Synergistic Eradication of Drug-Resistant Salmonella enteritidis in Food Matrices Through an Ag-MOF Nanozyme with Multiple Enzyme-like Activities

In this study, a silver-based metal–organic framework (Ag-MOF) nanozyme was synthesized for the synergistic eradication of drug-resistant Salmonella enteritidis in food matrices. Ag-MOF exhibits multiple enzyme-like activities, namely oxidase (OXD)-, peroxidase (POD)-, and superoxide dismutase (SOD)-like activities. It demonstrated excellent antibacterial and antibiofilm activities against erythromycin- and chloramphenicol-resistant S. enteritidis strains (N29 and P23). Specifically, treatment with 20 mg mL−1 Ag-MOF resulted in nearly complete eradication of S. enteritidis in in vitro suspension assays, including 1 × 107 CFU mL−1 N29 strain and 6 × 106 CFU mL−1 P23 strain. Moreover, treatment with 1 mg mL−1 Ag-MOF led to 80~90% biofilm inhibition of S. enteritidis. Mechanistic investigations revealed that Ag-MOF effectively interacted with amino-rich structures on the bacterial surface (such as membrane proteins and peptidoglycan components), generated abundant reactive oxygen species (ROS), released Ag+ ions, and depleted intracellular glutathione, which collectively disrupted cell membrane integrity and induced severe leakage of intracellular proteins and nucleic acids. Importantly, Ag-MOF maintained high antibacterial efficacy in complex simulated food matrices (pork, milk, and egg shell). Overall, this study offers key insights into enzyme-mimicking antibacterial materials and a promising strategy to combat multidrug resistant foodborne pathogens.