Capsular polysaccharide structure of Acinetobacter baumannii K58 from clinical isolate MRSN31468

Wei Zou; Evguenii Vinogradov; Frank St-Michael; Dean Williams; Lillian Zou; Jenny Peters; Melanie Arbour; Greg Harris; Wangxue Chen; Danielle Peters

doi:10.1016/j.carres.2024.109307

Capsular polysaccharide structure of Acinetobacter baumannii K58 from clinical isolate MRSN31468

Carbohydr Res. 2024 Nov 6:546:109307. doi: 10.1016/j.carres.2024.109307. Online ahead of print.

Authors

Affiliations

¹ Human Health Therapeutic Research Center, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6, Canada.
² Ashbury College, 362 Mariposa Ave, Rockcliffe Park, Ottawa, Ontario, K1M 0T3, Canada.
³ Human Health Therapeutic Research Center, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6, Canada. Electronic address: Danielle.Peters@nrc-cnrc.gc.ca.

PMID: 39549592
DOI: 10.1016/j.carres.2024.109307

Abstract

Capsular polysaccharides (CPS) of Acinetobacter baumannii is a virulence factor with diverse structures. CPS are produced by the CPS biosynthesis gene cluster in their K locus (KL). However, CPS variations may occur due to insertion of additional genes from external sources, e.g., prophages. Recently, the CPS structure from a clinical isolate, BAL062 which includes KL58 locus, was found to have a pseudaminic acid isomer (8ePse5NAc7NAc) as a result of prophage inserted epaA/epaB genes. Here, we report a CPS structure produced by A. baumannii strain MRSN31468 which also belongs to a KL58 type. The K58 CPS structure was determined by 1D and 2D NMR analysis of the oligosaccharides derived from the CPS by a phage depolymerase, and supported by the sugar composition analysis. The K58 CPS structure has the following tetra saccharide repeating unit. The K58 CPS differs from the CPS from BAL062 only by replacing 8-epimerized β-8ePse5NAc7NAc with β-Pse5NAc7NAc.

Keywords: A. baumannii; Capsular polysaccharide; Depolymerase; K58; Phage.