VtaA2 has no role in the adhesion to lung epithelial cells A549 cells. Adhesion of the clones E. coli BL21 (pLGR-vtaA2) and (pACYC184) to lung epithelial cells A549 after 1 h of incubation (black bars). Concentration of bacteria in the wells at the beginning of the assay are shown in gray bars. Bars represent the mean ± standard deviation of the concentration of bacteria from duplicate wells. Results are representative of 2 independent experiments.