FIG. 2.

ExoT inhibits internalization of P. aeruginosa by MDCK cells. Polarized monolayers of MDCK cells were infected apically at an MOI of 10 to 20 with the isogenic mutants of P. aeruginosa strain PA103 shown. (A) For strains containing no episomal vectors, the number of internalized bacteria for each well was normalized to the average number of internalized PA103pscJ::Tn5 bacteria. The normalized values were averaged to calculate the percentages of invasion, and the standard errors of the means for 17 to 18 experimental points are shown. The actual average numbers of internalized bacteria per well for PA103pscJ::Tn5 and standard errors of the means for the three experimental rounds shown were 691.67 ± 64.16, 955.00 ± 134.46, and 591.83 ± 119.14. (B) For strains containing episomal vectors, the number of internalized bacteria for each well was normalized to the average number of internalized PA103ΔUΔT+pUCP20 bacteria. The normalized values were averaged to calculate the percentages of invasion, and the standard errors of the means for 10 to 12 experimental points are shown. The actual average numbers of internalized bacteria per well for PA103ΔUΔT+pUCP20 and standard errors of the means for the two experimental rounds shown were 1,911.67 ± 484.49 and 3,873.33 ± 292.64.