High Prevalence of Triazole‐Resistant Aspergillus fumigatus sensu stricto in an Argentinean Cohort of Patients with Cystic Fibrosis

BRITO DEVOTO, TOMÁS; HERMIDA?ALVA, KATHERINE; POSSE, GLADYS; FINQUELIEVICH, JORGE L.; GARCÍA?EFFRÓN, GUILLERMO; CUESTAS, MARÍA L.

MYCOSES

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

0933-7407

Background Triazole resistance in Aspergillus fumigatus sensu stricto due to mutations in the cyp51A gene has been widely reported. Data from Argentina, and particularly from cystic fibrosis (CF) patients, are limited. Objectives to investigate the prevalence and molecular mechanisms of azole resistance in A. fumigatus sensu stricto recovered from this population. Methods Ninety‐three A. fumigatus isolates from 50 CF patients were retrospectively analyzed for azole resistance using the standard microbroth dilution method according to CLSI M38‐A2 guidelines. Sequencing analysis of the cyp51A gene and its promoter region was conducted in those isolates displaying high MICs values to itraconazole, voriconazole and/or posaconazole. Results Overall, 14% of isolates displayed high MIC values to at least one azole. Of them, 30.7% had the mutation TR34‐L98H. No mutations in the cyp51A gene or its promoter were found in the remaining non‐wild type strains. Therefore, other mechanisms associated with azole resistance can be highly prevalent in these isolates. Conclusions To the best of our knowledge, this is the first study in Latin America reporting azole resistant A. fumigatus strains recovered from respiratory secretions of CF patients. Noteworthy, the prevalence of azole resistance in A. fumigatus sensu stricto in the studied Argentinean CF population is alarmingly high.