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: Medicine
All are true about S.aureus endocarditis, EXCEPT: 
Select and explain. 
A. It is the leading cause of endocarditis worldwide, B. Embolic stroke is a well known complication, C. It can not cause right sided endocarditis, D. In the absence of antecedent antibiotics blood cultures are uniformly positive
C: It can not cause right sided endocarditis
Answer: C: It can not cause right sided endocarditis 
Explanation: S.aureus endocarditis: S.aureus is now the leading cause of endocarditis worldwide, accounting for 25-35% of cases. Increased use of intravascular devices causes this. Other factors associated with an increased risk of endocarditis are 1. Injection drug use 2. Hemodialysis 3. Presence of intravascular prosthetic devices at the time of bacteremia 4. Immunosuppression. Moality rates range from 20 to 40%, depending on both the host and the nature of the infection. MUST KNOW: Complications of S. aureus endocarditis 1. Cardiac valvular insufficiency 2. Peripheral emboli, 3. Metastatic seeding 4. Central nervous system (CNS) involvement (e.g - mycotic aneurysms, embolic strokes). Ref: Harrison, Edition-18, Page-1165.