Abstract
Antifungal susceptibility testing of Candida spp. in Japan is compliant with the Clinical and Laboratory Standards Institute (CLSI). The latest CLSI documents are M27 Fourth Edition and M27M44S-Ed3 (Ed4/M44S-Ed3), while most domestic kits use the old documents M27-A3 and M27-S3 (A3/S3). The main differences between the old and new documents are the determination time and the criteria, and there is a possibility that the measurement results may deviate significantly depending on the edition. In this study, two standard strains and 92 clinical isolates of Candida spp. were tested using ASTY (Kyokuto Seiyaku Kogyo), and the results were evaluated when measured according to A3/S3 and the latest Ed4/M44S-Ed3 as per the attached document. The MIC values were calculated according to both standards, and the accuracy evaluation and the MIC value agreement and sensitivity rates were examined. The MIC values of the standard strains were within the precision control range for both standards. The overall MIC concordance rate was 92.6% within a two-well difference. Discordant was observed in Candida albicans, Candida glabrata, Candida tropicalis, and Candida krusei in 33 isolates (CPFG: 24, FLCZ: 8, VRCZ: 1). Comparison of the M44S-Ed3 showed VME: 4 strains (CPFG: 2 strains of C. glabrata and CPFG: 2 strains of C. krusei.), mE: 29 strains. This study has clarified the trends and effects of the new and the old documents. In the future, clinical evaluation using MIC values based on the latest standards should be validated with a sufficient number of strains, including drug-resistant strains.
