Worldwide distribution of two new serotypes of group B streptococci: type IV and provisional type V

The candidates for new types proposed by the laboratories of H. W. Wilkinson, J. Jelínková, B. Perch, and S. Rabinowitz were antigenically compared and found to be distinct from the established types. On the other hand, identity between some of the candidates was found: three belonged to the new type IV and two shared the NT1 antigen. Strains with NT1 antigen were given the working label "provisional type V." A distribution study identified 102 type IV strains and 53 provisional type V strains among isolates from 15 countries.