Structure of the disaccharide repeating unit of O-specific polysaccharide isolated from Aeromonas veronii strain Bs8 pathogenic to common carp (Cyprinus carpio)

Abstract

The O-specific polysaccharide (OPS) was isolated from the lipopolysaccharide of Aeromonas veronii strain Bs8, which is pathogenic to common carp (Cyprinus carpio), after mild acid hydrolysis followed by gel-permeation chromatography. The high-molecular-mass OPS fraction was investigated using chemical methods, mass spectrometry, and ¹H and ¹³C NMR spectroscopy techniques, including 2D homonuclear ¹H,¹H TOCSY, DQF COSY, NOESY, and heteronuclear ¹H-detected ¹H,¹³C HSQC, and HMBC experiments. The analysis revealed that the O-specific polysaccharide contains sugars with the galacto configuration of the ring and is composed of a disaccharide repeating unit with the following structure.

Keywords: Aeromonas veronii; D-Fucp; Fish pathogen; GalpNAc; LPS; O-Antigen; O-specific polysaccharide; d-fucopyranose.