One pot synthesis and anti-biofilm potential of copper nanoparticles (CuNPs) against clinical strains of Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa, an opportunistic pathogen frequently associated with nosocomial infections, is emerging as a serious threat due to its resistance to broad spectrum antimicrobials. The biofilm mode of growth confers resistance to antibiotics and novel anti-biofilm agents are urgently needed. Nanoparticle based treatments and therapies have been of recent interest because of their versatile applications. This study investigates the anti-biofilm activity of copper nanoparticles (CuNPs) synthesized by the one pot method against P. aeruginosa. Standard physical techniques including UV–visible and Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy were used to characterize the synthesized CuNPs. CuNP treatments at 100 ng ml⁻¹ resulted in a 94, 89 and 92% reduction in biofilm, cell surface hydrophobicity and exopolysaccharides respectively, without bactericidal activity. Evidence of biofilm inhibition was also seen with light and confocal microscope analysis. This study highlights the anti-biofilm potential of CuNPs, which could be utilized as coating agents on surgical devices and medical implants to manage biofilm associated infections.

Keywords:

• copper nanoparticles
• Pseudomonas aeruginosa
• anti-biofilm
• cell surface hydrophobicity
• exopolysaccharides
• nosocomial infections

Acknowledgements

The clinical isolates of P. aeruginosa were gifted by Prof. S. Karutha Pandian, Department of Biotechnology, Alagappa University, India, and the Artemia cysts were gifted by Dr P. Santhanam, Department of Marine Sciences, Bharathidasan University, Tiruchirappalli, India. Their kind help is gratefully acknowledged. The Deanship of Scientific Research, College of Science Research Centre, King Saud University, Kingdom of Saudi Arabia also supported the work.

Conflict of interest disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors gratefully acknowledge DBT [BT/PR4815/AAQ/3/587/2012 and BT/PR6619/PBD/26/310/2012] for their financial assistance, and the CLSM facility provided by the DST-PURSE scheme [SR/FT/LS-113/2009]. Financial support provided to Dr C. Nithya by the DST INSPIRE faculty scheme is gratefully acknowledged (DST/Inspire Faculty Award/2012 [IFA12-LSPA13]) and Dr D. MubarakAli also acknowledges Incheon National University for financial assistance to a Postdoctoral Researcher Program.