OVINE LYMPHADENITIS 401 



Pseudo -Tuberculosis 



The term " pseudo -tuberculosis " (which is not a good 

 one, and should be discarded) has been applied to a 

 number of different conditions which have as a common 

 character the presence of tubercle-like nodules, but which 

 are not caused by the tubercle bacillus. Such are produced 

 by certain parasitic worms, by Blastomycetes , Streptothrix 

 and Aspergillus, Protozoa, and by several bacteria. 



Pfeiffer's Bacillus pseudo-tuberculosis produces nodular 

 deposits in the organs, accompanied by wasting, very like 

 true tuberculosis. The disease, however, runs a more 

 rapid course, death ensuing in the guinea-pig two to three 

 weeks after inoculation. Guinea-pigs, rabbits, mice and 

 monkeys can be readily infected. The nodules consist of 

 masses of round cells which undergo necrosis and casea- 

 tion. The bacillus in the tissues is not readily stained, 

 carbol-methylene blue being the best solution, as it is not 

 acid-fast, nor does it stain by Gram's method. Morpho- 

 logically it is a small non-motile rod 1-2 fi in length. On 

 gelatin it forms a whitish growth without liquefaction, 

 like that of the colon bacillus, but confined to the needle- 

 track. It produces alkali, forms no gas, and does not 

 curdle milk. Broth remains clear, with a whitish stringy 

 fiocculent deposit. The bacillus grows readily and rapidly. 



MacConkey has found that the fermentation reactions 

 of this organism and of the plague bacillus are practically 

 identical (see " Plague," p. 471), and sterilised cultures of 

 either will protect against the other. 



Ovine caseous lymphadenitis, a disease of sheep simu- 

 lating tuberculosis, is due to a short, plump bacillus with 

 rounded ends which stains well by Gram's method, and 

 grows best on blood serum, on which it forms greyish 

 colonies. 1 



1 Sixteenth Ann. Rep. Bureau of Animal Indust. U.S.A., p. 638. 

 M.B. 26 



