STUDY OF THE IMMUNITY AGAINST BACILLUS PYOCYANEUS 11 



culture killed a guinea-pig in 12 hours. 10 loopfuls of the chloroformed 

 culture produced no symptoms in another guinea-pig. 



I c.c. of a very thick emulsion of a chloroformed culture produced 

 death in 4 days. 



From these experiments it is manifest that toluolised bouillon cultures 

 are lethal in doses of -5 - i c.c. The bacillary bodies themselves, killed by 

 toluol or chloroform, are much less toxic. The toxicity of toluolised 

 broth cultures may be largely due to poisons which have slowly diffused 

 out of the bacillary bodies. It is also possible that it is due to secondary 

 products produced by the fermentation of the medium (bouillon) in 

 which the bacillus has been growing. The absence of toxic action 

 in young filtrates is in favour of the latter view, and against the opinion 

 of Wassermann, that the so-called " pyocyanic toxin " is a true exotoxin. 



Effects of Autolysed Cultures. 



Autolysed cultures were made according to the methods of Conradi (1°) 

 and Neisser (^i). Following the first of these methods, bacillus pyocyaneus 

 was grown in Roux's bottles at 37° C. for 20 hours. At the end of this 

 time the culture mass was washed into a saline solution and allowed to 

 digest in this for 24 hours, after which time the fluid was passed through 

 the Berkefeld filter. 



In the case of autolysates made by Neisser's method, large agar 

 cultures were suspended in saline solution, heated to 60° C. for i hour, 

 and then placed in the incubator for 2 days to digest. At the end of 

 this time the fluids were passed through the filter. 



Considering the large quantity of bacilli employed in the preparation, 

 these autolysates appear to be practically non-toxic in doses up to 15 c.c. 

 A lethal effect was first seen in doses of 20 c.c. 



(167) 



