Antibacterial activity of a novel Forsythia suspensa fruit mediated green silver nanoparticles against food-borne pathogens and mechanisms investigation.

In the present study, novel silver nanoparticles (AgNPs) were synthesized via a green method by using Forsythia suspensa fruit water extract. The synthesized AgNPs showed antibacterial activities against all the tested food-borne pathogens, including Listeria monocytogenes , Vibrio parahaemolyticus , Escherichia coli O157:H7, Staphylococcus aureus , Pseudomonas aeruginosa and Salmonella typhimurium. Furthermore, the S. aureus and V. parahaemolyticus were introduced as Gram-positive and Gram-negative model strains to explore the antibacterial mechanism of AgNPs. Minimal inhibitory concentrations (MICs) of V. parahaemolyticus and S. aureus were 6.25 μg/mL and 50 μg/mL, respectively, and the minimum bactericidal concentrations (MBCs) of V. parahaemolyticus and S. aureus were 12.5 μg/mL and 100 μg/mL, respectively. Results indicated that the AgNPs caused morphological alterations and damaged the membrane integrity of strains S. aureus and V. parahaemolyticus. In addition, the AgNPs induced the release of nucleic acids of V. parahaemolyticus cells, resulting in disrupting of cells reproduction. Unlabelled Image • A novel green synthesis method of silver nanoparticles based on Forsythia suspensa fruit was explored. • The silver nanoparticles showed good antibacterial activity against all tested food-borne pathogens. • The silver nanoparticles caused visualized morphological alterations of food-borne pathogens. • The silver nanoparticles damaged membrane integrity of food-borne pathogens. • The synthesized silver nanoparticles can induce the release of the nucleic acids of Vibrio parahaemolyticus. [ABSTRACT FROM AUTHOR]