Terbinafine susceptibility pattern of onychomycosis causative dermatophyte species and Scopulariopsis brevicaulis

CARRILLO MUÑOZ AJ; GIUSIANO G; CARDENES CD; HERNÁNDEZ-MOLINA JM; ERASO E; QUINDÓS G; GUARDIA C; RODRIGUEZ VJ; DEL VALLE O; GUARRO J

Venezuela, Caracas

Congreso; 6th Virtual Mycological Congress - Antifungal Antibiotics; 2007

By using a reference microdilution method, we have studied the antifungal susceptibility profile of terbinafine against 521 clinical isolates of seven species of dermatophytes, including four onychomycosis causative species and isolates of 5 Scopulariopsis brevicaulis. Results showed a high antifungal activity of terbinafine against all dermatophyte isolates (geometric MIC 0.026 ìg/ml; MIC50, 0.03 ìg/ml; and MIC90, 0.06 ìg/ml). Geometric mean MIC against onychomycosis causative dermatophyte species was better (0.024 ìg/ml) than the global MIC. Against S. brevicaulis, the in vitro activity of terbinafine was considerably lower (geometric mean MIC 1.38 ìg/ml) in comparison with dermatophytes (0.015 ìg/ml for T. rubrum; 0.017 ìg/ml for T. interdigitale; 0.024 ìg/ml for E. floccosum and 0.038 ìg/ml for T. mentagrophytes). Similar the terbinafine susceptibility patterns were found between the groups of isolates of T. interdigitale+T. rubrum and M. canis+M. gypseum+T.mentagrophtytes. This data confirm the high in vitro antifungal activity of terbinafine against dermatophytes, under standardized conditions. Nevertheless, a previously identification of aetiological agents to detect S. brevicaulis by the mycological laboratory, can be useful due to the different susceptibility pattern and the statistical differences to terbinafine in order to predict the antifungal activity of this drug.