GONOCOCCUS 137 



Habitat. Widely distributed; found in dirty water, sewage, air, 

 dust of streets and houses; also upon the skin; normally present 

 in the mouth, nose, rectum, anterior urethra, vagina, and external 

 ears. 



Pathogenesis. In man it is the cause of carbuncles, abscesses, 

 osteomyelitis, septicaemia, puerperal infection, and any inflamma- 

 tion of the serous membranes. It causes acne and boils; can, and 

 does attack any tissue of the body. Endocarditis is a very grave 

 affection that is caused by this organism. It also plays an important 

 role in secondary infection, causing necrosis of previously infected 

 tissues (tubercles) and is active in small-pox and diphtheria. Ex- 

 perimental endocarditis has been produced in animals by injecting 

 it into the veins. By passage through animals it is rendered highly 

 virulent. In young, diabetic and anaemic subjects, its action is 

 often rapidly fatal. Its pathogenic action is often wide and disas- 

 trous. By growing it under anaerobic conditions its virulence may 

 be intensified, and the activity with which it liquefies gelatine is an 

 index of its malignancy. 



In man acne, boils, and carbuncles have followed the rubbing of 

 culture into the skin. 



Immunity. Thus far it has been impossible to produce any 

 marked immunity either by anti-toxic sera, or by culture, living or 

 dead, but the bacterins made from this germ have been used with 

 excellent results in all but the very aggravated and fulminating 

 affections caused by it. Bacterin treatment of acne and furunculo- 

 sis has established itself as most efficacious. 



There is a member of this group infesting the deep layers of the 

 skin called Micro, epidermidis albus. It is of feeble pathogenic 

 power, but may delay the healing of surgical wounds. 



GONOCOCCUS. 



Micrococcus Gonorrhoeas (Neisser). 



Diplococcus Gonorrhoea, commonly called the gonococcus. (Fig. 43.) 



