Synergistic Antibacterial Activity and Mechanism of Arginine Combined with Florfenicol Against Escherichia coli

As a common opportunistic pathogen, the rapid development of resistance in Escherichia coli (E. coli) poses severe challenges to clinical anti-infective therapy. Against this backdrop, the combined use of amino acids and antibiotics is considered an effective strategy against multidrug-resistant bacterial infections.

This study investigated the antibacterial efficacy and mechanism of action of the combination of arginine (Arg) and florfenicol (FFC) against resistant E. coli. Results indicate that Arg significantly enhances the bactericidal activity of FFC against resistant E. coli both in vivo and in vitro, successfully reversing the resistance phenotype. Mechanistic studies reveal that Arg disrupts fatty acid β-oxidation by inhibiting the arginine succinyl-transferase (AST) pathway, leading to excessive free fatty acid (FFA) accumulation.