Drug Resistance Profiles of Aspergillus Species in Cases of Invasive Pulmonary Aspergillosis

Background: Invasive pulmonary aspergillosis (IPA) is a life-threatening fungal infection, particularly affecting immunocompromised individuals.The increasing emergence of antifungal resistance among Aspergillus species poses significant challenges to effective therapy, especially in regions with limited surveillance data.Objectives: To investigate the distribution of Aspergillus species isolated from IPA patients in Baghdad and evaluate their susceptibility patterns to commonly used antifungal agents.Methods: This cross-sectional study included 250 patients diagnosed with IPA at Medical City Hospital, Baghdad, between September 2024 and May 2025.Clinical diagnosis was confirmed through imaging, galactomannan, and (1,3)--D-glucan assays.Isolates were identified and tested for susceptibility to nine antifungal drugs, including triazoles, echinocandins, amphotericin B, and 5-fluorocytosine, using the Microorganism Identification and Antimicrobial Susceptibility Testing (ID&AST) System MA120 following Clinical and Laboratory Standards Institute (CLSI) guidelines.Results: Aspergillus flavus was the most prevalent species (58%), followed by A. fumigatus (30%), A. niger (8%), and A. terreus (4%).All isolates exhibited 100% resistance to fluconazole and 5-fluorocytosine.Moderate to high resistance was observed against triazoles (16.0-21.2%),echinocandins (56-58%), and amphotericin B (38%). A. flavus demonstrated the broadest resistance spectrum, whereas A. fumigatus retained better susceptibility to triazoles but showed emerging resistance. Conclusion:High levels of antifungal resistance in Aspergillus species, especially A. flavus, were revealed by this study, highlighting the rise of multidrug resistance.To treat IPA, it is critically important to implement new treatment approaches and routine susceptibility testing.