β-haemolytic streptococcus of Lancefield’s Group A, associated with scarlet fever, puerperal sepsis, and other forms of human infection. The species is provisionally differentiated from other haemolytic streptococci by its sensitivity to bacitracin. Exotoxins include two haemolysins-O-streptolysin (oxygen-labile) and S-streptolysin (not oxygen sensitive)—and erythrogenic toxin. Strains may also show leucocidin, fibrinolysin, and hyaluronidase.
Any of the group A β-hemolytic streptococci causing suppurative infections. These streptococci are the causative agents of scarlet fever, erysipelas, bacterial pharyngitis, puerperal sepsis, and necrotizing fasciitis.
A type of pyogenic streptococcus that exhibits β-hemolysis and produces toxins, leading to conditions such as septic sore throat, rheumatic fever, puerperal sepsis, acute glomerulonephritis, and other illnesses in humans.