Immunochemical Similarity Between Polysaccharide Antigens of Escherichia Coli 07:K1(L):NM and Group B Neisseria Meningitidis

Abstract

Abstract Polysaccharide antigens from Escherichia coli 07:K1(L):NM and group B Neisseria meningitidis have been isolated and purified. Like the meningococcal group B polysaccharide, the sialic acid antigen from E. coli was acidic in nature, was susceptible to neuraminidase degradation and lacked O-acetyl groups. Immunologically these two polysaccharides were indistinguishable in assays of hemagglutination inhibition and they produced lines of identity by immunodiffusion. Investigation of the immunogenicity of the E. coli polysaccharide showed that it induced antibody in rabbits after multiple injections but not in human volunteers given one or two injections of 50 µg each.