FIG 10.

The ClpP ATP-dependent protease contributes to P. stuartii fitness during single-species and polymicrobial CAUTI. P. stuartii BE2467 and the isogenic clpP mutant were assessed for heat sensitivity (A), fitness during single-species infection (B), and fitness during coinfection with P. mirabilis HI4320 (C). (A) Viable CFU/ml recovered for wild-type P. stuartii BE2467 and the clpP mutant following incubation at 37°C versus 45°C. Box-and-whisker plots show all data points with minimum, maximum, and mean values for results from at least 3 independent experiments. (B) CBA/J mice (n = 10) were transurethrally inoculated with 1 × 10⁵ CFU of a 1:1 mixture of wild-type P. stuartii and the clpP mutant, and a competitive index was calculated as described above. (C) CBA/J mice (n = 10) were transurethrally inoculated with 1 × 10⁵ CFU of a 1:1:2 mixture of wild-type P. stuartii, the clpP mutant, and wild-type P. mirabilis HI4320, a 4-mm segment of catheter tubing was retained in the bladder for the duration of the study, and a competitive index was calculated as described above. Statistical significance was assessed by Wilcoxon signed-rank test (**, P < 0.01).