FIG. 4.

Comparative colonization of bladders and kidneys of CBA/J mice coinfected with UPEC CFT073 derivatives defective in zinc transporter systems and virulent CFT073 Δlac derivative strain QT1081. A competitive coinfection model was used in which a mixture of QT1081 and different metal transporter mutants were inoculated simultaneously. At 48 h postinfection, tissues were sampled, and results are presented as the log₁₀ CI. The CI represents the ratio of numbers of the two test strains (mutant/Δlac virulent strain QT1081) from the tissues sampled (the output ratio) normalized for the initial numbers of each strain in the inoculum (input). Negative CI values indicate a decreased capacity for the mutant to compete with the virulent test strain QT1081. Horizontal bars indicate the median log₁₀ CI values. Each data point represents a sample from an individual mouse. Both kidneys were sampled separately. Strains tested: strain QT1434 (Δznu), strain QT1554 (ΔzupT), strain QT1555 (Δznu ΔzupT), and strain QT1932, the Δznu ΔzupT mutant complemented with znaACB. Statistically significant decreases in CI values are indicated by asterisks (*, P < 0.001) as determined by the Wilcoxon matched-pair test.