TcdA is one of the largest bacterial toxins known. With a molecular mass of 308 kDa, it is usually described as a potent enterotoxin,[3] but it also has some activity as a cytotoxin.[4] The toxin acts by modifying host cell GTPase proteins by glucosylation, leading to changes in cellular activities. Risk factors for C. difficile infection include antibiotic treatment, which can disrupt normal intestinal microbiota and lead to colonization of C. difficile bacteria.[5]
^Planche T, Aghaizu A, Holliman R, Riley P, Poloniecki J, Breathnach A, Krishna S (December 2008). "Diagnosis of Clostridium difficile infection by toxin detection kits: a systematic review". The Lancet Infectious Diseases. 8 (12): 777–84. doi:10.1016/S1473-3099(08)70233-0. PMID18977696.