This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Clostridium difficile infection occurs after 
Select and explain. 
A. Prolonged antibiotic therapy, B. Pantoprazole increases the risk, C. Associated with use of rectal thermometer, D. Increased with propoion of hospital stay
A: Prolonged antibiotic therapy
Answer: A: Prolonged antibiotic therapy 
Explanation: Clostridium difficile causes acute colitis with bloody diarrhea and pseudomembranous colitis. A common cause of nosocomial diarrhea. The disease follows the use of broad-spectrum antibiotics to which it is resistant. Exotoxin A and B involved in the pathogenesis. An oppounistic organism that causes disease only when the normal mechanism is altered. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 270