Genetic Diversity of Dematiaceous Fungi Using Random Amplified Polymorphic DNA

Suh, Moo Kyu; Suh, Jin Chun; Kim, Jung Chul; Lee, Ho Chung

Abstract

BACKGROUND
There are three kinds of diseases caused by dematiaceous fungi: chromoblastomycosis, phaeohyphomycosis, and eumycotic mycetoma. The dematiaceous fungi have been identified and classified by morphological, biochemical and physiological tests. Recently molecular analysis has been introduced to the field of medical mycology. OBJECTIVE: We investigated the genetic diversity of dematiaceous fungi using random amplified polymorphic DNA (RAPD). METHODS: The dematiaceous fungal strains studied were eight clinical isolates of chromoblastomycosis and phaeohyphomycosis agents (3 strains of Fonsecaea pedrosoi, 2 strains of Exophiala dermatitidis, 1 strain of Exophiala jeanselmei, 1 strain of Phialophora verrucosa, 1 strain of Rhinocladiella aquaspersa) and 4 standard strains (F. pedrosoi IFM 4889, E. dermatitidis IFM 4828, P. verrucosa IFM 4928, R. aquaspersa IFM 4930). Total twelve strains of dematiaceous fungi were cultured on Sabouraud's dextrose broth and their DNA were extracted by bead-beating method. RESULTS: The optimal condition for PCR was template DNA 0.025 mg and annealing temperature 39 degrees C. The RAPD analysis using OPA 10 primer (5'-GTGATCGCAG-3') of Operon kit showed different patterns among dematiaceous fungi. But one clinical isolate of F. pedrosoi showed intra-specific variability. CONCLUSION: The RAPD analysis is considered a rapid and reliable method for identification and classification of dematiaceous fungi if the procedure is carefully standardized with adequate primer.