Identification, Classification, and Phylogeny of the Pathogenic Species Exophiala jeanselmei and Related Species by Mitochondrial Cytochrome b Gene Analysis

Abstract

ABSTRACT We analyzed a 402-bp sequence of the mitochondrial cytochrome b gene of 34 strains of Exophiala jeanselmei and 16 strains representing 12 related species. The strains of E . jeanselmei were classified into 20 DNA types and 17 amino acid types. The differences between these strains were found in 1 to 60 nucleotides and 1 to 17 amino acids. On the basis of the identities and similarities of nucleotide and amino acid sequences, some strains were reidentified: i.e., two strains of E . jeanselmei var. hetermorpha and one strain of E . castellanii as E . dermatitidis (including the type strain), three strains of E . jeanselmei as E . jeanselmei var. lecanii-corni (including the type strain), three strains of E . jeanselmei as E . bergeri (including the type strain), seven strains of E . jeanselmei as E . pisciphila (including the type strain), seven strains of E . jeanselmei as E . jeanselmei var. jeanselmei (including the type strain), one strain of E . jeanselmei as Fonsecaea pedrosoi (including the type strain), and one strain of E . jeanselmei as E . spinifera (including the type strain). Some E . jeanselmei strains showed distinct nucleotide and amino acid sequences. The amino-acid-based UPGMA (unweighted pair group method with the arithmetic mean) tree exhibited nearly the same topology as those of the DNA-based trees obtained by neighbor joining, maximum parsimony, and maximum likelihood methods.