Antimicrobial activity of copper surfaces against carbapenemase-producing contemporary Gram-negative clinical isolates

J Antimicrob Chemother. 2013 Apr;68(4):852-7. doi: 10.1093/jac/dks473. Epub 2012 Dec 9.


Objectives: The antimicrobial activity of copper surfaces against a variety of contemporary carbapenemase-producing Gram-negative bacteria representative of the most problematic nosocomial pathogens worldwide was evaluated.

Methods: Twenty-four clinical isolates, comprising four of Escherichia coli, two of Enterobacter spp., eight of Klebsiella pneumoniae and five each of Pseudomonas aeruginosa and Acinetobacter baumannii producing either VIM-1 and/or KPC-2 or VIM-2 or OXA-type carbapenemases, were studied. The antimicrobial activity of 99% copper (Cu99%) and a 63% alloy (Cu63%) was evaluated in comparison with that of stainless steel (SS) and polyvinylchloride (PVC) by incubating ∼10(6) cfu/cm(2) of the tested strains on each surface at room temperature.

Results: Copper demonstrated antimicrobial activity against all studied isolates. This effect was observed earlier and was more pronounced for Cu99% than for Cu63%. Cu99% showed a bactericidal effect after <2 h for A. baumannii, 3 h for Enterobacter spp., 5 h for K. pneumoniae and 6 h for P. aeruginosa and E. coli. No viable colonies were recovered from five (20.8%) isolates after 3 h and from nine (37.5%) isolates after 5 h of incubation on Cu99%.

Conclusions: Copper has significant antimicrobial activity against multidrug-resistant nosocomial Gram-negative pathogens. This supports the hypothesis that replacement of high-contact materials with copper could reduce the high burden of environmental contamination around high-risk patients. However, this strategy should be seen as an adjunctive measure to established cleaning protocols and to good hygiene practices for prevention of hospital-acquired infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alloys / pharmacology
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / metabolism*
  • Copper / pharmacology*
  • Cross Infection / microbiology
  • Gram-Negative Bacteria / drug effects*
  • Gram-Negative Bacteria / enzymology
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Negative Bacterial Infections / microbiology
  • Humans
  • beta-Lactamases / metabolism*


  • Alloys
  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Copper
  • beta-Lactamases
  • carbapenemase