MICROCOCCUS TETRAGENUS 139 



Pathogenic Virulence. This organism does not infect any of 

 the lower animals. The " gonotoxin," if injected into small animals, 

 produces a doughy infiltrated area, which undergoes necrosis. It 

 has been found that filtrates of old cultures (sterile), if placed on 

 urethral mucous membranes, can produce suppuration. In man, 

 the organism causes a distressing disease (gonorrhoea), which may 

 become a dangerous one, ending even in death. It may produce vio- 

 lent inflammation of the urethra, vagina, uterus, fallopian tubes, 

 and the peritoneum. It frequently affects the conjunctiva? of the 

 newly born, and sometimes causes a pan-ophthalmia, which destroys 

 the sight. It is a common cause of suppurating arthritis gonor- 

 rhoeal rheumatism, endocarditis, pleuritis. In fact, any serous 

 membranes may be infected, and very serious results follow. Cysti- 

 tis caused by the gonococcus is sometimes followed by infection of 

 the kidneys. In the urethra, the cocci may burrow deep beneath 

 the epithelial cells, and set up a metaplasia, or abscess formation. 

 The purulent exudate is rich in phagocytes gorged with cocci, often 

 as many as 40 being found within a cell. 



Immunity. One infection does not confer immunity against 

 further infection. There is no reliable means of producing artifi- 

 cial immunity. However gonococcus bacterins are of some value 

 for chronic gonorrhoea. Torrey has been able to obtain from rabbits 

 an anti-serum of therapeutic value in gonorrhceal arthritis. 



MICROCOCCUS TETRAGENUS. 



Micrococcus Tetragenus. 



Morphology and Stains. Round or oval cocci; found in pairs; 

 more commonly in fours differing in size. In culture this form of 

 growth is apt to vary, and not to be characteristic. In sections of 

 human or animal tissues, tetrads only are found that are always 

 surrounded by a capsule which is stained easily by eosin. The 

 cocci are stained by Gram's method. It is not motile, and does not 

 form spores. 



