Postantifungal Effect Methods

Postantifungal effect (PAFE) is the evaluation of antifungal activity after the suppression of fungal growth when the drug is removed from the fungal suspension. In vitro, this effect might simulate the in vivo situation when the concentration of the drug falls to less than the minimum inhibitory concentration values and could be another tool, together with the classic in vitro susceptibility tests, to optimize the interaction of drugs-fungi. In this chapter, two model methods to evaluate the PAFE of yeasts and filamentous fungi are described in which practical advices and tricks are given to help the worker to develop the techniques. The procedures outlined include preparation of stock solutions of the drugs, concentration medium, exposure time colony count determination, and interpretation of the results to quantify the PAFE.