In vitro susceptibility of chromoblastomycosis agents to five antifungal drugs and to the combination of terbinafine and amphotericin B.

Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissues caused by several genera of dematiaceous fungi. There is not a treatment of choice. Thus, tools that help guide clinical practice are fundamental. In this sense, antifungal activity tests in vitro could be useful. However, trials with chromoblastomycosis agents are scarce. The aim of this study was to evaluate both the in vitro susceptibility of 60 chromoblastomycosis agents to five antifungals and the combination of amphotericin B (AMB) and terbinafine (TRB). TRB, itraconazole (ITZ) and ketoconazole (KTZ) were, in this order, the drugs which showed better activity against the chromoblastomycosis agents. The less active drugs were voriconazole (VRZ) and AMB. The more differentiated group was Exophiala spinifera. Cladophialophora carrionii and Fonsecaea spp. are significantly more susceptible to KTZ than Phialophora verrucosa, whereas C. carrionii is significantly more sensitive to VRZ than P. verrucosa and E. spinifera. Assays in this direction allow the knowledge of the susceptibility of the causative agents which may help the management of patients with this disease. This study includes the largest number of these agents and of genera found in the literature.