Molecular ecology and pathogenic potential of Fonsecaea species

The genus Fonsecaea is revised on the basis of ribosomal DNA internal transcribed spacer (ITS) sequence data. Two species are recognized, F pedrosoi and the new defined F monophora. The distinction between these species does not correspond with the classical distinction of F pedrosoi and F compacta. The latter appears to be no more than a morphological variant. Both species recognized in this study are agents of human chromoblastomycosis; however, in F pedrosoi a strict association with this disease is noted, while F monophora is a more general opportunist. Subspecific randomly amplified polymorphic DNA (RAPD) typing revealed a high degree of strain diversity, although clonal reproduction is also likely to occur. Most strains with Fonsecaea-like morphology isolated from environments to which symptomatic human patients were exposed were found to be more closely related to species of Cladophialophora than to Fonsecaea.