Abstract
The type-specific antigens of the serotype i and g Streptococcus milleri were extracted with trichloroacetic acid from purified cell wall preparation of the strains K39K and K1K, respectively, and then purified by DEAE-Sephadex A-25 column followed by Sephadex G-100 column. The serotype i-specific antigen was composed of rhamnose, galactose, and glucose in a molar ratio of 1.6: 6.8: 1.0, and the serotype g-specific antigen consisted of rhamnose, galactose, glucose, and galactosamine in a molar ratio of 1.3: 3.8: 1.0: 2.5. The quantitative precipitin inhibition test with various haptenic sugars showed that galactose and its related carbohydrates were the effective inhibitors of the reaction between type i antigen and anti-i serum, and galactosamine was the most effective inhibitor of the reaction between type-g antigen and anti-g serum. The purified serotype i specific antigen contained a significant amount of phosphorus, and the serotype g specific antigen contained a trace of peptides. The Rantz-Randall extracts from all the 15 strains tested belonging to serotype i contained galactose, and those from the 6 serotype g strains had galactosamine. The results suggest that galactose and galactosamine are involved in the major immunodeterminants of the serotype i-specific antigen and serotype g antigen of oral S. milleri, respectively.
