Susceptibility to 5-fluorocytosine, miconazole and amphotericin B of Candida albicans strains isolated from the throat of non-AIDS patients.

Eighty Candida albicans strains, isolated from throat of patients at the Universitary Clinic of the Faculty of Superior Studies Iztacala of the National Autonomous University of Mexico, were analyzed. They were identified by microscopic and colony morphologies, germ tube test, and by auxanogram and zimogram. Minimal inhibitory concentrations (MIC) of 5-fluorocytosine, miconazole and amphotericin B were determined by microtiter broth dilution. MIC frequency distribution of 5-fluorocytosine showed a single peak (0.25-8.0 microg/ml), with 65% susceptible strains (MIC < or = 1.0 < or =g/ml) and 35% intermediate susceptible strains (MIC = 1.1-8 microg/ml). MIC frequency distribution of miconazole was threemodal with 6.25% susceptible (MIC = 1.562 microg/ml), 48.75% intermediate susceptible (MIC = 3.125-12.5 microg/ml), and 45% resistant (MIC = 25-50 microg/ml) strains. All strains were susceptible to amphotericin B (MIC= 0.0156-0.125 microg/m). These results shows that amphotericin B was the more active antimycotic, followed by 5-fluorocytosine, against the strains analyzed, and that miconazole was the less effective one.