FIG 2.

AtvR is important for resistance to macrophages and affects their activation. J774 macrophages were treated with DPI for 4 h. Control and DPI-treated macrophages were incubated with P. aeruginosa PA14 or the ΔatvR mutant at an MOI of 10. (A) The cells were washed with PBS, R-10 medium containing 200 μg/ml gentamicin was added to the wells, the plate was incubated for 30 min, the wells were washed, and fresh medium was added. At the indicated time points, the supernatants were collected and diluted, and the number of CFU of extracellular bacteria was determined. **, P < 0.01; ***, P < 0.001. (B) The macrophages were infected, treated as described in the legend to panel A, and lysed with Triton X-100. The released bacteria were diluted, and the number of CFU of intracellular bacteria was determined.