Swarming motility of L. monocytogenes strains expressing chimeric DivIVA proteins. Strains EGD-e (wt), LMS2 (ΔdivIVA), LMS30 (+Lm divIVA), LMKK8 (+Bs divIVA), LMKK13 (+Lm-104-Bs divIVA), LMS157 (+Lm-71-Bs divIVA), LMKK12 (+Lm-57-Bs divIVA), LMKK14 (+Bs-57-Lm divIVA), and LMS149 (+Bs-17-Lm-104-Bs divIVA) were stab inoculated into LB soft agar (containing 1 mM IPTG) and cultivated for 24 h at 30°C. The diameters of their swarming halos were determined in four independent experiments and plotted in the diagram shown below. Significance levels are indicated: ***, P < 0.0001; **, P < 0.001; *, P < 0.01.