Structural and genetic characterization of the O-antigen of Enterobacter cloacae C5529 related to the O-antigen of E. cloacae G3054

• Published in: Carbohydrate research 2017-04, Vol.443-444, p.49-52
• Main Authors: Han, Runhua, Perepelov, Andrei V., Wang, Yuanyuan, Filatov, Andrei V., Wang, Min, Shashkov, Alexander S., Wang, Lei, Knirel, Yuriy A.
• Format: Article
• Language: English
• Subjects: Bacterial polysaccharide structure; Carbohydrate Sequence; Enterobacter cloacae; Enterobacter cloacae - chemistry; Enterobacter cloacae - genetics; O Antigens - chemistry; O Antigens - genetics; O-antigen; O-antigen gene cluster; Pseudaminic acid
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2017.02.006

On mild acid degradation of the lipopolysaccharide of Enterobacter cloacae C5529, the O-polysaccharide chain was cleaved at the linkages of 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Psep5Ac7Ac). The resultant oligosaccharide and an alkali-treated lipopolysaccharide were studied by sugar analysis along with 1H and 13C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit of the O-polysaccharide was established: →4)-β-Psep5Ac7Ac-(2 → 3)-β-d-Galp-(1 → 6)-β-d-Galf-(1 → 3)-α-d-Galp-(1→ It differs from a structurally related O-polysaccharide of E. cloacae G3045 studied early (Perepelov, A. V.; Wang, M.; Filatov, A. V.; Guo, X.; Shashkov, A. S.; Wang, L.; Knirel, Y. A. Carbohydr. Res. 2015; 407:59–62) in positions of substitution of β-Psep5Ac7Ac (O-4 vs. O-8) and β-Galp (O-3 vs. O-6) and the absence of a side-chain α-Galp residue. The O-antigen gene clusters of E. cloacae C5529 and G3045 are organized identically and include genes with the same putative functions in the O-polysaccharide synthesis. Based on these and serological data, it is suggested to combine E. cloacae C5529 and G3054 in one O-serogroup as two subgroups. [Display omitted] •Enterobacter cloacae is a pathogen causing respiratory and urinary infections, surgical site infection, and sepsis.•The OPS structure of E. cloacae C5529 was established.•The O-antigen gene cluster of E. cloacae C5529 has been sequenced and genes were annotated.•The O-antigen Enterobacter cloacae C5529 related to the O-antigen of E. cloacae G3054.