96 BACTERIA AS ANTAGONISTS 



reported that fresh, actively growing cultures of E. tyfhosa inhibited 

 the growth of E. coli, older cultures not being antagonistic (915). The 

 antagonistic properties of E. coli were often believed to be associated 

 with the formation of unstable, thermolabile lytic substances, that 

 would not pass through a filter (365, 367, 580). 



A bacteriophage was found (532) to develop as a result of the an- 

 tagonistic action of E. coli against the Shiga bacillus and was said to 

 occur in the intestines where antagonistic conditions are always present. 

 A similar effect was observed by Fabry (245), due to the antagonistic 

 stimulus of E. coli by a strain of S. albus. Gratia (348) found that 

 the filtrates of one race of E. coli inhibited another race and caused an 

 agglutination of the latter in fluid media. According to Hashimoto 

 (383), the weakest antagonists belong to the paracolon group, the 

 strains of medium activity to the colon group, and the strongest an- 

 tagonists to the colon-immobilis type. Whenever the feces were found 

 to contain large numbers of E. coli, no typhoid organisms were present. 

 The resistance of certain persons to intestinal diseases was, therefore, 

 ascribed to the high antagonistic colon index. By utilizing the principle 

 of antagonism of some strains of E. coli against others, two types of 

 E. coli resistant to the antagonistic substance were isolated ( 168) : one 

 produced giant colonies, the other small punctiform, translucent 

 colonies. 



E. coli exerts an antagonistic action also upon Salmonella schottmUl- 

 leri (305), C. difhtheriae (52, 905), staphylococci (366, 491), M. tu- 

 berculosis (6So,6Si)yB.anthracis (105,365-367,781, 823, 898), vari- 

 ous spore-forming soil bacteria (469), and putrefactive water bacteria 

 (759). The action against anthrax was said to be only temporary (336). 

 It was also suggested (448) that only living cultures of E. coli are ac- 

 tive. The simultaneous inoculation of S. aureus and E. coli was found 

 (736) to be injurious to the first and not to the second organism j this 

 effect was increased by an increase in the number of E. coli cells in the 

 inoculum. Gundel and Himstedt (366) have shown that E. coli, but 

 not A. aero genes y is antagonistic to S. aureus and S. albus. 



The term autophage has been used (334) to designate the process of 

 clearing a water emulsion of dead cells by a culture of an antagonist 

 such as E. coli. This clearing effect was said to be due to the fact that the 



