**Core Concept**
Blood cultures are a crucial diagnostic tool for detecting bacteremia, which is the presence of bacteria in the blood. Staphylococcus aureus is a common cause of bacteremia, particularly in cases of severe infections such as infective endocarditis. This condition involves the colonization of the heart valves by bacteria, leading to inflammation and damage.

**Why the Correct Answer is Right**
Infective endocarditis caused by Staphylococcus aureus is a severe and potentially life-threatening condition. The bacteria can enter the bloodstream through a damaged heart valve or other site of infection, leading to the formation of vegetations on the valve surface. These vegetations are composed of bacteria, platelets, and fibrin, and can cause damage to the valve and surrounding tissues. Blood cultures are often positive in cases of infective endocarditis due to the high bacterial load in the bloodstream. The presence of Staphylococcus aureus in blood cultures is a key diagnostic criterion for this condition.

**Why Each Wrong Option is Incorrect**

* **Option A:** Toxic Shock Syndrome (TSS) is a severe condition caused by Staphylococcus aureus or Streptococcus pyogenes, characterized by fever, rash, and organ failure. While blood cultures may be positive in TSS, it is not the most common condition associated with positive blood cultures in Staphylococcus aureus infections.
* **Option B:** Staphylococcal Scalded Skin Syndrome (SSSS) is a condition caused by Staphylococcus aureus that affects the skin, leading to blistering and peeling. Blood cultures are not typically positive in SSSS, as the infection is localized to the skin.
* **Option D:** Impetigo is a superficial skin infection caused by Staphylococcus aureus or Streptococcus pyogenes. While blood cultures may be positive in some cases of impetigo, it is not a common condition associated with positive blood cultures in Staphylococcus aureus infections.

**Clinical Pearl / High-Yield Fact**
In cases of suspected infective endocarditis, blood cultures should be drawn before starting antibiotic therapy to increase the likelihood of detecting the causative organism. This is particularly important for Staphylococcus aureus, as it is often resistant to multiple antibiotics.

**✓ Correct Answer:** C. Infective endocarditis