Abstract: Objective To evaluate the sensitivity and resistance of pathogenic yeasts isolated from patients to antifungal agents. Methods The in vitro susceptibilities of pathogenic yeasts isolated from clinical patients to amphotericin B(AmB),5-flucytosine(5-FC),itraconazole(ICZ),ketoconazole(KCZ) and fluconazole(FCZ) were determined by NCCLS M27-A method. Results MIC ranges of 65 strains of Candida spp.were: FCZ 0.125～64μg/mL, 95.38% (62/65) were sensitive,2 strains(3.08%) were resistant; ICZ 0.03～2μg/mL, 63.08%(41/65) sensitive,3 strains(4.62%) were resistant; 5FC 0.125～32μg/mL, 93.84%(61/65) sensitive, 2 strains(3.08%) resistant; AmB 0.06～2μg/ml,96.92% (63/65) were sensitive,2 strains(3.08%) were resistant; KCZ 0.03～0.5μg/mL,all strains(65/65) were sensitive. For 35 strains of Cryptococcus neoformans, the MIC were: FCZ 2～64μg/mL, ICZ 0.25～1μg/mL, 5FC 0.25～64μg/mL, AmB 0.03～1μg/ml,KCZ 0.125～1μg/mL. Conclusions NCCLS M27-A micro-dilution method is reliable, practical, reproducible and easy to use in the clinical laboratory. The sensitivity of various species and strains of fungi to the above mentioned antifungal agents is different.

Key words: Candida, Cryptococcus neoformans, Microbial sensitivity tests