ANTIFUNGAL SUSCEPTIBILITY TESTING OF YEASTS - A BRIEF OVERVIEW

Antifungal susceptibility testing of yeasts has lacked reproducibility because of the absence of universally accepted guidelines. The major sources of variation in susceptibility testing have been attributed to the choice of medium and pH, inoculum preparation and size, incubatio n temperature and time, and end-point criteria. These parameters have been addressed by the National Committee for Clinical Laboratory Stand ards (NCCLS) Subcommittee on Antifungal Susceptibility Testing, and pr oposed guidelines have recently been published. Although major advance s in antifungal susceptibility testing have been achieved, particularl y through the efforts of the NCCLS subcommittee, the results of studie s to date do not support a correlation between the results of in vitro susceptibility testing and in vivo response. Routine antifungal susce ptibility testing of yeasts should therefore be discouraged until the methodology is standardized such that it predicts clinical outcome.