Molecular taxonomy and identification of pathogenic fungi based on DNA sequence analysis

Abstract

Although approximately 80,000 fungi are known, less than 1% are associated with human infection. However, their taxonomy has long been insufficient. During the last decade, DNA sequence analysis was introduced to the taxonomy of pathogenic fungi. Taxonomic advances in the field of medical mycology are helping to identify the causative agents of infectious diseases accurately, facilitating diagnosis and treatment. For example, Malassezia furfur was long considered the major microflora in atopic dermatitis, yet recent studies have indicated that this is not the case, as M. furfur is taxonomically heterogeneous and consists of five species. DNA sequence analysis resolved its taxonomic heterogeneity. Similar examples can be seen in "Candida albicans and C. dubliniensis" and "Trichosporon cutaneum and T. asahii". DNA sequence analysis also enables accurate identification of fungi. At present, almost all pathogenic fungi can be identified by determining the D1/D2 26S rDNA and ITS region of rRNA gene. This paper describes the practical taxonomy and identification of pathogenic fungi based on DNA sequence analysis.