A 25 year old man with 3 weeks fever presented with tricuspid valve vegetation. The patient is an intravenous drug abuser. Most common cause of endocarditis in this patient is -

Infective endocarditis in intravenous drug abusers commonly involves the tricuspid valve and are caused by Staphylococcus aureus. M. C. cause of native valve endocarditis → Staph. Aureus M.C. cause of early-onset prosthetic valve endocarditis (< 2 mts & 2-12 mts) → Coagulase-negative staphylococci M. C. cause of late-onset prosthetic valve endocarditis (> 12 mts) → Streptococci (e.g. streptococcus viridans) M.C. cause of endocarditis in I.V drug abusers → Staph aureus.