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 ( 1 1 1 ) . 



BACTERIA AND VIRUSES 



The ability of certain strains of B. subtilis to inactivate the virus of 

 rabies has long been recognized. The activity was found to be due to a 

 substance produced in the culture filtrate j limited experimental evi- 

 dence pointed to the effectiveness of this substance not only in vitro but 

 also in vivo (619). When a mixture of the culture filtrate of B. subtilis 

 and the virus was injected into rabbits, the activity of the virus was sup- 

 pressed (619). It has been suggested (774a) that this action upon the 

 virus of rabies and of equine encephalitis is due not to a true antibiotic 

 but to a proteinase similar to the one which destroys bacterial toxins. 



An inactivating effect of B. subtilis upon the virus of vesicular stoma- 

 titis as well as staphylococcus phage, when in contact with them for 1 5 

 to 18 hours at 35° C, was also reported (750). This phenomenon has 

 been explained as due to the process of adsorption. The facts that it is 

 selective, that the phage cannot be reactivated, and that the virus is 

 rendered impotent by the action of the bacterium also point to a pos- 

 sible antagonistic effect. However, different specific antibiotics, includ- 

 ing penicillin, tyrothricin, and subtilin, when used either alone or in 

 combination with sulfonamides or acridine, have failed to prevent in- 

 fection of mice with influenza virus (537). 



A "nontoxic" inactivator has been defined (307) as a substance that 



