CGL, a Lectin from Crenomytilus grayanus, Exhibits Antibiofilm and Synergistic Antibacterial Activity Against Escherichia coli and Staphylococcus aureus.

Lectins are carbohydrate-binding proteins that specifically bind to sugar groups associated with other molecules. Several studies have reported that these proteins can also modulate the activity of antibiotics against multidrug-resistant (MDR) strains in addition to interacting with carbohydrates. This study reports that gentamicin exhibits enhanced antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacterial strains when complexed with Crenomytilus grayanus lectin (CGL). Enzyme-linked lectin, thermofluor, and isothermal titration calorimetry assays revealed that gentamicin interacts with CGL through a domain distinct from the carbohydrate recognition domain. An increase in antibacterial activity was observed when lectin and antibiotic were used together against S. aureus in living systems-specifically, sea urchin (Strongylocentrotus nudus) embryos.