance which may occur during treatment. They are also helpful for guiding the clinician in the establishment of new therapeutic schedules.