Comparison between serological classification and auxotyping in the analysis of Neisseria gonorrhoeae infections

Auxotyping and serological classification, using monoclonal antibodies, were performed on 730 gonococcal strains. These strains were isolated from 725 consecutive patients seen at the Venereal Outpatients Clinic at the Department of Dermatology, Södersjukhuset, Stockholm, during one year, up to April 1983. Strains from patients with repeated gonococcal infections were, besides auxotyping and serological classification, analysed with restriction endonuclease cleavage. The strains were distributed into 16 auxotypes, of which the eight most common accounted for 97.4% of all isolates. The same strains were distributed into 38 serovars, of which the eight most common accounted for 88.4% of all isolates. When the two methods were combined, 98 combinations of auxotypes and serovars were seen. The eight most common combinations included 60.0% of all strains. Correlations were found between auxotypes and serogroups as well as serovars. The serological classification gave a better resolution compared with auxotyping; however, when the two systems were combined the sensitivity was highly increased.