Abilities of C. jejuni strains to adhere to and invade INT407 cells. Strains 81–176 (black), 81–176cj0596 (red) and 81–176cj0596+ (blue) were grown to mid-log phase in biphasic culture. INT407 monolayers were inoculated with bacteria at an MOI of ~40. After 3 h, the cells were washed and bacteria adhered were enumerated (A). Gentamicin was added to another plate of cells and incubation was continued for an additional 2 h after which the cells were washed and bacteria invaded were enumerated (B). Statistical significance (p < 0.001) is represented by two asterisks.