<prompt> Staph aureus virulence is due to -CoagulaseEndotoxinHemolysisPigmented colonies  <response>: Staph aureus is a Gram positive bacteria. Virulence factors are: Coagulase binds to prothrombin and initiate fibrin polymerization. Coagulase test Tube coagulase test detects free coagulase Slide coagulase test detects bound coagulase. Hemolysins a, b, g, d - contribute in the pathogenesis but Coagulase enzyme is more potent virulence factor. Endotoxins -Lipopolysaccharides Gram-negative bacterial cell wall. Seen in Gram negative bacteria. Golden yellow pigmented colonies pigments made up of beta carotene are produced on Nutrient agar. It doesnt contribute in pathogenesis of S. aureus. 