FIG. 2.

INT-407 cell invasion assay. Cells were infected with the wild type and mutants for 2 h, and invasion values were calculated from the number of bacteria that survived 2 h of incubation in the presence of gentamicin. Values are given relative to the invasion of the wild-type strain 81-176, which was set at 100%. The experiment was performed in triplicate and repeated on at least three separate occasions. The error bars represent standard deviations of triplicate wells. Statistical significance was assessed with an unpaired Student t test. *, P < 0.01.