Activity of terbinafine on Trichophyton mentagrophytes in a human living skin equivalent model

Germination of arthroconidia of Trichophyton mentagrophytes in the presence of the allylamine antifungal terbinafine was assessed utilizing a human living skin equivalent model. Arthroconidia were inoculated onto the skin-equivalent previously exposed to low concentrations of terbinafine (0.01-1.0 mg l-1) and then incubated at 28 degrees C for 7 days. An assessment of fungal growth inhibition was made by light and scanning electron microscopy. In the absence of terbinafine, adherence, germination and hyphal extension were observed. Penetration of the model was seen, with hyphae present in the dermal component. In the presence of terbinafine, inhibition of fungal growth was apparent and the drug was seen to act as a barrier against fungal invasion of the dermis. The data indicate that the living skin equivalent model is a promising in vitro system for evaluating new antifungal agents.