The panel labels in Figure 1 do not line up with the images or with the callouts in the text, and it is hard to follow the colonization claim until they do.
As printed, panel A looks like Calcofluor White fluorescence of the spines, which matches the legend, but that panel is never cited. Calcofluor staining is only pointed to later, as Fig. S4. Panels B and C look like bright-field or epifluorescence of bacteria on spines, not SEM. Panels D and E look like the SEM overview and the pili close-up. The quantitative panels then appear to be F-H.
The main text cites a different map. It calls 1B bright-field and 1C SEM, then later cites SEM as 1B. It sends the day-6 / day-14 colonization percentages to 1D, the "one to three bacteria per cell" count to 1E, and the cell-wall attachment image to 1F. In the legend those letters are the SEM panels and the first quantification plot. The same letters are then reused: 1E is also cited for exclusive spine attachment versus the cell body (legend: H), and 1F-G later for the low number of spine-associated bacteria (legend: the counts), after 1F has already been used for the cell-wall image.
A single consistent key in the figure, the legend, and the Results would make the attachment observation much easier to trust. Right now a reader cannot tell which image is meant to support which sentence.