Mitochondrial DNA analysis of Exophiala spinifera

Restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA) was examined in 36 isolates of Exophiala spinifera (8 isolates from Brazil, 9 from China, 15 from Columbia, 1 from the United States and 2 from Venezuela). E. spinifera isolates displayed a high degree of mtDNA diversity in RFLP patterns and were clustered into six genetically heterogeneous groups (Group 1 through Group 6). Isolates of Group 2 including the type strain seemed to have a worldwide distribution. RFLP patterns of E. spinifera were also distinct from those of other dematiaceous fungi, such as E. jeanselmei, E. moniliae, E. dermatitidis, Fonsecaea pedrosoi, Cladosporium carrionii and Phialophora verrucosa. These results indicate that E. spinifera may be a taxonomic complex and that RFLP patterns will be useful in the identification, typing and epidemiology of the E. spinifera variants.