Clostridium difficile Mannan and Campylobacter jejuni Heptan

Abstract

Clostridium difficile infection in humans is on the rise and vaccine targets that will reduce both disease and colonization levels are needed. Potential vaccines comprised of C. difficile cell-wall polysaccharides PS-I, PS-II, and PS-III are being investigated in the Monteiro laboratory at Guelph. In this work, the discovery of mannan moieties in C. difficile is reported. The mannose units were present as end-groups [α-Man-(1→], 2-linked linear units [→2)-α-Man-(1→] and 2,6-linked branch-points [→2,6)-α-Man-(1→]. Within the limits of detection, no mannose residues were detected in the analysis of the growth media. Sporulating C. difficile preparations were observed to contain greater amounts of mannose. Campylobacter jejuni (C. jejuni ) is a food borne pathogen that is one of the leading causes of gastroenteritis in the world. Characterization of the surface polysaccharides is a crucial step in the development of a vaccine against C. jejuni infection. Knowledge about polysaccharide structure will also give insight into the function of bacterial surface and aid in conjugate vaccine development. In this study, the capsular polysaccharide of C. jejuni serotype HS:44 was investigated. Physico-chemical analysis of HS:44 capsular polysaccharide revealed that it was rich in heptose units.