We hypothesized that difference in EGR1 induction might be dependent on the amount of bacteria in contact with the host cells. We therefore determined the level of adhesion for each bacterial strain (Figures 1I–L). However, we could not find any correlation between attachment and EGR1 upregulation. For example, S. enterica serovar Enteritidis and S. enterica serovar Typhimurium adhered to the host epithelial cells at similar levels, but only S. Enteritidis induced EGR1 whereas S. Typhimurium did not (Figures 1D,L).