<prompt> Eight months after prosthetic valve replacement, most common organism causing infective endocarditis is:Staph. epidermidisStrep. viridansStaph. aureusHACEK  <response>: Ans. a Staph. epidermidis Coagulase negative staphylococci is the most common cause of endocarditis in posthetic value recepients with in one year of surgery. 