The epithelial cells were infected with bacteria to a MOI of 100. The bacteria were not removed after addition to the epithelial cells. After incubation, the cells were washed three times with PBS to remove unbound bacteria. Bacterial adherence was estimated from viable counts by lysing the host epithelial cells with 1% saponin in cell culture medium for 10 min and plating serial dilutions. Viable counts for P. aeruginosa were performed on Luria agar plates, incubated at 37°C and 5% CO2 and the colony forming units (cfu) were counted the following day. Viable counts for H. pylori were performed on blood agar plates incubated at 37°C under microaerophilic conditions for 4–7 days. Viable counts for all other bacteria were performed on GC agar and incubated at 37°C and 5% CO2 for 1–2 days.