Ultrastructural changes of Trichophyton rubrum in tinea unguium after itraconazole therapy in vivo observed using scanning electron microscopy

Abstract

Summary Background Tinea unguium is a dermatophyte infection of the nails. Itraconazole is a broad‐spectrum antifungal drug used to treat this disease. It works by interfering with the synthesis of ergosterol in the cell membrane, thus causing changes that can be seen under scanning electron microscopy (SEM). Aim To observe under SEM the in vivo ultrastructural changes of tinea unguium caused by Trichophyton rubrum before and after itraconazole (ICZ) therapy, and to explore the in vivo antifungal effect of ICZ. Methods Ten outpatients diagnosed by mycology and SEM as having with tinea unguium caused by T. rubrum were recruited. They received ICZ pulse therapy (200 mg twice/day for 1 week, stop for 3 weeks, repeated for 3–4 months). Clinical change, mycology and SEM results were obtained after therapy. Results After ICZ therapy, 3 of the 10 cases were positive by both mycology and SEM; the latter showed completely dry, shrivelled, curved and folded hyphae with a relatively smooth surface or local destruction. Several hyphae remained intact with only some local bumps or crimps. The other cases were negative by SEM, but two were positive by mycology. Conclusion In vivo ultrastructural changes of hyphae of T. rubrum in tinea unguium after ICZ treatment could be seen under SEM, demonstrating that ICZ fungistasis was effective and that SEM is a good tool for evaluating the effectiveness of ICZ in vivo. To our knowledge, this study is the first to show by SEM ICZ permeates the affected nail plate via the nail bed capillaries.

Ellagic Acid Inhibits Trichophyton rubrum Growth via Affecting Ergosterol Biosynthesis and Apoptotic Induction

“…On the basis of the published study on the effect of terbinafine on the morphology of Trichophyton rubrum, in our research, the morphological observations by SEM exhibited that treatment with EA and SK showed significant morphological changes, including hyphae appearing with rough and swollen surface, mycelium dry deformation and expansion, many fracture, visible surface peeling, mycelia rupture, mushy, and cell content overflow. e majority of T. rubrum hyphae were dry, shrivelled, curved, and folded (Figure 3) and in accordance with the previous report [26]. e shrinkage, flattening, bending, and twisting of the hyphae with wrinkled surface after application for 7 days were also identical to the morphological changes in hyphae cultured with luliconazole [27].…”

“…e results show that EA and SK are able to exert an efficient dose-dependent inhibitory activity on T. rubrum in vitro. Evidence-Based Complementary and Alternative Medicine Although a few researchers observed ultrastructural changes of Trichophyton rubrum after itraconazole therapy and terbinafine therapy observed using SEM [26], the structural changes of T. rubrum after EA and SK treatment in vitro have not been reported previously. On the basis of the published study on the effect of terbinafine on the morphology of Trichophyton rubrum, in our research, the morphological observations by SEM exhibited that treatment with EA and SK showed significant morphological changes, including hyphae appearing with rough and swollen surface, mycelium dry deformation and expansion, many fracture, visible surface peeling, mycelia rupture, mushy, and cell content overflow.…”