Fig 6.

Preincubation of S. suis and swH1N1 significantly increases bacterial adhesion to and invasion of NPTr cells. swH1N1 and S. suis serotype 2 strain 31533 cells (1:1 ratio; TCID₅₀/CFU) were preincubated for 1 h at 4°C. This mixture (V+B) was then added to NPTr cells for an incubation time of 1 or 2 h for adhesion or invasion assays, respectively, as described in Materials and Methods. Mock-treated bacteria were used as the control (B). Data are expressed as means ± standard errors of the means from at least three independent experiments. An asterisk indicates a significant difference (P < 0.01).