Vaccine Candidate For C. Difficile

When the pathogen Clostridium difficile attacks, it populates up to 40% of the human gut and produces a wide array of toxins that cause diarrhea, inflammation, and sometimes death. Scientists have now developed a vaccine candidate against this culprit of many hospital-based infections (Chem. Biol., DOI: 10.1016/j.chembiol.2011.03.009). To do so, researchers led by Peter H. Seeberger of the Max Planck Institute of Colloids & Interfaces, in Potsdam, Germany, first synthesized a complex hexasaccharide that is found in C. difficile’s cell wall. They found that C. difficile-infected mice and humans produce antibodies that recognize this sugar, suggesting that it’s a viable basis for a vaccine. The team then appended the hexasaccharide to a protein called CRM197, because sugars alone don’t elicit a strong enough immune response to build protecting antibodies (C&EN, May 30, page 53). Seeberger’s team next plans to test whether the vaccine protects mice against infection, and they aim to raise funds for a clinical trial to further develop a C. difficile vaccine for humans, which has remained elusive.