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

Abstract

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.

Keywords:

• AgNPs
• antibacterial
• antimicrobial
• antibiotic-resistant bacteria
• green synthesis
• phage therapy
• quorum sensing
• synergetic effect
• Biofilm clearance
• time–killing curve

Acknowledgments

We would like to thank Alyaa Dawoud and Mariam Hebishy for their kind help and Nawah Scientific center, Almokattam, Cairo, Egypt, for helping in AgNPs characterization.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

All data that support the findings of this study are included within the article (and any supplementary files).

Additional information

Funding

This research was funded by the Academy of Scientific Research and Technology (ASRT), Genetic call (51/2020), and Zewail City of Science and Technology internal grant No. ZC 019-2019.