THE BACTERIOPHAGE IN DISEASE 227 



FLACHERIE 



A few experiments have been made on this disease, but only 

 for the purpose of determining if defense against infection in 

 invertebrates is also assured by the bacteriophage. 



In a breeding-place in Cochin-China a certain number of silk 

 worms died of a disease presenting all of the characteristics of 

 flacherie. Examination of the excreta of the sick worms, as 

 well as of the cadavers, showed the presence of a cocco-bacillus, 

 Gram-negative, which was not present in the dejections of healthy 

 worms. The ingestion, on mulberry leaves, of some of the 

 culture of this cocco-bacillus reproduced the disease; eleven 

 out of twelve worms dying in from six to eleven days after the 

 infecting feeding. 



Three filtrates were prepared from the excreta of healthy worms 

 living in the baskets where the affected worms were found. These 

 three filtrates contained a bacteriophage of moderate or high 

 virulence (++, + ++, + + +) for the cocco-bacillus. On the 

 other hand, two filtrates were prepared, the one with the intestinal 

 contents of a sick worm, the other with the intestinal contents 

 of a worm which had died of the infection. Neither contained 

 a bacteriophage active for the coccobacillus. 



These experiments have not been carried further, since the 

 desired end had been attained. They were adequate to show 

 that the facts observed in infectious disease in mammals were 

 reproduced in an infectious disease of an invertebrate. From 

 this it seems logical to conclude that the defense of the organism 

 by the bacteriophage must constitute a general fact throughout 

 all animals. 



bility of a renewal of the epidemic. Such a demonstration might also be 

 useful in establishing a retrospective or doubtful diagnosis. Suppose a few 

 suspicious deaths have occurred in a group some time previously. The pres- 

 ence in the rats of the neighborhood of a bacteriophage showing a virulence 

 for B. pestis would eliminate all doubt; the deaths were due to plague. Or, 

 the question of the nature of a epizootic among the rats may be in question. 

 Was the mortality due to plague? The demonstration of a bacteriophage 

 active for B. pestis either in the dead rats or in those that have survived 

 provides the answer. 



