The structural elucidation of the Salmonella enterica subsp. enterica, reveals that it contains both O-factors 4 and 5 on the LPS antigen

Spectroscopic investigation of the O-antigen from Salmonella enterica subsp. enterica revealed fine details on the acetylation pattern, the biological repeating unit and the polymerization degree. Acetylation at O-2 of the abequose residue, defined both O-factors 4 and 5 in the O-antigen chain of the lipopolysaccharide. NMR observation of the terminal non-reducing end of the polymer confirmed previous data regarding the biological repeating unit and showed an average polymerization degree of 5. The information about these structural elements might contribute to the understanding of key features of the biology of this pathogen, as phase variation and/or adaptation to the external environment.