The effects of ClpP and ClpS/ClpA on P. aeruginosa virulence.

(A and B) The production of pyocyanin was evaluated in wild-type PAO1, ΔclpSΔclpA, ΔclpP, ΔclpSΔclpAΔcdpR, ΔclpPΔcdpR, and their complemented strains. **p < 0.05 based on Student’s t test. EV represents empty vector. (C) The expression of phzA1-lux in wild-type PAO1, ΔclpSΔclpA, ΔclpP, ΔclpPΔcdpR and ΔclpSΔclpAΔcdpR strains. Results represent means ± SD, and data are representative of two independent experiments. (D) Deletion of clpP or clpS/clpA in P. aeruginosa decreased the pathogenicity in a mouse model. C57BL6 mice were intranasally challenged with wild-type PAO1, ΔclpP, ΔclpSΔclpA, and the complemented strains (ΔclpP/CTX-clpP, ΔclpSΔclpA/CTX-clpSclpA) at 1x107 cfu in 50 μL PBS, and moribund mice were killed to obtain survival data (Kaplan-Meier Curve with Log-Rank test, p = 0.0043 (ΔclpP), p = 0.0028 (ΔclpSΔclpA), n = 6).