Extended Data Fig. 4: Activation of the Rcs pathway results in attenuated phage infection and reduced swimming motility.
a, During infection on plates, strain igaA is resistant to all phages. Faint clearing of the mdoG lawn is visible at high titers for flagellatropic phages OT8, JS26 and PCH45 (-1; ~109 PFU/ml and -2; ~108 PFU/ml). Infection of mdoG by LC53 is reduced on plates compared to WT. b, Strain mdoG is resistant to infection by flagellatropic phages in liquid, while remaining susceptible to phage LC53 (n = 3 biologically independent samples; lines represent the mean + /- the standard deviation). MOI, multiplicity of infection. c, Reduced swimming in mdoG and null swimming in igaA mutants is consistent with activation of the Rcs pathway. Deletion of rcsB (ΔrcsB) restores swimming motility to wild-type levels in mdoG and igaA mutant backgrounds, while deletion of the rcsA homolog RS09790 (ΔrcsA) does not. The partial restoration of swimming in strain igaA upon rcsA deletion is consistent with partial increase in flhDC expression (Extended Data Fig. 6), as well as partial re-sensitization to flagellatropic phages. (Extended Data Fig. 5). Deletion of both rcsA and rcsB (ΔrcsAB), results in similar swimming motility as the rcsB deletion.
