THE TYPHOCOLON BACILLI 181 



The toxin of the colon bacillus is within its body, 

 no extracellular poison being formed. If one inject the 

 dead organisms into an animal in sufficient number, 

 mucous membrane irritation, paralyses, and convul- 

 sions may occur. Living bacilli introduced into the 

 peritoneum cause peritonitis and septicemia, the 

 organisms entering the blood stream. An abscess will 

 usually result if they are brought under the skin. In 

 man colon bacilli seldom go beyond the mucous mem- 

 brane of the intestine because of the resistance offered 

 by that tissue. After death the organisms rapidly 

 invade the different organs of the body. Whenever 

 the resistance of the body is reduced an opportunity 

 is presented for the spread of these organisms. When 

 for any reason the colon bacillus gains in virulence or 

 the resistance of the intestinal wall decreases, there 

 arise inflammation of the mucous membrane of the 

 intestine, a swelling of Peyer's plaques comparable to 

 that seen in typhoid fever, and these changes permit 

 the bacteria to spread in the body. There may arise 

 inflammation of the gall-bladder, the pelvis of the 

 kidney, or abscesses in various parts of the body. 

 Cystitis may occur, which may be a part of a general 

 infection, descend from the kidney, or arise from 

 introduction of the organisms through the urethra. 

 An ascending infection from the bladder to the pelvis 

 of the kidney and on into the substance of the organ 

 is not an uncommon disease process. This frequently 

 occurs in pregnancy or after labor. The colon bacillus 

 is the commonest single organism to cause pyelitis. 



The inflammations of the gall-bladder and its pas- 

 sages and of the liver may arise either from introduction 



