Molecular and quantitative analyses of Malassezia microflora on the skin of atopic dermatitis patients and genotyping of M. globosa DNA

Abstract

To elucidate the role of Malassezia species in atopic dermatitis (AD) requires investigation of the Malassezia microflora on the skin of AD patients. Previously, M. furfur was considered the dominant species in the microflora, however, this microorganism has been reclassified into five species and reanalysis of the microflora based on the current Malassezia taxonomy is therefore needed. Malassezia is more difficult to isolate and culture than other pathogenic yeasts such as Candida and Cryptococcus, making it difficult to elucidate the microflora of AD patients accurately. We developed a PCR-based non-culture method that does not require the use of isolation or culture techniques. Of the members of the genus Malassezia, M. globosa colonized the skin of both AD patients and healthy subjects more frequently than other Malassezia species. In addition, we found polymorphisms in the intergenic spacer 1 region of the M. globosa rRNA gene. The genotypes of the microorganisms obtained from AD patients were significantly different from those obtained from healthy subjects. We believe that a specific genotype of M. globosa is responsible for exacerbation of AD.