Correlations among culture times,sugar composition and biological activities of Sporothrix schenckii antigens

Glycoproteins were isolated by ethanol precipitation, Con A-sepharose 4B and DEAE-sephadex A-50 chromatography from culture filtrates of Sporothrix schenckii ATCC 10268 at incubation periods of 2, 7, and 14 days, and their chemical and immunological properties investigated. Sugar composition of the isolated glycoproteins varied with time of culture, i.e. from mostly mannose on the 2nd day of culture to increasing amounts of rhamnose and small amounts of galactose in addition to mannose on the 7th and 14th day. The changes in sugar composition also were observed to be closely related to the growth morphology of the organisms. The isolated glycoproteins showed different serological reactivity in immunodiffusion tests against rabbit anti-S. schenckii antiserum. In addition, they showed varying degree of cross-reaction with rabbit anti Klebsiella pneumoniae K47, anti Cladosporium werneckii and anti Saccharomyces cerevisiae antisera. The immunodiffusion results correlate well with sugar composition and strongly suggest the possibility that rhamnose, galactose and mannose determinants participate in the serological reaction of S. schenckii. In delayed hypersensitivity skin tests in guinea pigs immunized with S. schenckii, only Con A-binding glycoproteins were reactive. These fractions also resembled each other in amino acid content. The results from the present work indicate that the immunochemical properties of S. schenckii glycoproteins vary with incubation period, and suggest the need for standardization of sporotrichin test antigens.