Antimicrobial Activity of Copper Alloys Against Invasive Multidrug-Resistant Nosocomial Pathogens
The emergence and spread of antibiotic resistance demanded novel approaches for the prevention of nosocomial infections, and metallic copper surfaces have been suggested as an alternative for the control of multidrug-resistant (MDR) bacteria in surfaces in the hospital environment. This study aimed to evaluate the antimicrobial activity of copper material for invasive MDR nosocomial pathogens isolated over time, in comparison to stainless steel. Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) (n:4), OXA-23 and OXA-58 positive, MDR Acinetobacter baumannii (n:6) and Pseudomonas aeruginosa (n:4) were evaluated. The antimicrobial activity of coupons containing 99 % copper and a brass alloy containing 63 % copper was assessed against stainless steel. All the materials demonstrated statistically significant differences within each other for the logarithmic reduction of microorganisms. Among the three materials, the highest reduction of microorganisms was seen in 99 % copper and the least in stainless steel. The result was statistically significant especially for 0, 2, and 4 h (P = 0.05). 99 % copper showed a bactericidal effect at less than 1 h for MRSA and at 2 h for P. aeruginosa. 63 % copper showed a bactericidal effect at 24 h for P. aeruginosa strains only. Stainless steel surfaces exhibited a bacteriostatic effect after 6 h for P. aeruginosa strains only. 99 % copper reduced the number of bacteria used significantly, produced a bactericidal effect and was more effective than 63 % copper. The use of metallic copper material could aid in reducing the concentration of bacteria, especially for invasive nosocomial pathogens on hard surfaces in the hospital environment.
KeywordsCopper Alloy Bactericidal Effect Colistin Acinetobacter Baumannii Hospital Environment
This study was presented in the 114th General Meeting of the American Society for Microbiology, May 17–20, 2014, Boston, Massachusetts, USA. We would like to thank Selçuk Korkmaz (Hacettepe University, Department of Biostatistics) for interpreting the statistical analysis of the data and Tülay Özçelik for technical assistance.
- 1.Borkow G, Monk A (2012) Fighting nosocomial infections with biocidal non-intrusive hard and soft surfaces. World J Infect Dis 2:77–90Google Scholar
- 3.Clinical and Laboratory Standards Institute (CLSI) (2013) Performance standards for antimicrobial susceptibility testing; twenty-third informational supplement CLSI document M100-S23, Wayne, PA, USAGoogle Scholar
- 4.Efstathiou PA (2011) The role of antimicrobial copper surfaces in reducing healthcare-associated infections. Eur Infect Dis 5:125–128Google Scholar
- 9.Huang HI, Shih HY, Lee CM, Yang TC, Lay JJ, Lin YE (2008) In vitro efficacy of copper and silver ions in eradicating Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii: implications for on-site disinfection for hospital infection control. Water Res 42:73–80PubMedCrossRefGoogle Scholar