Activities of caspofungin, itraconazole, posaconazole, ravuconazole, voriconazole, and amphotericin B against 448 recent clinical isolates of filamentous fungi

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 less than or equal to1 mug/ml, followed by ravuconazole (915c), voriconazole (90%), and itraconazole (79%). Caspofungin and amphotericin B inhibited 93% and 89% of isolates at less than or equal to1 mug/ml, respectively, with caspofungin demonstrating an MEC 90 of 0.12 mug/ml. All three new triazoles and caspofungin inhibited >95% of Aspergillus spp. at :51 mug/ml compared to 83% for itraconazole and 91% for amphotericin B. Amphotericin B inhibited only 38% of Aspergillus terreus isolates at less than or equal to1 mug/ml, whereas the three new triazoles and caspofungin inhibited all A. terreus at less than or equal to0.5 mug/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.