FIG 4.

The NRG857ΔPI-6 and NRG857ΔarlA strains exhibit decreased competitive fitness during infection. (A to E) CD-1 mice were infected with equivalent numbers of each strain indicated, and wild-type and mutant AIEC were quantified in fecal output. Data represent the means plus standard errors of the competitive index from 10 to 15 animals from three separate experiments. (F) Complementation of NRG857ΔPI-6 strain with PI-6 in vivo. Data are the means plus standard errors from two separate experiments (five animals per experiment).