Allergy in experimental rat tuberculosis

Abstract

1. This paper confirms and extends several observations during the past 20 years that, despite many reports to the contrary, the rat is not unduly resistant to initial infection with tubercle bacilli provided they lodge in the lungs.2. The pattern of pathogenesis in the rat is probably closest to the now classical picture in the mouse, i.e. the response of a species with a low hypersensitivity potential. The pathology of the lesions agreed closely with the descriptions of Wessels (1941) and Kumashiro (1958b) resembling the mouse in most respects but, unlike the mouse, including the production of giant cells.3. When tested by footpad inoculation with 1/3·5 Old Tuberculin a positive reaction was demonstrated, commencing between 2 and 5 weeks after infection and persisting for several weeks. A fatal systemic reaction could often be induced with large doses of tuberculin given intraperitoneally.4. In a few cases loss of allergy was shown to be associated with a terminal anergic flare of the type observed previously in mice and guinea-pigs.