Clostridioides difficile

[Display omitted] Clostridioides difficile is a spore-forming, anaerobic, intestinal pathogen that causes severe diarrhea that can lead to death. In 2011, C. difficile infected ∼500000 people in the USA and killed ∼29000 people. C. difficile infection (CDI) is the most common healthcare-related infection in the USA, leading to increased healthcare costs of $4.8 billion. This pathogen transmits via the oral–fecal route as a highly contagious and resilient spore. Upon exposure to primary bile acids in the intestine, C. difficile germinates, and in the absence of colonization resistance from the normal microbiota, the bacterium colonizes the colon and produces toxins. These toxins inhibit actin polymerization in host cells, leading to cell death. C. difficile cells can then sporulate in the intestine and exit the body via diarrheal shedding. In culture, sporulation is induced at stationary phase in a nutrient-limiting environment, but the intestinal triggers of sporulation are still unknown.