Figure 4.

CcScsC wt functionally complements PmScsC in P. mirabilis swarming-motility assays. P. mirabilis strain PM54 with scsC deleted (PM54ΔscsC; Furlong et al., 2017 ▸) was complemented with pSU2718 plasmid vectors expressing PmScsC, CcScsC wt or the empty vector control (VC). Strains were assessed for swarming motility on the surface of LB agar in the presence of copper (a) or in the absence of sodium chloride (b), as detailed in Section 2 and described previously (Subedi et al., 2021 ▸; Furlong et al., 2017 ▸). (a) The swarming surface area was measured for each strain after 24 h of incubation at 37°C on LB Lennox agar plates containing 1.6 mM CuSO₄, 100 µM IPTG and 17 µg ml⁻¹ chloramphenicol and expressed as the percentage swarming increase over PM54ΔscsC vector control (VC). The median with interquartile range for the percentage swarming increase over the VC is plotted for each strain from eight biological repeats. (b) Swarming-plate images of each strain streaked on NaCl-free LB agar. Plates were incubated at 37°C for 24 h in NaCl-free LB agar (1.5% agar) supplemented with 100 µM IPTG and 17 µg ml⁻¹ chloramphenicol. The swarming-motility fronts are marked by black arrows. Images are representative of three independent biological repeats.