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.