VtaA8 and VtaA9 reduced the bacterial interaction with porcine alveolar macrophages (PAM). E. coli EPI300 clones pMCH-vtaA8 (vtaA8) and pMCH-vtaA9 (vtaA9), also carrying pEGFP, were incubated for 1 h or 3 h with PAM and the interaction with the macrophages was analysed by flow cytometry. Results show the macrophages with fluorescent bacteria given by GFP and measured in FL1 (gates B and C, for 1 h and 3 h, respectively). E. coli with the empty vector pACYC184 and pEGFP was used as a control. Percentages of macrophages in gates A, B and C are included in the panels.