FIG 6.
Loss of σB activity is associated with a competitive advantage at 42°C. Shown are data for mixed cultures at ratios of 1,000:1 of the WT with 2RsbU (E103K) (A), the WT with B14:A6 (B), and the WT with the ΔsigB mutant (C) incubated at 42°C and the WT with the ΔsigB mutant incubated at 30°C (D). Passages were made every 24 h for 5 days. WT and transposon mutant strains were distinguished by erythromycin resistance. WT and ΔsigB mutant strains were distinguished by colony color. Results are depicted as relative abundances of CFU per milliliter. Data were generated from three independent biological replicates. Statistical analysis was performed using a paired Student t test (*, P value of <0.05; **, P value of <0.01; ***, P value of <0.001; NS, nonsignificant).