Virulence factor. Causes hemolysis of erythrocytes from sheep (HD(50)=2.63 mM), rabbit (HD(50)=2.37 mM), guinea pig (HD(50)=1.98 mM), dog (HD(50)=1.02 mM) and human (HD(50)=2.07 mM). Acts synergistically with beta-hemolysins from S.aureus ATCC 25923. Cytotoxic towards human dermal fibroblasts. Belongs to the staphylococcal hemolytic protein family.