Failure of the fluorescent antibody reaction to identify penicillinase-producing gonococci

The fluorescent antibody test is now widely used to confirm the identity of Neisseria gonorrhoeae but may fail to identify penicillinase-producing strains (PPNG). This problem arises when conjugates are used that incorporate only gonococci that are not penicillinase-producers. We have shown that conjugates prepared from mixtures of PPNG and non-penicillinase producing gonococci give good fluorescent reactions. This difference in the reactions of PPNG strains is clearly related to their penicillinase-producing abilities, further study of the antigenic relation between penicillinase production and the antigenic structure of N gonorrhoeae is evidently required.