 TSST-1 is a protein encoded by the "tstH" gene, which is part of the mobile genetic element staphylococcal pathogenicity island 1.The toxin is produced in the greatest volumes during the post-exponential phase of growth, which is similar among pyrogenic toxin superantigens, also known as PTSAgs.Oxygen is required in order to produce TSST-1, in addition to the presence of animal protein, low levels of glucose, and temperatures between 37-40°C (98.6-104°F).