In vitro activity of six antifungal drugs against clinically important dermatophytes

Introduction and objective: Dermatophytosis is a common fungal disease which involves the keratinized tissue. Several antifungal agents can be used to manage these infections. Unfortunately, drug resistant can result in treatment failure. The disk diffusion in vitro assay is a simple method that can be used to evaluate antifungal susceptibility in dermatophytes. The main aim of this study was to evaluate the antifungal activity of six antifungal drugs against several fresh clinical dermatophyte Iranian isolates.

Materials and methods: Forty clinical dermatophytes were isolated from patients suspected of having active dermatophytosis. Paper disks containing terbinafine, griseofulvin, clotrimazole, miconazole, fluconazole and ketoconazole were used in the disk diffusion method to evaluate the in vitro activity of the antifungal agents by measuring the mean diameter of inhibition around the disks.

Results: The isolates belong to three genera and eight species as: Trichophyton mentagrophytes 13(32.5%), T. rubrum 8(20%), Epidermophyton floccosum 7(17.5%), T. violaceum 4(10%), Microsporum gypseum 3(7.5%), T. tonsurans 2(5%), T. verrucosum 2(5%), T. schoenleinii 1(2.5%), and an unknown dermatophyte 1(2.5%). No isolates were resistant to clotrimazole and miconazole.

Conclusion: This study revealed that clotrimazole, miconazole, terbinafine, and griseofulvin were the most ideal antifungal drugs for the treatment of dermatophytosis. Disk diffusion method is a simple and valuable method for the evaluation of antifungal susceptibility of dermatophytes.