Clostridioides difficilespore-entry into intestinal epithelial cells contributes to recurrence of the disease

Clostridioides difficile spores produced during infection are essential for the recurrence of the disease. However, how C. difficile spores persist in the intestinal mucosa to cause recurrent infection remains unknown. Here, we show that C. difficile spores gain entry into the intestinal mucosa via fibronectin-α 5 β 1 and vitronectin-α v β 1 specific-pathways. The spore-surface exosporium BclA3 protein is essential for both spore-entry pathways into intestinal epithelial cells. Furthermore, C. difficile spores of a bclA3 isogenic mutant exhibited reduced entry into the intestinal mucosa and reduced recurrence of the disease in a mouse model of the disease. Inhibition of C. difficile spore-entry led to reduced spore-entry into the intestinal epithelial barrier and recurrence of C. difficile infection in vivo . These findings suggest that C. difficile spore-entry into the intestinal barrier is a novel mechanism of spore-persistence that can contribute to infection recurrence and have implications for the rational design of therapies.