Molecular analysis of malassezia microflora from patients with pityriasis versicolor.

BACKGROUND

Pityriasis versicolor (PV) is a superficial infection of the stratum corneum caused by Malassezia species. Eleven species have been identified within this genus, namely M. globosa, M. restricta, M. sympodialis, M. furfur, M. obtusa, M. slooffiae, M. pachydermatis, M. dermatis, M. japonica, M. yamatoensis, M. nana. M. furfur has long been identified as the causative fungus of PV. However, recent studies using the culture and isolation identified by morphological and physiological characteristics suggest that M. globosa is the causative agent of PV.

OBJECTIVES

The aim of this study was to examine the distribution of PV microorganisms with a molecular-based non-culture method.

PATIENTS

The subjects were 49 patients with PV (32 males, 17 females; 16-83 years old) who visited our outpatient clinic.

METHODS

Samples were taken from lesions for direct microscopy with methylene blue and detected Malassezia species without M. pachydermatis and M. nana using a non-culture-based method consisting of nested PCR with specific primers.

RESULTS

The most frequently isolated species were M. globosa and M. restricta (both 93.9%). Only M. globosa was detected from the lesion in which the mycelial form alone was observed microscopically, but M. restricta was not.

CONCLUSIONS

Our results suggest that M. globosa is the causative agent of PV.