COLON BACILLUS INFECTIONS. 467 



significance which was once attached to it. It has 

 been recognized that the colon bacillus in particu- 

 lar, and less commonly other intestinal organisms 

 may enter the circulation a short time before death, 

 at a time when resistance is very low, and may 

 obtain the general distribution which is so often 

 encountered at autopsy ; this is the so-called "ago- 

 nal invasion/' which may occur without much re- 

 gard to the primary cause of death. The condi- 

 tions which favor agonal invasion remain, to a 

 large extent, obscure. Distinct defects of the in- 

 testinal mucosa probably are not essential, al- 

 though this view has its representatives. In states 

 of low vitality in which resistance to infection is 

 decreased (disappearance of complement), the or- 

 ganisms find conditions favorable to proliferation 

 when they have once reached the circulation. In 

 spite of the low virulence of the colon bacillus, it 

 commonly has a certain amount of toxicity and it 

 may often be of significance even as an agonal in- 

 fection. 



Post-mortem invasion of adjacent structures, as 

 the gall bladder and liver through the biliary pas- 

 sages, and of the peritoneum through the intesti- 

 nal wall, also occurs. 



It has been shown that the colon bacillus occa- True 

 sionally causes the following conditions : Suppura- Infections - 

 tive cholecystitis which may extend to the liver, 

 peritonitis, septicemia, meningitis, cystitis, pyeli- 

 tis and ascending suppurative nephritis, and ab- 

 scesses in various organs, including suppurative 

 processes in the middle ear. In one or more in- 

 stances it has been thought that it caused vegeta- 

 tive endocarditis. Probably colon infections of the 

 gall bladder do not occur in the absence of biliary 



