Invasive capacity of P. mosselii ATCC BAA-99, P. mosselii MFY161 and P. aeruginosa PAO1. 4 h after infection of Caco-2/TC7 cells with the bacteria, extracellular germs were killed by gentamicin. Cells were lysed and the intracellular bacteria were enumerated by plating onto nutrient agar medium. Results were calculated as the mean values (+/−SEM) of three independent experiments. * P < 0.05 versus P. mosselii ATCC BAA-99 and P. mosselii MFY161, NS not significant between P. mosselii ATCC BAA-99 and P. mosselii MFY161.