How the Anaerobic Enteropathogen <i>Clostridioides difficile</i> Tolerates Low O <sub>2</sub> Tensions
Nicolas Kint, Carolina Alves Feliciano, Maria C. Martins, Claire Morvan, Susana F. Fernandes, Filipe Folgosa, Bruno Dupuy, Miguel Texeira, Isabelle Martin‐Verstraete
Abstract
Although the gastrointestinal tract is regarded as mainly anoxic, low O 2 tension is present in the gut and tends to increase following antibiotic-induced disruption of the host microbiota. Two decreasing O 2 gradients are observed, a longitudinal one from the small to the large intestine and a second one from the intestinal epithelium toward the colon lumen. Thus, O 2 concentration fluctuations within the gastrointestinal tract are a challenge for anaerobic bacteria such as C. difficile . This enteropathogen has developed efficient strategies to detoxify O 2 . In this work, we identified reverse rubrerythrins and flavodiiron proteins as key actors for O 2 tolerance in C. difficile . These enzymes are responsible for the reduction of O 2 protecting C. difficile vegetative cells from associated damages. Original and complex detoxification pathways involving O 2 -reductases are crucial in the ability of C. difficile to tolerate O 2 and survive to O 2 concentrations encountered in the gastrointestinal tract.