Figure 6: Cell-tracking analysis of bacterial motility on mannosylated surfaces.

E. coli cells piliated with FimH^F18 or the FimH^F18-Ala188Asp variants were tracked under static conditions in the absence of shear force. (a) The fraction of bacteria attached to mannose-coated (1M-BSA) or BSA-coated surface (negative control) at the beginning of the time-lapse movies (white bars) and after 5 min (black bars) are given. Bacterial motility on 1M-BSA was analysed in the absence and presence of HM. The delay between application of bacteria and movie recording was ∼1 min. (b) Fraction of tracked cells that were pre-attached (yellow; speed <0.5 μm s⁻¹), permanently attach (red), were mobile (white), transiently attach (green) or permanently detach (blue) during the entire observation time (5 min). Right: schematic depiction of the observed cell behaviour. FimH^F18-piliated E. coli show almost exclusively transient attachment events on 1M-BSA. FimH^F18-Ala188Asp-piliated E. coli show less transient attachment but enhanced permanent attachment to 1M-BSA. Transient and permanent attachment to 1M-BSA is significantly reduced in the presence of HM. For each experiment five to seven independent replicates were analysed.