Serology of Neisseria gonorrhoeae. Demonstration of strain-specific antigens by immunoelectrophoresis, immunofluorescence and co-agglutination techniques.

Among a group of four selected strains of Neisseria gonorrhaeae, common and strain-specific antigens were demonstrated by immunoelectrophoresis, indirect immunofluorescence (IFL) and co-agglutination (COA). In preparations of ultrasonically-disrupted organisms, the strain-specific antigens appeared in crossed-line immunoelectrophoresis (C-LIE) with antigen containing intermediate agar gel as a two-peak precipitin line, one peak close to the antigen well, the other towards the anode. A similar pattern was found for each of the four strains studied. These strain-specific precipitin lines were also identified in rocket-line immunoelectrophoresis (R-LIE) tests, which were found useful for comparative studies. Using whole cells, strain-specific antigens were also demonstrated by COA and IFL tests with the use of cross-absorbed antibodies. The results corresponded to those obtained with C-LIE and R-LIE. Immunosorption experiments indicated identity between the strain-specific antigens shown by COA tests and those demonstrated by C-LIE and R-LIE tests.