Figure 2. Capacity of E. coli strains to invade HeLa cells. Results are shown as UFC/mL. Data represent the average and standard deviation of at least three assays done in quadruplicates for each strain. MT78 and DH5α strains represent the positive and negative controls for invasiveness. Statistical analysis showed significant difference between MT78 and 278/94 (p < 0.05). None bacterium was recovered from inside HeLa cells after gentamicin protection assay with DH5α strain.
