A species of facultatively anaerobic, Gram positive, cocci shaped bacteria in the phylum Firmicutes. This species is beta hemolytic, Lancefield group A, pyrrolidonylarylamidase, and arginine deaminase positive and catalase negative. It can ferment salicin, rhamnose, and trehalose but not sorbitol, or ribose. S. pyogenes is found on normal human skin but can act as a pathogen causing streptococcal pharyngitis, acute rheumatic fever, scarlet fever, skin infections, acute glomerulonephritis and necrotizing fasciitis.

A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group A hemolytic Streptococcus that can cause SCARLET FEVER and RHEUMATIC FEVER.

Any bacterial organism that can be assigned to the species Streptococcus pyogenes.

Species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans; it is a group A hemolytic Streptococcus that can cause scarlet fever and rheumatic fever; virulent strains penetrate deep into the body, with catastrophic results; it has been demonstrated that invasive streptococcus A infections can trigger a toxic shock syndrome, myositis, or destroy the sheath that covers the muscle, necrotizing fasciitis.