SEROTYPE VARIATION IN STREPTOCOCCUS-ANGINOSUS, S-CONSTELLATUS AND STRONGYLOCENTROTUS-INTERMEDIUS

Various serotypes reported in three serotyping systems for the `Strept ococcus group, i.e., Ottens I-IV, Osano I-IV and serotypes a-k, were c ompared with each other in a capillary precipitation test and by the d ouble immunodiffusion test. Only two of the 19 serotypes, f and Ottens -III, were identical, and the other 17 serotypes were independent. Thu s, 18 serotypes and another three candidates (a-, b- and g-cross-react ive) were found in the 'S. milleri' group. Of the 248 strains tested, 197 were serotypable, and 23 strains carried two type antigens. Genera lly, the Ottens I, II, III (serotype f), IV and Osano IV antigens, oft en together with the Lancefield group F antigen, were found in S. angi nosus and S. constellatus. In addition, the serotype a, c, d, e and k antigens with the group A, C or G antigen were distributed in S. angin osus, the serotype b antigen in S. constellatus and the g, h, i, j, Os ano I, II and III antigens in S. intermedius. Twenty-five of the untyp able strains were Lancefield groupable (mostly F).