Influence of genetic factors on natural resistance of mice to Pseudomonas aeruginosa.

In order to determine whether genetic background influences natural resistance to Pseudomonas aeruginosa, a series of 16 different strains of inbred mice were challenged intraperitoneally with P. aeruginosa. Significantly greater natural resistance to infection was found in mice of C3H background genome than in mice of A background genome. This phenomenon was documented for two different strains of P. aeruginosa but could not be demonstrated in control studies in which mice were intraperitoneally challenged with Staphylococcus aureus or Escherichia coli. The enhanced resistance of C3H mice was independent of currently defined haplotypes at the H-2 locus. The killing activity of serum against Pseudomonas was not greater in C3H mice than in A mice. The extension of these findings to disease in humans suggests that the particular susceptibility of certain populations of patients to Pseudomonas may be partially related to genetic factors.