Inheritance of susceptibility to induced Escherichia coli bladder and kidney infections in female C3H/HeJ mice

In the present study, the inheritance of resistance and susceptibility to bladder and kidney infections in BALB/c, C3H/HeJ, F-1, and backcross mice was investigated, and the number of genes contributing to the phenotypes was estimated. Infections were induced in female mice by intravesical inoculation with Escherichia coli, and the number of bacteria in bladder and kidneys was quantified at 10 days. The (BALB/c x C3H/HeJ) F-1 mice had bladder and kidney infection intensities equivalent to those observed in the resistant BALB/c parents. Twelve percent of the (F-1 x C3H/HeJ) backcross mice had severe bladder infections, similar to the susceptible C3H/HeJ parents. Kidney infections ranging in intensity between those observed in BALB/c and C3H/HeJ parents were present in one-half of the backcross mice. Statistical analyses indicated that greater than or equal to1 gene is responsible for the increased susceptibility of C3H/HeJ mice and that the trait appears to be recessive.