Which organism causes prosthetic valve endocarditis within 60 days of surgery?

Staphyloccocus epidermidis is a coagulase negative staphylococci. It constitute the major component of normal flora of human body. Staph. epidemidis is invariably present on human skin. It is non pathogenic ordinarly but can cause disease when the host defence are breached. It is a common cause of stitch abscess. It has a predilection for growth on implanted foreign bodies such as aificial hea valves, shunts, intravascular catheters and prosthetic appliances, leading to bacteremia. Hospital strains of Staph. epidermidis are usually multiple drug resistant. Other coagulase negative Staphylococci are Staph. haemolyticus, Staph.saprophyticus. Ref: Ananthanarayanan & paniker's 8th ed page - 202.