Fig 8. Adhesion and invasion to Ca9-22 epithelial cells.

The percentage (vs. inoculum) of (A) adherent external and internal bacteria (“associated”), or (B) internal bacteria, which are remaining after incubation with Ca9-22 was assayed by counting colony forming units of bacterial cells per millilitre. Wild-type (■), cydAB mutant (▲) and complemented cydAB mutant (●). Bars represent mean with standard errors and asterisks indicate statistically significant differences between values of wild-type strain, mutant and complemented mutant strains (** p<0.01).