Figure 5.

Effect of chiB correction on virulence. (a) Invasion of the gastroenteritis isolate 15-01121, the invasive isolate 15-01429 and the gastroenteritis isolate with the corrected chiB gene 15-01121-chiB⁺ into different cell types. L. monocytogenes strain EGD-e was included as control. EGD-e values were set to 100%, average values are shown and standard deviations are indicated. Significant differences compared to 15-01121 are indicated by asterisks (t-test, P < .01). (b) Intracellular growth of the same set of strains in J774 mouse macrophages. L. monocytogenes strains EGD-e and LMS2 (ΔdivIVA) were included as controls here. All experiments were performed as triplicates and average values and standard deviations are shown. Significant differences are indicated by asterisks (t-test, P < .01). (c–d) Mouse infection experiment. C57BL/6 mice (n = 5) were infected via their tail vene with 5 × 10⁴ bacteria and the bacterial load in liver (c) and spleen (d) was determined on day 3 post infection. Data are represented as box plot and differences statistically significant according to the Brown–Forsythe test are indicated with asterisks.