368 PSEUDOTUBERCULOSIS AND ACID-FAST BACILLI 



growth of the glanders bacillus on the same medium. The bacillus of 

 pseudotuberculosis grows well in milk without changing its reaction 

 or physical properties. The organism is not very resistant to dis- 

 infectants and is easily killed by desiccation. It grows both at room 

 and at incubator temperature. 



Natural Infection. This is probably brought about by ingestion. 

 The animals most susceptible to artificial inoculation are the rabbit, 

 guinea-pig, and mouse. Horses, goats, dogs, rats, and cats are not 

 susceptible to the Bacillus pseudotuberculosis rodentium. 



BACILLUS PSEUDOTUBERCULOSIS MURIUM. 



This organism, obtained by Kutscher from a mouse which had 

 died spontaneously with pseudotuberculous lesions, is characterized 

 by great polymorphism. It forms in artificial cultures large club- 

 and dumb-bell-shaped individuals, which stain unequally, and often 

 closely resemble certain forms of the diphtheria bacillus. It is Gram 

 negative. The bacillus of mouse pseudotuberculosis forms on agar 

 delicate, yellowish, serrated colonies, with short lumpy processes. 

 It grows well on gelatin, which it does not liquefy. In gelatin stick 

 cultures a whitish growth, which sends put processes into the mass of 

 the culture medium, is formed along the canal. It clouds bouillon 

 in twenty-four to forty-eight hours and forms a pellicle on its surface. 

 It does not grow on potatoes. It is pathogenic to mice if administered 

 by inhalktion, subcutaneously or intraperitoneally. 



Bongert has investigated a mouse epizootic, also characterized by 

 pseudotuberculous lesions, and has isolated from the latter a small 

 bacillus somewhat resembling the pseudodiphtheria bacillus. He 

 has named this mouse pathogenic bacterium Corynethrix pseudo- 

 tuberculosis murium. The organism grows aerobically and anaero- 

 bically best in the incubator. It is 1 to 2 micra long, 0.5 micron thick, 

 and has a tendency, like the diphtheria and pseudodiphtheria bacilli, 

 to form pallisade-like groups. 



BACILLUS PSEUDOTUBERCULOSIS OVIS. 



Occurrence. Pseudotuberculosis of sheep, or ovine caseous lymph- 

 adenitis, is a disease which was first recognized as something different 

 from true tuberculosis by Preisz, whose discovery, however, did not 

 attract much attention at first. Within a few years, however, it was 

 shown that this disease of sheep is by no means uncommon, and it 

 has since been encountered extensively in Australia, New Zealand, 

 Argentina, the United States, and other countries. According to 

 Sivari 10 per cent, of the sheep slaughtered in Buenos Ayres are 

 infected with the disease. It rarely occurs in young animals, and 

 when it does is limited to one or a few lymph glands. In older 



