Comparative overview of Aspergillus fumigatus, A. flavus, and A. niger: Pathogenicity, resistance, and public health significance

Fungal diseases represent a major global health challenge, with Aspergillus species like A. fumigatus, A. flavus, and A. niger acting as key opportunistic pathogens. These fungi cause a spectrum of illness from allergy to life-threatening invasive aspergillosis in immunocompromised patients. This review synthesizes evidence (2000-2025) on their pathogenicity, resistance, and clinical impact, providing a comparative analysis of species-specific differences in conidial morphology, secondary metabolite production, and virulence factors such hydrophobins, galactosaminogalactan, melanin, siderophores, biofilms. The increasing threat of triazole resistance, fueled by environmental fungicide use and climate change, is critically examined. The review also summarizes the current antifungal therapies (polyenes, triazoles, echinocandins) and investigational drugs, highlighting the urgent need for improved surveillance, stewardship and diagnostics, particularly in low- and middle-income countries, to guide targeted management and reduce the global burden of aspergillosis.