Neisseria gonorrhoeae Recombinant Strains Expressing Hybrid Serological Reactivities of Outer Membrane Proteins IA and IB

Abstract

The inheritance of epitopes of protein I, the principal protein of the outer membrane of Neisseria gonorrhoeae, was investigated by DNA-mediated transformation. Protein I transformants were isolated by selection for the linked spectinomycin-resistance determinant. Twelve monoclonal antibodies used in coagglutination tests identified epitopes of the two forms of protein I (P.IA and P.IB). A given gonococcal culture from patients expresses epitopes of either P.IA or P.IB and rarely, if ever, exhibits hybrid P.IA/P.IB reactivities. Nevertheless, we found 35 P.IA/P.IB recombinants among 1506 transformants. Transmission by DNA of the hybrid reactivities and the apparent molecular mass characteristic of a given P.IA/P.IB species verified the genetic basis of the phenotypic changes. A recombinant that expressed six P.IA and two P.IB epitopes is of interest as a possible component of a gonococcal vaccine, because one or more of these epitopes are shared with 99.8% of a worldwide collection of 1858 clinical strains.