In Vitro Antifungal Activities of Amphotericin B, Fluconazole, Itraconazole, Terbinafine, Caspofungin, Voriconazole, and Posaconazole against 30 Clinical Isolates of Cryptococcus neoformans var. neoformancs

Aantifungal agents were tested against 30 clinical isolates of Cryptococcus neoformans var. neoformans using the NCCLS method(M27-A2). Posaconazole, itraconazole and amphotericin B had lower MIC than the remaining four antifungal agents. The MIC result for posaconazole was over 220-fold lower active than fluconazole. Fluconazole MICs for most isolates fell within the dose-dependant range. The overall MIC ranges and $MIC_{50}s$ were amphotericin B(0.03-0.25; 0.25), fluconazole(0.5-64; 16), itraconazole(0.015-1; 0.125), terbinafine(0.06->2; 1), caspofungin(8-32; 32), voriconazole(0.015-0.5; 0.25), and posaconazole(0.015-0.25; 0.06 ${\mu}g/ml$), respectively. In conclusion, the $MIC_{50}s$ of these drugs did not exhibit any sign of an upward shift with the exception of fluconazole and tendency cross-resistance between the seven drugs was not observed. We conclude that in vitro resistance to antifungal agents has not significantly changed despite the recent wide-spread use of triazoles for long-term treatment of Cryptococcal meningitis.