Antagonistic Activity of Malassezia Spp. towards Other Clinically Signifi cant Yeast Genera

Antagonistic activity of Malassezia yeast towards clinically signifi cant yeast species was studied. Ten Malassezia strains exhibited this activity. M. furfur strain exhibited maximum activity and the least sensitivity to “foreign” metabolites. M. globosa proved to be the most sensitive and the least active. M. furfur metabolites exhibited pronounced activity towards 6 Basidiomycetes strains. This effect was signifi cantly higher in comparison with antagonistic activity towards 13 Ascomycetes species. Studies of a complex of M. furfur antagonistic metabolites showed that it has at least two components: thermolabile proteins with molecular weights of 33 and 35 kDa and a thermostable one, proteinase-resistant. In contrast to metabolites of many other yeast species, this substance is more effective against related Basidiomycetes microorganisms (Cryptococcus albicans), while antagonistic proteins are active mainly towards Ascomycetes, such as Candida albicans. It was found that mycocin-like activity of Malassezia is encoded by chromosomes, but not plasmids.