TABLE 3.
Quantitative assessment of the ability of atypical EPEC strain E128012 and its isogenic derivatives to adhere to cultured epithelial cells
| Strain | Characteristic(s) | Adherence to HEp-2 cells (%)a | Adherence to T84 cells (%)b |
|---|---|---|---|
| E128012 | Wild type | 56.9 ± 8.9 | 109.6 ± 21.7 |
| CY88 | pstCA mutant | 10.4 ± 1.4c | 8.8 ± 6.6c |
| CY88(pAC2) | Trans-complemented pstCA mutant | 42.9 ± 4.0 | 90.8 ± 25.8 |
| CY91 | pstCA phoB double mutant | 54.4 ± 5.4 | 96.9 ± 16.2 |
For HEp-2 cells, bacterial adherence is expressed as the number of cells with at least five attached bacteria as a percentage of the total number of cells counted. At least 100 cells were counted in each assay, which were performed in triplicate. Data are the means ± SD of the results.
For T84 cells, bacterial adherence is expressed as the percentage of the initial inoculum recovered from T84 cells after incubation for 3 h at 37°C and removal of nonadherent bacteria. Data are the means ± SD of the results of five separate determinations.
Significantly lower (P < 0.001) than the results for all other strains tested (two-tailed Student's t test).