Figure 4

Effect of the supernatant of wild-type and isogenic mutants on the viability of bovine umbilical vein endothelial cells. The graph shows the percentage of viable cells relative to viable untreated cells (negative control) and cells treated with supernatant of the wild-type strain (positive control) after 1.5 h incubation with 6 and 1% supernatant of ΔpfoA Δplc double mutant (ΔpfoA Δplc), pfoA-complemented ΔpfoA Δplc mutant (pfoA-c.), plc-complemented ΔpfoA Δplc mutant (plc-c.) and double-complemented ΔpfoA Δplc mutant (double-c.). The values are the average of three independent experiments conducted in duplicate with error bars representing the standard deviations (SD). Asterisks indicate significant difference between that strain and all other strains for each concentration (p < 0.001).