C. difficile and C. difficile Infection (CDI) Overview and Risk Factors for CDI

Paul Feuerstadt, MD: Hello, and welcome to this HCPLive® Contagion® Peer Exchange titled “Emerging Treatment Options for Recurrent C difficile Infection.” My name is Dr Paul Feuerstadt, and I’m an assistant clinical professor of medicine at the Yale School of Medicine in New Haven, Connecticut and an attending gastroenterologist at the PACT [Physicians Alliance of Connecticut] gastroenterology center. I’m delighted to be joined by 3 of my esteemed colleagues: Dr Teena Chopra, who is a professor at Wayne State University School of Medicine in Detroit, Michigan; Thomas Lodise, who is a professor at the Albany College of Pharmacy and Health Sciences in Albany, New York; and Dr Bincy Abraham, who is a professor at Houston Methodist hospital, affiliated with Weill Cornell Medical College in Houston, Texas. During our discussion, we’ll cover advances in diagnosis, treatment, and management of C [Clostridioides]difficile infection. We’re going to share data with emerging C difficile therapies and the promise they hold for treatment for recurrent Clostridioides difficile infection.

Hello, everybody. Let’s go ahead and get started. During our first section, we’re going to talk about C difficile and what it is. C difficile is a gram-positive, spore-forming anaerobic rod. There are 2 main phases of C difficile infection: the spore phase and the vegetative phase. The vegetative phase is the phase that most clinicians think about when they hear the term C difficile, because the vegetative phase is the phase that releases 2 main toxins: toxin A and toxin B, most commonly associated with the abdominal pain, fevers and diarrhea of C difficile infection. Importantly, the vegetative phase is susceptible to gastric acid and alcohol-based hand sanitizers. Plainly stated, when it comes in contact with these things, it gets wiped out. Alternatively, the spore phase is a much more resistant phase. The spore phase is resistant to gastric acid and alcohol-based hand sanitizers. In fact, the spore phase can last on dry surfaces in a viable form for upward of 6 to 8 months. The spore phase explains recurrence of C difficile and the frequent transfer of this infection.

How do patients get C difficile? Classically, individuals will swallow the spore phase. It’s resistant to the gastric acid. It gets into the small bowel, where there’s a conversion to the vegetative phase called germination. Within the small bowel there’s rapid multiplicity and division of the vegetative phase as it builds an army heading toward the colon. I’m a gastroenterologist. The colon is a brilliant organ because it has its own defense system independent of the blood-borne defense system that protects it from foreign invaders, such as the vegetative phase of C difficile. What’s that foreign defense system? The microbiota or colonization resistance. What classically weakens colonization resistance? Amoxicillin, ampicillin, clarithromycin, fluoroquinolones, cephalosporins, and piperacillin tazobactam. We weaken colonization resistance, creating an environment that’s more welcoming for the C difficile, and the C difficile proliferates.

Transcript edited for clarity