Antifungal Susceptibility Profile and Molecular Identification of Cyp51C Mutations in Clinical and Environmental Isolates of Aspergillus flavus from Argentina

HERMIDA?ALAVA, KATHERINE; BRITO DEVOTO, TOMÁS; SAUTUA, FRANCISCO; GORDÓ, MANUELA; SCANDIANI, MERCEDES; FORMENTO, NORMA; LUQUE, ALICIA; CARMONA, MARCELO; CUESTAS, MARÍA L.

MYCOSES

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

0933-7407

Background: The emergence of azole resistance in non-fumigatus Aspergillus strainsis on the raise.Objectives: To study the susceptibility profiles and the molecular mechanisms of azoleresistance of environmental and clinical strains of Aspergillus flavus from Argentina.Methods: Thirty-five A flavus isolates (18 from soybean seeds and chickpea seedsand 17 from the clinic) were analysed for amphotericin B and azole resistance usingthe standard microbroth dilution method according to CLSI M38-A2 guidelines.Sequencing analysis of the cyp51 genes was conducted in those isolates displayinghigh MICs values to itraconazole, voriconazole and/or posaconazole.Results: Among the environmental isolates, 33.3% of them showed high MIC valuesfor at least one triazole whereas 23.5% of the clinical isolates displayed high MICvalues for amphotericin B. Point mutations in the Cyp51C gene were recorded in mostenvironmental isolates with non-wild-type MIC values.Conclusions: Susceptibility differences among environmental A flavus isolates mightsuggest the possibility of native resistance to certain triazole antifungals used in theclinic. To the best of our knowledge, this is the first report of antifungal screening ofenvironmental strains of A flavus in soybean seeds and chickpea seeds from Argentinathat showed increased resistance to voriconazole and itraconazole in comparison toclinical strains.