Synthesis of a panel of glycans from ATCC 17978 and ATCC 17961 Acinetobacter baumannii polysaccharides

Acinetobacter baumannii is an opportunistic Gram-negative pathogen, responsible for a variety of infections occurring essentially in hospital settings, and hence, targeting immunodeficient patients. In addition, its recent resistance to antibiotics poses a substantial threat to human health. Thus, according to the World Health Organization, A. baumannii has become a priority for the development of new treatments1. To date, over twenty surface saccharides of A. baumannii have been structurally elucidated, including those from the highly virulent ATCC 17978 and ATCC 17961 strains.2 Both strains share the same pentasaccharide repeating unit, with the only structural difference being a single O-acetylation found in ATCC 17978 (Figure 1). This research, as part of the MSCA-DN ACINETWORK project, aims to synthesise a panel of glycans from both ATCC strains repeating unit for future conjugation to carriers such as nanoparticles, nanocelluloses and proteins. Furthermore, these functionalised ligands will be subjected to immunological evaluation in order to investigate the design and development of a semi-synthetic carbohydrate-based vaccine. In this communication, we will introduce this ongoing project's preliminary findings, highlighting the modulable synthetic approach employed and the synthesis of monosaccharide and disaccharide building blocks of each strain. This project has received funding from the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie Grant Agreement no. 101119795.