330 Suppuration 



especially at the temperature of the incubator. It has no distinctive 

 peculiarities. 



Pathogenesis. — The introduction of tuberculous sputum or of a 

 minute quantity of a pure culture of this coccus into white mice 

 usually causes a fatal bacteremia in which these organisms are found 

 in small numbers in the heart's blood, but are numerous in the 

 spleen, lungs, liver, and kidneys. 



Japanese mice and white mice are highly susceptible to the 

 organism and die three or four days after inoculation. 



House-mice, field-mice, and rabbits are comparatively immune. 

 Guinea-pigs may die of general septic infection, though local ab- 

 scesses result from subcutaneous inoculation. 



The tetracocci, when present, probably hasten the tissue-necrosis 









i. 'S- ri^ \ ■ 



Fig. no. — Bacillus pyocyaneus, from an agar-agar culture. X looo 

 (Itzerott and Niemann). 



in tuberculous cavities, aid in the formation of abscesses of the lung 

 and contribute to the production of the hectic fever. 

 ' An interesting contribution to the relationship of this coccus 

 to human pathology has been made by Lartigau,* who succeeded 

 in demostrating that the tetracoccus may be the cause of a pseudo- 

 membranous angina, 3 cases of which came under his observation. 

 Bezanfonf has isolated this organism from a case of meningitis. 

 ForneacaJ has reported a case of generalized tetragenous septicemia. 



Bacillus Pyocyaneus (Gessard) 



General Characteristics. — A minute, slender, actively motile, flagellated, non- 

 sporogenous, chromogenic and feebly pathogenic, aerobic or facultative anaerobic, 

 liquefying bacillus, staining by ordinary methods, but not by Gram's method. 



* "PhUa. Med. Jour.," April 22, 1899. 

 t " Semaine Medicale," 1898. 

 i "Riforma Medica," 1903. 



