Fig. 3
In vivo validation of the phenotype of a S. Typhimurium ptsN mutant. (a) The TraDIS fitness scores of transposon-insertion mutants of ptsN indicate attenuation in MLNs but not in the ileal wall. (b) Competitive index scores of ST4/74 nalR ∆ptsN::cat compared to the wild-type ST4/74 nalR confirmed the phenotype predicted by TraDIS in the ileal wall and MLNs. CIs in the caecal lymph node, liver and spleen show attenuation of ST4/74 nalR ∆ptsN::cat in these tissues. CIs in faecal samples decreased over time. (c) Bacterial counts confirmed the total challenge dose of 3.07 × 108 CFU of mutant and wild-type bacteria and recovery of viable bacteria per tissue per calf is shown