Cryptococcus gattii : in vitro susceptibility to the new antifungal albaconazole versus fluconazole and voriconazole
Abstract
Minimal inhibitory concentrations (MIC) and minimal fungicidal activity of albaconazole, voriconazole and fluconazole against 55 strains of Cryptococcus gattii , clinically or environmentally isolated in Spain and some Latin American countries, were assessed. By means of the microbroth method (National Committee for Clinical Laboratory Standards; document M27-A2), the geometric mean value for fluconazole was 5.01 µg/ml; however, MIC for 12.7% of isolates ranged from 16 to 32 µg/ml, suggesting increased resistance against fluconazole. Geometric mean values of 0.02 and 0.03 µg/ml for albaconazole and voriconazole, respectively, were found, indicating not only a higher susceptibility to these new azoles but also a better performance of albaconazole ( P = 0.003). Minimal fungicidal concentrations were also very low for albaconazole and voriconazole ( P <0.001; geometric mean values of 0.023 µg/ml and 0.07 µg/ml, respectively). Both azoles may be good alternatives for the treatment of C. gattii cryptococcosis.