THE MENINGOCOCCUS GROUP 



295 



not demonstrable in cultures of the organism. Acid, but no gas, is 

 produced with considerable regularity in dextrose and maltose broths; 1 

 other ordinary carbohydrates are unattacked. These fermentation 

 reactions are of considerable value in the cultural differentiation of 

 meningococci from other organisms which may readily be confused 

 with them. 



Toxins. Soluble exotoxins have never been demonstrated among 

 the products produced by the meningococcus; killed cultures of the 

 organism appear to be as fatal for ordinary experimental animals 

 as the living organisms. This would suggest that the toxic phenomenon 

 may be attributable to the liberation of endotoxins rather than to a 

 soluble toxin. 



FIG. 40. Meningococci from cerebrospinal fluid. X 1200. (Kolle and Hetsch.) 



Pathogenesis. The meningococcus possesses but feeble pathogenic 

 powers for guinea-pigs; all attempts to induce infection by subcuta- 

 neous injections, according to Councilman, Mallory and Wright, 2 

 were negative. Occasionally successful results were obtained from 

 intraperitoneal and intrapleural inoculation. A slight fibrinopurulent 

 exudate was found postmortem in the peritoneal or pleural cavities 

 in the fatal cases. Intracranial inoculations were uniformly negative. 

 One successful infection of a goat by spinal canal inoculation was 

 obtained by these observers; the animal died within twenty-four 

 hours, and autopsy revealed intense congestion of the meninges of 

 the cord and brain. A small amount of purulent spinal fluid was 



1 Kopetsky, Meningitis, The Laryngoscope, 1912, xxii, 797, has called attention to the 

 early disappearance of the reducible substance (dextrose?) normally present in the 

 spinal fluid in cerebrospinal meningitis. It is possible that the action of the organism 

 upon this substance explains the phenomenon. 



2 Loc. cit., p. 76. 



