Thursday, 1 December 2016

Engineering against antibiotic resistance with antimicrobial copper

In the WHO’s Global Action Plan on Antimicrobial Resistance (AMR), backed by the UN, the prevention of infection is one of five strategies to tackle the global rise of AMR.

Pathogenic bacteria can survive on standard environmental surfaces in healthcare facilities, leading to the risk of patients acquiring an infection. Bacteria deposited and surviving on a surface can exchange genes, including those for antibiotic resistance, which can result in new, resistant strains.

Hand hygiene, and surface cleaning and disinfection are standard measures to prevent and control HCAIs, but more needs to be done to prevent the spread of pathogens by staff, visitors and patients touching contaminated surfaces.

Professor Bill Keevil, Chair in Environmental Healthcare at the University of Southampton, is a leading expert on the hygienic properties of copper, and believes replacing frequently-touched surfaces with antimicrobial copper equivalents, teamed with good hygiene practices, could help address both the environmental spread of contamination and the rise of antibiotic resistance.

Copper is a powerful antimicrobial with rapid, broad-spectrum efficacy against bacteria and viruses, and has been shown to kill disease-causing pathogens, including influenza A, E.coli and norovirus, and resistant bacteria including Methicillin-resistant Staphylococcus aureus (MRSA), Carbapenem-resistant Enterobacteriaceae (CRE) and Vancomycin-resistant Enterococcus (VRE). It shares this benefit with a range of copper alloys, such as brasses and bronzes, forming a family of materials collectively called ‘antimicrobial copper’.

‘We’ve shown that antimicrobial copper touch surfaces produce a rapid kill of bacteria, viruses and fungi, usually within minutes,’ says Professor Keevil. ‘EPIC 3 - the national, evidence-based guidelines for preventing HCAIs in NHS Hospitals in England - recognise high-touch surfaces made from antimicrobial copper harbour 80-90% fewer bacteria than equivalent, non-copper surfaces. A multicentre trial in the US further showed a concurrent 58% reduction in HCAIs in ICU rooms equipped with antimicrobial copper touch surfaces.’

Professor Keevil also observes that gene transfer between bacteria does not occur on copper because bacteria are destroyed rapidly and completely. This means the genes for antibiotic resistance can’t be exchanged, contributing to a reduced likelihood of new resistant strains emerging.

Posted by Dr. Tim Sandle