Figure 2.

(A) Hemolytic activity assay. Overnight cultures of USA500, ΔctaB mutant and complemented strains were spotted (20 μl) on sheep blood agar plates and grown at 37°C for 24 h. The result is representative of triplicate experiments. (B) Survival of S. aureus strains in a Balb/C challenged by subcutaneous injection. Comparison of CFU counts was performed using the Student's t-test. Results are means with standard error (errors bars).