Extended Data Figure 2. The FimH adhesin is required for type 1 pilus-dependent colonization of the mouse gut and for binding to human intestinal epithelial cells.

(a) C3H/HeN mice from Envigo were pretreated with streptomycin and concurrently colonized with 1×10⁸ CFU of WT UTI89 and UTI89ΔfimH. The WT strain outcompetes the strain lacking the FimH adhesin. (b) The ability of purified FimH lectin domain (FimH^LD) to bind to Caco-2 cells was assessed by a FimH-ELISA. Pre-incubation of FimH^LD with D-mannose (1mM) or M4284 (1mM) results in significant reductions in FimH binding to Caco-2 cells while 10% cyclodextrin (M4284 vehicle) had no significant effect. All data shown are normalized to wells that were not exposed to the purified adhesin. Abbreviations CI= competitive index. Ce= cecum, Col= colon. Bars represent mean values ± SEM, *p<0.05, **p<0.01, ***p<0.001, Wilcoxon Signed Ranked test in (a). Bars represent median (b). n=14 mice, 3 biological replicates (a); n=4 wells examing FimH binding to Caco-2 cells per protein concentration, 4 technical replicates (b).