CHAPTER XXVI. 



THE PRODUCERS OF ABSCESS, CELLULITIS, SEPTI- 

 CAEMIA, ETC. 



THE STAPHYLOCOCCI. THE MICROCOCCUS 

 TETRAGENUS. 



The Staphylococcus Pyogenes Aureus. (The Golden 

 Staphylococcus.) 



THE Staphylococcus pyogenes aureus is one of the 

 commonest pathogenic bacteria, being almost every- 

 where present, and is the organism most frequently 

 concerned in the production of acute, circumscribed, 

 suppurative inflammations. It was first observed by 

 Ogston (1881) in the pus of acute abscesses, but was 

 not obtained by him in pure culture. It was isolated 

 from the pus of acute abscesses and accurately described 

 by Rosenbach (1884). 



Morphology. Small, spherical cells, having a diameter 

 of 0.87/y. (Passet), occurring solitary, in pairs as diplo- 

 cocci, in short chains of three or four elements, or in 

 groups of four, but most commonly in irregular masses, 

 simulating clusters of grapes ; hence the name staphylo- 

 COOGUS. (See Fig. 59.) 



It stains quickly in aqueous solutions of the basic 

 aniline colors. When previously stained with methyl- 

 violet it is not decolorized by Gram's method. 



Biology. The Staphylococcus pyogenes aureus is an 

 aerobic, facultative anaerobic, liquefying micrococcus, 



