A, B), D66-resistant mutants selected for in an ΔacrAB mutant strain background. A) Diagram showing the hns mutation in six independent D66-resistant clones. B). RAW 264.7 cells were infected with S. Typhimurium SL1344, ΔacrAB or the six D66 resistant mutants as indicated. After 18 hours of infection, cells were lysed and plated for enumeration of CFU. Numbers above bars indicate percent of wildtype (SL1344) CFU/mL. Mean and SEM of biological triplicates with technical triplicates. A one-way ANOVA with a Dunnet’s multiple comparison test: P = 0.005 for ΔacrAB and < 0.001 for all resistant mutants, compared to the wild-type strain. C) D66-resistant mutants selected for in the presence of PMB. The five independent clones identified were all resistant to PMB at concentrations 4-8X higher than the parent strain, which grew to an OD600 of 1.2. A one-way ANOVA with a Dunnet’s multiple comparison test: * P < 0.05 compared to the corresponding strain without PMB.