Genotyping and Antifungal Susceptibility Testing of lt;i gt;Aspergillus flavus lt;/i gt; Isolated from Clinical Specimens

After Aspergillus fumigatus, A. flavusis the second leading cause of invasive and non-invasive aspergillosis. These fungi are of significant epidemiological importance in provinces with dry and hot climates. Objectives: In the present study, antifungal susceptibility testing (AFST) and genotyping of sixty-five A. flavusclinical isolates originating from patients in Mazandaran and Tehran were performed. Methods: Antifungal susceptibility testing of 65 clinical isolates of A. flavuswas conducted against amphotericin B (AMB), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), isavuconazole (ISA), luliconazole (LUL), lanoconazole (LAN), and 5-fluorocytosine according to the Clinical Laboratory Standards Institute (CLSI) method (M38-A2). The minimum inhibitory concentrations (MICs) were determined for each antifungal drug against all strains. Additionally, microsatellite typing using six variable number tandem repeat (VNTR) markers was performed to assess the genetic diversity and potential relationships among the clinical strains. Results: Luliconazole had the lowest geometric mean MIC (0.020 μg/mL), followed by LAN (0.021 μg/mL), POS (0.089 μg/mL), ISA (0.115 μg/mL), ITR (0.220 μg/mL), VOR (0.244 μg/mL), AMB (0.870 μg/mL), and 5-fluorocytosine (58.76 μg/mL). Microsatellite typing revealed sixty-five distinct sequence genotypes. Statistically, there was no significant relationship between genotypes and AFST profiles (P ≥ 0.05). Conclusions: Luliconazole and lanoconazole demonstrated the greatest in vitroactivity among all tested antifungals. However, most A. flavusstrains exhibited reduced sensitivity to AMB. Microsatellite genotyping indicated no genetic similarity among the clinical strains, revealing high genetic diversity among A. flavusisolates obtained from clinical samples.