260 THE PYOGENIC COCCI 



under the finger nails and in the hair follicles in man, which makes 

 sterilization of the skin and hands difficult. 



Chemotaxis. The bodies of staphylococci appear to contain sub- 

 stances of unknown composition which attract leukocytes; the cell 

 substance of killed cocci injected in the cornea frequently causes an 

 accumulation of leukocytes in the anterior chamber of the eye 



hypopyon. 



Pathogenesis. Man. Ordinarily the organisms exist on the intact 

 surfaces of man as "opportunists," occasionally gaining entrance to 

 the underlying tissues through abrasions, chiefly in the skin, causing 

 localized abscesses, furuncles, or metastatic inflammations. Of the 

 metastatic inflammations, acute osteomyelitis and endocarditis are 

 the more common; less commonly generalized purulent pyemias 

 develop. It is assumed that metastatic pyemias are caused either by 

 direct invasion of the blood stream or less commonly by transmission 

 of staphylococci in leukocytes to remote parts of the body; there 

 they escape from the leukocytes and set up new foci of infection. 

 Suppurative pleurisy and pericarditis are not uncommon. The occur- 

 rence of furunculosis in diabetics is so frequent as to lead to the sup- 

 position that not only is the general average resistance to invasion by 

 staphylococci reduced in this disease, there may be a peculiar local 

 lack of resistance in the skin itself. Occasional individuals exhibit 

 a certain vulnerability to infection in particular regions; the neck 

 and buttocks are more frequently affected. One invasion appears to 

 predispose to subsequent infection. Staphylococci frequently are 

 secondary invaders in pulmonary tuberculosis, diphtheria and other 

 severe infections. Generally speaking, staphylococci cause acute 

 focal inflammations. Generalized infections of staphylococcus causa- 

 tion are relatively uncommon. Prolonged infections frequently result 

 in profound generalized symptoms; chills with intermittent fever are 

 the more common clinical signs. Parenchymatous or even amyloid 

 degeneration of certain glandular organs, notably the kidneys, is the 

 more common pathological lesion in such cases. 



Experimental Reproduction of Lesions. A satisfactory explanation 

 of the pathogenesis of staphylococci for man is not available. Neither 

 the staphylolysin nor the leukocidin appears to play a prominent part 

 in the morbid process. There is little definite evidence that the cell 

 substance of the organisms themselves is the important factor. Never- 

 theless, the etiological relationship of staphylococci to furunculosis 



