The antibacterial and biofilm inhibition activity of encapsulated silver nanoparticles in emulsions and its synergistic effect with E. coli bacteriophage

The paper investigates the efficiency of phage-nano combinational therapy in treating planktonic and biofilm bacteria. Silver nanoparticles (AgNPs) were synthesized by olive oil as a coating emulation and characterized. Then, the antibacterial activity, biofilm inhibition, and the compatibility of phage ZCEC5 with AgNPs were evaluated. The results revealed that AgNPs were effective against a wide range of bacteria including Enterobacter spp., Listeria monocytogenes, Klebsiella pneumoniae, Salmonella Enteritidis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus sciuri, with a minimum inhibitory concentration (MIC) ranging from 0.6 to 3.15% and a minimum bactericidal concentration (MBC) ranged from 3.15 to 12.5%. As a model bacteria, E. coli O157:H7 was tested against the formulated AgNPs alone, and in combination with bacteriophage ZCEC5. While the MIC and MBC for E. coli treated with the AgNPs only were 1.1% and 3.15%, respectively, when combined with phage ZCEC5 (∼108 PFU/mL), the MIC and MBC were reduced to be 0.13% and 0.25%, respectively. Therefore, this paperwork introduces an antibacterial AgNPs against a wide spectrum of Gram-positive and Gram-negative bacteria, along with a novel combinational therapy of AgNPs and bacteriophage.