Genetics of resistance to infection with Salmonella typhimurium in mice

Eight strains of inbred mice fell into two sharply defined groups. Four strains (CBA, A/JAX, C3H/He, and DBA/2) were resistant (LD50, greater than 10(5)) to Salmonella typhimurium C5 given subcutaneously. The other four strains (Balb/c, C57BL, B10.D2 [new line], and DBA/1) were susceptible (LD50, less than 10). No intermediate resistance was seen. Examination of the F1, F2, and parental backcross generations bred from matings of CBA and Balb/c mice showed that resistance behaved as a simple Mendelian dominant. Resistance was not linked to H-2 genes, and no useful marker has yet been found. However, as previously demonstrated in the parent strains, resistance in the hybrids was related to the ability to produce a good delayed-type hypersensitivity reaction to an extract of S. typhimurium.