Lack of correlation between killing of gonococci by serum and antibodies directed against pili from strain 2686 of Neisseria gonorrhoeae.

In patients experiencing initial or repeated gonococcal infections there appeared to be little correlation between elevated levels of serum antibody to pili from Neisseria gonorrhoeae strain 2686 and the presence or absence of serum bactericidal activity against the patients' infecting isolates. Of eight patients who experienced their first gonococcal infection, four had elevated antipili antibody levels; all eight sera from patients who had repeated gonococcal infections had high antipili antibody levels. All the patients' sera were bactericidal for strain 2686 of N. gonorrhoeae.