Serology of Neisseria gonorrhoeae. Characterization of rabbit hyperimmune antisera by line-rocket immunoelectrophoresis for use in coagglutination.

The co-agglutination (COA) and line-rocket immunoelectrophoresis (L-RIE) techniques were investigated for the serological classification of Neisseria gonorrhoeae. COA with absorbed sera was found to demonstrate "strain-specific" as well as cross-reacting antigens. The results were dependent on the immunizing, absorbing and agglutinating properties of a particular strain. Heated (100 degrees C) whole cells were found to be more reactive in the COA tests than untreated or formalin-fixed organisms. It was possible by L-RIE to compare the antigenic relationship between at least 20 strains in a single test run. This technique was applied on the 16 major outer membrane protein (MOMP) reference strains, which could then be divided into two separate groups with regard to cross-reacting antigens. Based on the findings by the L-RIE tests, selective absorptions of antibodies were performed for use in preparation of COA reagents. It was found that the reactions of these reagents with the MOMP reference strains could be assigned to three different antigenic classes. Reagents prepared for these classes are proposed as a basis for serological classification of Neisseria gonorrhoeae.