Knowra Streptococcus pyogenes Streptococcus pyogenes Streptococcus pyogenes is a Gram-positive bacterium that causes illnesses ranging from strep throat and scarlet fever to invasive infections, and can trigger post-infection autoimmune disease.
M protein : A variable surface protein that helps Streptococcus pyogenes evade immune clearance and attach to host tissues. This major virulence factor resists phagocytosis and can resemble human tissues.
Streptococcal pharyngitis : An infection of the throat caused by Streptococcus pyogenes, commonly called strep throat. This familiar illness is a common reason to test for the bacterium.
Acute rheumatic fever : An inflammatory illness that can follow group A streptococcal infection and affect the heart, joints, skin, or nervous system. Immune cross-reaction after infection can damage heart valves and other tissues.
Group A streptococcus : A group of bacteria classified by the Lancefield group A cell-wall antigen, chiefly comprising Streptococcus pyogenes. This clinical name is commonly used for the organism and its infections.
Streptococcus agalactiae : A group B streptococcal bacterium that can cause neonatal infection and disease in pregnant or medically vulnerable people. Its group B classification and disease profile differ from those of group A streptococcus.
Streptolysin O : An oxygen-labile toxin that forms pores in cell membranes and is produced by several streptococcal species. Its tissue-damaging activity contributes to disease, while antibodies against it help document recent infection.
Scarlet fever : A toxin-associated illness marked by a characteristic rash, usually accompanying group A streptococcal throat or skin infection. Its distinctive rash can reveal toxin-producing infection.
Rheumatic heart disease : Chronic heart-valve damage resulting from acute rheumatic fever. Repeated or severe post-streptococcal inflammation can leave lasting valve injury.
Gram-positive bacteria : Bacteria that retain crystal violet stain because their cell walls have a thick peptidoglycan layer. Its Gram-positive cell wall is a defining laboratory feature.
Streptococcus pneumoniae : An encapsulated Gram-positive bacterium that commonly causes pneumonia, meningitis, and middle-ear infection. Despite sharing a genus, it is not the usual cause of strep throat.
Show all 27