Elucidation of the Lipopolysaccharide Core Structures of Bacteria of the Genus Providencia

Abstract

Enterobacteria of the genus Providencia are opportunistic pathogens causing diarrhea in travelers and children. Lipopolysaccharide (LPS) is the major surface antigen of Providencia and the major target of the immune response. O‐polysaccharide structures have been elucidated in several Providencia O‐serogroups, but little is known about the LPS core structure. We isolated core oligosaccharides from the R‐type LPS of a number of Providencia O‐serogroups and studied them by high‐resolution mass spectrometry, including capillary skimmer dissociation technique; three selected oligosaccharides were analyzed also by NMR spectroscopy. The conserved inner core and variable outer core regions were distinguished and the full core oligosaccharide structures established in Providencia O8, O35, and O49. Providencia LPSs were found to share some structural features with Proteus LPSs.

Keywords:

• Providencia
• Core oligosaccharide
• Lipopolysaccharide structure
• Electrospray ionization mass spectrometry

Acknowledgements

This work was supported by grants of the Russian Foundation for Basic Research for N.A.K. (project 05‐04‐48439) and the Council on Grants at the President of the Russian Federation for Support of Young Russian Scientists for A.N.K. (project MK‐2204.2006.4). A.N.K. thanks the Borstel Foundation for scholarship.