Isolation, Phenotypic and Molecular Identification of Otomycosis Fungi, with their antifungal susceptibility profiles in Duhok, Iraqi Kurdistan Region

Otomycosis is a fungal infection with varying prevalence based on climate conditions. Common causal agents of fungi include Aspergillus and Candida. This study aims to identify common fungal species in Duhok Province patients and assess their susceptibility to antifungal medications using traditional and molecular methods. A study conducted in Duhok province investigated 121 patients with fungal otitis externa. Samples from the external ear canal were cultured, and fungal species were identified through PCR for genetic identification. Antifungal susceptibility was assessed using the disc diffusion method. Moulds were the most frequently isolated organisms, followed by yeasts. Aspergillus flavus (13.22%) was the predominant filamentous fungi species, followed by A. fumigatus (7.43%), A. tubingensis (4.95%), A. niger (4.95%), A. terreus (4.13%), and A. foetidus (0.82%). Candida parapsilosis (9.91%) was the most identified yeast, followed by Cyberlindnera fabianii (6.61%), C. albicans (1.65%) and Pichia manshurica (0.82%). Antifungal susceptibility testing showed that voriconazole was effective against most isolated species. All Aspergillus isolates were resistant to nystatin and fluconazole, except for one isolate of A. foetidus. Fluconazole showed intermediate sensitivity in C. albicans, C. parapsilosis, and Cy. fabianii, while P. manshurica exhibited resistance. Nystatin showed low activity against all tested yeast isolates. Aspergillus and Candida species were identified as the most prevalent pathogens. This study reports, for the first time in Iraq, the isolation of Aspergillus tubingensis, Cyberlindnera fabianii, and Pichia manshurica from clinical cases of otomycosis, in Iraq, with voriconazole being the most effective antifungal agent, emphasizing the importance of local resistance patterns and standardized testing methods.