Use of RAPD (random amplified polymorphic DNA) to analyse genetic diversity of dematiaceous fungal pathogens.

Thirteen strains of chromoblastomycosis and phaeohyphomycosis etiologic agent fungi were obtained from different geographical origins. These strains were genotypically compared by means of the RAPD (Random Amplified Polymorphic DNA) technique. The data generated showed a high degree of polymorphism between distinct species and a low polymorphism between strains of the same species. The results generated by these tests were subjected to a numerical taxonomy analysis, using the unweighted pair-group method. A phenogram was constructed for the set of strains studied. Based on its structure, we concluded that genotypical data provide enough information to us to use the unweighted pair-group method to cluster the strains in accordance to their respective species. The phenogram grouped in a single branch the strains of Fonsecaea pedrosoi and F. compacta species, indicating a great similarity between these fungi, and suggesting that the classification as distinct species may not be appropriate for these species of the genus Fonsecaea.