Activities of Caspofungin, Itraconazole, Posaconazole, Ravuconazole, Voriconazole, and Amphotericin B against 448 Recent Clinical Isolates of Filamentous Fungi

Abstract

We examined the in vitro activity of caspofungin, posaconazole, voriconazole, ravuconazole, itraconazole, and amphotericin B against 448 recent clinical mold isolates. The endpoint for reading caspofungin was the minimum effective concentration (MEC). Among the triazoles, posaconazole was most active, inhibiting 95% of isolates at ≤1 μg/ml, followed by ravuconazole (91%), voriconazole (90%), and itraconazole (79%). Caspofungin and amphotericin B inhibited 93% and 89% of isolates at ≤1 μg/ml, respectively, with caspofungin demonstrating an MEC 90 of 0.12 μg/ml. All three new triazoles and caspofungin inhibited >95% of Aspergillus spp. at ≤1 μg/ml compared to 83% for itraconazole and 91% for amphotericin B. Amphotericin B inhibited only 38% of Aspergillus terreus isolates at ≤1 μg/ml, whereas the three new triazoles and caspofungin inhibited all A. terreus at ≤0.5 μg/ml. The new triazoles and caspofungin have excellent in vitro activity against a very large collection of recent clinical isolates of Aspergillus spp., and some in vitro activity against selected other filamentous fungi.