Toward Enhanced Antibiotic Efficacy: Exploring the Synergistic Potential of Marine-Derived Lectins Against Human Pathogenic Bacteria.

Abstract

This study aimed to assess the combined antibacterial effect of lectins and antibiotics on S. aureus ATCC 25923, multidrug-resistant E. coli ATCC 11303 and S. aureus ATCC 700698. Using the checkerboard assay, we evaluated the antibacterial effects of eight lectins isolated from marine organisms combined with two common antibiotics, oxacillin and tetracycline, on three virulent bacterial strains. Initially, none of the tested lectins exhibited antibacterial effects when used individually. However, when combined with antibiotics, the lectins exhibited synergistic, additive, antagonistic, or no interaction. Overall, the tested lectins alone had no effect on the efficacy of oxacillin. On the other hand, different lectins in combination with tetracycline potentiated its antimicrobial effect. Lectins from red algae of the Bryothamnium genus, for example, exhibited the most significant synergistic effects, reducing the minimum inhibitory concentration (MIC) of tetracycline by up to 16 times. Lectins from the Hypnea genus also reduced the MIC of tetracycline. Our findings suggest that some lectins binding to complex carbohydrates containing fucosylated cores (α1-6) are excellent candidates to boost the efficacy of some antibiotics.