Germinated and Nongerminated Conidial Suspensions for Testing of Susceptibilities of Aspergillus spp. to Amphotericin B, Itraconazole, Posaconazole, Ravuconazole, and Voriconazole

The effect of germinated and nongerminated conidia of Aspergillus spp. on the fungistatic (National Committee for Clinical Laboratory Standards document M38-P) and fungicidal activities (MICs and minimal fungicidal concentrations [MFCs] respectively) of amphotericin B, itraconazole, posaconazole (SCH56592), ravuconazole (BMS-207147), and voriconazole was evaluated. MFCs were the lowest drug dilutions that showed fewer than three colonies (99.9% killing). Overall, the MICs (0.12 to 4 μg/ml) and MFCs (0.5 to >8 μg/ml) of all of the agents tested with both inocula were the same or within 2 dilutions for the 72 isolates. Therefore, MICs and MFCs can be obtained with convenient and standardized nongerminated conidia.