Serotypes among Lancefield-group G streptococci isolated in Nigeria.

Six serotypes were found among haemolytic streptococci of Lancefield-group G. Members of these types accounted for about one-third of the strains isolated from human infections and carriers in Nigeria. The type antigens were similar to the M-protein antigens of group-A streptococci in that they were associated with the ability of the streptococci to survive and multiply in fresh human blood unless specific antibody was present. It was also possible to demonstrate in these group-G streptococci and non-type-specific M-associated protein similar to that formed by M-positive strains of group-A streptococci.