Combination of silver nanoparticles and Drosera binata extract as a possible alternative for antibiotic treatment of burn wound infections caused by resistant Staphylococcus aureus

PLoS One. 2014 Dec 31;9(12):e115727. doi: 10.1371/journal.pone.0115727. eCollection 2014.

Abstract

Staphylococcus aureus is the most common infectious agent involved in the development of skin infections that are associated with antibiotic resistance, such as burn wounds. As drug resistance is a growing problem it is essential to establish novel antimicrobials. Currently, antibiotic resistance in bacteria is successfully controlled by multi-drug therapies. Here we demonstrate that secondary metabolites present in the extract obtained from Drosera binata in vitro cultures are effective antibacterial agents against S. aureus grown in planktonic culture and in biofilm. Moreover, this is the first report demonstrating the synergistic interaction between the D. binata extract and silver nanoparticles (AgNPs), which results in the spectacular enhancement of the observed bactericidal activity, while having no cytotoxic effects on human keratinocytes. Simultaneous use of these two agents in significantly reduced quantities produces the same effect, i.e. by killing 99.9% of bacteria in inoculum or eradicating the staphylococcal biofilm, as higher amounts of the agents used individually. Our data indicates that combining AgNPs with either the D. binata extract or with its pure compound (3-chloroplumbagin) may provide a safe and highly effective alternative to commonly used antibiotics, which are ineffective towards the antibiotic-resistant S. aureus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Biofilms / drug effects
  • Burns / microbiology
  • Cells, Cultured
  • Drosera / metabolism*
  • Drug Resistance, Multiple, Bacterial
  • Humans
  • Keratinocytes / drug effects
  • Metal Nanoparticles / therapeutic use*
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Methicillin-Resistant Staphylococcus aureus / pathogenicity
  • Microbial Sensitivity Tests
  • Naphthoquinones / therapeutic use
  • Plant Extracts / therapeutic use*
  • Silver / therapeutic use
  • Silver Compounds / therapeutic use
  • Wound Infection / drug therapy*
  • Wound Infection / microbiology

Substances

  • Anti-Bacterial Agents
  • Naphthoquinones
  • Plant Extracts
  • Silver Compounds
  • Silver
  • plumbagin

Grants and funding

The research was supported by the National Centre for Research and Development (project LIDER/32/36/L-2/10/NCRiR/2011). Publication costs were covered by the EU FP7 project MOBI4Health, GA. 316094. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.