134 BACTERIA 



Cultures. 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 

 serum. 



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 sub-dural 

 injection. 



Chemical Activities. Produces an endo-toxin but no soluble 

 toxin. It is not chromogenic. 



Agglutination is caused by immune serum. 



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 sub-dural space. 



Specific Therapy. Flexner and Jobling have produced an anti- 

 serum for meningitis. It has anti-bacterial powers. Horses are 

 injected with bacterial suspensions until their serum possesses 

 curative properties. This anti-serum is injected directly into the 

 arachnoid space by lumbar puncture, after withdrawal of some 

 of the meningitic exudate. Little anti-serum will appear in the 

 cerebro-spinal fluid if it be injected subcutaneously. Therapeutic 

 results have been brilliant. 



There is another important Gram negative diplococcus in the 

 nose called Micrococcus catarrhalis. It is differentiated from 

 the meningitis organism by its free yellow growth on agar and 

 absence of active pathogenic properties. It is thought to have 

 some relation to acute coryza. 



