(A) Defective recovery of ClpB-deficient Mtb from stationary phase. Growth of H37Rv (circles), H37RvΔclpB (squares) and the complemented strain H37RvΔclpB∷clpB (triangles) in 7H9 medium using inocula from logarithmic phase (black), early stationary phase (gray) or late stationary phase (open symbols). Mean ± SD of 2 experiments, each in duplicate.
(B) Excessive accumulation of carbonyls in ClpB-deficient Mtb in stationary phase. ATPAH reactivity (arbitrary fluorescence units) was compared in late stationary phase in H37RvΔclpB and H37RvΔclpB∷clpB cells relative to that in wild type H37Rv, which was set to 1. Mean ± SD of 4 experiments, each in duplicate.
(C) Attenuation of ClpB-deficient Mtb in mice. Colony-forming units (CFU) of H37Rv (circles), H37RvΔclpB (squares) and H37RvΔclpB∷clpB (triangles) in lungs of C75BL/6 mice at the indicated times after aerosol infection. Means ± SD for 5 mice per time point from one experiment representative of 2.
(D) Diminished histopathology caused by ClpB-deficient Mtb. Sections of lungs collected at day 120 from mice infected with the indicated strains were stained with hematoxylin and eosin. Photographs show the sections at their actual size.