A 40-year old woman presented to the surgical OPD with features suggestive of colitis. She was on prolonged treatment with clindamycin. Fecal sample was positive for toxin produced by this agent. Her condition improved on treatment with metronidazole. The clinical condition is associated with –
**Core Concept**
Clindamycin-associated colitis is a type of antibiotic-associated diarrhea caused by an overgrowth of Clostridioides difficile (C. difficile). This condition arises due to the disruption of the normal gut flora by broad-spectrum antibiotics, leading to an imbalance in the microbiome.
**Why the Correct Answer is Right**
The toxin produced by C. difficile is responsible for the symptoms of colitis. Metronidazole is an effective treatment for this condition, as it targets the anaerobic bacteria, including C. difficile. The mechanism of action of metronidazole involves the reduction of the nitro group in its structure, which forms a highly reactive intermediate that damages the DNA of the bacterial cell, ultimately leading to its death. This results in the resolution of symptoms.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the condition associated with clindamycin treatment. Pseudomembranous colitis is a hallmark of C. difficile infection, not a separate entity.
**Option B:** This option is incorrect as it does not accurately describe the condition associated with clindamycin treatment. Antibiotic-associated diarrhea can be caused by various bacteria, but the specific condition associated with clindamycin is C. difficile infection.
**Option C:** This option is incorrect as it does not accurately describe the condition associated with clindamycin treatment. Clostridium perfringens is a different bacterium that can cause food poisoning, but it is not associated with clindamycin treatment.
**Clinical Pearl / High-Yield Fact**
Remember that C. difficile infection is often associated with the use of broad-spectrum antibiotics, and metronidazole is a first-line treatment for this condition. However, in severe cases, vancomycin is preferred due to its higher efficacy.
**Correct Answer: D. C. difficile infection.**