Group C and Group G Streptococci

The Streptococcus milleri group (SMG) is a highly diverse group which includes three species: Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus. The group also includes hemolytic streptococci belonging to Lancefield group A, C, F or G as well as non-groupable and non-hemolytic streptococci. The nomenclature, identification and classification of Streptococcus milleri have been confusing. In 1989, it was proposed in the United States to rename this different group under one species name, Streptococcus anginosus, while in Great Britain the designation Strep. milleri was preferred. SMG is commensal organisms commonly isolated from mouth, oropharynx, gastrointestinal tract and vagina, but they can cause a variety of human and animal infections. The roles of group C streptococci in causing endemic pharyngitis are still controversial. This book provides data concerning phenotypic characterization of group C and G streptococci in patients with acute pharyngitis, their virulence and antibiotic resistance, and their role in causing pharyngitis among other groups of Streptococci.