Staphylococci Pyogenes Aureus et Albus 259 



filtered cultures provoke little local or general reaction in 

 animals, even when the staphylococcus is highly virulent. 



Pathogenesis. The virulent, golden staphylococcus is 

 a dangerous and often deadly organism. When introduced 

 subcutaneously, abscesses commonly result and not infre- 

 quently lead to a fatal generalization of the organisms. In 

 such cases the organisms may be cultivated from the stream- 

 ing blood, though the greater number collect in, and fre- 

 quently obstruct, the capillaries. In the lungs and spleen, 

 and still more frequently in the kidneys, infarcts are formed 

 by the bacterial emboli. The Malpighian tufts of the kid- 

 neys 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. Bockhart 

 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, 

 the staphylococcus be injected into the circulation, osteo- 

 myelitis may occur. Numerous observers have demon- 

 strated its presence in ulcerative endocarditis. Rodet has 

 been able to produce osteomyelitis without previous injury 

 to the bones; Rosenbach was able to produce ulcerative 

 endocarditis by injecting some of the Staphylococci into the 

 circulation in animals whose cardiac valves had been injured 

 by a sound passed into the carotid artery ; and Ribbert has 

 shown that the injection of cultures of the organism may 

 cause valvular lesions without preceding injury. 



