NONSPORE-FORMING BACTERIA 



89 



of the antagonist was shown (62, 1 20) to reduce considerably the action 

 of the pathogen. When grown on artificial media the pyocyaneus or- 

 ganism was found (299) to be strongly antagonistic to a number of 

 bacteria, including E. tyfhosa, Pjeijferella mallei, V. comma, and Bac- 

 terium tyrogenes. The growth of staphylococci, micrococci, diplococci, 

 and spore-forming rods was also reduced. The antagonist inhibited its 

 own growth as well. 



These early observations were amply substantiated (Table 14). Ps. 

 aeruginosa was shown to be active against E. coU, M. tuberculosis (62, 

 81, 120, 760, 999), and a variety of other bacteria (522). The addition 

 of top minnows {Gambusia) to water polluted with E. coli caused the 

 disappearance of the bacteria j this was shown to be due to the inhibit- 

 ing effect of the pyocyaneus organism present in the intestinal flora of 

 Gambusia. The presence of this antagonist in water renders the colon 

 index of the water an unreliable guide to pollution (384). When a mix- 

 ture of the antagonist and the colon organism was incubated, the former 

 tended to outgrow the latter after 24 hours {2)S(>)- Even after steriliza- 



TABLE 14. NONSPORE-FORMING BACTERIA AS ANTAGONISTS TO BACTERIA 



ANTAGONIST 



Ps. aei-uginosa 

 Ps. aeruginosa 

 Ps. fluorescens 



ORGANISMS AFFECTED 



B. anthraciSy E. typhosa, V . 

 comma, etc. 



Gram-negative bacteria, M. 

 tuberculosis, and yeasts 



E. coli, S. marcescens, C. 

 difhtheriae, B. ant hr acts, 

 etc. 



Ps. fluorescens Actinomycetes 



5. marcescens CI. chauvoei, B. anthracts, 



staphylococci, micrococci 



5. marcescens 



Gram-positive but not gram- 

 negative bacteria 



KNOWN PROPERTY 



Thermostable, filter- 

 able substance 



Depresses growth 



Thermostable, filter- 

 able substance 



Lytic action 



Colorless, thermo- 

 stable, lytic sub- 

 stance 



Alcohol-soluble 

 pigment 



REFERENCES 

 62, 81, 120, 235, 

 236, 299 



62, 81, 760, 762, 



763,999 



246, 302, 311, 326, 



406, 407, 409, 410, 



430-432, 524, 525, 



656, 827 



50, 209, 230, 743, 

 764 



409 



