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Facultative anaerobic Gram-positive coccal bacterium
Appears as grape-like clusters when viewed through a microscope, and has large, round, golden-yellow colonies, often with hemolysis, when grown on blood agar plates
Catalase-positive
-Able to convert hydrogen peroxide (H2O2) to water and oxygen
Virulence factors:
Enzymes
-Coagulase clots plasma and coats the bacterial cell which probably prevent phagocytosis
-Hyaluronidase breakdown hyaluronic acid and help in spreading
Toxins
-Superantigens (TSST-1) induce toxic shock syndrome (TSS), usually from prolonged tampon use. Cause non-specific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release (IFNγ)
-Enterotoxin that is the causative of gastroenteritis that is self-limiting, characterized by vomiting and diarrhea one to six hours after ingestion of the toxin with recovery in eight to 24 hours. Symptoms include nausea, vomiting, diarrhea, and major abdominal pain.
-Exfoliative toxins implicated in (SSSS), which occurs most commonly in infants and young children. Protease activity of the exfoliative toxins causes peeling of the skin observed with SSSS.
Other
-Protein A, an IgG-binding protein, binds to the Fc region of an antibody 