Clostridioides difficile toxin A and B (TcdA, TcdB)

Toxigenic Clostridioides difficile refers to strains of the anaerobic, Gram-positive bacterium C. difficile capable of producing large clostridial toxins TcdA and TcdB, which are directly responsible for the pathology of CDI, including colonic epithelial damage, intense inflammation, and diarrhea. The toxins act as glucosyltransferases, modifying host cell GTPases, disrupting cytoskeletal architecture and cell signaling. Therapeutic strategies focus on toxin neutralization, suppression of toxin production, and reconstitution of the intestinal microbiome. Direct molecular targeting of TcdA and TcdB with monoclonal antibodies and vaccines represents a key approach; antibiotic therapy remains the first-line, though it does not target the toxins directly and carries risk of recurrent infection[1][3][6][7].

Other names

Clostridioides difficile toxin A (TcdA)Clostridioides difficile toxin B (TcdB)Large clostridial toxinsToxigenic C. difficile

Antibodies: Neutralization of toxins (e.g., bezlotoxumab binds TcdB to block cellular receptor interaction). Vaccines: Elicit immunity to prevent toxin-mediated disease (using TcdA/TcdB antigens). Antibiotics: Eradicate C. difficile bacteria, ending toxin production.