FIG 1.

DksA is required for S. Typhimurium growth in minimal medium but not in rich LB broth. (A) The growth of the clinical isolates 85982 (containing the amino acid substitution N88D in DksA) and 87541 (harboring wild-type DksA) and that of isolate 85982 harboring pWSK29 or pWSK29::dksA₈₇₅₄₁ were compared in M63 minimal medium at 37°C under aerobic growth conditions. (B and C) S. Typhimurium SL1344 (WT), its derivative dksA-null mutant strain, and the dksA mutant harboring the plasmid pWSK29 or the dksA gene (from SL1344) cloned into pWSK29 were grown in LB for 16 h, diluted 1:100 into fresh LB (B) or M63 (C) and grown at 37°C with aeration. OD₆₀₀ was recorded at the indicated time points. Data are mean OD₆₀₀ for three to four independent cultures and standard errors of the means (SEM).