Multi-azole resistance in Aspergillus fumigatus.

Azole resistance in Aspergillus spp. is unusual. We report a patient who received long-term treatment with itraconazole and voriconazole for bilateral chronic cavitary aspergillosis with aspergillomas whose isolates of Aspergillus fumigatus developed simultaneous resistance to itraconazole and voriconazole. A novel mutation (G138C) in the target gene (cyp51A) encoding 14alpha-demethylase was detected. The patient had some response to intravenous caspofungin, which he received six times weekly, without the development of resistance over 9 months.