FIG. 5.

Effects of single and double mutations on iagB87::lacZY expression and invasion of HEp-2 cells. The following mutations were used in these experiments: fadD1::Tn5, pst-4::Tn10, sirA2::kan, envZ182::cam, and flhC4::Tn5. fliA51::Tn5 was used in combination with the pst-4::Tn10 mutation, but all other fliA mutants contain fliA36::Tn5B50. (A) Fold reduction in iagB87::lacZY expression. Each value was calculated by dividing the β-galactosidase activity of CL87 (613 ± 100 Miller units) by the β-galactosidase activity (Miller units) of each mutant (n ≥ 4). a, standard deviation (SD) ≤ 0.6; b, SD < 2; c, SD ≤ 3.4; d, SD = 4.9. (B) Fold reduction in invasion indices. Values were calculated by dividing the invasion index of CL87 by the invasion index of each mutant (n ≥ 3). The invasion index for each strain was determined by measuring the percentage of bacterial inoculum surviving gentamicin treatment. a, SD ≤ 1.5; b, SD = 2.8; c, SD ≤ 18.1; d, SD ≤ 31.5. ND, not determined.