Étude in vitro de la sensibilité au posaconazole de souches de Scytalidium spp. isolées de lésions superficielles

Abstract

Scytalidium spp. is a dematiaceous fungi that has been frequently reported from tropical to semi subtropical regions. We distinguish two pathogenic species: S. dimidiatum and S. hyalinum which is an homologous non-pigmented mutant of S. dimidiatum. This keratinophilic mold may produce superficial disease (skin, nails) indistinguishable from dermatophytes. In Martinique, this pseudodermatophyte could represent more than 50 % of onychomycosis. Contrary to dermatophytes, the clinical response of Scytalidium spp. are typically very poor and topical treatment or systemic agents ineffective. To evaluate the potential efficacy of the new antifungal agent posaconazole, we tested in vitro 12 clinical isolates of Scytalidium spp. (seven S. dimidiatum and five S. hyalinum) against posaconazole by Etest method. For the totality of the isolates, the minimum inhibitory concentrations (MICs) were low: MICs less or equal to 0.25 microg/ml (maximum MICs of 0.25 microg/ml for S. dimidiatum and 0.032 microg/ml for S. hyalinum). These in vitro efficacy suggest that the new agent posaconazole may be a future alternative treatment.