FIG 6.

Confocal spinning-disk microscopy images of biofilm formed by adhesin mutants in flow cells. The indicated strains were grown as described in Materials and Methods and incubated at room temperature under constant flow for 96 h before imaging. Shown are representative images taken from one of two biological replicates. (A) The WT forms a thick biofilm that fills most of the flow cell chamber. (B) The ΔlapA mutant is severely deficient in biofilm formation, and only small clumps of cells are observed attached to the surface. (C) The ΔmapA mutant appears able to attach to the surface of the chamber, but the thickness of the biofilm is reduced compared to that of WT. (D) The ΔlapA ΔmapA mutant results in a biofilm comprised of sparsely distributed clumps of cells.