Antifungal susceptibility testing has developed rapidly during the last decade. Through the intensive collaborative work, the National Committee for Clinical Laboratory Standards(NCCLS) has published a standardized antifungal susceptibility method M27-A which included interpretive guidelines for 3 antifungal agents. Meaningful large-scale, longitudinal studies of antifungal susceptibility and resistance, based on standardized methodology and interpretive guidelines, have been published and serve as the basis for analysis of resistance trends. Resistant isolates have been further characterized using molecular biological techniques. Candida albicans and related species become resistant to antifungal agents, in particular triazoles, by expression of efflux pomps that reduce drug accumulation, alteration of the structure or concentration of antifungal target enzymes, and alteration of membrane sterol composition. On the other hand, there are several ongoing problems in antifungal susceptibility testing such as trailing phenomenon, ability to detect amphotericin B resistance, and application for other fungal pathogens.
In this paper, we review studies which focused on the reliability of antifungal susceptibility testing, epidemiology of resistant isolates, and resistant mechanisms. Furthermore, we provide several recommendations for antifungal susceptibility testing in the clinical laboratory.

*1Department of Laboratory Medicine, Kinki University school of Medicine, Osakasayama 589-8511

【Key Words】mycosis, antifungal resistance, antifungal susceptibility test-ing, mechanisms of resistance