Zinc oxide nanoparticles reduce biofilm formation, synergize antibiotics action and attenuate Staphylococcus aureus virulence in host; an important message to clinicians

BMC Microbiol. 2022 Oct 11;22(1):244. doi: 10.1186/s12866-022-02658-z.

Abstract

Background: Biofilm-related infections are difficult to be treated because of higher resistance to antimicrobial agents. Current study aims to characterize the influence of zinc oxide nanoparticles (ZnO-NPs) on both S. aureus susceptibility to antibiotics and pathogenesis.

Methods: The influence of ZnO-NPs on biofilm formation by S. aureus was characterized by the crystal violet and tube assay. The synergistic effect of ZnO-NPs in combination with antibiotics on S. aureus was characterized using the checkerboard method. The effect of ZnO-NPs on S. aureus cell surface hydrophobicity and blood hemolysis was investigated. RT-qPCR was used to investigate the effect of ZnO-NPs on the expression of biofilm related genes (icaA, icaR and sarA), katA and sigB. The impact of ZnO-NPs on S. aureus pathogenesis was evaluated using mice infection model.

Results: ZnO-NPs exhibited a good antibiofilm activity against S. aureus. The findings indicate a synergistic antibiofilm effect of combination between ZnO-NPs and tested antibiotics. ZnO-NPs were capable of decreasing S. aureus cell surface hydrophobicity which could account for observed decrease in bacterial biofilm forming capacity. Moreover, ZnO-NPs-treated bacteria exhibited a significant decrease in blood hemolysis relative to control untreated S. aureus. The expression of biofilm related genes was significantly repressed in ZnO-NPs treated bacteria as compared to untreated cells. Finally, the effect of ZnO-NPs on S. aureus pathogenesis was investigated using mice infection model where ZnO-NPs accelerated healing of wounds in mice as compared to control untreated mice.

Conclusions: Present data support the efficiency of ZnO-NPs as antibiofilm agent in treatment of S. aureus infections. This study recommends the incorporation of ZnO-NPs as adjuvant with other antibiotics targeting S. aureus based on the promising findings obtained herein in order to control infection with this pathogen.

Keywords: Antibiofilm; Pathogenesis; Staphylococcus aureus; Zinc oxide nanoparticles (ZnO-NPs).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Bacteria / metabolism
  • Biofilms
  • Gentian Violet / pharmacology
  • Hemolysis
  • Iron-Dextran Complex / pharmacology
  • Metal Nanoparticles* / chemistry
  • Mice
  • Microbial Sensitivity Tests
  • Nanoparticles* / chemistry
  • Staphylococcal Infections* / drug therapy
  • Staphylococcus aureus
  • Virulence
  • Zinc Oxide* / chemistry
  • Zinc Oxide* / pharmacology

Substances

  • Anti-Bacterial Agents
  • Iron-Dextran Complex
  • Gentian Violet
  • Zinc Oxide