FIG 5.

Blocking yersiniabactin import attenuates E. coli during systemic infection. Ten female CBA/J mice were intravenously coinoculated with an equal mixture of wild-type E. coli 536 and E. coli 536ΔfyuA::kan, and organ colonization was measured 21 h postinoculation. Competitive indices were calculated by dividing the fraction of the mutant in the output (CFU/g tissue) by the fraction of the mutant in the input (CFU/g inoculum). The median value for each group is represented as a solid line, and the dotted line indicates a theoretical median of zero, which would occur if both wild-type and mutant E. coli strains had equal representation in both the input and the output. Three mice succumbed to the infection before being euthanized and were excluded from the analysis. Significance was determined by the Wilcoxon signed-rank test with a theoretical median of zero, and the P value for each group was 0.0313 for the kidneys and 0.0313 for the spleen.