470 THE BACTERIOPHAGE AND ITS BEHAVIOR 



All of the cases discussed up to this time have ended in a complete recovery 

 without complicating incidents. A number of the other cases have showed re- 

 lapses, and the charts of all of these resemble the one which follows. In some of 

 the cases a relapse has only been threatened; cases in which the temperature, once 

 become normal, has showed a tendency throughout a few days to rise again. But 

 despite this event, recovery took place without any serious complications. Chart 

 18 is illustrative of a case of this type. 



These observations of Hauduroy agree in all respects with those which 

 I have reported. 



Typhoid fever is not a purely intestinal infection as is dysentery. 

 In the latter it can be understood how, when all of the pathogenic 

 bacteria of the intestine or of the mucosa, that is, those in proximity 

 to the bacteriophage corpuscles, have been destroyed the disease ends 

 ipso facto. In typhoid fever there is in addition a septicemia and even 

 though the destruction of the bacUli contained in the intestinal contents 

 is sufficient to delay the appearance of the disease or to restrain it from 

 the beginning, it may not be adequate to overcome the infection once 

 the pathogenic bacilli have invaded the organism. 



In the last chapter we learned that the ''products resulting from 

 bacteriophagy" are possessed of an extremely potent opsonizing power. 

 For example, we may precipitate a suspension of the Typhoid-bacterio- 

 phage by the addition of four volumes of 96 per cent alcohol. We allow 

 this precipitate to remain in contact with the alcohol for 48 hours, a 

 period adequate to ensure the complete destruction of all of the bacterio- 

 phage protobes. One centigram of this moist precipitate is dissolved 

 in 10 cc. of saline. If, with this, we determine the opsonic index, we 

 find that the leucocytes become so loaded with typhoid bacilli that it 

 is quite impossible to count the number of organisms ingested. The 

 opsonic index found is certainly higher than 50. It is possible that these 

 "products of bacteriophagy," occurring in the intestine as the bacterio- 

 phage acquires a virulence adequate to dissolve the typhoid bacilli, 

 may be resorbed and pass into the circulation, thus assuring a destruc- 

 tion of the bacilli through a phagocytic process. 



On the other hand, as we know, the bacteriophage does not remain 

 strictly localized in the intestinal tract; at times it passes into the 

 circulation. 



Inasmuch as I have not had an opportunity to make studies on the 

 blood of patients, I have been forced to study the experimental disease 

 induced in rats by the ingestion of particularly virulent strains of B. 

 typhi murium. In these examinations I have found that every time 



