<prompt> The organism that most commonly causes infective endocarditis isStreptococcus mitisStreptococcus viridiansStaphylococcus aureusStaphylococcus pyogens  <response>: Streptococcus sanguis is most common species in Viridans streptococcus to cause infective endocarditisReference: Jawetz, Melnick, Adelbergs Medical Microbiology; 27th edition 