GROUP OF PYOGENIC COCCI. 
45 
The aureus is the most virulent of all staphylo¬ 
cocci. The infections caused by the staphylococci vary 
with the virulence of the organism and the resistance 
of the individual infected. The infection may be local 
like a boil or an abscess, or it may extend to involve 
large areas of tissue (cellulitis). 
General infections, septicemia, and pyemia are 
very often caused by these organisms. Malignant 
endocarditis and puerperal fever come under this head. 
They are usually the cause of infection in wounds, 
although there are other bacteria that may do this. It 
is to remove all bacteria, especially the pus-cocci 
coming in contact with the patient, that the precau¬ 
tions or technique of the operating-room is directed. 
Since the pus-cocci are so often found on the skin, 
careful washing and scrubbing of the hands followed 
by a disinfectant is employed to destroy them. It is 
important to remember that these precautions cannot 
be safely performed in a careless manner, as the pyo¬ 
genic cocci may be located in rather than on the skin. 
They are to some degree resistant to disinfectants, and 
require an exposure of at least ten minutes in a i: 1000 
solution of bichloride of mercury. 
The injury caused in infections by the staphylo¬ 
cocci is due almost wholly to the toxins in part set 
free and in part retained in their cell bodies and liber¬ 
ated in the dissolution after death. The toxins cause 
the formation of pus and also attack the red blood-cells, 
dissolving them (hemolysis). This explains the 
anemia that always accompanies these infections. 
