QseC influences, but is not essential for, increased faecal excretion of Salmonella Typhimurium in response to 6-OHDA treatment. Plasma NE (ng/mL) was quantified by ELISA immediately before and 1 h after treatment with 40 mg/kg 6-OHDA or diluent 16 days post-inoculation with CFU ST4/74 nalR ΔqseC (panel A). The impact of 6-OHDA treatment on the course of faecal excretion of ST4/74 nalR ΔqseC is shown in panel B. Values shown are the least square means (LSM) ± standard error (SE) of the LSM. p values ≤ 0.05 are marked with an asterisk.