Azole-resistant Aspergillus fumigatus harboring TR34/L98H, TR46/Y121F/T289A and TR53 mutations related to flower fields in Colombia

Resistance to triazoles in Aspergillus fumigatus has been reported in azole-naive patients in Europe, Asia, Australia and North America. This resistance has been linked to fungicide-driven mutations in the cyp51A gene and its promoter region. We investigated the presence of environmental azole-resistant A. fumigatus strains related to the use of azole fungicides in Colombia. Soil samples were collected from flower beds, flower fields and public gardens from the outskirts, suburbs and city centre of Bogotá. Out of the 86 soil samples taken, 17 (19.8%) grew A. fumigatus of whom eight (9.3%) contained 40 strains able to grow on azole-containing itraconazole and/or voriconazole supplemented media. All but one triazole-resistant strains were isolated from soil samples collected from flower fields and flower beds (39/40). Importantly, the majority had the TR46/Y121F/T289A, TR34/L98H, and TR53 molecular resistance mechanisms and one azole resistant strain had a wild-type cyp51A gene. Soil samples from flower fields and beds contained 4 azole fungicides (penconazole, difenoconazole, tetraconazole and tebuconazole) above the limit of detection. Our findings underline the need for extensive investigations to determine azole-resistant A. fumigatus prevalence in both clinical and environmental samples in other regions of Latin America.