In vitro evaluation of voriconazole against clinical isolates of yeasts, moulds and dermatophytes in comparison with itraconazole, ketoconazole, amphotericin B and griseofulvin

Abstract

The in vitro activity of voriconazole (UK-109, 496), a new antifungal triazole derivative, against 650 clinical isolates of yeasts, moulds and dermatophytes was compared with that of itraconazole, ketoconazole, amphotericin B and griseofulvin. The geometric means of the minimum inhibitory concentrations (MICs) of voriconazole were 0.05 μgml-1 against yeasts (n = 187), 0.58 μgml-1 against moulds (n=260) and 0.08 μg ml-1 against dermatophytes (n = 203). The overall activity of voriconazole against yeasts and moulds was good, being similar to that of itraconazole, ketoconazole and amphotericin B. Voriconazole was highly effective against Aspergillus fumigatus (mean MIC 0.23 μgml-1) and other Aspergillus species and showed noteworthy activity (mean MICs 0.08-0.78 μg ml-1) against emerging and less common clinical isolates of opportunistic moulds, such as Alternaria spp., Cladosporium spp., Acremonium spp., Chrysosporium spp. and Fusarium spp. On the other hand, voriconazole was less active in vitro than the comparative agents studied against various species of zygomycetes, such as Mucor spp., Rhizopus spp. and Absidia spp. Voriconazole and the other two azoles, itraconazole and ketoconazole, were more active than griseofulvin in vitro against most dermatophytes tested.