104 BACTERIA AS ANTAGONISTS 



intravenous injection, and was believed to offer promise as a chemo- 

 therapeutic agent, 



Freudenreich (298) first emphasized the antagonistic action o£ 

 staphylococci against various bacteria. The list was later enlarged to in- 

 clude gram-positive acid-resisting forms, corynebacteria, and the plague 

 organism. Some of these antagonists were found to be able to lyse the 

 dead cells of their own kind as well as those of various other organisms. 

 Gundel (372) isolated from staphylococci an active lipoid which had 

 bactericidal properties. A water-soluble, alcohol-insoluble substance, 

 said to be an enzyme capable of bringing about the lysis of corynebac- 

 teria, was also isolated from a strain of staphylococcus (215). 



Various micrococci possess strong antagonistic properties. Lode 

 (580) isolated a micrococcus which affected a variety of microorganisms 

 three or more centimeters away, the active substances being dialyzable. 

 An organism related to Micrococcus tetragenus and described as M. an- 

 tibioticus was found to possess a strong antagonistic action against V. 

 comma y M. tuberculosis y E. tyfhosaj Ph. tumejaciensy Br. melitensisy 

 various spore-forming bacteria, numerous cocci, and others. 



Diplococci exerted an antagonistic action against various bacteria, in- 

 cluding pyogenic staphylococci and streptococci in the sputum, spore- 

 formers, and gram-negative bacteria. They produced, under aerobic 

 conditions only, a filterable substance that was heat resistant. 



The antagonistic action of pneumococci has definitely been estab- 

 lished. The active substance of these organisms was said to be thermo- 

 labile, since it was destroyed at 80° to 85° C.j it was produced only 

 under aerobic conditions. In reviewing the literature on the longevity 

 of streptococci in symbiosis, Holman (440) observed that many 

 chances of error are inherent in mixed cultures, particularly with closely 

 similar organisms j pneumococci, for example, were found to be able to 

 live for long periods in association with nonhemolytic streptococci. 

 Peculiar antagonistic relations between pneumococci and staphylococci 

 were also reported (13). Adaptive alterations could be expected in the 

 growth of bacteria in mixed cultures (32). Which of the two organisms 

 antagonizes the other was believed to depend frequently upon the nu- 

 merical abundance of one or the other (243). 



