Toxic shock syndrome (TSS) is a potentially fatal illness caused by a bacterial toxin. Different bacterial toxins may cause toxic shock syndrome, depending on the situation. The causative bacteria include Staphylococcus aureus, where TSS is caused by enterotoxin type B or TSST-1, and Streptococcus pyogenes, where it is caused by streptococcal pyrogenic exotoxins. Streptococcal TSS is sometimes referred to as toxic shock-like syndrome (TSLS) or streptococcal toxic shock syndrome (STSS).