522 Bacilli Resembling the Typhoid Bacillus 



reach the neighborhood of the colon, and by that time the tryptic 

 peptones have been formed and absorbed to a great extent. 



"During the process of inflammation in the digestive tract a very 

 different condition may exist. The peptic and tryptic enzymes may 

 be partially suppressed. Fermentation of carbohydrates and proteid 

 foods then begins in the stomach, and continues after the mass of 

 food is passed on into the intestine. The colon bacillus cannot, there- 

 fore, spend its force upon fermentation of sugars, because they are 

 already broken up and an alkaline fermentation of the proteids is in 

 progress. It also cannot form peptones from the original proteids, 

 for it does not possess this property, and unless trypsin is present it 

 must be dependent upon the proteolytic activity of other bacteria for 

 a suitable form of proteid food. Perhaps these bacteria form an albu- 

 minate molecule which, like leucin and tyrosin, cannot be broken up 

 into indol, and thus there might be caused an important modification 

 of the metabolism of the colon bacillus, which might have either an 

 immediate or remote influence upon its acquisition of disease-producing 

 properties, for our own experiments indicate that the power to form 

 indol, and the actual forming of it, are to some extent an indication 

 of the possession of pathogenesis." 



For the laboratory animals the colon bacillus is patho- 

 genic in varying degree. Intraperitoneal injections into 

 mice cause death in from one to eight days if the culture be 

 virulent. Guinea-pigs and rabbits also succumb to intra- 

 peritoneal and intravenous injection. Subcutaneous injec- 

 tions are of less effect, and in rabbits seem to produce 

 abscesses only. 



When injected into the abdominal cavity, the bacilli 

 set up a sero-fibrinous or purulent peritonitis, and are very 

 numerous in the abdominal fluids. 



Cumston,* from a careful study of thirteen cases of summer 

 infantile diarrheas, comes to the following conclusions : 



Bacterium coli seems to be the pathogenic agent of the greater 

 number of summer infantile diarrheas. 



The organism is often associated with Streptococcus pyogenes. 



The virulence, more considerable than in the intestine of a healthy 

 child, is almost always in direct relation to the condition of the child 

 at the time the culture is taken, and does not appear to be propor- 

 tionate to the ulterior gravity of the case. 



The mobility of Bacterium coli is, in general, proportionate to its 

 virulence. The jumping movement, nevertheless, does not correspond 

 to an exalted virulence in comparison with the cases in which the 

 mobility was very considerable, without presenting these jumping 

 movements. 



The virulence of Bacterium coli found in the blood and other organs 

 is identical with that of Bacterium coli taken from the intestines of the 

 same individual. 



Lesage,f in studying the enteritis of infants, found that 



* "International Medical Magazine," Feb., 1897. 

 f"La Semaine medicale," Oct. 20, 1897. 



