Species identification of Wickerhamomyces anomalus and related taxa using ß-tubulin (ß-tub) DNA barcode marker.

ABSTRACT

Wickerhamomyces anomalus is used in food and feed processing, although the species has been reported as an opportunistic human pathogen, predominantly in neonates. Neither phenotypic nor the most frequently applied genotypic marker (D1/D2 LSU ribosomal DNA) provide sufficient resolution for accurate identification of this yeast. In this study, the ß-tubulin gene was used for species identification by direct DNA sequencing and as marker in a species-specific PCR assay. The results showed that all examined W. anomalus strains were clearly distinguished from the closely related species by comparative sequence analysis of the ß-tubulin gene. In addition, the species-specific primers were also developed based on the ß-tubulin gene, which was employed for polymerase chain reaction with the template DNA of Wickerhamomyces strains. A single 218 bp species-specific band was found only in W. anomalus. Our data indicate that the phylogenetic relationships between these strains are easily resolved by sequencing of the ß-tubulin gene and combined with species-specific PCR assay.