Which infection is commonly associated with antibiotic use leading to pseudomembranous colitis?

• A. Listeria monocytogenes infection
• B. Salmonella enterica infection
• C. Clostridioides difficile infection
• D. Escherichia coli infection

Answer: (C)

Antibiotic use disrupts the normal gut microbiota, allowing Clostridioides difficile to overgrow and produce toxins that injure the lining of the colon, leading to pseudomembranous colitis. The toxins damage mucosal cells and trigger inflammation, and the surface becomes studded with yellowish plaques that are composed of inflammatory debris, mucus, and fibrin. This condition is most often seen after broad-spectrum antibiotics and in individuals with recent antimicrobial exposure.

The other infections listed don’t typically arise from antibiotic disruption in the same way. Listeria monocytogenes is a foodborne pathogen that can cause meningitis or bacteremia, not pseudomembranous colitis. Salmonella enterica and certain pathogenic Escherichia coli strains cause gastroenteritis, but they don’t characteristically produce pseudomembranes in the colon as a result of antibiotic use.