Clinical profile and azole resistance in clinical and environmental isolates of Aspergillus flavus complex from Pakistan
DOI:
https://doi.org/10.61529/idjp.v35i3.490Abstract
Objective: To determine the azole susceptibility profile of Aspergillus flavus (A. flavus) complex isolates from clinical and environmental sources in Pakistan, where data on azole resistance are limited.
Materials and Methods: A cross-sectional study was conducted at Aga Khan Hospital, Karachi, from January 2020 to December 2022. A total of 225 A. flavus complex isolates (151 clinical and 74 environmental) were included. Minimum inhibitory concentrations (MICs) for voriconazole, itraconazole, and posaconazole were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Epidemiological cut-off values (ECVs) were used to identify non–wild-type (NWT) isolates. Clinical data were available for 94 patients.
Results: Invasive aspergillosis was the most common clinical presentation (67/94; 71%), predominantly affecting patients with COVID-19 (35/67). Overall mortality was 32%. One clinical isolate exhibited MICs above the ECV for all three azoles, while two additional clinical isolates showed elevated MICs to posaconazole only. Among environmental isolates, two demonstrated MICs exceeding the ECV for posaconazole. Overall, NWT isolates were identified in 1.98% of clinical and 2.7% of environmental samples.
Conclusion: Azole resistance in A. flavus complex remains uncommon in Pakistan; the detection of NWT isolates in both clinical and environmental settings underscores the importance of ongoing surveillance and molecular studies to better characterize resistance mechanisms.
Keywords: Antifungal susceptibility testing, Aspergillosis, Aspergillus flavus, Azoles, Drug resistance, Fungal, Epidemiological cut-off values, Pakistan
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