Prevalence, mechanisms and genetic relatedness of the human pathogenic fungus Aspergillus fumigatus exhibiting resistance to medical azoles in the environment of Taiwan
Journal
Environmental Microbiology
Journal Volume
20
Journal Issue
1
Pages
270-280
Date Issued
2018
Author(s)
Wang H.-C.
Huang J.-C.
Lin Y.-H.
Chen Y.-H.
Hsieh M.-I.
Choi P.-C.
Lo H.-J.
Liu W.-L.
Hsu C.-S.
Shih H.-I.
Wu C.-J.
Abstract
Emerging azole resistance in Aspergillus fumigatus poses a serious threat to human health. This nationwide surveillance study investigated the prevalence and molecular characteristics of azole-resistant A. fumigatus environmental isolates in Taiwan, an island country with increasing use of azole fungicides. Of the 2760 air and soil samples screened from 2014 to 2016, 451 A. fumigatus isolates were recovered from 266 samples and 34 isolates from 29 samples displayed resistance to medical azoles (itraconazole, voriconazole or posaconazole). The resistance prevalence was 10.9% and 7.5% in A. fumigatus-positive samples and isolates respectively. Most (29, 85.3%) azole-resistant isolates harboured TR34/L98H mutations, which were widely distributed, clustered genetically with clinical isolates, and had growth rates that were similar to those of the wild-type isolates. Microsatellite genotyping revealed both the global spread of the TR34/L98H isolates and the occurrence of TR34/L98H/S297T/F495I isolates belonging to local microsatellite genotypes. AfuMDR3 and atrF, two efflux transporter genes, were constitutively upregulated in two individual resistant isolates without cyp51A mutations, highlighting their potential roles in azole resistance. These results emphasize the need for periodic environmental surveillance at the molecular level in regions in which azole fungicides are applied, and agricultural fungicide management strategies that generate less selective pressure should be investigated. ? 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd
SDGs
Other Subjects
antifungal agent; cytochrome P-450 CYP51A, Aspergillus; cytochrome P450; fungal protein; itraconazole; microsatellite DNA; posaconazole; pyrrole derivative; triazole derivative; voriconazole; antifungal resistance; aspergillosis; Aspergillus fumigatus; drug effect; genetics; genotype; human; isolation and purification; microbial sensitivity test; microbiology; mutation; prevalence; Taiwan; Air Microbiology; Antifungal Agents; Aspergillosis; Aspergillus fumigatus; Azoles; Cytochrome P-450 Enzyme System; Drug Resistance, Fungal; Fungal Proteins; Genotype; Humans; Itraconazole; Microbial Sensitivity Tests; Microsatellite Repeats; Mutation; Prevalence; Soil Microbiology; Taiwan; Triazoles; Voriconazole
Publisher
Blackwell Publishing Ltd
Type
journal article