Classification of Neisseria meningitidis group B into distinct serotypes. I. Serological typing by a microbactericidal method.

Neisseria meningitidis group B was subdivided into a number of different serotypes. A sensitive microbactericidal assay procedure was developed, and, with this method, over 10 different serotypes were provisionally established. The method by which distinct serotype designations were assigned is described. Almost half of the strains examined thus far contained a common serotype antigen which was distinct from the grouping antigen. Differentiation of group B meningococci into distinct types will aid in epidemiological studies and in the selection of appropriate strains for vaccines against group B meningococci.