Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens

Abstract

There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable.

Bacteriostatic Activity of LLDPE Nanocomposite Embedded with Sol–Gel Synthesized TiO2/ZnO Coupled Oxides at Various Ratios

“…In fact, numerous techniques have been proposed to integrate antimicrobial properties in a polymer matrix. For instance, incorporation of antimicrobial agents directly into polymers [4] can be performed by coating or adsorbing antimicrobials onto polymer surfaces [5,6], immobilization of antimicrobials to polymers via ion or covalent linkages [7], and the use of polymers that are inherently antimicrobial [8]. Amongst these methods, incorporation of inorganic metal/metal oxide in a polymer has gained priority in a number of studies due to the unique antibacterial activity of metal/metal oxide at low concentration [7], stability in extreme conditions [5,6], and non-toxicity [8,9,10].…”

Antimicrobial Activity of Copper Alloys Against Invasive Multidrug-Resistant Nosocomial Pathogens

“…According to our results, 99 % copper exhibited the highest reduction of microorganisms and the significance was particularly apparent at 0, 2, and 4 h time intervals. The bactericidal effect of 99 % copper was shorter than the other studies that have evaluated multidrug-resistant bacteria [2,7,22,23]. Two separate studies, Warnes and Keevil [26] and Santo et al [20], recently published that killing of bacteria on a dry copper surface can be as short as 2-10 min.…”

Antimicrobial Functionalization of Textile Materials with Copper Silicate

“…The SEM method confirmed the nanostructure of Cu particles in the silica matrix. The shells of nanocomposites Cu/SiO 2 tested can also be used for the microbial protection of metal and ceramic surfaces [46].…”