Rationalized development of antiadhesive natural products against Campylobacter jejuni: molecular structure and antiadhesive activity of chitosans

Infections caused by the food-borne bacteria Campylobacter are main causes of acute bacterial gastroenteritis worldwide [1]. Campylobacteriosis can range from mild symptoms to fatal illness. Multifactorial prevention strategies should be implemented to reduce prevalence of Campylobacter in the food chain. Especially antiadhesive strategies, inhibiting early host-pathogen interaction, are an innovative concept for reducing Campylobacter bacterial load in feedstock production [1].

During in vitro screening of natural compounds for antiadhesive activity against C. jejuni by flow cytometry of fluorescence labelled C. jejuni (DSM27585) on CaCo-2 epithelial cells, significant anti-adhesive effects were found for chitosans (poly-β-1,4-glucosamine, partially acetylated). Detailed structure-activity investigations using chitosans with varying degree of polymerization (DP) and different degrees of acetylation (DA) were performed (see [Fig. 1]). Data indicate that a high DP and a medium-range DA can be correlated with a strong anti-adhesive activity at a concentration of about 100 µg/mL. Antiproliferative activity of the chitosans tested against C. jejuni was observed only at higher concentrations (> 1 mg/mL). Vitality of the host cells is not influenced negatively by the selected chitosans at the concentrations tested. The reduced bacterial adhesion was also verified by advanced fluorescence and confocal microscopy. For identification of the potential molecular targets of the antiadhesive chitosan, C. jejuni whole protein lysates of chitosan-treated bacteria were investigated by 2D-gels, followed by MS-based proteome analysis.

Fig. 1 Antiadhesive activity of different chitosans against C. jejuni on Coco-2 and HT-29 cells in flow cytometric assay.

The data described here provide a rationalized basis for further development of optimized chitosan as antiadhesive polysaccharide against C. jejuni and use in food technology and food processing.

Publikationsverlauf

Artikel online veröffentlicht:
12. Dezember 2022

• Reference

• 1 Kreling V, Falcone FH, Kehrenberg C, Hensel A. Campylobacter sp.: Pathogenicity factors and prevention methods-new molecular targets for innovative antivirulence drugs?. Appl Microbiol Biotechnol 2020; 104 (24) 10409-10436