The organism that most commonly causes infective endocarditis is: (A) Streptococcus mitis, (B) Streptococcus viridians, (C) Staphylococcus aureus, (D) Staphylococcus pyogens
Answer is B. Streptococcus sanguis is most common species in Viridans streptococcus to cause infective endocarditisReference: Jawetz, Melnick, & Adelberg's Medical Microbiology; 27th edition