CHAPTER VIII. 

 THE GENUS AUROCOCCUS. 



Pyogenic organisms, differing in morphology from the 

 streptococci, were recognized by Ogston (1880), before 

 the advent of the pure culture method, and called by him 

 Staphylococci. Rosenbach (1884) described two varie- 

 ties of the Staphylococcus pyogenes, which he named 

 var. aureus and var. albus, from the orange and white 

 color of their respective growth masses. Later, a third 

 type, producing a lemon yellow pigment, was recognized 

 by Passet (1885). The group of the staphylococci gen- 

 erally includes all cocci found on the surface of the body, 

 or in diseased conditions, which do not occur in chains, 

 and which produce a fairly abundant growth on media, 

 whether white, yellow, or orange. Organisms of this 

 general type are normally present in the respiratory and 

 intestinal tract of man, on the other exposed surfaces of 

 the body, and to a considerable depth in the skin. They 

 are the commonest forms associated with suppurative 

 processes, causing acne, carbuncle, abscesses, osteomye- 

 litis, endocarditis, and even puerperal infection and general 

 septicaemia. As secondary invaders, they cause serious 

 complications in such diseases as tuberculosis and the 

 exanthemata. 



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