In vitro susceptibility patterns of clinically important Trichophyton and Epidermophyton species against nine antifungal drugs

Despite the common, worldwide, occurrence of dermatophytes, little information is available regarding susceptibility profiles against currently available and novel antifungal agents. A collection of sixty-eight clinical Trichophyton species and Epidermophyton floccosum were previously identified and verified to the species level by sequencing the internal transcribed spacer (ITS) regions of rDNA. MICs of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine and MECs of caspofungin and anidulafungin were performed based on CLSI M38-A2. The resulting MIC(90)s of all strains were, in increasing order, as follows: terbinafine (0.063mgl(-1)); posaconazole (1mgl(-1)); isavuconazole and anidulafungin (2mgl(-1)); itraconazole, voriconazole, amphotericin B, and caspofungin (4mgl(-1)) and fluconazole (>64mgl(-1)). These results confirm that terbinafine is an excellent agent for treatment of dermatophytosis due to T. rubrum, T. mentagrophytes, T. verrucosum, T. schoenleinii and E. floccosum. In addition, the new azoles POS and ISA are potentially useful antifungals to treat dermatophytosis. However, the clinical effectiveness of these novel antifungals remains to be determined.