STAPHYLOCOCCIC INFECTION 163 



The old filtered cultures agglomerate and dissolve red blood cells. 

 Only in dilute or weak solutions is agglutination observable; in strong 

 solutions there is rapid or immediate hemolysis. The hemolytic agent 

 is most in evidence in cultures from six to ten days old. However, 

 this is variable and it may be more abundant in still older cultures. 

 Whether it is the same agent that acts on the white and red corpuscles 

 is not certainly known, but both effects are prevented by heating the 

 filtrate to 60 C. 



Both antileukocidin and antihemolysin are easily prepared by 

 repeated injections of small doses of filtered cultures of the staphylo- 

 coccus in animals. This is further evidence that these bodies are 

 toxins and should be classed among the ferments. 



Filtered cultures when injected into animals have injurious effects 

 on other cells. Hyalin casts are formed in the uriniferous tubules 

 and necrotic areas appear in the kidney cortex. The subcutaneous 

 tissue about the point of injection becomes indurated, the hairs over 

 it fall out and in some instances necrosis results. Some investigators 

 have observed similar changes in the intestinal mucosa and others 

 report degenerative changes in the central nervous system. It will 

 appear from these statements that the staphylococcus, living or dead, is 

 harmful to body cells. Whether the noxious constituents of filtered 

 cultures are to be considered as secretions of the cocci or as frag- 

 ments resulting from autolytic cleavage has not been definitely deter- 

 mined, though the prevalent opinion is in favor of the first alternative. 



It has long been known that amyloid degeneration results in man 

 after long-continued suppurative processes. This change has been 

 induced in animals by repeated small inoculations of living cultures 

 and by injection of dead cultures. 



Bail and his students have used the staphylococcus, as well as 

 other bacteria, in the study of their aggressins. A large amount of 

 an agar culture of a staphylococcus, whose virulence has been greatly 

 increased by passage through animals, is injected into the pleural 

 cavity of a rabbit. The exudate which is formed is drawn off and 

 found to contain cocci, dissolved red corpuscles and degenerated 

 leukocytes. This is freed from bacteria by centrifugation and then 

 it is found that some of the supernatant fluid plus less than a fatal 

 dose of the staphylococcus injected into a half-grown rabbit, kills it 



