STAPHYLOCOCCUS PYOGENES AUREUS 327 



Japanese mice, show considerable susceptibility. Guinea-pigs possess 

 a relatively higher resistance. 1 



Subcutaneous or intramuscular inoculation of a susceptible animal 

 usually results in the formation of a localized abscess with much pus 

 formation and eventual recovery. Intraperitoneal inoculation is more 

 often fatal. Intravenous inoculation of doses of 0.5 c.c., or more, of 

 fresh broth cultures of virulent staphylococci usually leads to pyemia 

 with the production of secondary abscesses, located chiefly in the kid- 

 neys and the heart and voluntary muscles, but not infrequently in 

 other organs as well. In the kidney they occur as small foci, situated 

 most often in the cortex, composed of a central, necrotic pus cavity, 

 surrounded by a zone of acute inflammatory exudation. Staphylo- 

 coccus lesions form histologically the typical, "acute abscess." Not 

 infrequently the pyemic condition is accompanied by suppurative 

 lesions in the joints. Intravenous injections of virulent staphylococci 

 preceded by injury to a bone is often followed by the development of 

 osteomyelitis. Mechanical or chemical injury of the heart valves 

 preceding intravascular staphylococcus inoculation may result in 

 localization of the infection on or about the heart valves, leading 

 to "malignant endocarditis." The pyemic conditions following staphy- 

 lococcus inoculation usually lead to chronic emaciation and death 

 after an interval dependent upon the relative virulence of the micro- 

 organism, the amount injected, and the resistance of the infected 

 subject. Large doses of unusually virulent cultures cause death within 

 twenty-four hours, or even less, without abscess formation. 



As above stated, the susceptibility of man to spontaneous staphy- 

 lococcus infection is decidedly more marked than is that of animals. 

 The form of infection most frequently observed is the common boil 

 or furuncle. As Garre, 2 Biidinger, 3 Schimmelbusch, 4 and others have 

 demonstrated by experiments upon their own bodies, energetic rubbing 

 of the skin with virulent staphylococcus cultures may often be followed 

 by the development of a furuncle. Subcutaneous inoculation of the 

 human subject invariably gives rise to an abscess. The pathological 

 lesions which may be produced in man by virulent staphylococci are 

 naturally of great variety, depending upon the mode of inoculation, and 



1 Terin, Ref. in Lubarsch und Ostertag, Ergebnisse, 1896; Lingelsheim, "Aetiol. 

 d. Staph. Inf.," etc., Wien, 1900. 



2 Garre, Beit. z. klin. Chir., x, 1893. 



3 Biidinger, Lubarsch und Ostertag, ErgebrtfipjB, etc., 1896. 

 * Schimmelbusch, Ref. by Biidinger. 



