ANTIGENIC STRUCTURE OF THE OONOCOCCUS 547 



Complement Fixation. — Bruck (1906) was the first to study the presence of 

 immune bodies in artificially prepared gonococcal serum. He showed that the 

 injection of watery extracts of gonococci into rabbits called forth the production 

 of specific antibodies, which were detectable by the complement-fixation teat. 

 Vannod (1906) found the complement-fixation test to be more suitable than agglu- 

 tination for distinguishing between the gonococcus and the meningococcus, since 

 no group reaction was apparent. Watabiki (1910) was likewise able to distinguish 

 between these two organisms by the complement-fixation test. Teague and Torrey 

 (1907) showed that the serum of an animal immunized to one strain of gonococcus 

 might not cause fixation of complement when tested against another strain ; they 

 concluded that the gonococci formed a heterogeneous family. Martin (1911) found 

 both specific and group antibodies for the gonococcus and the meningococcus in 

 their corresponding sera. The work of Oliver (1929) and Price (1933) indicates the 

 existence of a group relationship between the gonococcus and certain other members 

 of the Neisseria group. Pearce (1915) divided her strains into 2 groups. 



Jotten (1921) found that the results of the complement-fixation test ran parallel 

 with the agglutination test ; by both he was able to place 20 out of 27 strains in 

 4 separate groups. A, B, C and D. Cook and Stafford (1921), on the other hand, 

 were unable by the complement-fixation test to obtain any evidence of grouping 

 amongst the gonococci. Thomsen and VoUmond (1921), though unable to classify 

 their strains by direct agglutination, succeeded by employing the complement- 

 fixation test, with previous absorption of the sera, in dividing 26 strains into 4 

 different groups, a, b, c and d. Of these, the group b strains were most toxic for 

 rabbits. 



Bactericidins, Opsonins. — Torrey (1908), who studied the bactericidins present 

 in normal and immune rabbit serum, found that gonococci varied in their suscep- 

 tibility to these bodies. His experiments indicated too that there was a parallelism 

 in the specificity of the results obtained by the complement-fixation and the 

 bactericidin tests, both of which demonstrated the heterogeneity of the gonococcus 

 group. The bactericidal action of the sera did not run parallel with the agglutination 

 results. Martin (1910) found that the normal serum of the guinea-pig, rabbit, 

 cat and man, was bactericidal to both gonococci and meningococci, though the 

 action of guinea-pig and of human serum was more marked with meningococci 

 than with gonococci. In immime sera the bactericidins were found to be relatively 

 specific ; an immune serum prepared against the meningococcus had but little effect 

 on the gonococcus, and vice versa. Jotten (1921), who divided the gonococci by 

 agglutination and complement fixation into 4 groups. A, B, C and D, found that 

 the strains of A and B groups were more resistant to the opsonins, tropins, and 

 bactericidins present in normal serum than were the strains of C and D groups. 

 This was correlated with the greater toxicity of the A and B groups to human beings. 



The serological study of the gonococci therefore shows that the group is not 

 absolutely homogeneous ; that there are certain sub-groups in it ; that these 

 sub-groups are not very clearly defined ; and that there is a close relation 

 between the gonococcus and the meningococcus. 



Later work, on the chemical fractionation of the gonococcus, by Boor and Miller 

 (1934, 1944) and Miller and Boor (1934) suggests that the gonococci contain poly- 

 saccharide and nucleoprotein substances shared in part by other members of the 

 Neisseria group (see also Stokinger et al. 1944). Casper (1937a, 6), who recognizes 

 two main antigenic types, has been able to separate a specific protein-free poly- 

 saccharide-like substance from each type, and to obtain type-specific allergic skin 

 reactions with them in human subjects suffering from gonorrhoea. 



