Fumaric acid restores neomycin efficacy against carbapenem-resistant Vibrio parahaemolyticus through metabolic...

Carbapenems are last-resort antibiotics for multidrug-resistant bacterial infections. The emergence of carbapenem-resistant Vibrio parahaemolyticus (CRVP) therefore represents a growing threat to aquaculture and public health, yet its resistance mechanisms remain poorly understood. In this study, we employed liquid chromatography-mass spectrometry metabolomics to explore metabolic changes associated with meropenem resistance in V. parahaemolyticus. Meropenem-resistant V. parahaemolyticus exhibited marked disruption of the pyruvate/tricarboxylic acid (TCA) cycle, including reduced enzymatic activity, lower NADH and ATP levels, and impaired energy metabolism. Building on this metabolic profile, we tested a reprogramming strategy using exogenous fumaric acid. Fumaric acid restored antibiotic resistance by activating the downstream TCA cycle flux, enhancing nitric oxide production through arginine biosynthesis, and increasing bacterial membrane permeability. It also disturbed the proton motive force, impaired efflux activity, and promoted intracellular neomycin accumulation, resulting in bacterial death. In a Nile tilapia infection model, the combined fumaric acid and neomycin treatment significantly improved survival rates, eradicated CRVP from infected organs, and reduced tissue damage. These results identify a metabolic vulnerability underlying carbapenem resistance and demonstrate that metabolic reprogramming can resensitize CRVP to antibiotics. This approach offers a promising therapeutic strategy for controlling antibiotic-resistant infections in aquaculture and mitigating associated public health risks.