0 1987 The Pathological Society of Great Britain and Ireland Serological relationships between serotype- I I I Streptococcus sanguis and Lancefield group- H

Summary. Certain strains of Streptococcus sanguis and group-H streptococci have been shown to have similar physiological properties and serological specificities. Serological studies revealed that serotype-I11 S. sanguis shared a common antigen with the so-called “British ” group-H streptococci, but not with the “American” group-H streptococci. Serotype-I11 antigen was extracted in cold 5 % trichloroacetic acid from isolated cell walls of S. sanguis ATCC 10558, and purified chromatograph-ically. The purified serotype-I11 antigen consisted of neutral and amino sugars and some phosphorus, and was negatively charged. Hapten inhibition of the quantitative precipitin reaction between serotype-I11 antigen and antiserum indicated the strong possibility of a-glucosidic linkages being an immunodeterminant of the antigen