Copper could control MRSA contamination

A new study by scientists at the University of Southampton suggests that MRSA contamination can be reduced by using copper alloys for surfaces in healthcare facilities.

Methicillin resistant Staphylococcus aureus (MRSA) is a virulent organism, essentially resistant to all beta-lactam antibiotics (for example: penicillins, ampicillins, cephalosporins). It can cause skin, bone and life-threatening blood infections, as well as pneumonia.

In a study co-funded by the International Copper Association and Copper Development Association in New York, Professor Bill Keevil, Head of the Environmental Healthcare Unit in the University of Southampton’s School of Biological Sciences, and Dr. Jonathan Noyce examined the survival rates of the organism on stainless steel, the most commonly used metal in healthcare facilities, and on selected copper alloys.

Their findings, which were reported recently at a meeting of the American Society for Microbiology in New Orleans, showed that at room temperature, MRSA was able to persist and remain viable in dried deposits on stainless steel for periods up to 72 hours.

For copper alloys containing 55%, 80%, and 99% copper, significant reductions in viability were achieved after four and a half hours, three hours, and one and a half hours, respectively. Yellow brass rendered the bacteria completely inviable after 270 minutes, while the high-copper alloy took only 90 minutes.

‘Our results strongly indicate that use of the copper metals in such applications as door knobs, push plates, fittings, fixtures and work surfaces would considerably mitigate MRSA in hospitals and reduce the risk of cross-contamination between staff and patients in critical care areas,’ said Professor Keevil.

‘However, despite the significant performance of copper alloys in our study, we also noted that the survivability of MRSA on all metals at lower temperatures is much greater, indicating that hygiene is particularly imperative in those environments.’

Professor Keevil added that the antimicrobial effects of copper have been well documented. ‘Recent studies on E. coli O157 and Listeria monocytogenes on copper alloy surfaces show similar dramatic results, reducing viability of those pathogens from several weeks on stainless steel to only a matter of hours on copper alloys,’ he said.

The MRSA study was co-funded by the International Copper Association and Copper Development Association, New York, and managed by CDA.

A copy of the study report presented to the American Society for Microbiology, ‘The Antimicrobial Effect of Copper and Copper-based Alloys on Methicillin Resistant Staphylococcus aureus,’ may be obtained from the CDA.