An Escherichia Coli Antigen Cross-Reactive with the Capsular Polysaccharide of Haemophilus Influenzae Type b: Occurrence Among Known Serotypes, and Immunochemical and Biologic Properties of E. Coli Antisera Toward H. Influenzae Type b

摘要

An Escherichia coli antigen was shown to be cross-reactive with the capsular polysaccharide of Hemophilus influenzae type b. The cross-reactive antigen was identified as a thermostable, acidic, capsular polysaccharide consistent with its designation as E. coli “K” antigen (type A). Antibodies raised by intravenous injection of formaldehyde-treated E. coli possessing the cross-reactive antigen precipitated with the H. influenzae type b capsular polysaccharide and had “protective” activity against H. influenzae type b in biologic assays. The cross-reactive antigen was identified in E. coli with various O and H serotypes and did not appear to be associated with pathogenicity.