The Vibrio cholerae RND efflux systems impact virulence factor production and adaptive responses via periplasmic sensor proteins
Fig 2
(A & B) The indicated V. cholerae strains were cultured under AKI conditions for 3.5h when total RNA was isolated and used for qRT-PCR to quantify aphA, aphB, tcpP and toxR expression. P-values are relative to a hypothetical ratio of 1.0 and were determined using the Student’s t-test. * P<0.05. (C) ToxR Western blot. The indicated strains were grown under AKI conditions for 6h when aliquots were collected, normalized by OD600, and subjected to Western blotting with anti-ToxR antibody. The extra non-specific bands serve as loading controls. (D & E) Overexpression of leuO represses aphA-lacZ, but not rxtB-lacZ expression in E. coli. E. coli containing pBAD33::leuO or pBAD33 and a (D) aphA-lacZ or (E) rtxB-lacZ reporter plasmid was cultured in LB broth to mid-log phase (5h) when β-galactosidase activity was quantified. The data are the mean ±SD of 3 independent experiments. * P≤0.05 relative to the no arabinose control.