FIG 6.
Virulence gene expression during TC-promoted biofilm detachment. (A) Expression of major virulence factor tcpA in biofilm-resident cells and detached cells as shown by a tcpA promoter-luciferase reporter fusion (PtcpA-lux). Data are means and SD from three independent experiments. ****, P < 0.0001. RLU, relative light units. (B) Flow cytometry plot of V. cholerae harboring a plasmid with constitutive mCherry (Ptet-mCherry) and PtcpA-gfp, in which mCherry indicates cells and GFP indicates tcpA expression. Average percentages of GFP-positive cells from three independent experiments are listed in each graph. (C) TC promotes both dispersal of individual cells from V. cholerae biofilms as well as induction of virulence program in the small intestine, synergistically enhancing colonization.