The serological classification of Neisseria gonorrhoeae. I. Isolation of the outer membrane complex responsible for serotypic specificity.

Abstract

Neisseria gonorrhoeae has been subdivided into several classes of serological distinct groups. The serotyping system is based upon the antigenic specificity of a protein serotype antigen. This protein is the major polypeptide of the outer membrane of the gonococcus and accounts for over 60% of that membrane's total protein. The serotype antigen complex was isolated by mild extraction of intact organisms in 200 mM lithium acetate buffer, pH 6.0 with 10 mM EDTA for 2 h at 45 degrees C. The extract was fractionated on Sepharose 6B and partially purified by precipitation at pH 4.2 by addition of 10% (vol/vol) acetic acid. Each serotype antigen has a unique subunit molecular size as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Preliminary typing of a gonococcal strain may be performed by comparative SDA-PAGE. To date, 16 different serotypes, representing a diverse distribution, have been isolated.

The Surface Properties of Neisseria gonorrhoeae: Isolation of the Major Components of the Outer Membrane

“…Indeed preliminary experiments indicate that these components are among the major antigenic determinants of the strain (P. Lambden, unpublished observations). Previous attempts at serological classification of gonococci have utilized LPS (Glynn & Ward, 1970), pili (Buchanan, 1975;Novotny & Turner, 1975) and a major outer membrane protein (Johnston et al, 1976)~ but several of these preparations were heterogeneous. The methods described here should allow production of purer antigens and perhaps extend the specificity of these tests.…”

“…Thus pilus preparations used in serological studies contained contaminating LPS (Novotny & Turner, I975), and although the outer membrane complex similarly used contained one major protein, significant amounts of LPS and a secondary protein were present (Johnston et al, 1976). For this reason our approach to the study of EDTA in 10 mM-Tris/HCl buffer, pH 7.0, were applied to a discontinuous gradient of 60 % to 20 "/o (w/w) sucrose solution and centrifuged at 250000 g for 18 h as described by Johnston & Gotschlich (1974).…”

“…A complex derived from the outer membrane has been used to subdivide gonococci into serologically distinct groups based on the antigenic specificity of a major outer membrane protein (Johnston, Holmes & Gotschlich, 1976). The outer membrane must also be involved in the firm adhesion between gonococci and host cells.…”

The Systematic Serology of Neisseria Gonorrhoeae: Antigens Associated with Pathogenesis in Neisseria Spp. from Man

“…The geographical distribution of the internal cell components in zone 2 amongst gonococci from local and international sources was clear. This class of antigen may prove a useful addition to current serotyping systems (Johnston et al, 1976;Danielsson and Sandstrom, 1979). In future studies, it will be important to identify responder rabbits for raising antisera because, in our series, only two of five animals produced high levels of antibody to the 2 complex, to the exclusion of several other precipitins.…”

“…Early work was compromised by the instability of the gonococcus in culture. Intracellular genus-specific antigens (Danielsson, 1965a), both surface (Johnston, Holmes and Gotschlich, 1976) and internal (Geizer, 1975) type-specific antigens and also surface-located subgeneric antigens (Johnston et al, 1976) have been described. Since about 1970 there have been great improvements in methods for the culture of 'stable gonococci of known infectivity (Kellogg et al, 1968) which may be considered antigenically "complete".…”