Panel of reference strains for evaluating serologic reagents used to identify gonococci

A panel of strains for evaluating Neisseria gonorrhoeae serologic reagents was developed. The strains selected for the panel were antigenically diverse and representative of strains isolated worldwide and had been isolated from a variety of anatomic sites. A few strains with characteristics that can cause problems in serologic tests were included. The panel of 52 gonococcal and 20 nongonococcal strains was used to evaluate two commercially produced kits with monoclonal antibody reagents, GonoGen and Phadebact, and one Phadebact kit with absorbed rabbit antiserum. The GonoGen reagent correctly identified all gonococcal strains and did not react with any of the nongonococcal strains. The Phadebact absorbed antiserum reagent correctly identified 47 of 48 gonococcal strains but reacted with 2 of the 20 nongonococcal strains. The Phadebact monoclonal antibody reagent correctly identified all of the gonococcal strains; however, it gave positive reactions with 8 and trace reactions with 4 of the 20 nongonococcal strains. In evaluating diagnostic reagents, clinical studies serve an important function but have limited value in that they usually involve only one lot of the reagent and the strains tested are representative of those isolated in a particular geographic area at a particular time. Thus, in a clinical study, a reagent or kit could be inadequately tested for both homologous and heterologous reactions. For use in evaluating serologic re-agents that identify Neisseria gonorrhoeae, we developed a panel of test strains selected from collections worldwide and with specific characteristics. We used these to determine the efficacy of three commercially produced kits for identifying gonococci. MATERIALS AND METHODS The strains selected for the test panel are listed in Tables 1, 2, and 3 and were obtained from the Neisseria Referenc