FIG 2.

Persister formation during stationary phase in pcm mutants. Percentages of viable cells tolerant to treatment with 5 μg ml⁻¹ ofloxacin for the indicated times at 0 h (A) and 24 h (B) after the onset of stationary phase. The strains used are JV1120 (wild type; ●), JV1121 (Δpcm; ○), JV1136 (ΔglpD; ■), and JV1154 (Δpcm ΔglpD; □); asterisks indicate values significantly (P < 0.05) different from wild type. (C) Percentages of viable cells tolerant to 24-h treatment with ofloxacin at indicated times after cultures entered stationary phase; strains and symbols are as described for panel A. (D) Percentages of viable cells tolerant to 24-h treatment with ofloxacin 24 h after the onset of stationary phase for strains JV1120 (wild type [wt]), JV1121 (Δpcm), JV1155 (ΔphoU), JV1132 (Δpcm ΔphoU), JV1136 (ΔglpD), and JV1154 (Δpcm ΔglpD); asterisks indicate values significantly (P < 0.05) different from wild type. (E) Percentages of viable cells tolerant to 24-h treatment with ofloxacin after the indicated number of days in long-term stationary phase; strains and symbols are as described for panel A. (F) Percent survival (total viable cells) after the indicated number of days in long-term stationary phase; strains and symbols are as described for panel A. All values are averages of at least three replicates, and error bars represent one standard deviation.