FIG 5.

A prfA* mutation in L. monocytogenes strain 10403S leads to increased production of InlB and InlB-dependent hepatocyte invasion. (A) Bacterial lysates (1.6 × 10⁸ cells) were subjected to Western blot analysis using anti-InlB and anti-p60 (loading control) antibodies. A representative Western blot is shown (n = 3). (B and C) PLC5 cells were infected with WT, ΔinlB, WT-prfA*, or ΔinlB-prfA* bacteria (MOI of 5) for 30 min at 37°C. Cells were washed, fixed, and labeled with fluorescent antibodies and DAPI. (B) The bacterial association efficiency was calculated as the total number of bacteria associated per host cell. (C) The bacterial internalization efficiency was calculated as the percentage of intracellular bacteria. (B and C) A minimum of 2,000 bacteria were counted per condition, and a minimum of 500 host cells were counted per condition. Results are expressed as the mean ± SEM (n = 4; *, P < 0.01; **, P < 0.001, n.s., non-statistically significant).