Pseudomonas aeruginosa is an antibiotic-resistant pathogen and leading cause of hospital-acquired infections. Its ability to form biofilms enables persistent colonization by protecting bacterial cells from antibiotics and host immune action. The Pel exopolysaccharide is a key component of the biofilm, contributing to intercellular adhesion and structural integrity. Although Pel has been implicated in P. aeruginosa pathogenesis, its immunogenic potential remains underexplored. In this study, a panel of synthetic Pel-derived oligosaccharides was prepared with a thiol-functionalized linker to enable site-selective conjugation to the carrier protein CRM197. The resulting glycoconjugates were administered to mice and elicited robust antibody responses. Among these, one hexasaccharide conjugate induced antibodies that bound strongly to both the natural Pel polysaccharide and biofilm forming P. aeruginosa cells. These findings support the feasibility of using well-defined synthetic Pel-structures in glycoconjugate vaccine development and provide a molecular framework for targeting biofilm-associated antigens in P. aeruginosa.
Wu et al. (Mon,) studied this question.