Fig. 6.

Substantial loss of fitness during infection requires multiple deletions in importers with overlapping functions. (A−D) CBA/J mice (n = 10) were transurethrally inoculated with a 1:1 mixture of E. coli CFT073 wild-type and the indicated mutant. Log₂ Competitive Index (C.I.) was calculated for each organ site (mutant/wild-type). The dashed line at 0 signifies no deficiency for either the wild type (CFT) or mutant, a positive value indicates the mutant outperformed the WT, and a negative value defines the mutant as having a fitness defect. Wilcoxon-signed rank test was performed using a hypothetical mean of 0. P values are listed. (E) Three separate cochallenges were performed (n = 10, per mutant) in the same mouse model using a double (pink), triple (purple), and quadruple (blue) ABC importer mutants. Wilcoxon-signed rank test was performed using a hypothetical mean of 0. *P < 0.05, **P < 0.01. An additional mixed-effects analysis with Tukey’s multiple comparison test was used to determine differences among mutants within each organ site. *P < 0.05, **P < 0.01.