XXIV. SENSITIZERS FOR THE TUBERCLE BACILLUS.* 



By J. BORDET and O. GENGOU. 



One of us demonstrated in 1900 that if red blood cells or bacteria 

 axe added to a specific immune serum which contains a specific sen- 

 sitizer, the cells become capable of absorbing the destructive sub- 

 stances in the serum (alexin). With this fact as a basis, Bordet 

 and Gengou have described a method which allows one to prove 

 the existence of a sensitizer in a given serum. By preparing a 

 suitable mixture of typhoid bacilli, fresh normal human serum, 

 and heated serum (55 degrees) of a convalescent from typhoid, it 

 is found that the alexin of the normal serum is absorbed by the 

 bacilli; this is proved by the fact that subsequently added sen- 

 sitized corpuscles undergo no hemolysis. Consequently we may 

 conclude that the serum of patients convalescent from typhoid con- 

 tains a sensitizer that endows the typhoid bacillus with the power 

 of fixing alexin. By this method we have endeavored to determine 

 whether a guinea-pig can form an active sensitizer for the tubercle 

 bacillus ; our results follow : 



Guinea-pigs injected with living human tubercle bacilli soon 

 show generalized tuberculosis and produce no sensitizer. A nega- 

 tive result is obtained in any stage of their disease. If the guinea- 

 pigs receive a subcutaneous inoculation of the avian tubercle 

 bacillus, on the contrary,! for two or three times they resist infec- 

 tion, and soon form a sensitizer in their blood which has the property 

 of provoking alexin fixation when added to the bacillus. It is 

 interesting to note that this sensitizer shows an equal activity 

 with the human tubercle bacillus; the same amount of sensitizing 

 serum will fix the same amount of alexin with the same volume 



*Les sensibilisatrices du bacille tuberculeux: Comptes Rendus de l'Acad&nie 

 des Sciences, vol. 137, 1903, 351. 



j Our culture of avian bacillus was derived from pigeons and had been grown 

 for some time on glycerinated potato. 



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