New research from Jagiellonian University Medical College in Poland found that coagulase-negative staphylococci were the most common bacteria recovered from touch surfaces in three hospitals, and reported that frequently touched surfaces made form copper and copper alloys could help reduce the threat of these bacteria to vulnerable patients.
31 August 2017
In the study—recently published in Antibiotic Resistance & Infection Control—swabs were taken from surfaces that could act as reservoirs of bacteria which could then be transmitted around the hospital on the hands of staff, patients and visitors, potentially spreading infection. The surfaces included bedside tables, computer keyboards, dressings trolleys, door handles and worktops in 13 wards across three hospitals. The recovered bacteria were characterised in the laboratory, including their strains, antibiotic resistance and susceptibility to copper.
Staphylococci accounted for the vast majority of the bacteria detected, of which almost 97% were coagulase-negative staphylococci. There were eight different species, the most frequent of which were S. epidermidis, S. haemolyticus and S. hominis.
The bacteria were tested for antibiotic resistances and 67% were found to be methicillin-resistant. Four strains were resistant to all six of the tested antibiotics, and 14 were resistant to all except one. All isolates—including those with antibiotic resistance—were found to be susceptible to copper and copper alloys, though some inter-species and inter-alloy variation was reported. These differences could be observed due to the type of test used: an adaption of the Japanese test standard JIS Z 2801, a wet test which precludes the rapid contact efficacy that occurs in a dry touch simulation test.
Coagulase-negative staphylococci are bacteria that come from normal human flora (e.g. hand skin) and the environment (air) and are not dangerous to healthy people with normal immune systems. However, they pose a threat to patients, especially those who are severely ill, elderly, immunocompromised, in intensive care or neonatal intensive care (new-borns). They cause skin and invasive infections, which can be difficult to treat due to their antibiotic resistance.
The researchers recommended that any new Polish test for antimicrobial materials should include representative coagulase-negative staphylococci as they can serve as a reservoir for antibiotic-resistance genes in hospitals.
They concluded that copper and copper alloy touch surfaces can provide an additional hygiene measure and help eliminate genes for antimicrobial resistance from hospitals.
Antibiotic resistance, ability to form biofilm and susceptibility to copper alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards
A Różańska, A Chmielarczyk, D Romaniszyn, M Bulanda, M Walkowicz, P Osuch and T Knych. Antimicrobial Resistance & Infection Control, August 2017
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.