Identification and in vitro antifungal susceptibility of dermatophyte species isolated from lesions of cutaneous dermatophytosis: A cross-sectional study

Abstract

The objectives of the study were to determine the in vitro susceptibility of dermatophyte species, isolated from the clinically diagnosed lesions of cutaneous dermatophytosis to fluconazole, and terbinafine. The skin scrapings from clinically diagnosed lesions of cutaneous dermatophytoses were cultured in Sabouraud dextrose agar to identify the causative dermatophyte. Antifungal susceptibility testing was performed using microbroth dilution assay. During the study period, 94 specimens from clinically diagnosed lesions of cutaneous dermatophytoses were received for fungal culture. Dermatophytes were identified as the causative agent in 44 specimens (Trichophyton rubrum was identified in 18/44 (40.9%), Trichophyton mentagrophytes in 17/44 (38.6%), Trichophyton interdigitale in 5/44 (11.4%), and Nannizia gypsea in 4/44 (9.1%) isolates). Minimum inhibitory concentration (MIC) of fluconazole was ≥64 µg/ml in 22.7% (10/44) and MIC of terbinafine was ≥0.5 µg/ml in 36.4% (16/44) of specimens. When compared to fluconazole, terbinafine showed a lower MIC 50 of 0.0019 µg/ml for Nannizia gypsea. Small sample size and lack of clinical correlation were the major limitations of the study. Antifungal susceptibility testing limited to fluconazole and terbinafine was another limitation of the study. Trichophyton rubrum was the most common isolate identified in culture of scrapings from clinically diagnosed lesions of cutaneous dermatophytosis. A rising trend in MIC values of isolates to terbinafine and fluconazole was observed.