Streptococcus pyogenes activates human platelets via streptolysin S-mediated calcium ion influx.

Introduction: Streptococcus pyogenes (group A streptococcus, GAS) is an exclusively human pathogen. It causes a wide spectrum of diseases, ranging from mild infections such as pharyngitis to severe life-threatening conditions such as streptococcal toxic shock syndrome (STSS). Thrombocytopenia is a common feature of STSS and is associated with severe outcome.