Antifungal susceptibility of dermatophytes from racehorses in Japan

Background: Luliconazole (LCZ) is an imidazole antifungal medication that exhibits excellent activity against dermatophytes. As a topical cream and lotion (approved for human use), LCZ has demonstrated a broad spectrum of activity against human dermatophytoses. Objectives: This is the first study to investigate the in vitro susceptibility of clinical isolates from horse dermatophytoses to LCZ. Animals: No animals were used in this study. Methods and materials: In the present study, the in vitro susceptibilities of clinical isolates of dermatophytes to LCZ, clotrimazole (CTZ), miconazole (MCZ) and terbinafine (TRF) were investigated using the Clinical & Laboratory Standards Institute M38-A2 test. Results: The minimum inhibitory concentrations (MICs) for all 16 clinical isolates of Trichophyton equinum, Microsporum equinum/canis and M. gypseum for LCZ were <0.03 mg/L. The MICs of all isolates were <0.03–0.5 mg/L for CTZ, 0.03–16 mg/L for MCZ and <0.03–1 mg/L for TRF. Conclusions: LCZ demonstrated a broad spectrum of activity against clinical isolates from horse dermatophytoses. We consider that LCZ will become the primary antifungal agent for treating horse dermatophytosis.