Environmental isolates of multi-azole-resistant aspergillus spp. in Southern Italy

Azole resistance in Aspergillus spp. has been increasingly reported worldwide. Acquired azole resistance is probably linked to environmental exposure to fungicides used in agriculture. We collected a total of 84 soil and leaf samples from eight farms in Southern Italy. Aspergillus isolates were tested for resistance to itraconazole, posaconazole, and voriconazole by the EUCAST method. Five out of 84 samples yielded A. fumigatus isolates: four of them were itraconazole-resistant and were identified as A. fumigatus sensu stricto, three of them were posaconazole-resistant, and two were also voriconazole-resistant. All three isolates harbored the TR34/L98H resistance mechanism, which was detected by DNA sequencing of the cyp51A gene. Fifteen out of 84 samples yielded Aspergillus spp. isolates and included 11 itraconazole-resistant isolates: Aspergillus section Nigri (9) and Aspergillus section Flavi (2). Our study reports for the first time the isolation of azole-resistant A. fumigatus harboring TR34/L98H mutation from the environment of Southern Italy. The present work provides a better understanding of the magnitude of the environmental spread of azole resistance in the context of a necessary effective surveillance program to improve the management of Aspergillus-related disease.