Influence of carp intestinal mucus molecular size and glycosylation on bacterial adhesion

Abstract

The first step of the pathogenesis of many infectious diseases is the colonisation of the mucosal surface by the pathogen. Bacterial colonisation of the mucosal surface is promoted by adherence to high molecular weight mucus glycoproteins. We examined the effect of carp intestinal mucus glycoproteins on the adhesion of different bacteria. The bacteria used were 3 strains of Aeromonas hydrophila, and A. salmonicida, Edwardsiella tarda and Yersinia ruckeri. All bacteria adhered to mucus, but at varying intensities. All tested bacteria adhered best to molecules of 670 to 2000 kDa in size, less to molecules larger than 2000 kDa and weakest to molecules of 30 to 670 kDa. In general, bacteria that showed a stronger adhesion to intestinal mucus were cytotoxic to cells in vitro, and bacteria that showed a weaker adhesion to intestinal mucus did not lead to alterations of monolayers of EPC-cells. Furthermore, the involvement of glycan side chains of the glycoproteins for bacterial adhesion was analysed for one A. hydrophila strain. After cleavage of terminal sugar residues by treatment of mucus glycoproteins with different glycosidases, binding of bacteria was modulated. When mannose was cleaved off, adhesion significantly increased. Blocking of glycan receptors by incubation of bacteria with different oligosaccharides had no clear effect on bacterial binding to mucus glycoproteins. Our results suggest that bacteria interact with carbohydrate side chains of mucus glycoproteins, and that the carbohydrates of the core region are involved in bacterial binding.

Differences between intestinal segments and soybean meal-induced changes in intestinal mucus composition of common carpCyprinus carpioL.

“…Luminal mucin might be essential for protection of the intestinal surface, as higher bacterial adhesion to smaller mucus molecules has been observed (Schroers et al . ). Mucin degradation by pathogenic bacteria has been suggested earlier for C. carpio (Van der Marel et al .…”

The nutritional background of the host alters the disease course in a fish–myxosporean system

“…Other possible changes in the cellular architecture and composition of the digestive tract might favour parasite entrance and proliferation in the intestinal epithelium, through changes at the host-parasite interface (Yoshino et al, 2001), alterations of the gut barrier or the mucosal immunity (Kasper and Buzoni-Gatel, 2001), or alterations of the biochemical makeup of the cell membrane lipid rafts/caveolae microdomains (Chapkin et al, 2008). In fact, the effect of PLs, FAs and soybean meal on tight-junction permeability and therefore in bacterial translocation (Sawai et al, 2001), on fish intestinal mucus and bacterial adhesion (BakkeMcKellep et al, 2007;Schroers et al, 2008) have been reported. Thus, further studies are needed to determine the effect of vegetable diets in the distribution and composition of enzymes, other molecules of interest and leucocyte populations in the intestinal tract.…”

Mice Overexpressing β-1,4-Galactosyltransferase I Are Resistant to TNF-Induced Inflammation and DSS-Induced Colitis

“…Different bacterial species groups bind to different N-glycan epitopes [62], [63]. Therefore, a change in glycosylation of the mucosa can influence the binding of bacteria to it.…”