Lack of Involvement of Fenton Chemistry in Death of Methicillin-Resistant and Methicillin-Sensitive Strains of Staphylococcus aureus and Destruction of Their Genomes on Wet or Dry Copper Alloy Surfaces

Abstract

The pandemic of hospital-acquired infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has declined, but the evolution of strains with enhanced virulence and toxins and the increase of community-associated infections are still a threat. In previous studies, 10 7 MRSA bacteria applied as simulated droplet contamination were killed on copper and brass surfaces within 90 min. However, contamination of surfaces is often via finger tips and dries rapidly, and it may be overlooked by cleaning regimes (unlike visible droplets). In this new study, a 5-log reduction of a hardy epidemic strain of MRSA (epidemic methicillin-resistant S. aureus 16 [EMRSA-16]) was observed following 10 min of contact with copper, and a 4-log reduction was observed on copper nickel and cartridge brass alloys in 15 min. A methicillin-sensitive S. aureus (MSSA) strain from an osteomyelitis patient was killed on copper surfaces in 15 min, and 4-log and 3-log reductions occurred within 20 min of contact with copper nickel and cartridge brass, respectively. Bacterial respiration was compromised on copper surfaces, and superoxide was generated as part of the killing mechanism. In addition, destruction of genomic DNA occurs on copper and brass surfaces, allaying concerns about horizontal gene transfer and copper resistance. Incorporation of copper alloy biocidal surfaces may help to reduce the spread of this dangerous pathogen. Intrinsic penicillin resistance and acquisition of resistance to methicillin in the 1980s by Staphylococcus aureus led to a pandemic of infections worldwide. Initially, the majority of infections were contracted in health care environments, but incorporation of measures to control the spread, including preadmission screening, decolonization, improved disinfection, and antibiotic treatment, have stemmed the tide (1). The increased use of antibiotics required for the epidemic of infections caused by Gram-positive pathogens has allowed the evolution of multidrug-resistant Gram-negative pathogens, effectively transforming some commensal gut bacteria into potential killers. However, new strains of S. aureus that have acquired further virulence factors and toxins or that have adapted to a specific environment, for example, an increased ability to cause bacteremia (2), are still a considerable threat. There is now widespread community-associated methicillin-resistant S. aureus (CA-MRSA), and infections can spread within households, day care centers, and schools (3). In addition, Giuffre et al. observed an increasing incidence of MRSA in neonates (4). The ability of some strains of MRSA to revert to methicillin-susceptible isolates, particularly in skin and soft tissue infections, has been observed (5).Colonization with MRSA increases the risk of MRSA infection, particularly following illness, surgical procedures, and treatment with immunosuppressive drugs. Colonization and/or infection may also occur from touching contaminated surfaces. In the community, a recent study observed that 58% and 82% of surfaces in 19 f...

Antiparasitic Effect of Copper Alloy Surface on Cryptocaryon irritans in Aquaculture of Larimichthys crocea

“…Studies have suggested that both lipid peroxidation and cell death occur before genomic DNA degradation, but in some cases genomic DNA is not degraded during the course of cell death (14,22). This finding indicates that genomic DNA degradation is not the main cause of cell death (14) but may play a role in preventing the horizontal transfer of antibiotic resistance genes in other organisms (13).…”

“…In 2008, more than 300 copper surfaces were registered by the Environmental Protection Agency as antimicrobial materials (12). Studies have confirmed that contact with copper surfaces kills Staphylococcus aureus, Escherichia coli, and most other bacteria within hours or even seconds, due to the combinatory effects of copper-ion-induced reactive oxygen species (ROS) generation (13), lipid peroxidation (14), damage to cell membrane integrity (15), DNA degradation (16), aberrant protein expression (17), inactivation of metalloproteins (18), and other factors. In marine fish farming, copper is used for corrosion-resistant cages, and copper coating is also used for its anticorrosive, antibacterial, and antiadhesive properties (19).…”

Investigation of Polyaniline and a Functionalised Derivative as Antimicrobial Additives to Create Contamination Resistant Surfaces

“…The longer a bacterium persists on a surface, the greater the opportunity to be spread [ 4 ]. Therefore, rapid decontamination times will decrease the chance that bacteria may be transferred to a new surface before sterilisation is achieved, and will decrease the likelihood of resistance developing [ 72 ].…”

Reduction of bacterial burden by copper alloys on high-touch athletic center surfaces

“…[6][7][8][9][10][11][12] Studies have found that copper surfaces rapidly reduce bacterial loads through a process known as contact killing against both gram-positive and gram-negative bacteria. [13][14][15][16][17] With the rise of antibiotic-resistant bacteria, such as MRSA, the use of copper alloy surfaces provides a mean of not only reducing bacterial burden, but also mitigating the spread of antibiotic-resistant bacteria in the environment. The implementation of copper alloys on high-touch surfaces in the hospital resulted in decreased bacterial counts on surfaces in comparison with control surfaces.…”