Fig. 6

Cell phagocytosis, adhesion and invasion assays. a Phagocytosis of ΔqseBC, ΔapfA, ΔapfB, ΔapfC and ΔapfD strains. The strains were incubated with RAW264.7 cells at the multiplicity of infection (MOI) of 100 at 37 °C for 2 h. b, c Adhesion (b) and invasion (c) of ΔqseBC, ΔapfA, ΔapfB, ΔapfC and ΔapfD strains. The strains were incubated with NPTr cells at the MOI of 100 for 2 h of incubation at 37 °C. After washing out the unbound bacteria, the NPTr cells were lysed and the bacterial counts in the lysates were determined. Data are shown as mean ± SD (N = 3). *P < 0.05