1911.] Cultivating the Mycobacterium enteritidis, etc. 



535 



to be free from tuberculosis but with well developed pseudo-tuberculous 

 enteritis. The bull was kindly presented to us by a breeder interested in 

 this disease, and showed marked clinical symptoms, besides numerous clumps 

 of acid-fast bacilli in the faeces. 



The vaccine inoculations and results are set forth in the accompanying table, 

 a + sign indicating a positive reaction and a — sign a negative one. On 

 referring to the table it will be noticed that vaccine No. 1 gave a positive 

 result with bovines Nos. 1, 2, 4, and 5, but not with the control bull. It is 

 also evident from the tuberculin tests and from post-mortem examination that 

 animals 1, 2, and 5 had contracted tuberculosis. 



In considering these results it must be remembered that vaccine No. 1 was 

 prepared by growing the specific bacillus on a medium containing the 

 tubercle bacillus, and it might be expected that tubercular animals would 

 react to the vaccine on account of the substances dissolved from the 

 tubercle bacilli in the medium, in which case the positive results obtained 

 •do not prove the presence of pseudo-tuberculous enteritis. That the rises 

 ■of temperature with vaccine No. 1 were actually caused by the presence 

 of these substances is finally proved by the absence of any reaction in 

 the control bull, and also by the negative results obtained with vaccines 

 Nos. 4 and 5,, which contained no tubercle bacilli. 



From the results obtained with vaccine No. 1 it is quite clear that if a 

 specific vaccine for pseudo-tuberculous enteritis is to be obtained, the 

 tubercle bacillus must not be incorporated in the medium. It will be 

 seen from the table that a timothy-grass bacillus vaccine causes no rise of 

 temperature in normal animals, or in animals suffering from tuberculosis 

 or pseudo- tuberculous enteritis. This bacillus should therefore be suitable 

 for incorporating in the medium. 



It will be remembered that vaccines 4 and 5 were prepared by growing 

 Johne's bacillus in media containing the timothy-grass bacillus; but, as 

 will be seen from the table, these vaccines caused no reaction in any of 

 the experimental or control animals, which further proves the harmlessness 

 of the timothy-grass bacillus. 



It may seem surprising that no reaction was obtained with these vaccines 

 in the animals affected with Johne's disease, but, in point of fact, the 

 negative results might have been expected, as the greater part of the 

 bacillary emulsion used was obtained from growths on solid media. It 

 must also be remembered that infected animals rarely, if ever, show a 

 temperature during the course of the disease, and it is probable that a 

 more concentrated vaccine will be required for Johne's disease than for 

 tuberculosis. 



2 K 2 



