Is a species of Gram-positive bacterium in the genus Streptococcus. These bacteria are aerotolerant and an extracellular bacterium, made up of non-motile and non-sporing cocci. It is clinically important for humans. It is an infrequent, but usually pathogenic, part of the skin microbiota. Group A streptococci when grown on blood agar typically produces small zones of beta-hemolysis, a complete destruction of red blood cells. (A zone size of 2–3 mm is typical.) It is thus also called group A (beta-hemolytic) streptococcus (GABHS), and can make colonies greater than 5 mm in size.