THE COLOX BACILLUS GROUP 243 



invade the tissues in which their toxins act, causing injury to the intes- 

 tinal tract. Thus in the case of ulceration in typhoid fever the colon 

 bacilli enter the blood, or in perforation produce peritonitis. In dying 

 conditions they at times pass through the intact mucous lining. In 

 the gall-bladder or urinary tract the spread of bacilli from the intestines 

 may cause disease. The virulence of the colon bacillus in endogenous 

 infection is usually somewhat increased over that which it possessed 

 when it was latent in the intestine. The specific serum reaction in the 

 body is a sign of infection, but great care has to be observed in deciding 

 that it is present, as group agglutinins also occur. Up to the present 

 time it is very difficult to state in any colon infection whether the 

 bacilli were previously present in the intestines or were derived from 

 outside. 



Colon Bacillus in Sepsis. In lesions of the intestinal mucous mem- 

 branes or in colon cystitis, pyelitis, or cholecystitis, there is frequently 

 just before death a terminal dissemination of the bacilli and conse- 

 quent septicaemia. Here special symptoms of intoxication may occur, 

 such as diarrhoea, changes in temperature, heart weakness, and hemor- 

 rhages. In most of these cases infection proceeds from the in^stines, 

 but in not a few from the wounded urethra or bladder. The colon 

 septicaemia is detected by blood cultures. At times very few bacilli 

 are found, and then the blood infection may be less important than 

 the local one. Cases occurring in typhoid and cholera are often observed, 

 especially in relapses in typhoid. In very young infants a malignant 

 septicaemia with tendency to hemorrhages is due to colon septicaemia. 

 An epidemic due to colon infection of water has been noted. Infection 

 through food and water are usually brought about by other closely 

 allied bacilli not belonging to the colon group. 



Colon Bacillus in Diarrhoea. Lesage, in 1898, stated that 25 per cent, 

 of 770 cases reported by him of breast-fed children were due to pure 

 colon infection, while the others were from mixed infection in which 

 thf meaning of the colon bacilli present was more doubtful. The 

 majority of bacteriologists are inclined to doubt that the typical colon 

 bacillus is an important etiological factor in the production of diarrhoea, 

 but believe that it is due rather to other, slightly different, micro-organ- 

 isms, colon-like in their characteristics. The reasons for this opinion 

 are given by Escherich and Pfaundler as follows: 



1. Animals are certainly affected by epidemic infections of bacteria 

 closely allied to the colon group e. g., diarrhoea of calves and cows, 

 hog-cholera, enteritis with ulceration in horses, etc. 



2. The histories of attacks of acute diarrhoea in men after eating 

 food of such infected animals, and the presence of the serum reaction 

 afterward. These bacteria are colon-like, though classed with the 

 enteritidis group. 



3. The diseases of typhoidal nature are due to the closely allied 

 paracolon or paratyphoid bacilli, and others are due to the dysentery 

 group, in which the inflammatory and necrotic process localizes itself 

 mostly in the lower colon and rectum. 



