MICROBIAL ANTAGONISTS 263 



antagonistic bacteria. He believed that in many cases of artificial infec- 

 tion, the favorable action of the antagonist may have been due entirely 

 to increased body resistance. Nevertheless, he accepted the possibility 

 of utilizing the antagonistic effects of microorganisms, for the treatment 

 of skin surfaces, including those of the intestinal canal and the vagina, 

 but not for tissue or blood infection. 



Until very recent years, attempts to utilize the activities of antagonis- 

 tic microorganisms for the control of disease did not always meet with 

 success. This failure may have been due to an insufficient understanding 

 of the nature of the chemical agent produced by the antagonist, to a 

 lack of knowledge concerning the mechanism of its action, especially 

 as regards the production of the active antibacterial substance or anti- 

 biotic. 



MICROBIAL ANTAGONISTS AND DISEASE CONTROL 



In 1885, Cantani treated a tubercular patient with a culture of a sapro- 

 phytic organism, designated as Bacterium tenno; the results were 

 highly favorable (109). He expressed the hope that other infectious 

 diseases readily accessible and of a local nature could be effectively 

 treated with saprophytic bacteria which are antagonistic to the patho- 

 gens. Following this work of Cantani, Zageri ( 1043) inoculated S. pyo- 

 genes into animals suffering from anthrax j the rise in temperature 

 caused by the streptococcus reduced the viability of the anthrax. The 

 growth of an antagonistic organism was found to change the environ- 

 mental conditions favorable to the pathogen, thus causing its attenua- 

 tion. 



These results received the immediate attention of other inve;sti- 

 gators. In most instances saprophytic organisms such as lactic acid bac- 

 teria or beer yeasts were used, in other cases mild pathogens were em- 

 ployed. Lorenz and Ravenel (582a), for example, sprayed the throats 

 of diphtheria carriers with cultures of S. aureus; although the treat- 

 ment was successful in eliminating the pathogens, the staphylococci 

 sometimes caused sore throat. 



Gate and Papacostas (323) observed that mixed infections were usu- 

 ally mild, a phenomenon later confirmed. Mixed cultures of the Fried- 



