Anti-biofilm activity of silver nanoparticles against different microorganisms

Abstract

Biofilms confer protection from adverse environmental conditions and can be reservoirs for pathogenic organisms and sources of disease outbreaks, especially in medical devices. The goal of this research was to evaluate the anti-biofilm activities of silver nanoparticles (AgNPs) against several microorganisms of clinical interest. The antimicrobial activity of AgNPs was tested within biofilms generated under static conditions and also under high fluid shears conditions using a bioreactor. A 4-log reduction in the number of colony-forming units of Pseudomonas aeruginosa was recorded under turbulent fluid conditions in the CDC reactor on exposure to 100 mg ml⁻¹ of AgNPs. The antibacterial activity of AgNPs on various microbial strains grown on polycarbonate membranes is reported. In conclusion, AgNPs effectively prevent the formation of biofilms and kill bacteria in established biofilms, which suggests that AgNPs could be used for prevention and treatment of biofilm-related infections. Further research and development are necessary to translate this technology into therapeutic and preventive strategies.

Keywords:

• silver nanoparticles
• biofilm
• Pseudomonas aeruginosa
• CDC reactor
• polycarbonate membrane
• anti-biofilm activity

Acknowledgments

This study was supported by the Center for Biofilm Engineering (CBE), Montana State University, Bozeman, MT, USA. The authors thank Drs J. William Costerton and Philip S. Stewart for their support in this project. Jeffrey Helm is also acknowledged for helpful discussions.