A New Serological Group (E) of Neisseria meningitidis

Abstract
A new serological group of encapsulated N. meningitidis, tentatively classified as group E, produced halo precipitates with homologous antiserum. Group-specific complement-fixing antibodies were produced in rabbits by inoculation with lysed cells. The group E isolates are immunologically related to group C, as shown by precipitation and quantitative agglutination. Antisera to group E strains did not protect mice challenged with groups A, B, or C organisms. Until now, group E strains were not compared with the X, Y, and Z strains of Slaterus.