Virulence factor. Causes hemolysis of erythrocytes from sheep (HD(50)=7.53 mM), rabbit (HD(50)=28.07 mM), guinea pig (HD(50)=4.23 mM), dog (HD(50)=4.37 mM) and human (HD(50)=3.32 mM). Acts synergistically with beta-hemolysins from S.aureus ATCC 25923. Cytotoxic towards human dermal fibroblasts. Belongs to the staphylococcal hemolytic protein family.