Fucoidan from Sargassum sinicola is in vitro recognized by the bacteria Campylobacter jejuni

Abstract

Campylobacteriosis is a significant global public health issue that requires new methods for preventing and treating the infection. One promising approach is to prevent the adhesion of Campylobacter jejuni to intestinal cells by blocking its binding sites with molecules that mimic the fucosylated receptors it recognizes. In this study, the fucosylated polysaccharide fucoidan was isolated from the brown algae Sargassum sinicola. The fucoidan was characterized, and its recognition by Campylobacter jejuni was tested in vitro. Fucoidan was extracted using aqueous methods at various temperatures, followed by selective precipitation with ethanol, trichloroacetic acid, calcium chloride, and additional ethanol. The yield of fucoidan was found to be 3.1 ± 0.29%, with 16.8 ± 0.46% fucose, 14.2 ± 1.2% sulfates, and 6.8 ± 0.02% uronic acids. The structural characteristics of the fucoidan were analyzed using Fourier transform infrared spectroscopy, which revealed the characteristic signals of carbohydrates and sulfate groups. The extracted fucoidan showed a Zeta potential of -18.5 ± 0.10 mV, a particle size of 127.3 ± 34.7 nm, and a Polydispersity Index of 0.80 ± 0.21. In vitro experiments demonstrated that Campylobacter jejuni recognized the extracted fucoidan, indicating its potential as a glycomimetic antagonist for this bacterium, which is currently the leading cause of infectious bacterial gastroenteritis worldwide.