Serotypes of “Streptococcus milleri” Group

Abstract

“Streptococcus milleri” group are divided into 3 distinct species, Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius.1 Strains of the “S. milleri” group show wide serological variation on the basis of their cell surface carbohydrate antigens apart from the Lancefield group antigens A, C, F, G. Ottens and his colleagues have first demonstrated the occurrence of 5 carbohydrate type antigens, I to V, shared among “indifferent” streptococci of the Lancefield groups and non-groupable,2 and Osano et al. have reported that S. intermedius has 5 carbohydrate type antigens, I to V.3 We have demonstrated the presence of 11 serotypes, a to k, among “S. milleri” isolates from the mouth and systemic infections.4, 5 However, relationship between these serotypes in the three typing systems remains unknown.