Figure 6.

Impact of SprY to hemolytic activity in Staphylococcus aureus in different models of infection. (A and B) The supernatants of different strains of HG003 (WT, ΔsprY, ΔrnaIII) containing empty plasmid (pICS3) or overexpressing sprY (pICS3-sprY) were collected after 6 h of growth in BHI at 37°C. Hemolysis was performed by incubating cell culture supernatants with mouse and human blood samples at a ratio 50:50 at 37°C for 1 h. The hemolytic activity was observed in a flat-bottom 96-well microtiter plate at OD 540 nm. The blood samples prepared in PBS1X represent as negative control and in Triton 0.1% as 100% hemolysis. (C and D) Survival of mice infected with S. aureus wild-type strain (WT), deleted strain for sprY (ΔsprY) and complemented strains for sprY (ΔsprY pICS3-sprY). Groups of 5 eight-week-old Swiss female mice were inoculated i.v. with 2 × 10⁸ bacteria and monitored daily for 3 weeks. All statistical analyses were performed using Student’s t test. The error bars correspond to the average values from three independent experiments. Statistical significance is indicated by bars and asterisks as follows: **, P < 0.01; ****, P < 0.001.