SPORE-FORMING BACTERIA 



91 



passage. The action of filtrates of B. mesenterkus against diphtheria 

 organisms was considered (984) as highly specific. Other strains of this 

 organism were reported to be active against Pasteurella festis (244). 

 Living gram-positive bacteria were found (806) to be more susceptible 

 than gram-negative organisms to the antagonistic action of spore-form- 

 ing aerobes J in the case of dead organisms, the reverse was true. Plates 

 were heavily seeded with the test bacteria and the centers of the plates 



TABLE 



I. LYSIS OF PATHOGENIC BACTERIA BY VARIOUS STRAINS OF A 

 SPORE-FORMING ANTAGONIST (cYTOLYTICUs) 



ORGANISM LYSED 



E. tyfhosa 



Paratyphoid A 



Paratyphoid B 



Shigella 



Y bacillus 



E. coli 



C. diphtherias 



Ps. pyocyaneus 



S. aureus 



S. alius 



S. citreus 



S. viridis 



S. /laemolyticus 



S. mucosus 



P. vulgaris (Weil-Felix) 



Pneumococcus 



STRAIN NUMBER OF CYTOLYTICUS 



II III VI VII VIII 



IV 

 o 



+-H- 

 O 



o 



+ 

 o 

 + 

 o 



From Franke and Ismet (292). 



O no clearing. 



+ trace but no true clearing. 



++ clearing, slight sediment. 

 +++ clearing without sediment. 



inoculated with the antagonist. Inhibition of growth and lysis were used 

 as measures of antagonistic action. 



Hettche and Weber (419) isolated 41 strains of B. mesenterkus 

 from 25 samples of soil. These were streaked on blood agar, and the 

 diphtheria organism was used for testing their effect. In 18 strains the 

 antagonistic action was detected in 24 hours j there was no parallelism 



