Fig 2.

Analysis of FlfA surface exposure in G. anatis 12656-12. (A) FACS analysis demonstrating FlfA surface exposure on WT cells in the mid-logarithmic growth phase. Bacterial cells were incubated with preimmune serum (gray shaded) or anti-FlfA immune serum (red line). (B) The specificity of the signal in panel A was verified by incubation of WT cells (red line) or ΔflfA mutant cells (blue line) in anti-FlfA immune serum. (C) The surface exposure of FlfA was confirmed by using confocal immunofluorescence microscopy. G. anatis 12656-12 WT cells (panels a and b) or ΔflfA mutant cells (panel c) were incubated with anti-FlfA immune serum, followed by incubation with rhodamine RedX-labeled secondary antibody (red staining). DAPI (blue staining) was used to localize the bacterial cells. Staining of the WT cells from the same culture indicated the presence of a low-level (panel a) and a hyperfimbriated (panel b) population of cells. Magnification, ×63. Scale bar, 1 μm.