458 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



was rapid, the curves representing the virulence of the bacteriophage 

 are comparable. It is also to be noted that in all, the accessory viru- 

 lences for B. dysenteriae Shiga and for B. coli are very high, and that the 

 acquisition of virulence for B. typhosus and B. paratyphosus A and B 

 is early and is maintamed up to the beginning of convalescence. In 

 the case of Louis Pi the abrupt deflection in virulence on the 



Chart 12. Gilberte Fon (4 years) Typhoid Fever {B. typhosus) 



IB. typhosus from the patient 

 B. typhosus, stock strain 

 B. coli 



Condition serious =^= 



twenty-second day preceded a sHght relapse which occurred on the 

 twenty-fifth to the thirty-second day. This complication did not 

 prove serious since the virulence of the bacteriophage increased gradually 

 from the twenty-third day. 



2, Severe infections 



The three cases to be cited here were serious, with both stool and blood 

 cultures positive. All were infected with B. typhosus. 



