Clostridium difficile Infection

Abstract

Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis -the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota. Competing interests statement W.K.S. has performed research for Cubist. D.L. has performed research for Immuron and Adenium Biotech. D.B.L. has performed research for MedImmune and Merck. M.H.W. has received consulting fees from Abbott, Actelion Pharmaceuticals, Astellas, AstraZeneca, Bayer, Cerexa, Cubist, Durata, The European Tissue Symposium, The Medicines Company, MedImmune, Merck, Motif Biosciences, Nabriva, Optimer, Paratek, Pfizer, Roche, Sanofi Pasteur, Seres Therapeutics, Summit Pharmaceuticals, and Synthetic Biologics. M.H.W. has also received lecture fees from Abbott, Alere, Astellas, AstraZeneca, Pfizer and Hoffmann La Roche, and received grant support from Abbott, Actelion, Astellas, bioMérieux, Cubist, Da Volterra, The European Tissue Symposium, Merck and Summit Pharmaceuticals. E.J.K. has performed research for Cubist, Novartis and Qiagen, and has participated in advisory forums of Astellas, Optimer, Actelion, Pfizer, Sanofi Pasteur and Seres Therapeutics. These companies had no role in the writing of this Primer. HHS Public AccessAuthor manuscript Nat Rev Dis Primers. Author manuscript; available in PMC 2017 June 01. Published in final edited form as:Nat Rev Dis Primers. ; 2: 16020. doi:10.1038/nrdp.2016.20. Author Manuscript Author ManuscriptAuthor Manuscript Author ManuscriptClostridium difficile is a Gram-positive obligate anaerobic bacterium that was originally identified as part of the flora of healthy infants in 1935, described as an "actively motile, heavy-bodied rod with elongated subterminal or nearly terminal spores" (REF. 1) (FIG. 1). At that time, the strain was named Bacillus difficilis to reflect the difficulty experienced in isolating and culturing it. De...