Decreased fitness of ΔrqlI mutants within diverse host niches is attributable to RqlH.

(A) WT F11 or F11ΔrqlI were inoculated into Balb/c mice via oral gavage and feces were collected, homogenized, and plated to determine bacterial titers at the indicated time points. For competitive assays, (B) F11 and F11ΔrqlI or (C) F11 and F11ΔrqlHI were mixed 1:1 prior to delivery into mice via oral gavage. Graphs show competitive indices (CI), as determined by dilution plating of fecal homogenates on selective media at the indicated time points. (D) F11 and F11ΔrqlHI were inoculated transurethrally as a 1:1 mixture into the bladders of Balb/c. CI values were calculated from bacterial titers recovered from bladders at 3 d post-inoculation. (E) F11 and F11ΔrqlHI were mixed 1:1 and injected intraperitoneally into mice to initiate systemic infections. At 12 h post-inoculation, the spleen, liver, and a kidney were isolated from each mouse, homogenized, and titered to determine the CI of the ΔrqlHI mutant. Bars indicate median values.