Figure 8.

Assessment of the role of vacuolar pH in PhoPQ induction. (A) Experimental design. The diagram indicates when concanamycin A (CcA; 30 nm) was added to the cells with respect to the time of infection. N.T., not-treated with CcA. Note that each protocol corresponds to one of the symbols used in B-E. (B-D) RAW264.7 macrophages subjected to the specific protocol described in A were infected with Salmonella Typhimurium pMLZ205 at a MOI of 10 for 15 min and analyzed by flow cytometry at the specified times. (B) Total fluorescence; (C) mean fluorescence intensity of infected cells; (D) percentage of cells expressing GFP. Data in B-D are representative of five similar experiments. (E) Quantitation of viable bacteria recovered from infected cultures, performed by cell lysis and plating of lysates on LB agar plates. Data in E are means ± SE of three independent experiments with triplicates for each determination.