Identification and pathogenicity of Malassezia species isolated from human healthy skin and with macules

Abstract

This study investigated the ocurrence of Malassezia species in clinically healthy students and with macules with a slight fawn discoloration and characterized the isolates as to the pathogenicity factors such as growth at 37oC, lipase, phospholipase and protease detection. Clinical samples were collected from different body sites of one hundred students of different ages and both sexes. The samples, obtained by scrapping the skin surface and the scalp, were treated with potassa and cultured. Cultures were obtained in Petri dishes containing Sabouraud agar medium added of olive oil, incubated at room temperature and at 37oC. Culture identifications were based in their morphological and physiological properties. Lipase, phospholipase and protease detection was performed in specific media on Petri dishes for formation of a zone. Globose, spherical yeast cells and hypha were investigated by direct microscopy of clinical materials. Malassezia furfur was detected in seven samples and M. sympodialis in four. All Malassezia cultures presented lipase activity, but none was phospholipase positive. Protease activity was observed in two M. furfur and two M. simpodialis isolates.