Genetic Relatedness between the Type Strain of Streptococcus anginosus and Minute-Colony-Forming Beta-Hemolytic Streptococci Carrying Different Lancefield Grouping Antigens

Abstract

The taxonomic relationships among Streptococcus anginosus type strain NCTC 10713, beta-hemolytic streptococci belonging to serological groups A, C, G, and F, and related organisms were determined by using deoxyribonucleic acid-deoxyribonucleic acid hybridization (S1 nuclease method), deoxyribonucleic acid base composition, and conventional biochemical tests. Minute-colony-forming beta-hemolytic streptococci which carry various Lancefield grouping antigens (antigens A, C, F, and G) or none of the known group antigens were closely related genetically and biochemically to the type strain of the S. anginosus, which carries group G antigen.