P034 : Distribution of Malassezia species in east Asian seborrheic dermatitis patients and analysis bioactivities of Malassezia species

Background: Malassezia species play an important role in the pathogenesis of seborrheic dermatitis. Previous studies demonstrated that M. globosa was considered to be the predominant organism in seborrheic dermatitis of westernpopulation. Objectives: This research was conducted to investigate the distribution of malassezia species on the scalp of seborrheic dermatitis patients in Korea and China using PCR-RFLP analysis. Methods: Swap samples from the scalp of 140 participants, including 120 Chinese population and 20 Korean population of seborrheic dermatitis were obtained. 26S rDNA PCR-RFLP was used to identify malassezia species. To compare the bioactivities of malassezia strains, we quantified the sebum lipid production and IL-8 cytokines from cultured human primary sebocytes and HaCaT keratinocytes stimulated by seborrheic dermatitis mimic in vitro system with five nonviable malassezia stratin extracts; M. globosa, M. restricta,M. sympodialis, M. dermatis, M. slooffiae. Results: M. resticta and M. globosa is the most frequently isolated species in both Korean and Chinese seborrheic dermatitis patients. The production of sebum lipid and IL-8 is most high in M. restricta and M. globosa among the five malassezia straines. Conclusion: Our results show that M. restricta and M. globosa are the main pathogen of seborrheic dermatitis in Korean and Chinese patients. In addition, the bioactivity producing sebum lipid and IL-8 is higher in both strains than other malassezia species.