166 



STAPHYLOCOCCUS PYOGENES AUREUS. 

 Rosenbach (1884). 



GOLDEN PUS PRODUCING COCCUS. 



Origin. One of the most common organisms in pus 

 in about 80 per cent. Has been found on the surface of 

 the skin, in saliva, air, water, dust and soil. 



Form. Smail cocci, arranged in irregular groups; 

 may also grow single or lorm diplococoi. Size varies with 

 the medium. 



Motility. Has no motion. 



Sporulation. No spores observed. Possesses a high 

 degree of resistance to desiccation, heat, chemicals, etc. 



Anilin Dyes. Siains readily, also by Gram's 

 method. 



Growth. Is rapid. 



Plates. On (jelatin plates the colonies are round, with sharp smooth 

 borders, strongly granular and of a dark-brown or yellow color. The gelatin 

 is liquefied somewhat rapidly. On cigar the surface colonies are bright yellow 

 in color. 



Slich Cultures. In gelatin development takes places along the entire 

 line ol inoculation, forming a finger-shaped liquefaction. The growth settles 

 to the bottom as a yellowish deposit while the liquid above remains clouded 

 for some time. Peculiar acid odor. 



Streak Cultures. On ayar it forms a moist, glistening orange-yellow 

 covering. On potatoes the growth is excellent forming a thick, moist yellow 

 mass. The peculiar odor is also present. 



Bouillon. A slight cl'HUi permeates the liquid and eventually a yellow 

 sediment forms. 



Milk. Coagulation results and the casein is then slowly peptonized. 



Oxygen requirements. Is a facultative anaerobe. 

 Pigment formation depends on presence of oxygen. 



Temperature. Grows at ordinary temperature; best 

 at 39-37 0. 



Behavior to Gelatin. Liquefies rapidly. 



Attenuation. The virulence is rapidly decreased on 

 artificial media. 



Pathogenesis. Pure cultures applied to man pro- 

 duced suppuration and carbuncles. Subcutaneous appli- 

 cation in mice, rabbits, and guinea-pigs induces local ab- 

 scesses. Intraperitoneal and intravenous injections pro- 

 duce fatal results with formation of minute abscesses in 

 the different organs and tissues pyaemia. Intravenous in- 

 joction of potato cultures induces ulcerative endocarditis. 

 Osteomyelitis results when the bones of the leg are first 

 fractured. 



Infection. Usually through scratches and wounds. 

 May penetrate the uninjured skin. 



NOTE In suppuration other staphylococci may be found, as the S. 

 pyogenes albus and the 8. pyogenescitreus. These perhaps are less frequent 

 and less virulent. The cultural properties are nearly the same with the ex- 

 ception of the difference in pigment production. 



