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
A 25-year-old IV drug abuser presents with fever for 3 weeks. ECHO shows tricuspid vegetation. The most likely organism associated with endocarditis in this case is: 
Select and explain. 
A. Staph. aureus, B. Candida albicans, C. Pseudomona, D. Strep. viridans
A: Staph. aureus
Answer: A: Staph. aureus 
Explanation: Ans. (a) Staph. aureus Endocarditis in IV drugs addicts Right sided (more common) Left sided Staph. aureus Varied (Stapti, aureus, enterobacter, polymicrobial)