Resistance of gnotobiotic nude mice to Listeria infection.

Unlike the acute and short-term course of experimental listeriosis in phenotypically normal (nu/+) mice, Listeria monocytogenes infection in conventionally raised athymic Nude mice results in chronic inflammation with persistence of bacteria and lesions in the internal organs such as liver and spleen. Although it could be shown that germfree Nude mice had no intestinal microbial flora and lacked measurable serum immunoglobulins, neither the course nor the histomorphology of experimental listeriosis differed significantly from that of their conventionally raised littermates. The results indicate that the typical response of Nude mice to Listeria infection is primarily determined by inborn factors and not by prior antigenic stimulation.