FIG. 1.

Effect of different inhibitors on GAS, S. enterica serovar Typhimurium, and E. coli HB101(pVM101) invasion of HEp-2 cells. Confluent monolayers were preincubated with the inhibitors for 30 min, and the standard invasion assay was performed in the presence of the inhibitor. Values are mean and standard deviation for at least three experiments. The results are expressed as percent inhibition, which is calculated as follows: [(CFU_{no inhibitor} − CFU_inhibitor)/CFU_{no inhibitor}] × 100. Percent inhibition by staurosporine (a) and genistein (b) is shown. In the absence of inhibitor, 25% of the inoculum (1 × 10⁸ to 5 × 10⁸ CFU per well) was ingested by epithelial cells.