Carbapenem-resistant Enterobacteriaceae (CRE) are often considered the most problematic healthcare-associated infections (HCAIs) worldwide. This study evaluated the antimicrobial activity of copper surfaces against 24 clinical isolates of carbapenemase producing bacteria—including, four isolates of E. coli, two isolates of Enterobacter spp., eight isolates of K. pneumonia, five isolates of P. aeruginosa, and five isolates of A. baumannii.
Synopsis of Methodology
Antimicrobial activity was examined by inoculating copper (Cu99%), brass (Cu63%), stainless steel (SS), and polyvinylchloride (PVC) coupons with 24 clinical isolates of multidrug resistant (MDR) bacteria from the Enterobacteriaceae family—including, four isolates of E. coli, two isolates of Enterobacter spp., eight isolates of K. pneumonia, five isolates of P. aeruginosa, and five isolates of A. baumannii. The average number of surviving colony forming units per square centimeter (CFU/cm2 ) over time was plotted for each group of isolates of the same species.
- Copper alloys (Cu99% and Cu63%) provided a significant reduction in survival of carbapenemase-producing bacteria. On average, after 3 hours of exposure, the Cu99% alloy reduced all tested isolates of CRE by >99%, and a 77% reduction was observed on the Cu63% alloy compared to a 46% reduction on stainless steel, and a 49% reduction on plastic (PVC).
- The continuous killing of carbapenemase-producing bacteria on copper surfaces suggests that the use of copper alloys in high-contact surfaces in a hospital may help reduce the spread of “difficult-to-treat” HAIs, if coupled with optimal cleaning procedures and compliance with infection-control practices.
What is it?
- Enterobacteriaceae comprise a large family of gram negative bacteria. While the carbapenem class of antibiotics is used to combat many of these pathogens, CRE infections can occur when the bacteria begin to break down carbapenems into carbapenemase, making the antibiotics ineffective and the infection more lethal. CRE bacteria have become resistant to nearly all antibiotics.
- Carbapenem-resistant Enterobacteriaceae, also known as carbapenemase-producing Enterobacteriaceae (CPE), kill patients at a rate much higher than other types of multidrug-resistant (MDR) infections, such as MRSA or Clostridium difficile.
How is it contracted?
- Information from the US Centers for Disease Control and Prevention (CDC) suggests that CRE bacteria are most often spread from person to person contact or through contact with contaminated surfaces.
Where is it prevalent?
- CRE infections are most commonly seen in people in hospitals, nursing homes, and other healthcare settings. Patients whose care requires medical devices—such as breathing machines, urinary catheters or intravenous catheters—and patients who are taking long courses of certain antibiotics are most at risk for CRE infections.
- According to the CDC, CRE bacteria contribute to death in up to 50% of patients who become infected.
Copper and copper alloys are engineering materials that are durable, colourful and recyclable and are widely available in various product forms suitable for a range of manufacturing purposes. Copper and its alloys offer a suite of materials for designers of functional, sustainable and cost-effective products.
Copper and certain copper alloys have intrinsic antimicrobial properties (so-called ‘Antimicrobial Copper’) and products made from these materials have an additional, secondary benefit of contributing to hygienic design. Products made from Antimicrobial Copper are a supplement to, not a substitute for standard infection control practices. It is essential that current hygiene practices are continued, including those related to the cleaning and disinfection of environmental surfaces.