ANTI-BACTERIAL RESISTANCE IN MICE INFECTED WITH MYCOBACTERIUM-LEPRAEMURIUM

Abstract

The differences in susceptibility among C57Bl/6, DBA/2 mice and their F1 hybrids to infections with M. lepraemurium were shown to depend upon the route of infection and size of the inoculum. A method was developed to measure the ability of lymphocytes obtained from M. lepraemurium-infected donors to effect adoptive immunization of syngeneic naive mice against infection with M. tuberculosis. This required sublethal irradiation of recipient mice prior to cell transfer and bacterial challenge. Using this method, it was found that mice infected s.c. generated antituberculous immune mechanisms concordantly with the development of delayed-hypersensitivity to antigens of M. lepraemurium. I.v. infected mice demonstrated only a transient form of delayed hypersensitivity and little or no antimycobacterial immunity in the progresson of infection was associated with a rapid decay of both these functions. During the terminal stages, M. lepraemurium-infected mice lost the ability to control the growth of a sublethal i.v. inoculum of the antigenically unrelated bacterium, Listeria monocytogenes.