This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': '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 - \nSelect and explain. \nA. Staph. aureus, B. Candida albicans, C. Pseudomonas, D. Strep. viridans', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Infective endocarditis in intravenous drug abusers commonly involves the tricuspid valve and are caused by Staphylococcus aureus.\nM. C. cause of native valve endocarditis → Staph. Aureus\nM.C. cause of early-onset prosthetic valve endocarditis (< 2 mts & 2-12 mts) → Coagulase-negative staphylococci\nM. C. cause of late-onset prosthetic valve endocarditis (> 12 mts) → Streptococci (e.g. streptococcus viridans)\nM.C.\xa0cause of endocarditis in I.V drug abusers → Staph aureus.', 'role': 'assistant'}]