Comparative evaluation of Sensititre YeastOne vs. the NCCLS M27A protocol and E-test for antifungal susceptibility testing of yeasts

A recently developed microdilution method (Sensititre) YeastOne) may represent a valid alternative to the National Committee for Clinical Laboratory Standards (NCCLS) method for routine testing. The Medical Mycology Committee of the Associazione Microbiologi Clinici Italiani (AMCLI) decided to evaluate its reproducibility and reliability compared with the NCCLS M27A protocol and the E-test. Nineteen strains each of Candida albicans and Ca. parapsilosis, isolated from systemic infections, were tested against amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole. All the participating laboratories tested the YeastOne panels, while the E-test and the NCCLS method were performed by two laboratories each. Interlaboratory reproducibility showed a good correlation (from 95% for amphotericin B to 92.5% for flucytosine). The agreement between NCCLS and YeastOne ranged from 95 (ketoconazole and itraconazole) to 100% (amphotericin B and flucytosine), whereas the agreement between E-test and YeastOne ranged from 72.5 (fluconazole) to 100% (amphotericin B and flucytosine). The Sensititre YeastOne panels appear to be an excellent alternative to both the E-test and the NCCLS protocol for antifungal susceptibility testing.