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 examined for their belonging to the known species Malassezia pachydermatis, Malassezia sympodialis, Malassezia furfur, Malassezia obtusa, Malassezia restricta, Malassezia globosa and Malassezia slooffiae by means of phenotypic and biochemical characteristics as well as their ability to assimilate polyethylen(20)-sorbitan-esters (Tween 20, 40, 60, 80). The electrophoretic karyotypes of all isolates were studied by pulsed-field gel electrophoresis. Of the 220 Malassezia isolates examined, 217 were identified as M. pachydermatis and three were classified as M. sympodialis. Moreover, the proof of limited lipid-dependence of M. pachydermatis indicated that the commonly used criterion 'lipid-independence' is not sufficient to differentiate this species from the other known Malassezia species.