Abstract
A group G streptococcal strain was coated with antibody against six different serotypes (Ia, Ib, II, III, IV, and V) of group B streptococci. The coagglutination patterns of 114 strains of group B streptococci were compared with the serotypes determined after immunoprecipitation. The specificity of the method was 100% and the sensitivity 97%. It was used for the typing of 89 invasive and 101 colonizing isolates. The new method is swift, specific, and highly sensitive. It consumes only minute amounts of antibody.