SCHIZOPHYTA— SCHIZOMYCETRS 



173 



isease. The organism itself may or may not gain entrance into the circula- 

 on or organs. 



Immunity. .A^s before stated, anti-toxins are not developed. Agglutinins, 

 Dwever, are developed. 



Bacillus typhosus, Zopf 



Disease produced. Typhoid fever. 



Animals infected. Man. Inoculation of experimental animals usually 

 sgative, except when injected in considerable quantities. 



Fig. 29. Typhoid fever bacillus. (Bacillus typhosus). 

 Section from spleen showing bacteria clustered in center. 

 After Flugge. 



Pathogenesis. The organism invades the solitary lymph nodes and Peyer's 

 itches in the intestine and produces more or less necrosis and sloughing of 

 5sue. By means of the lymphatic channels, the internal organs are all infected, 

 irticularly the spleen which becomes very much enlarged. The bacilli invade 

 le blood, and hence the disease is a true bacteremia. When they lodge in bony 

 5sues, osteitis, periosteitis, and osteomyelitis may be produced. 



Poisonous properties. No soluble toxin has been discovered, an endotoxin, 

 )wever, is present and may be secured through self digestion in cultures, or by 

 inding and extracting the bodies of the bacteria. 



Immunity. No true anti-toxin serum has been produced, inasmuch as no 

 xin has been discovered. The blood serum of typhoid patients agglutinates 

 e bacteria. Vaccination with killed cultures produces an immunity which lasts 

 obably in most cases several years. The blood serum of animals immunizes 

 [ainst typhoid bacilli, but is not used because it is quickly throvim out of the 

 stem when injected, and because it possesses very little curative quality. 



