HEMOLYTIC STAPHYLOCOCCI 27 



work to include all the strains. No sharp difference in the ability of 

 the strains to fix complement was manifested, as the serums were 

 increased in dilution. 



It would seem, therefore, that staphylococci are able to fix comple- 

 ment in more or less the same degree. Further, the reaction is a 

 specific one for antigens prepared of streptococci and B. friedlander 

 were unable to prevent hemolysis. But no evidence is given of a 

 possible classification of staphylococci by complement fixation either in 

 a qualitative or quantitative way. 



This is not in the least surprising, however, when we recall that 

 complement fixation does not show divisions into groups with those 

 cocci which have been proved to be of different serologic types by 

 agglutination reactions. 



AGGLUTINATIONS 



The agglutination reactions of the staphylococci have been studied by sev- 

 eral investigators. Kolle and Otto L ' found that immunized serum distinguished 

 the pathogenic from the nonpathogenic forms. This was confirmed by Klop- 

 stock and Bockenheimer, 53a Van Durme, 3 Proscher, 54 Kutscher and Konrich, 22 

 Veiel, 55 Fraenkel and Baumann 58 and Montegazza. 49 Trincas " states that serum 

 prepared with hemolytic strains shows strong agglutination with hemolytic 

 strains, and slight agglutination with nonhemolytic strains ; and vice-versa. 

 Walker and Adkinson M found that an aureus immune serum would agglutinate 

 aureus and not albus strains ; and that an albus immune serum would agglu- 

 tinate albus and not aureus strains. 



Our object was to group staphylococci by agglutination into as 

 many serologic groups as would evidence themselves, without regard 

 to virulence or pigment. The same serums used in the complement- 

 fixation test were used for agglutination, and the same antigens also, 

 except that they were diluted until their turbidity equaled that of the 

 Dreyer standard for the typhoid group agglutinations. The agglutina- 

 tions were set up in serum dilutions of 1 : 10 and going as far as was 

 necessary to include the agglutination titer of the respective serums. 

 The serum dilutions and antigens were added in 0.5 c c amounts each, 

 and incubation was effected in a water bath at 56 C. for 16 hours. 



In table 12 the figures represent the dilution at which final agglutina- 

 tion was observed with naked eye. There was present in the serums a 

 proagglutinoid zone. 



An analysis of the table shows that serum Al agglutinates strains 

 Al, Fl, P2, S2, T2, T5, T8, T9, X, CIS, C16 and CIS. Serums AS, 



5311 Centr. f. Bakt., 1903, 34, p. 437. 



54 Arch. f. klin. Chir., 1903, 72, p. 325. 



55 Munchen. med. Wchnschr., 1904, 51, p. 13. 

 M Ibid., 1905, 52, p. 937. 



57 Biochem. Centralbl., 1908, 8, p. 609. 



58 Jour. Med. Res., 1917, 35, p. 373. 



