THE MENINGOCOCCUS GROUP 299 



O Q 3 O S ^ % 



Meningococcus + + 



Pseudomeningococcus + + 



Gonococcus + 



Micrococcus catarrhalis 



Diplococcus crassus 3 + + + + + + + 



Diplococcus flavus + + + 



Micrococcus pharyngis siccus . + + + 



Pigmented coccus I + + + + 



II. .-""'." ... : .'', . + + + 



" III. . . . . . + + 



Micrococcus cinereus 4 



It will be seen that the meningococcus produces acid in dextrose 

 and maltose. A differentiation between the gonococcus, Micrococcus 

 catarrhalis and the meningococcus can frequently be made by their 

 growths upon cultural media. The gonococcus grows poorly or not at 

 all upon blood serum (Loffler's), the meningococcus grows with mod- 

 erate rapidity upon it, and Micrococcus catarrhalis grows even upon 

 plain agar. 



The final diagnosis of the meningococcus depends upon its agglu- 

 tination with specific sera. Positive agglutination will take place in 

 dilutions of 1 to 500, even in 1 to 2000. Kutscher 5 has isolated strains 

 of the organism which failed to agglutinate (macroscopic method) at 

 37 C., but agglutinated typically at 55 C. This should be tried in 

 doubtful cases. 



Serological Diagnosis. Bettencourt 6 and Franca, 7 von Lingelsheim, 

 Elser and Huntoon 8 and others have shown that the sera of convales- 

 cent cases of cerebrospinal meningitis very frequently exhibit specific 

 agglutinins for the meningococcus. Of 593 tests, von Lingelsheim 

 found 24.1 per cent, positive during the first five days of the disease, 

 56.7 per cent, positive from the sixth to the tenth day. Normal sera 

 did not agglutinate with the organism in dilutions greater than 1 to 

 25; the sera of patients agglutinated in dilutions as high as 1 to 200. 

 Elser and Huntoon have obtained agglutination in dilutions as high 

 as 1 to 400. 



The method of complement-fixation has not been satisfactory in 

 the diagnosis of cerebrospinal meningitis. 9 



1 + = Gram-positive 2 + = acid produced 



- = Gram-negative - = no acid produced. 



3 Jaeger's meningococcus. 4 Micrococcus catarrhalis? 



5 Kolle and Wassermann, Handb. d. path. Mikroorganismen, I. Erganzbd., 1907, 518. 



6 Zeit. f. Hyg., 1904, xlvi, 463. 7 Klin. Jahrb., 1906, xv, Heft 2. 



8 Loc. cit. 



9 Von Lingelsheim XIV Cong, for Demog. and Hyg., Berlin, September, 1907. 



