Athlete's foot fungus Trichophyton mentagrophytes. Coloured Scanning Electron Micrograph (SEM) of the fungus Trichophyton mentagrophytes. This dermatophyte fungus causes human skin infections. It is an agent of athlete's foot (Tinea pedis) and scalp ringworm (Tinea capitus). Here, hyphal threads of the fungal mycelium can be seen. Trichophyton mentagrophytes has two varieties: interdigitale infects the feet; mentagrophytes inhabits skin of the scalp giving rise to round scaly lesions and itchy patches of hair loss, mainly in children. It is treated with anti-fungal drugs. Magnification x6600 (x1375 at 10cm wide) .