An elderly patient in a nursing home is recovering from bacterial pneumonia.The patient has been on a lengthy regiment of antibiotics to kill the organism causing the disease.A few days later, the patient is diagnosed with pseudomembranous colitis.What organism is the most likely cause?

Question

Quizplus · Accepted Answer

C.difficile is the most common but not the sole cause of antibiotic-associated diarrhea and pseudomembranous colitis.Following antimicrobial therapy, many organisms of the gastrointestinal flora other than C.difficile are killed, thus allowing C.difficile to multiply and produce abundant quantities of two types of toxins: toxin A and toxin B.Bloody diarrhea, with associated necrosis of colon mucosa, is seen in patients with pseudomembranous colitis.

An Elderly Patient in a Nursing Home Is Recovering from Bacterial