FIG 4 .

Antibiotic priming increases the invasive capacity of UPEC. (A) E. coli UTI89 IBC quantity at 6 h p.i. of C3H/HeN bladders. (B and C) Representative confocal images of control (B) and antibiotic-pretreated (C) E. coli UTI89 IBCs in C3H/HeN mouse bladders 6 h p.i. (red, GFP/UTI89; blue, Syto9/nuclei; green, WGA/cell). (D) Early pathogen evacuation from an IBC via filamentation (arrows) in a ciprofloxacin-pretreated sample. (E) Volumetric analysis of confocal images is depicted for both control and antibiotic-pretreated IBCs. Means from at least two independent experiments are shown. Significance was determined using a one-way ANOVA, Dunnett’s multiple comparison test, or the Mann-Whitney test. *, P < 0.05; **, P < 0.01.