Molecular identification and antifungal susceptibility of clinically relevant and cryptic species of sections and .

sections and comprise clinically relevant and cryptic species that differ significantly in drug susceptibility, meaning that effective treatment depends on correct species identification. There are no comprehensive data for molecular identification and antifungal susceptibility testing (AFST) of clinically relevant and cryptic species of sections and as the main agents of invasive and non-invasive aspergillosis in Iran. We aimed to perform molecular identification and AFST of 213 clinical isolates belonging to sections and . Molecular identification of isolates was performed using sequencing of the β-tubulin gene and AFST was conducted according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 guidelines. The most common isolates in sections and were (110/113, 97.3 %) and (49/100, 49.0 %), respectively. A total of 62/213 (29.1 %) isolates belonging to cryptic species were identified; among them, was the most prevalent (49/62, 79.0%). and isolates that responded to the minimum inhibitory concentrations (MICs) of itraconazole above the epidemiological cutoff values were the most frequently detected: 8/110 (7.3 %) and 3/41 (7.3 %), respectively. In section , responded to amphotericin B at a high MIC (>16 µg mL) and in section , one of the three isolates responded to itraconazole at an MIC >16 µg ml. Interestingly, for all isolates, the MIC and MIC of itraconazole were both 16 µg ml. A considerable presence of and isolates showing non-wild-type responses to azoles in clinical cases of aspergillosis indicates the importance of classifying clinical isolates at the species level and performing antifungal susceptibility testing on the isolates, which would ensure appropriate treatment.