The Study of Causative Organisms Affecting Fungal Nail Perforation Test

Objective: To evaluate the capacity of dermatophytes, non-dermatophyte, and yeast to invade nails.Materials and Methods: Nine normal nails were clipped from healthy volunteers and sterilized in an autoclave. Each nail was inoculated with one of nine fungal species, including dermatophytes, non-dermatophyte (Neoscytalidium dimidiatum, N. dimidiatum), and yeast (Candida albicans, C. albicans) for two, four, and eight weeks at 26 °C. A positive result was determined by the presence of fungal hyphae or pseudohyphae penetrating the nail plate.Results: Fungal penetration increased with longer durations. At two weeks, Trichophyton mentagrophytes (T. mentagrophytes) variety mentagrophytes, Nannizzia gypsea, Microsporum canis, and N. dimidiatum showed positive nail perforation. At four weeks, T. mentagrophytes variety interdigitale also tested positive. The remaining fungi (Trichophyton rubrum, Trichophyton tonsurans, Epidermophyton floccosum, and C. albicans) demonstrated negative test results at eight weeks.Conclusion: This in vitro study confirmed the highly virulent dermatophytes can penetrate the nail plate in a short time. Furthermore, this study highlighted the significant virulence of N. dimidiatum in nail invasion