Drug susceptibility testing of clinical isolates of Candida albicans against Amphotericin B and Ketoconazole by microdilution and disk diffusion methods

Background and Objective: Candida albicans is the normal flora of the body as opportunistic fungi. It causes candidiasis in immunocompromised condition. This study was done to drug susceptibility testing of Candida albicans isolated from patients against Amphotericin B and Ketoconazole. Methods: In this descriptive – analytic study, drug susceptibility of 30 Candida albicans isolated from patients admitted to Tehran hospitals, Iran was tested against Amphotericin B and Ketoconazole by micro dilution method in accordance with CLSI M27-A2 guideline and disk diffusion method in accordance with CLSI M44-S2 guideline. Standard isolate Candida albicans PTCC (5027) and Candida krusei PTCC (5295) were used for quality control. Results: The minimum and maximum MIC against Amphotrericin B was 0.0625 µg.ml-1 and 4 µg.ml-1, respectively. The minimum and maximum MIC against Ketoconazole was 0.5 µg/ml-1 and 32 µg/ml-1, respectively. The minimum and maximum zone diameter was 6 and 28 mm for both drugs. The results of drug susceptibility testing by two methods did not show significant differences. 25 isolates (83.3%) against ketoconazole and 2 isolates (6.7%) against Amphotericin B were resistant. Conclusion: Amphotericin B administration seems better choice in candidiasis treatment in comparision with Ketoconazole