title: A/J mice are susceptible and C57BL/6 mice are resistant to Listeria monocytogenes infection by intragastric inoculation.
abstract: Previous studies demonstrated that the innate resistance of mice to Listeria monocytogenes infection by intravenous or intraperitoneal inoculation is regulated principally by the Hc locus on mouse chromosome 2. The A/J and C57BL/6 mouse strains were identified as prototype L. monocytogenes-susceptible and -resistant strains, respectively. In the present study, we compared the relative susceptibilities of A/J and C57BL/6 mice to intragastric (i.g.) inoculation with L. monocytogenes. The results of our study indicate that A/J mice are significantly more susceptible than C57BL/6 mice to an i.g. challenge with L. monocytogenes. This was reflected in the estimated 50% lethal doses for the two strains (10(6) and 10(8) CFU for A/J and C57BL/6 mice, respectively) and a more rapid and severe dissemination of the infection to the spleen and liver in A/J mice than in C57BL/6 mice. Histopathological examination of tissues from the infected mice confirmed the greater severity of disease in A/J mice. Clearance of a primary infection enhanced the resistance of both A/J and C57BL/6 mice to reinfection with L. monocytogenes via the gastrointestinal tract. However, the relative difference in susceptibility between the two strains was evident even after immunization. The A/J mouse holds promise as a model for investigating the pathogenesis of gastrointestinal listeriosis because of its ability to develop systemic infection following challenge with numbers of organisms similar to those recovered from some L. monocytogenes-contaminated food products.
authors.affiliation: Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 53706, USA. czuprync@svm.vetmed.wisc.edu
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Czuprynski
authors.forename: Nancy G
authors.initials: NG
authors.lastname: Faith
authors.forename: Howard
authors.initials: H
authors.lastname: Steinberg
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D005260:Female; D005767:Gastrointestinal Diseases / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D006801:Humans; D008089:Listeria monocytogenes / Q000472:pathogenicity*; D008088:Listeriosis / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D008099:Liver / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D013045:Species Specificity; D013154:Spleen / Q000382:microbiology / Q000473:pathology