Extracellular phospholipase activity of Malassezia strains isolated from individuals with and without dermatological disease

BACKGROUND: The Malassezia genus includes mainly lipophilic yeasts belonging to the cutaneous microbiota of man and other mammals. Some Malassezia species have been associated with various dermatological diseases. The factors permitting the transformation of yeasts of the Malassezia genus from a commensal organism to a pathogenic agent are still little known but the production of various enzymes such as lipase, phospholipase and lipoxygenase could contribute to the pathogenic activity of these yeasts. AIMS: Here we have determined and compared the extracellular phospholipase activity of sixty human isolates of Malassezia so as to relate this feature to the species of Malassezia and to the origin (from dermatological diseases or not) of the strains examined. METHODS: Phospholipase production was determined using the semi-quantitative egg-yolk plate method. RESULTS AND CONCLUSIONS: Malassezia obtusa, Malassezia slooffiae, Malassezia globosa, Malassezia restricta had difficulty developing in the chosen culture medium so that it was not possible to measure phospholipasic activity. Malassezia pachydermatis showed the highest phospholipase activity. Twenty-nine Malassezia sympodialis strains produced phospholipase; the isolates from patients with pityriasis versicolor had significantly higher phospholipasic activity than those isolated from healthy individuals. This observation suggests that the phospholipasic activity of Malassezia may play a role in the onset of skin lesions, especially in the case of pityriasis versicolor.