Rex is required for full virulence in an oral listeriosis model.
Female BALB/c mice were orally infected with 108 CFU of wt (black open squares), Δrex (blue circles), or Δrex p-rex (blue open triangles) and the number of bacteria present in each tissue was determined at 1 and 4 days post-infection. A. The body weights of the mice over time, reported as a percentage of body weight prior to infection. For wt and Δrex, data are the means and SEMs of n = 30 (day 1), n = 20 (day 2), n = 15 (day 3), and n = 10 (day 4). For Δrex p-rex, data represent the means and SEMs of n = 10 (day 1) and n = 5 (days 2–4). Significance between wt and Δrex is denoted by *, while # indicates significance between Δrex and Δrex p-rex. B-H. Mice were sacrificed each day and organs were harvested to enumerate bacterial burden. Each symbol represents an individual mouse (n = 10 per group for wt and Δrex and n = 5 per group for Δrex p-rex) and the solid lines indicate the geometric means. Dashed lines indicate the limit of detection (l.o.d.). Data are combined from two independent experiments for the wt and Δrex strains. Results are expressed as log-transformed CFU per organ or per gram of feces. p values were calculated using a heteroscedastic Student’s t test. * or # p < 0.05; ## p < 0.01; *** p < 0.001; **** p < 0.0001.
