Toxic Shock Syndrome is most commonly caused by which organism?

• A. Streptococcus pyogenes
• B. Escherichia coli
• C. Staphylococcus aureus
• D. Pseudomonas aeruginosa

Answer: (C)

Toxic Shock Syndrome occurs when a bacterial toxin acts as a superantigen, triggering massive, nonspecific activation of T cells and a flood of cytokines that produce fever, a widespread rash, hypotension, and organ dysfunction. The organism most commonly responsible is Staphylococcus aureus, particularly toxin-producing strains that give rise to tampon-associated or wound-related toxin-mediated TSS. While Streptococcus pyogenes can also cause a toxin-mediated TSS, it is less common overall. Escherichia coli and Pseudomonas aeruginosa are not typical causes of TSS. Therefore, Staphylococcus aureus is the best answer.