Abstract
Biological typing of the lipophilic yeast Malassezia furfur was attempted in taxonomical and epidemiological studies of this unique and medically important species. Forty strains of M. furfur comprising 12 cultures stocked in our laboratory and 28 fresh isolates from patients with pityriasis versicolor were used in this study. These strains were identified as M. furfur on the basis of lipid requirement, chromaticity with Diazonium Blue B test, positive urea hydrolysis and specific characters of the ubiquinone system. Based on the morphological characteristic of colonies grown on Dixon medium at 27°C for 10 days, the strains were grouped into 5 types, Types I, II, III, IV and V. Slide-agglutination test with the cells of each strain and antiserum generated by immunizing a rabbit with each representative strain of the 5 colonial types revealed that all the strains have a common antigen and a type-specific antigen. Types I-IV were clearly distinguished from Type V by theier ability to assimilate Tween 20-85, ammonium sulfate and sodium glutamate and theier susceptibility to two antifungal antibiotics, nikkomycin Z and blasticidin S. Additionally, electrophoretic analyses of the activities of 10 kinds of somatic enzymes extracted from growing M. furfur cells suggested the existence of several different groupsof strains in terms of alloenzymic pattern.
From these results, we are led to the possibility that M. furfur can be grouped into 5 morphological and serological types, with which some physiological characteristics were associated. The DNA typing of these different biological types is in progress.
