Title:Synergistic Antibacterial Effect of ZnO Nanoparticles and Antibiotics against Multidrug-resistant Biofilm Bacteria
Volume: 22
Issue: 1
Author(s): Majed M. Masadeh*, Noor M. Bany-Ali, Mai S. Khanfar, Karem H. Alzoubi, Majd M. Masadeh and Enaam M. Al Momany
Affiliation:
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid,
Jordan, 22110
Keywords:
ZnO nanoparticles, antibiotics, multidrug-resistant biofilm bacteria, MBC, over the counter (OTC), optical density (OD).
Abstract:
Background: The misuse of antibiotics leads to a global increase in antibiotic resistance.
Therefore, it is imperative to search for alternative compounds to conventional antibiotics. ZnO nanoparticles
(Zn NP) are one of these alternatives because they are an effective option to overcome
biofilm bacterial cells and a novel way to overcome multidrug resistance in bacteria. The current
research study aims to characterize the efficacy of ZnO nanoparticles alone and in combination with
other antibacterial drugs against bacterial biofilms.
Methods: ZnO NPs were prepared by co-precipitation method, and their anti-biofilm and antibacterial
activities alone or combined with four types of broad-spectrum antibacterial (Norfloxacin, Colistin,
Doxycycline, and Ampicillin) were evaluated against E. coli and S. aureus bacterial strains.
Finally, the cytotoxicity and the hemolytic activity were evaluated.
Results: ZnO NPs were prepared, and results showed that their size was around 10 nm with a spherical
shape and a zeta potential of -21.9. In addition, ZnO NPs were found to have a strong antibacterial
effect against Gram-positive and Gram-negative microorganisms, with a minimum inhibitory concentration
(MIC) of 62.5 and 125 μg/mL, respectively. Additionally, they could eradicate biofilmforming
microorganisms at a concentration of 125 μg/m. ZnO NPs were found to be non-toxic to
erythrocyte cells. Still, some toxicity was observed for Vero cells at effective concentration ranges
needed to inhibit bacterial growth and eradicate biofilm-forming organisms. When combined with
different antibacterial, ZnO NP demonstrated synergistic and additive effects with colistin, and the
MIC and MBEC of the combination decreased significantly to 0.976 μg/mL against planktonic and
biofilm strains of MDR Gram-positive bacteria, resulting in significantly reduced toxicity.
Conclusion: The findings of this study encourage the development of alternative therapies with high
efficacy and low toxicity. ZnO nanoparticles have demonstrated promising results in overcoming
multi-drug resistant bacteria and biofilms, and their combination with colistin has shown a significant
reduction in toxicity. Further studies are needed to investigate the potential of ZnO nanoparticles
as a viable alternative to conventional antibiotics.