Table 2.

Binding of E. coli strains expressing or not expressing OapA to Chang epithelial cells

E. coli strains and phenotypeNo. of bacteria bounda
CFU/well% of inoculum
DH5α(pUC4)1.0 × 106 ± 0.2 × 106 3.9 ± 0.76
DH5α(pE214) OapA+ 4.65 × 106 ± 0.2 × 106 12.2 ± 0.53b
DH5α(pE219) OapA 1.23 × 106 ± 0.5 × 106 4.1 ± 1.74
DH5α(pEL1) OapA+ 5.35 × 106 ± 0.7 × 106 13.5 ± 1.76b
  • a Mean ± standard deviation of at least three separate experiments done in triplicate.

  • b P < 0.01 by two-tailed t test compared to OapA strains.