Figure 3From: DctR contributes to the virulence of avian pathogenic Escherichia coli through regulation of type III secretion system 2 expressionBacterial resistance to specific-pathogen-free (SPF) chicken serum. APEC strains were incubated with different dilutions of SPF chicken serum at 37 °C for 30 min and the surviving bacteria were counted. Mutant strain shows decreased survival in SPF chicken serum compared with wild-type and complemented strains. A two-way ANOVA was performed for the survival assays (*P < 0.05).Back to article page