New Structure of Aeromonas salmonicida O-Polysaccharide Isolated from Ill Farmed Fish

• Published in: Microorganisms
• Main Authors: Karolina Ucieklak, Sylwia Wojtys-Tekiel, Garance Leroy, Laëtitia Le Devendec, Sandrine Baron, Marta Kaszowska
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2024
• Subjects: Aeromonas salmonicida; O-polysaccharide diversity; HR MAS NMR; lipopolysaccharide; Biology (General); QH301-705.5; Turbot
• Online Access: https://doi.org/10.3390/microorganisms12081575; https://doaj.org/article/49796edaf0954a4daff87ba2c102ea3b

The diversity of O-polysaccharides (O-antigens) among 28 Aeromonas salmonicida strains isolated from ill fish has been determined by using high-resolution magic angle spinning (HR MAS) NMR spectroscopy. The new O-polysaccharide has been identified in two isolates. This new structure was investigated by 1 H and 13 C NMR spectroscopy and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The following structure of the linear hexasaccharide repeating unit of A. salmonicida O-antigen has been established: →3)-α-L-Rha p -(1→3)-α-D-Man p NAc-(1→2)-β-D-Glc p -(1→3)-α-L-Rha p 2OAc4OAc-(1→3)-β-D-Man p NAc-(1→3)-α-D-Glc p -(1→. This new A. salmonicida O-polysaccharide was detected among two isolates collected from trout and turbot fish in 2010 and 2011, respectively. Further investigations should be conducted to evaluate the distribution of this new O-polysaccharide among a larger collection of isolates, depending on their geographic origin, the species of fish, and the health status of the fish.