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PC-17

Structure and biological activity analysis of exopolysaccharides from

Aeromonas hydrophila ATCC-7966

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1
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Kuan-Yu Liang, Po-Jen Chen, I-Ming Lee*

1 Department of Marine Biotechnology and Resources, National Sun Yat-sen University,
Kaohsiung 804201, Taiwan
2 Department of Pharmacology, Kaohsiung Medical University, Kaohsiung 804201, Taiwan
* E-mail: leeiming@mail.nsysu.edu.tw

Abstract
Aeromonas hydrophila is a zoonotic pathogen that causes bleeding on the fins and trunk of
fish, commonly known as redfin disease. This pathogen also infects human and secretes
enterotoxins to cause severe diarrhea, cellulitis, pneumonia, peritonitis, and sepsis. A.
hydrophila ATCC-7966 (Ah-ATCC-7966) is a widespread strain and its exopolysaccharide
(EPS) is regarded as a critical virulence factor. Hence, unveiling the structure and biological
activity of Ah-ATCC-7966 EPS turns into an attractive issue. In this study, we purified the Ah-
ATCC-7966 EPS and its monosaccharide composition analysis suggests that Ah-ATCC-7966
EPS is composed of Glc, Man, GlcN, Gal, and GalN, which is in agreement with five anomeric
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hydrogen signals of Ah-ATCC-7966 EPS in proton nuclear magnetic resonance ( H NMR)
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spectrum. Moreover, the signal near 2 ppm signal in H NMR spectrum inferred that GlcN/GalN
contain the N-acetyl group. With bio-activity test, we strikingly found that Ah-ATCC-7966 EPS
has anti-inflammatory activity against the fMLP-induced inflammatory response in
polymorphonuclear neutrophils (PMNs), which is contrast to the enterotoxins secreted by A.
hydrophila.This result implies that Ah-ATCC-7966 EPS enable to reduce the host inflammated
response. Subsequent research will elucidate the complete structure of this EPS and further
explore its anti-inflammatory mechanisms to evaluate its potential as a therapeutic agent.

Keywords: Aeromonas hydrophila; Exopolysaccharide; Inhibit inflammation