Infection with minute-colony-forming beta-haemolytic streptococci.

One hundred and thirty-one strains of minute-colony-forming beta-haemolytic streptococci were isolated during the course of routine investigations in clinical bacteriology. Each strain was examined for the presence of polysaccharide antigens of Lancefield's groups A, C, G, and F and characterized in detail as to biochemical and cultural features. On the results of these tests it is concluded that the strains should be placed in the species Streptococcus milleri. The clinical details relevant to the various strains are summarized according to the site of isolation, and their pathological significance is discussed.