FIG 7 .

Phenotypic readouts of the ipuS phase state in a CFT073 background. (A) Swimming motility of phase-locked strains. One microliter of liquid culture normalized to an OD₆₀₀ of 0.01 of each of the strains WAM2266 (WT), WAM5088 (ipuS ON/fimS OFF), WAM5063 (ipuS OFF/fimS OFF), WAM5064 (ipuS ON/fimS ON), and WAM5065 (ipuS OFF/fimS ON) was inoculated in the center of 7 plates containing Adler’s motility medium. Values represent diameter of the swimming zone after ~21 h of room-temperature incubation (Mann-Whitney test, P < 0.005). (B) Seventy-two-hour competitive infection of WAM5064 (fimS ON, ipuS ON) versus WAM5146 (fimS ON, ipuS OFF, lacZYA). Relative competitive indexes were calculated from bladder and kidney homogenates at 72 hpi with lines representing the medians. WAM5064 (ipuS ON) has a 5-fold advantage in the kidneys (*, P < 0.05, Wilcoxon signed-rank test) at 72 hpi. (C) Adherence to A-498 human kidney epithelial cells. WAM2266 (WT), WAM5088 (ipuS ON/fimS OFF), WAM5063 (ipuS OFF/fimS OFF), WAM5064 (ipuS ON/fimS ON), and WAM5065 (ipuS OFF/fimS ON) were allowed to adhere to monolayers of A-498 cells, and then unbound bacteria were removed by washing. In a fimS OFF background, turning ipuS ON causes a 5% increase in adherence (WAM5088 versus WAM5063) (P < 0.05, t test).