A 46-year-old man comes to the physician for a 2-day history of fever and chills. One week ago, he underwent a root canal. He has history of rheumatic fever as a child. A diastolic rumble is auscultated in the left mid-clavicular line. Blood cultures are drawn. Empiric therapy is initiated with vancomycin and gentamicin. Which of the following best describes the most likely causal organism?
Catalase positive
Clear zone of hemolysis on blood agar
Coagulase positive
Gram-positive diplococci
Gram-positive cocci in clusters
Green zone of hemolysis on blood agar
