Mutations in the Cyp51A gene and susceptibility to itraconazole in Aspergillus fumigatus isolated from avian farms in France and China.

Abstract

Azole resistance in the fungal pathogen Aspergillus fumigatus is an emerging problem and may develop during azole therapy in humans and animals or exposure to azole fungicides in the environment. To assess the potential risk of azole-resistance emergence in avian farms where azole compounds are used for the control of avian mycoses, we conducted a drug susceptibility study including A. fumigatus isolates from birds and avian farms in France and Southern China. A total number of 175 isolates were analyzed: 57 isolates were collected in France in avian farms where chemoprophylaxis with parconazole was performed; 51 isolates were collected in southern China in avian farms where no chemoprophylaxis was performed; and 67 additional isolates came from the collection of a mycology laboratory. No resistant isolate was detected, and the distribution of minimum inhibitory concentrations was similar for isolates collected in farms with or without azole chemoprophylaxis. For 61 randomly selected isolates, the full coding sequence of the Cyp51A gene was determined to detect mutations. Nine amino acid alterations were found in the target enzyme, 3 of which were new.