192 



THE BACTERIOPHAGE 



1. Marie Mo. . . . (fifty-five years, fig. 6). 



2. Louis Pi. . . . (seventeen years, fig. 7). 



3. Francois Jod. . . . (thirty-four years, fig. 8). 



In these cases the virulence of the intestinal bacteriophage 

 was determined for B. coli, B. typhosus, B. paratyphosus A and 

 B, and B. dysenteriae Shiga. It is needless to comment on these 

 observations, since examination of the curves is more instructive 

 than would be an explanation. 



Fig. 8. Francois Jod (34 years) Clinically, Typhoid Fever 



ijB. typhosus 

 B. coll 

 B. paratyphosus A 

 B. paratyphosus B - 

 B. dysenteriae Shiga 



What is the causative bacillus in each of these three cases? 

 It is indeed difficult to make a diagnosis by means of the bacterio- 

 phage, which as we have seen, but rarely develops a single 

 virulence. 



This virulence extends to other bacteria of the same group to 

 a more or less marked degree, and this fact is particularly in 

 evidence when working with the representatives of the colon- 

 typhoid-paratyphoid-dysentery group. It appears, however, in 

 the case of Louis Pi. . . . that the causative bacillus must have 

 been the typhoid bacillus, with Marie Mo. . . . B. paratyphosus A, 

 and in Francois Jod. . . . B. paratyphosus B. 



