<p>(A) Wild-type (WT) <i>Salmonella</i> carrying a chromosomal <i>invF-lacZ</i> fusion and either the control plasmid, pUHE21-2<i>lacI<sup>q</sup></i> or the <i>lasR</i><sup>+</sup> plasmid pJH1 were grown in LB with shaking for 4 h. Production of LsrR was induced by the addition of 100 µM IPTG. (B) WT <i>Salmonella</i> carrying pJH1 were grown LB or LB supplemented with 100 µM IPTG, with shaking for 4 h. The mRNA levels of SPI-1 genes were determined by qRT-PCR. Shown in (A) and (B) are the mean values and standard deviation of three independent experiments. (C) Western blot analysis was conducted on cell extracts prepared from the strain harboring either pUHE21-2<i>lacI<sup>q</sup></i> or pJH1 grown in LB with 100 µM IPTG, with shaking for 4 h. These strains express the SopB protein tagged with a HA-epitope from the normal chromosomal location.</p
