Toxin A (TcdA) is a major virulence factor produced by the bacterium Clostridioides difficile (formerly known as Clostridium difficile), which is responsible for causing Clostridioides difficile infection (CDI). This bacterium releases two primary toxins, TcdA and TcdB, which disrupt the normal function of the gut, leading to symptoms such as diarrhea, colitis, and, in severe cases, toxic megacolon.
