RT Journal Article SR Electronic(1) A1 Inoue, M. A1 Eifuku-Koreeda, Hiroko A1 Kitada, K. A1 Takamatsu-Matsushita, Nobumi A1 Okada, Yasuko A1 Osano, E.YR 1998 T1 Serotype variation in Streptococcus anginosus, S. constellatus and S. intermedius JF Journal of Medical Microbiology, VO 47 IS 5 SP 435 OP 439 DO https://doi.org/10.1099/00222615-47-5-435 PB Microbiology Society, SN 1473-5644, AB Various serotypes reported in three serotyping systems for the ‘Streptococcus milleri’ group, i.e., Ottens I–IV, Osano I–IV and serotypes a–k, were compared with each other in a capillary precipitation test and by the double immunodiffusion test. Only two of the 19 serotypes, f and Ottens-III, were identical, and the other 17 serotypes were independent. Thus, 18 serotypes and another three candidates (a-, b- and g-cross-reactive) were found in the ‘S. milleri’ group. Of the 248 strains tested, 197 were serotypable, and 23 strains carried two type antigens. Generally, the Ottens I, II, III (serotype f), IV and Osano IV antigens, often together with the Lancefield group F antigen, were found in S. anginosus 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. anginosus, the serotype b antigen in S. constellatus and the g, h, i, j, Osano I, II and III antigens in S. intermedius. Twenty-five of the untypable strains were Lancefield groupable (mostly F)., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-47-5-435