<prompt> Which among the following is the most common cause of acute infective endocarditis?Staphylococcus aureusStreptococcus viridansStreptococcus intermediusCandida albicans  <response>: Streptococci and staphylococci are the cause of greater than 80 of infective endocarditis IE cases in which a responsible organism is identified. Streptococcal species were historically the most common group of pathogens, but S. aureus as the most frequently isolated microbial agent worldwide. Viridans group streptococci, or alpha-hemolytic streptococci, are a frequent cause of community-acquired native valve endocarditis NVE. Ref: OGara P.T., Haldar S.M. 2011. Chapter 86. Infective Endocarditis. In V. Fuster, R.A. Walsh, R.A. Harrington Eds, Hursts The Hea, 13e. 