COCCUS OF MENINGITIS I$I 



65C. and is easily destroyed by drying, and by light. It dies 

 out rapidly on artificial culture media. 



Cultures. Best isolated on neutral semi-solid ascitic fluid or 

 serum agar in a moist chamber. Growth is pale gray white 

 translucent moist separate colonies. On glycerine agar it grows, 

 sparingly as white viscid colonies; occasionally it develops on 

 potato ; thrives on blood serum, especially if smeared with blood, 

 and does not liquefy the serom. 



Habitat. It is found in the pus from the meninges, sputum, 

 and nasal mucus of persons afflicted with epidemic meningitis, or 

 spotted fever. It has been found in the mucous membranes of 

 healthy individuals, and these persons may be "carriers" of infec- 

 tion. After spinal puncture, it may be seen in the pus cells, and 

 the diagnosis of the disease can be made in this way. 



Virulence. It is scarcely virulent for lower animals. If given 

 by hypodermics into the pleura, or peritoneum, it produces death 

 in mice. Meningitis may be, in monkeys, produced by subdural 

 injection. 



Chemical Activities. Produces an endo-toxin but no soluble 

 toxin. It is not chromogenic. 



Agglutination is caused by immune serum and it is upon their 

 property that anti-sera are standardized. It has been discovered, 

 by means of this anti-body and by the failure of certain sera to do 

 good, that there are several types of meningococci of different 

 antigenic qualities. Anti-sera are made now with all available 

 varieties. 



Method of Infection. The infection atrium of the coccus is 

 not certainly known but most of the evidence points to the nasal 

 passages and cribriform plate to the subdural space. 



Specific Therapy is practicable; it has been discussed just above 

 and on page 76. 



There is another important Gram-negative diplococcus in the 

 nose called Micrococcus catarrhalis. It is differentiated from 

 the meningitis organism by its free growth on agar, its sugar reac- 



