DIPLOCOCCUS GONORRHCE^: 



383 



The gonococcus will develop sparsely under anaerobic conditions, 

 but has marked preference for aerobiosis. The optimum temperature 

 is 37.5 C. Growth ceases above 38.5 and below 30. 



Upon suitable media colonies appear as extremely delicate, grayish, 

 opalescent spots, at the end of twenty-four hours. The separate colo- 

 nies do not tend to confluence 

 and have slightly undulated 

 margins. Touched with a 

 platinum loop their consist- 

 ency is found to be slimy. In 

 fluid media, growth takes 

 place chiefly at the surface. 



Until recent years the 

 gonococci were regarded as a 

 compact group, within which 

 individual members, isolated 

 from different cases, were 

 identical in all respects. How- 

 ever, work done by Torrey, 1 

 and by Teague and Torrey, 2 

 has shown that immunologic- 

 ally gonococci can be divided FlG> 82 .-GoNococcus COLONY. Low power 

 into a number of different of magnification. (After Mallory and Wright.) 

 groups. The situation here is 



closely analogous to that which has developed in the case of the pneumo- 

 coccus group. By cross agglutinations and agglutinin absorption expe- 

 riments, Torrey has been able to show that gonococci fall into about 10 

 groups, A, B, C, G, K, L, N, O, Q, S, which are serologically separable one 

 from the other. The practical importance of this is that in all diagnostic 

 serum reactions, such as the complement-fixation test, it is necessary 

 to make a polyvalent antigen in which these various groups shall be 

 represented. Otherwise, of course, many cases would react negatively 

 if infected with a particular group which is not included in the antigen. 



Resistance. Recent cultures of gonococcus, if not transplanted, 

 usually die out within five or six days at incubator temperature. At 

 room temperature they die more rapidly. 



The resistance of the gonococcus to light and heat is slight. A tem- 

 perature of 41 to 42 kills it after a brief exposure. Complete drying 



1 Torrey, Jour, of Med. Research, 1907, xvi, 329. 



2 Teague and Torrey, Jour, of Med. Research, Dec., 1907, xvii, 223. 



