MICROBIAL ANTAGONISTS 225 



The application of bacteriotherapy for the treatment of chronic infec- 

 tions of the middle ear (706) and actinomycosis in man has also been 

 suggested. Filtrates of E. tyfhosa and of E. coli were found (810) to 

 check the growth of the typhoid organism, whereas E. coli grew readily 

 in such filtrates; the more sensitive typhoid bacterium was checked 

 earlier in its growth than the colon organism. In general, E. tyfhosa 

 was found to be readily inhibited by the growth of antagonistic bacteria. 

 Because of this, it was believed that pasteurized milk contaminated with 

 a pathogenic organism presents a particular danger, since no antago- 

 nists are present to inhibit the rapid multiplication of the pathogen. 

 Metchnikov (596a) suggested utilization of the antagonistic relations 

 between lactic acid bacteria and proteolytic bacteria for repressing the 

 growth of the latter. Thus, pure cultures of the former are introduced 

 into the food system of man, in order to repress in the intestinal canal 

 the proteolytic organisms that are supposed to bring about intoxication 

 in the system. In recent years, L. acidofhilusy an inhabitant of the hu- 

 man intestine possessing antagonistic properties against pathogenic in- 

 testinal bacteria, has come into general use (744). The problem of com- 

 bating pathogenic intestinal bacteria by means of nonpathogenic forms 

 (703) has thus been given wide consideration. The utilization of yeasts 

 for combating streptococci and staphylococci may also be classified 

 among the phenomena of antagonism (893). On the basis of the rapid 

 destruction of pathogenic bacteria added to natural water, the storage 

 of drinking water in large reservoirs was recommended as an important 

 safeguard against the water's becoming a carrier of bacterial diseases 

 (295-297). 



Clinical methods have been proposed for evaluating the results ob- 

 tained by treating tooth gangrene by means of antagonists (325). Don- 

 aldson (181) found that CI. sforogenes or a closely related form had a 

 marked effect in suppressing the growth of pathogenic organisms in 

 septic wounds. He believed the antagonistic anaerobe is present in the 

 majority of gunshot wounds, but that its activities are held in abeyance 

 by the method of wound-dressing. This antagonist acts by virtue of its 

 proteolytic enzymes which hydrolyze the dead protein, from which the 

 pathogenic organisms operate, as well as the toxic degradation products 

 of other organisms. 



