Antibiotic resistance is a serious global threat, and the misuse of antibiotics is considered its main cause. It is characterized by the expression of bacterial defense mechanisms, e.g., β-lactamases, expulsion pumps, and biofilm development. Acinetobacter baumannii and Pseudomonas aeruginosa are antibiotic-resistant species that cause high morbidity and mortality. Several alternatives are proposed to defeat antibiotic resistance, including antimicrobial peptides, bacteriophages, and plant compounds. Terpenes from different plant essential oils have proven antimicrobial action against pathogenic bacteria, and evidence is being generated about their effect against antibiotic-resistant species. That is the case for oregano essential oil (Lippia graveolens), whose antibacterial effect is widely attributed to carvacrol, its main component; however, minor constituents could have an important contribution. The analyzed evidence reveals that most antibacterial evaluations have been performed on single species; however, it is necessary to analyze their activity against multispecies systems. Hence, another alternative is using plant compounds to inactivate hydrolytic enzymes and biofilms to potentiate antibiotics’ effects. Despite the promising results of plant terpenes, more extensive and deep mechanistic studies are needed involving antibiotic-resistant multispecies to understand their full potential against this problem.

Fucoidan is a sulfated fucan marine polysaccharide with potential therapeutic applications, including antibacterial activity and the control of virulence factors associated with quorum sensing. This study investigates the bioactivity of fucoidan derived from the brown algae Ascophyllum nodosum, as well as their fucoidan oligosaccharides (OFuc; <3 kDa), on the growth, motility, biofilm formation, and adhesion of Campylobacter jejuni, the leading cause of bacterial gastroenteritis worldwide. The results showed that fucoidan decreased the growth rate of C. jejuni at concentrations greater than 25 µg/mL, while no effect was observed with different concentrations (5–100 µg/mL) of OFuc. Neither compound affected bacterial motility. Both fucoidan and OFuc inhibited abiotic biofilm formation and diminished pathogen adhesion in a concentration-dependent manner. The study also found that C. jejuni recognized the fucoidan molecule through an enzyme-like lectin assay (ELLA) showing a lectin-like adhesin-carbohydrate recognition. Overall, these results suggest the potential of fucoidan from A. nodosum for controlling abiotic biofilm formation in the food industry, and they open new avenues for research into the use of fucoidan as a molecule aimed at blocking infections caused by C. jejuni.

Campylobacteriosis produced by Campylobacter jejuni is the main cause of bacterial gastroenteritis worldwide and the binding of this pathogen to fucosylated glycoconjugates expressed on host cells is a determining factor for the infection. The aim of this work was to synthesize and characterize core-shell nanoparticles from fucoidan neoglycans as potential glycomimetic ligands for Campylobacter jejuni. Fucoidan oligosaccharides (OFuc) were obtained by mild hydrolysis of fucoidan. OFuc were separated by ultrafiltration, characterized by dynamic light scattering (DLS), infrared spectroscopy (FTIR), Fluorophore-assisted carbohydrate electrophoresis and lectin recognition. The OFuc₁ were then conjugated with bovine serum albumin (BSA) by controlled glycation. The formation of fucosylated BSA (BSA-OFuc₁) was confirmed by FTIR, increased surface charge, polyacrylamide gel electrophoresis, mass spectrometry and Ulex europaeus I lectin recognition. Afterwards core-shell BSA/BSA-OFuc₁ nanoparticles were obtained by crosslinking. These nanoparticles presented hemispherical form with size and charge distribution of 312.1 ± 3.2 nm and -34.4 ± 0.3 mV respectively and were selectively recognized by C. jejuni by an ELISA-like lectin assay (ELLA). These results revel the potential of core-shell nanoparticles from fucoidan neoglycans as glycomimetic ligands for Campylobacter jejuni and open further opportunities to explore potential applications in the pharmaceutic industry.