348 Suppuration 



however, very variable both for the lower animals and for 

 man. The classical test for virulence is to inject T V c.c. of 

 a twenty-four-hour old bouillon culture into the ear vein of a 

 middle-sized rabbit. If of the ordinary virulence, the 

 organism should kill the rabbit in from four to eight days. 

 During this time the animal suffers from fever and wasting, 

 and when examined postmortem almost invariably shows 

 small abscesses in the kidneys and heart. In cases in which 

 the rabbits are highly susceptible or the cocci virulent, 

 purulent arthritis may be found. Highly virulent cultures 

 kill the animal in from one to two days, commonly by 

 occasioning endocarditis. 



When the cocci enter human beings subcutaneously, ab- 

 scesses commonly result, and occasionally lead to a fatal 

 generalization of the organisms. In such cases the organisms 

 may be cultivated from the streaming blood, though the 

 greater number collect in, and frequently obstruct, the capil- 

 laries. In the lungs and spleen, and still more frequently in 

 the kidneys, infarcts are formed by the bacterial emboli. 

 The Malpighian tufts of the kidneys are sometimes full of 

 cocci, and become the centers of small abscesses. 



The coccus is almost equally pathogenic for man and the 

 lower animals, though the fatal outcome of human infection 

 is more rare, possibly because of the conditions of infection. 

 It enters the human system through scratches, punctures, 

 or abrasions, and when virulent usually occasions an ab- 

 scess. Garre* applied the organism in pure culture to the 

 uninjured skin of his arm, and in four days developed a large 

 carbuncle, with a surrounding zone of furuncles. Bockhartf 

 suspended a small portion of an agar-agar culture in salt 

 solution, and scratched it gently into the deeper layer of the 

 skin with his finger-nail; a furuncle developed. Bumm 

 injected the coccus suspended in salt solution beneath his 

 skin and that of several other persons, and produced an 

 abscess in every case. 



Staphylococcus aureus is not only found in the great 

 majority of furuncles, carbuncles, abscesses, and other in- 

 flammatory diseases of the surface of the body, but also plays 

 an important role in a number of deeply seated diseases. 

 Becker and others obtained it from the pus of osteomyelitis, 

 demonstrating that if, after fracturing or crushing a bone, 



* "Fortschritte der Med.," 1885, No. 6. 



f "Monatschrift fur prakt. Dermatologie," 1887, iv, No. 10. 



