**9. Endogenous IFN-gamma, TNF, and IL-6 in** *Staphylococcus aureus* **infection**

Endogenous IFN-g plays a detrimental role in S. aureus infection. IFN-g, TNF, and IL-6 levels are elevated within 24 hours of infection even though whether the infection is lethal or non-lethal. In nonlethal cases, Bacteria is not present in the blood but in the kidneys and remains there for up to three weeks of infections. IFN-g peaks again in the spleens and kidneys. Among these three cytokines, the only cytokine that is detected in the serum is IL-6. In lethal infection, IFN-g and IL-6 in the sera and TNF in the kidneys peaked before death [98–102].
