Fig. 6.

Intracellular bacterial growth in polarized macrophages induced by different LPS. LPS derived from biofilm-forming or planktonic PAO1 was added to Raw264.7 cells and PMA-differentiated THP-1 cells respectively at a concentration of 100 ng ml⁻¹. The cells were washed twice with PBS 5 h later. Polarized macrophages were infected with PAO1 at an MOI of 10. Two hours later, the cells were washed twice with PBS, gentamicin (200 µg ml⁻¹) was added to kill non-phagocytosed bacteria. Intracellular bacteria were determined 2 h later. Data are shown as the mean of triplicate wells±SD. Significant differences were calculated using the Student’s t-test; *P<0.05, **P<0.01, ***P<0.001.