Which of the following is responsible for antibiotic-associated colitis :
**Core Concept**
The underlying principle being tested is the understanding of antibiotic-associated colitis, which is primarily caused by an imbalance in the normal gut flora. This imbalance allows harmful bacteria to overgrow, leading to colitis. **Clostridioides difficile** is a key bacterium implicated in this condition.
**Why the Correct Answer is Right**
The correct answer is related to the bacterium **Clostridioides difficile**, which produces toxins that cause colitis. The use of broad-spectrum antibiotics disrupts the normal gut flora, allowing **C. difficile** to overgrow and release its toxins, leading to antibiotic-associated colitis.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not specifically related to the primary cause of antibiotic-associated colitis.
**Option B:** Incorrect as it does not directly relate to the condition in question.
**Option C:** Incorrect because, while it may be involved in other types of infections, it is not the primary cause of antibiotic-associated colitis.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **Clostridioides difficile** infection is a significant cause of diarrhea and colitis in patients who have taken antibiotics, highlighting the importance of judicious antibiotic use.
**Correct Answer:** D. Clostridioides difficile.