Silver nanoparticles synthesized with Eucalyptus critriodora ethanol leaf extract stimulate antibacterial activity against clinically multidrug-resistant Acinetobacter baumannii isolated from pneumonia patients

Microb Pathog. 2019 Jan:126:245-257. doi: 10.1016/j.micpath.2018.11.018. Epub 2018 Nov 13.

Abstract

The increasing multidrug resistance of Acinetobacter baumannii has been highlighted as a worldwide therapeutic problem. Despite the wide range of studies on green synthesis of silver nanoparticles, there is currently no alternative treatment for MDR A. baumannii infection. This study investigated the potential of silver nanoparticles synthesized with Eucalyptus critriodora leaf extract as an inhibitor of MDR A. baumannii infection. The results demonstrated that silver nanoparticles synthesized with E. critriodora leaf extract triggered MDR A. baumannii DNA condensation, induced bacterial cell death and had a significant effect on biofilm formation, biofilm-grown cells, bacterial attachment and invasion of human lung cells in a concentration dependent manner. Silver nanoparticles synthesized with E. critriodora leaf extract had no obvious effects on the viability of human lung cells. The synthesized silver nanoparticles inhibited MDR A. baumannii infection by approximately 90% without cytotoxicity with a 50% effective concentration of 0.028 μg/ml. Thus silver nanoparticles with E. critriodora leaf extract had the potential to be a promising anti-MDR A. baumannii agent for effective treatment and they point the way to further development of a wide range of effective biomedical applications.

Keywords: Acinetobacter baumannii; Antibacterial activity; Eucalyptus critriodoro; Multidrug resistance; Silver nanoparticles.

MeSH terms

  • A549 Cells
  • Acinetobacter Infections / drug therapy
  • Acinetobacter baumannii / drug effects*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Apoptosis / drug effects
  • Biofilms / drug effects
  • Cell Survival / drug effects
  • DNA Damage
  • Drug Resistance, Multiple, Bacterial / drug effects*
  • Eucalyptus / chemistry*
  • Green Chemistry Technology
  • Humans
  • Metal Nanoparticles / chemistry*
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Plant Extracts / pharmacology*
  • Plant Leaves / chemistry*
  • Pneumonia / microbiology
  • Silver / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Plant Extracts
  • Silver