Species-specific extracellular antigen production by ascomycetous yeasts, detected by ELISA.

Abstract

In this study many yeasts produced heat-stable immunogenic extracellular polysaccharides (EPS). These antigens could be easily detected by competitive enzyme-linked immunosorbent assay (ELISA) or by sandwich ELISA. The antigens of most ascomycetous yeast species tested were almost all species-specific, but those of some basidiomycetous species gave cross reactions with many yeast species, ascomycetes included. Antigens related or similar to those produced by Saccharomyces cerevisiae were detected in culture liquids of 11 strains of the latter, of Kluyveromyces marxianus, of Zygosaccharomyces florentinus and in several samples of beer and wine, but not in culture liquids of 63 other ascomycetous yeast species, 5 Saccharomyces species included. The EPS ELISA of Saccharomyces exiguus gave positive reactions with culture liquids of Candida milleri, C. tropicalis, Hanseniaspora vineae, S. dairensis, S. exiguus, S. unisporus and Saccharomycodes ludwigii. The EPS ELISA of Hansenula wickerhamii gave positive reactions with H. henricii, H. wickerhamii and Pichia pinus, thus showing the relationship of these two genera. The EPS ELISA of Geotrichum candidum appeared to be genus-specific like that of filamentous moulds. In addition to several G. candidum strains, G. fermentans, G. klebahnii responded positively, as well as Candida blankii and C. hydrocarbofumarica. The EPS ELISA of Stephanoascus ciferrii was very specific. Except for 10 strains of this species, only Trichosporon terrestre gave a strong positive reaction in the competitive ELISA.