FIG. 2.

Caco-2 invasion efficiencies of L. monocytogenes 10403S, ΔinlA, ΔflaA, and ΔinlAΔflaA strains grown to early stationary phase with aeration (i.e., shaking at 220 rpm) at either 30°C or 37°C. Data represent the mean of four biological replicates. Error bars represent SDs. Strains with different letters had significantly different invasion efficiencies at a given growth temperature (p < 0.05; post hoc Tukey HSD); lower invasion for the ΔflaA strain than the parent strain (for growth at 37°C) was only borderline significant (p = 0.0279; Tukey HSD). Two-way ANOVA was performed within each temperature to determine effects of single and double mutations on invasion efficiency (see Table 3 for p-values). HSD, honestly significantly different.