FIG 6.

LecB promotes crawling of P. aeruginosa underneath cells. (A) Sparsely seeded MDCK cells were incubated with GFP-tagged PAO1-wt or LecB-deficient PAO1-dLecB (green) at an MOI of 50 for 1 h. After fixation, β1-integrins were stained in red. For each condition, a confocal x-y section at the level of cell adhesion to the substrate, which was taken from a complete three-dimensional confocal stack, is displayed. Arrows indicate bacteria underneath cells. (B to D) After carrying out an experiment as described for panel A but with the indicated MOIs and incubation periods, the numbers of bacteria underneath cells were determined per cell. Each data point represents an individual cell, and the black lines indicate the mean and the SEM. For evaluating statistical significance, Mann-Whitney testing using GraphPad Prism 5 was applied; ****, P < 0.0001.