Activity of Azole and Non-Azole Substances Against Aspergillus fumigatus in Clinical and Environmental Samples to Address Antimicrobial Resistance

Aspergillus fumigatus is a common fungus which has gained attention due to its resistance to azole compounds, substances used in both medical and agricultural settings. One of the genetic alterations responsible for this resistance is the mutation TR34/L98H in the cyp51A gene. The aim of this study was to understand the impact of azoles and non-azoles on Aspergillus fumigatus. By examining clinical samples, soil samples, and compost material, this research aims to provide insights into the susceptibility of these strains to antifungal substances. To deepen our understanding of the factors potentially involved in antifungal resistance, we combined in vitro studies of sixteen compounds against Aspergillus fumigatus with results from the sequencing of the cyp51 gene. We observed that compounds generally displayed a similar pattern activity against wild-type Aspergillus fumigatus. Non-azoles, except Pyrisoxazole and Amisulbrom, did not show any activity against Aspergillus fumigatus, while azole compounds displayed differential activity against the fungus, except for Tetraconazole. For the mutant strains, a generally similar activity was observed in both clinical and environmental samples, likely due to the same mutation in all the isolates. The implications of these findings may be relevant for better understanding the relationship between Aspergillus fumigatus and its ability to develop resistance to antifungal substances.