10 INFECTIONS OF THE DIGESTIVE TRACT 



of this high mortality among the colon bacilli is ascribed 

 by Conradi and Kurpjuweit to increased opportunities 

 to make bactericidal substances. 



In their experiments these writers found that the 

 growth of the typhoid bacillus and of the paratyphoid 

 bacillus is definitely inhibited by the activities of the 

 colon bacillus, and this restraint is referred by them to 

 the specific inhibitory products of the latter microbe. 

 It will be shown in subsequent pages that the claims of 

 Conradi and Kurpjuweit have not been successfully 

 sustained. The observations related by them are of 

 great interest, but the interpretation placed on them 

 appears to be erroneous. 



The inhibitory action of B. coli upon the putrefactive 

 anaerobes is shared by a closely related group of bacteria 

 first described as B. bifidus by Tissier. 1 This group of 

 bacteria was originally included by Escherich with the 

 colon bacilli, but for reasons which will be mentioned 

 later, has now been separated from them. Tissier 

 found that B. bifidus, under certain conditions, inhibits 



1 "La Flore intestinale normale et pathologique du nourrisson," 

 These de Paris, 1900. 



There are certain bacteria that have the ability to check the 

 growth of B. coli. Streptococci derived from human faeces I have 

 repeatedly observed to repress the growth of B. coli from the same 

 individual, in the anaerobic limb of the fermentation tube. B. 

 lactis aerogenes may be repressed in the same way. Heinemann 

 (" The Significance of Streptococci in Milk," Journ. Infect. Dis.,iii, 

 p. 173, 1906) has found that streptococci from milk interfere with 

 the development of B. lactis aerogenes. Gabricewski and Mal- 

 jatai (" Ueber die bakterienfeindlichen Eigenschaften des Cholera- 

 bacillus," Centralbl. f. Bakt., xiii, p. 780, 1893) observed that B. 

 coli is inhibited by the growth of cholera vibrios. 



