SPECIFIC INFECTIOUS DISEASES PRODUCED BY COCCI 219 



Milk is not changed. Frequent transfers are necessary to the 

 preservation of cultures in artificial media. 



Physiology. The meningococcus is killed almost immediately 

 by desiccation. In culture-media autolysis rapidly occurs, and 

 the organism soon disappears. No acids are produced in carbo- 

 hydrate media. Proteolytic enzymes are not produced. 



Pathogenesis. The meningococcus does not readily infect 

 common laboratory animals unless intraperitoneal injections of 

 comparatively large amounts of the culture be used. Even in 



Fig. 93. Micrococcus meningitidis in a preparation of pus from a brain abscess. 

 Note that the organism is generally intracellular (Flexner). 



this case the result seems to arise from the absorption of the toxic 

 products, rather than from an invasion of the tissues. Injection 

 of pure cultures into the spinal cavity of the goat has been found 

 to produce meningitis, and inoculation into the monkey has 

 resulted practically in a duplication of the disease as it occurs in 

 man. The relationship of the organism to the disease is, therefore, 

 well demonstrated. 



The disease is an acute inflammation of the meninges, accom- 

 panied by a purulent exudate. The organism sometimes, though 



