Figure 2.
L. monocytogenes outbreak strains exhibit increased virulence in mice. BALB/c mice were infected intravenously with 1–2 × 104 CFU (a) or orogastrically inoculated with 3–4 × 109 CFU of L. monocytogenes 10403S, LS741 or LS743 (b). At 72 hours post-infection the liver, spleen, and brain of each mouse were collected and the bacterial burden determined. Horizontal lines indicate median values. The Mann-Whitney test was used to assess statistical significance between bracketed groups: *P < 0.05, **P < 0.01. The dotted line in panel b indicates a limit of detection of 5 CFU per organ.