Characterization of Malassezia species by means of phenotypic characteristics and detection of electrophoretic karyotypes by pulsed-field gel electrophoresis (PFGE)

A total of 220 isolates of the genus Malassezia obtained from affected skin of animals and humans were included in this study. The isolates were exami ned for their belonging to the known species Malassezia pachydermatis, Mala ssezia sympodialis, Malassezia furfur, Malassezia obtusa, Malassezia restri cta, Malassezia globosa and Malassezia slooffiae by means of phenotypic and biochemical characteristics as well as their ability to assimilate polyeth ylen(20)-sorbitan-esters (Tween 20, 40, 60, 80). The electrophoretic karyot ypes of all isolates were studied by pulsed-field gel electrophoresis. Of t he 220 Malassezia isolates examined, 217 were identified as M. pachydermati s and three were classified as M. sympodialis. Moreover, the proof of limit ed lipid-dependence of M. pachydermatis indicated that the commonly used cr iterion 'lipid-independence' is not sufficient to differentiate this specie s from the other known Malassezia species.