Azole Resistance and CYP51A/B Mutations in Aspergillus Clinical Isolates Before and During the COVID-19 Pandemic: A Molecular Surveillance Study
Abstract
We conducted a cross-sectional study to (I) determine the relative frequency of antifungal-resistant Aspergillus clinical isolates, (II) address changes in susceptibility to available antifungals in patients infected with Aspergillus spp. with COVID-19, and (III) determine mutations in the CYP51A and CYP51B genes of Aspergillus spp. Isolated from the clinical specimens. A total of 30 fungal species were enrolled in the study. The antifungal activities of itraconazole and voriconazole were assessed using azole-containing agar media in Petri dishes. After identifying resistance in the isolates, the CYP51A and CYP51B gene regions were sequenced using the designed primers, and mutations were identified. To amplify CYP51A and CYP51B, primers with the specified sequences were used. Genomic DNA from 22 azole-resistant Aspergillus isolates was amplified using the CYP51-A and CYP51-B gene primers. 12/22 (54.54%) azole-resistant A. flavus isolates with the Tandem Repeat (TR34)/L98H (leucine-to-histidine substitution) mutation, MICs above the CLSI Epidemiological Cutoff Value. One carried the F46Y /TR34. 5/22 azole non-WT A. fumigatus isolates, CYP51-A analysis revealed that M220I, S297T/ TR34/L98H mutations, 4 A.orezea isolates had C498T/TR34 at a CYP51-B gene. Antifungal susceptibility testing should be performed when possible, and efficient systems must be implemented to monitor the evolution of newly introduced azole-resistant Aspergillus spp. In addition, these data are useful for clinicians to understand the incidence of azole resistance, enabling optimal management of affected patients and helping choose the right solution for infection management.