A 55-year-old woman develops Janeway lesions, Osler nodes, splinter hemorrhages, and Roth spots about 1 month after a tooth extraction. She has a history of rheumatic heart disease. What is the most common causative microbe?
Answer: This patient has infective endocarditis. Viridans group Streptococcus is the most common cause of subacute infective endocarditis, while S. aureus is the most common cause of acute infective endocarditis.