CHAPTER 9 



ANTAGONISTIC RELATIONSHIPS BETWEEN 



MICROORGANISMS, VIRUSES, AND OTHER 



NONSPECIFIC PATHOGENIC FORMS 



Antagonistic phenomena in relation to viruses have been but little in- 

 vestigated. It has been established, however, that certain microorgan- 

 isms are capable of destroying viruses, and particularly that some vi- 

 ruses possess the capacity of antagonizing other viruses. The rapid in- 

 activation of poliomyelitis virus in the process of aeration of sewage 

 sludge has also been indicated ( io6). 



BACTERIA AND VIRUSES 



B. subtilis was found (718) capable of inactivating the virus of vesicu- 

 lar stomatitis as well as staphylococcus phage, when in contact with 

 them for 15 to 18 hours at 35° C. This phenomenon has been ex- 

 plained as due to the process of adsorption. The facts that it is selective 

 in nature, that the phage cannot be reactivated, and that the virus is ren- 

 dered impotent by the action of the bacterium, all point to an antagonis- 

 tic eflFect rather than mere physical adsorption. The virus of rabies is 

 said to be influenced in certain ways by B. subtilis , the culture filtrate of 

 the organism suppressing the activity of the virus when a mixture of the 

 two is injected into rabbits (173). 



However, different antibiotic substances, including penicillin, ty- 

 rothricin, and subtilin, when used either alone or in combination with 

 sulfonamides or acridine, have failed to prevent infection of mice with 

 influenza virus (508). 



A "nontoxic" inactivator has been defined (306) as a substance that 

 inactivates plant viruses and is not detrimental to most forms of life. 

 Various microorganisms are capable of producing such inactivators. 

 Plant viruses differ in their sensitivity to "nontoxic" inactivators. Ac- 

 cording to Johnson (457, 458) various microorganisms are capable of 

 forming such inactivators against tobacco-mosaic virus j A. aero genes 



