Which among the following is the most common cause of acute infective endocarditis?
Staphylococcus aureus
Streptococcus viridans
Streptococcus intermedius
Candida albicans
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: O'Gara P.T., Haldar S.M. (2011). Chapter 86. Infective Endocarditis. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.