Clumping factor A

Clumping factor A, or ClfA, is a virulence factor from Staphylococcus aureus (S. aureus) that binds to fibrinogen.

ClfA also has been shown to bind to complement regulator I protein.

It is responsible for the clumping of blood plasma observed when adding S. aureus to human plasma. Clumping factor can be detected by the slide test.