STUDIES ON THE PARASITIC FORMS OF TRICHOPHYTON RUBRUM ISOLATED FROM PATIENTS WITH GRANULOMA TRICHOPHYTICUM USING THE “AGAR‐IMPLANTATION METHOD”

Abstract

We studied the conversion of T. rubrum from hyphae to spherical cells using the agar‐implantation method. Thirteen cultures of T. rubrum were isolated from tinea superficialis and granuloma trichophyticum and they were implanted into the peritoneal cavities of ddY male mice. The cultures were divided into three groups according to their parasitic forms. The first group consisting of two cultures were isolated from tinea unguium and tinea pedis (hyperkeratotic type); they were destroyed in the peritoneal cavities of mice by the sixth week. The eight cultures in the second group were isolated from tinea cruris, tinea circinata and tinea pedis (vesicular type); they converted to spherical cells and survived for 16 weeks. The three cultures of the third group were isolated from granuloma trichophyticum; they survived and grew as hyphal forms in the peritoneal cavities of mice for over 26 weeks without spherical cell conversion. In conclusion, the parasitic forms of the three cultures isolated from granuloma trichophyticum differed from the cultures isolated from tinea superficialis.

Extensive and deep dermatophytosis caused by Trichophyton mentagrophytes var. Interdigitalis in an HIV‐1 positive patient

“…Mucocutaneous mycosis can be unusually severe and resistant to treatment. Trichophytic granuloma is a rare deep dermatophytosis usually caused by T. rubrum, 3 but no cases have been described in HIV‐positive patients to date.…”

A Giant Dermatophyte Abscess Caused by <I>Trichophyton rubrum</I> in an Immunocompromised Patient

“…According to Nishiyama et al 9) , fungal strains isolated from dermatophyte granuloma show higher levels of protease activity, despite the lower growth rate, than those isolated from tinea superficialis. This observation suggested that the fungi isolated from dermatophyte granuloma can survive and grow in the dermal environment despite morphological and functional changes, causing formation of a subcutaneous cyst.…”

A Patient with Cystic Granuloma Trichophyticum who Required Surgical Resection

“…Apart from the patient factor of being a "compromised host," the fungus factor has also been mentioned to explain why granuloma does not heal even when patients ingest an antifungal drug. In particular, Nishiyama et al cited morphological differences in Trichophyton rubrum species, which were isolated from both the superficial infection and granuloma trichophyticum according to the agar implementation method 4) . They reported that the strain isolated from granulomas neither weakened nor produced a spherical alteration and could sustain its hyphal form also in an adverse environment where keratin, which Trichophyton species normally require, was not available.…”