Immunochemical studies and gene cluster relationships of closely related O-antigens of Aeromonas hydrophila Pt679, Aeromonas popoffii A4, and Aeromonas sobria K928 strains classified into the PGO1 serogroup dominant in Polish aquaculture of carp and rainbow trout

Carbohydr Res. 2023 Jul 7;531:108896. doi: 10.1016/j.carres.2023.108896. Online ahead of print.ABSTRACTThe present study included three Aeromonas sp. strains isolated from fish tissues during Motile Aeromonas Infection/Motile Aeromonas Septicaemia disease outbreaks on commercial farms, i.e.: Aeromonas hydrophila Pt679 obtained from rainbow trout as well as Aeromonas popoffii A4 (formerly Aeromonas encheleia) and Aeromonas sobria K928 both isolated from carp, which were classified into the new provisional PGO1 serogroup prevailing among aeromonads in Polish aquaculture. The structure of the O-specific polysaccharides of A4 and K928 has been previously established. Here, immunochemical studies of the O-specific polysaccharide of A. hydrophila Pt679 were undertaken. The O-specific polysaccharide was obtained from the lipopolysaccharide of A. hydrophila Pt679 after mild acid hydrolysis and separation by gel-permeation chromatography. The high-molecular-mass fraction was studied using chemical methods and 1H and 13C NMR spectroscopy, including 1H,1H NOESY, and 1H,13C HMBC experiments. The following structure of the branched repeating unit of the O-polysaccharide from A. hydrophila Pt679 was determined: [Formula: see text] The studies indicated that O-polysaccharides from A. hydrophila Pt679, A. popoffii A4 and A. sobria K928 share similarities but they also contain unique characteristics. Western blotting and an enzyme-linked immunosorbent assay revealed that the cross-reactivity ...
Source: Carbohydrate Research - Category: Genetics & Stem Cells Authors: Source Type: research