Model systems for the study of dermatophyte and non-dermatophyte invasion of human keratin

Both dermatophyte and non-dermatophyte fungi can colonise and invade the keratin of skin, nail and hair. The fungal morphological forms that adhere to these keratinaceous substrates are most probably arthroconidia and hyphal fragments in association with exfoliated corneocytes. Towards a greater understanding of the ability of fungi to utilise keratin we have developed a series of experimetal models to stimulate the invasion of the stratum corneum, the human nail and the hair follicle. In many respects the mode of invasion mimicked human disease. The models were used to determine the bioavailability of terbinafine in keratinous substrata. Terbinafine prevented invasion of keratin by Trichophyton mentagrophytes. These models appear to be very suitable for the study of the mode of action of antifungal drugs used in the treatment of dermatomycoses.