Figure 2 | Scientific Reports

Figure 2

From: Vibrio cholerae autoinducer-1 enhances the virulence of enteropathogenic Escherichia coli

Figure 2

EPEC grown in the presence of a V. cholerae supernatant shows elevated T3SS activity. (A) Scheme of the experiment: WT EPEC was grown in DMEM medium (red) in the presence of supernatants of bacteria grown in LB or plain LB (yellow). After 6 h of growth, the bacterial EPEC pellets and supernatants (sup) were separated and analyzed for T3SS activity. (B) WT EPEC strain was grown in DMEM medium mixed 1:1 (v/v) with plain LB, V. cholerae supernatant or E. coli DH10B supernatant for 6 h. The secreted proteins were then concentrated from supernatants of bacterial cultures and analyzed by 12% SDS-PAGE and western blot analysis using anti-EspB or anti-EspA antibodies (translocators). While low secretion of EspB and EspA were detected for EPEC grown in DMEM medium mixed 1:1 (v/v) with plain LB or in the presence of E. coli DH10B supernatant, high secretion of EspB and EspA were observed for WT EPEC grown in the presence of V. cholerae supernatant. (C) Whole cell lysates were analyzed for the expression of the structural T3SS protein, EscJ, and the effector protein Tir by loading the bacterial samples on SDS-PAGE and performing western blot analysis using anti-EscJ and anti-Tir antibodies. While low expression of EscJ and Tir were detected for EPEC grown in DMEM medium mixed 1:1 (v/v) with plain LB or in the presence of E. coli DH10B supernatant, high expression of EscJ and Tir was observed for WT EPEC grown in the presence of V. cholerae supernatant. Samples were also probed with anti-DnaK antibody to confirm equal loading of lysates.