Isolation, Molecular Identification, Virulence Factors, and Antifungal Susceptibility of Some Dermatophytes in Karbala, Iraq

Background: Dermatophytes are a group of keratinophilic fungi responsible for a wide range of superficial mycoses known as dermatophytosis This study aimed to isolate and identify dermatophytes from clinically infected patients in Karbala province, Iraq, and to assess their virulence factors and antifungal susceptibility profiles. Objectives: The aims of this study were isolation, molecular identification, virulence factors determination, and antifungal susceptibility of some dermatophytes in Karbala province, Iraq. Methodology: A total of 126 clinical samples were collected from infected skin, hair, and nail sites under the supervision of a dermatologist. Dermatophyte isolation was performed using Sabouraud Dextrose Agar (SDA), followed by morphological, microscopic, and molecular identification via PCR. A total of 43 isolates (34%) were confirmed as dermatophytes. Results: Among these, Microsporum canis was predominant (86%, n=37), while its teleomorphic (sexual) stage (Arthroderma otae) represented 14% (n=6). Virulence factors such as lipase, protease, phospholipase, keratinase, and hemolysins were investigated. Most isolates exhibited the ability to produce multiple virulence enzymes. Antifungal susceptibility testing revealed high sensitivity to clotrimazole, followed by itraconazole and ketoconazole, whereas fluconazole showed no inhibitory effect. Conclusions These findings offer insights into the prevalence, pathogenicity, and therapeutic responsiveness of local dermatophyte infections, contributing to the development of improved management strategies for dermatophytosis in the region.