[Evaluation of the in vitro susceptibility pattern of clinical isolates of Trichophyton mentagrophytes and Trichophyton rubrum in Santiago, Chile]. / Evaluación del perfil de sensibilidad in vitro de aislamientos clínicos de Trichophyton mentagrophytes y Trichophyton rubrum en Santiago, Chile.

ABSTRACT

BACKGROUND: Dermatophytes are a group of keratinophilic fungi able to produce dermatophytosis or tinea infections. In Chile, Trichophyton rubrum and Trichophyton mentagrophytes are the ones most commonly isolated in adults, while Microsporum canis is found among children. Treatment of these infections is usually with topical or oral antifungals, such as griseofulvin or azole derivatives (clotrimazole, itraconazole, fluconazole), allylamines (terbinafine) or new drugs that are available. AIMS: Evaluation of the in vitro susceptibility of dermatophytes to five antifungal agents and the comparison of the susceptibility pattern with that of previous years. METHODS: Sixty-two clinical isolates of dermatophyte fungi were studied (March-June 2010). The CLSI M38-A2 micromethod was used. RESULTS: Fluconazole MIC values for T. rubrum and T. mentagrophytes varied between 0.25 and 1 µg/ml; MIC range to clotrimazole, terbinafine and itraconazole was 0.03-0.06 µg/ml, and MIC values for griseofulvin were 0.015-0.03 µg/ml. No statistically significant differences were found between susceptibility patterns, except for fluconazole. CONCLUSIONS: Fluconazole was less active in comparison with other drugs tested (0.25-1 µg/ml). None of the isolates were resistant to any of the drugs, and no changes in the susceptibility pattern were observed when comparing the results with data previously reported concerning dermatophytes in Chile.