Klebsiella pneumoniae is a Gram-negative pathogenic bacterium that emerges a challenge for modern medicine due to intensively rising multi-drug resistance. Polysaccharides linked to the core region of LPS O-chains represent promising targets for development vaccines for immunoprophylaxis or immunotherapy of K. pneumoniae-caused diseases. The O-antigens of the most prevalent O1 serotype are built up from galactan I, galactan II and galactan III.
Herein we report the synthesis of biotinylated 2-,4- and 6-saccharides 1‑6 structurally related both to galactan I and galactan II (scheme 1). For the assembling of target oligosaccharides convergent strategy based on disaccharide donors 9 and 11 was used. The key step for preparation of galactofuranose-containing synthetic blocks was pyranoside-into-furanoside (PIF) rearrangement .
Biotinylated oligosaccharides 1-6 were immobilized on the surface of streptavidin coated plates to form glycoarray which was applied for screening of sera against K. pneumoniae. The obtained results demonstrate the applicability of such a glycoarray-based assay for typing Klebsiella strains belonging to most frequent O1 serogroup .
This work was supported by RSF grant 19-73-30017.
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