Staphylococcus Pyogenes Aureus, Rosenbach (1884). 



GOLDEN PUS PRODUCING COCCUS. 



Origin. — One of the most common organisms in pus — in about 80 

 per cent. Pound on the skin, in saliva, air, water, dust and soil. 



Form. — Small cocci, arranged in irregular groups (Fig. 10e,,p. 44); 

 may grow single or form diplococci. 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. — Stain readily; so does Gram's method. 



Growth. — Is rapid. 



Plates. — On gelatin plates the colonies are round, with sharp smooth borders, very 



franular and of a dark-brown or yellow color; The gelatin is liquefied somewhat rapidly, 

 'he yellowish colony lies in the center of a broad liquefied disc. On agar the surface colon- 

 ies are bright yellow in color. 



Stab culture. — \n gelatin development takes place along the entire line of inoculation, 

 forming a finger-shapecf liquefaction. The growth settles to the bottom as a yellowish 

 deposit while the liquid above remains clouded for some time. Peculiar acid odor. 



Streak culture. — On agar it forms a moist, glistening orange-yellow covering. On 

 jfotaio tlie growth is excellent, forming a thick, moist yellow mass. Peculiar odor present. 



Bouillon.— K slight cloud permeates the liquid and eventually a yellow sediment 

 iorms. Lactic and other acids develop. 



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



Oxygen requirements. — Is a facultative anaerobe. Pigment for- 

 mation depends on presence of oxygen. 



Temperature. — Grows at ordinary temperature: best at 30-37°. 



Behavior to gelatin. — Liquefies rapidly. 



Attenuation. — The virulence is rapidly decreased on artificial 

 media. The vitality is not decreased, even in very old cultures. 



Immunity. — Repeated injections of small doses of dead or living 

 ■cultures immunize. The serum of such animals seems to protect. 



Pathogenesis. — Pure cultures applied to the unbroken skin in 

 man produced' suppuration and carbuncles (p. 261). Subcutanebus ap- 

 plication in mice, rabbits, and guinea-pigs induces local abscesses. 

 Intraperitoneal and intravenous injections produce fatal results with 

 formation of minute abscesses in the different organs and tissues — 

 pyemia. Purulent peritonitis may result and the cocci are present 

 in the leucocytes in enormous numbers. The organism is present in 

 the blood as well as in the internal organs. Intravenous injection of 

 potato cultures induces ulcerative endocarditis. Osteomyelitis re- 

 sults when the bones of the leg are first fractured. It is especially 

 pathogenic for man. The virulence of the culture and the avenue of 

 infection are of great importance. The cells contain the active 

 toxin which is not destroyed by heat. This is seen in the fact that 

 sterilized cultures induce suppuration. 



The golden staphylococcus is by far the most common cause of 

 pus formation. It may occur alone, or may be associated with the 

 white or lemon staphylococcus, or with streptococci and other bac- 

 teria. It is, therefore, to be expected, as a rule, in acute abscesses 

 and boils; also in angina, , empyema, otitis and osteomyelitis Its 

 presence in endocarditis and pyemia has been referred to. 



Infection.— Usually through scratches and wounds. May pene- 

 trate the uninjured skin. 



Diagnosis. — A microscopical and cultural examination of the pus 

 will reveal the characteristic organism if present. In suspected 

 pyemia 2 c.c. of the blood may be plated (p. 364). 



In suppuration other staphylocodci may be found, as the S. pyo- 

 genes albus and the S. pyogenes citreus. These perhaps are less fre- 

 quent and less virulent. The cultural proijerties are practically the 

 same with the exception of the difference in pigment. 



366 



