A patient with colorectal cancer develops septicemia complicated by endocarditis. You would expect the blood cultures to grow?
**Core Concept**
Colorectal cancer patients are at an increased risk of developing bacteremia due to the potential for tumor lysis syndrome and subsequent sepsis. Furthermore, the presence of a central line or invasive medical devices increases the risk of catheter-related bloodstream infections, which can lead to endocarditis. The most likely causative organism in this scenario is a gram-positive bacterium.
**Why the Correct Answer is Right**
The patient's septicemia and endocarditis are likely caused by a bacterium that is commonly found in the gut flora. In this case, the most likely organism is **Enterococcus faecalis**, a gram-positive bacterium that is commonly associated with urinary tract infections, bacteremia, and endocarditis. This organism is particularly likely to cause infection in patients with colorectal cancer due to its natural presence in the gut.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while **Staphylococcus aureus** can cause endocarditis, it is more commonly associated with skin and soft tissue infections. While it can cause bacteremia, it is less likely than **Enterococcus faecalis** in this scenario.
**Option B:** This option is incorrect because **Pseudomonas aeruginosa** is more commonly associated with hospital-acquired infections, such as ventilator-associated pneumonia, and is less likely to cause endocarditis.
**Option C:** This option is incorrect because **Candida albicans** is a fungus that can cause endocarditis, particularly in patients with prosthetic heart valves or central lines. However, it is less likely than **Enterococcus faecalis** in this scenario.
**Option D:** This option is incorrect because **Streptococcus pneumoniae** is more commonly associated with community-acquired pneumonia and is less likely to cause endocarditis.
**Clinical Pearl / High-Yield Fact**
In patients with colorectal cancer, the risk of bacteremia and endocarditis is increased due to the potential for tumor lysis syndrome and the presence of central lines. **Enterococcus faecalis** is a common cause of bacteremia and endocarditis in this population, and should be considered in the differential diagnosis.
**Correct Answer:** C. **Enterococcus faecalis**