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.

Photocatalytically active films of TiO 2 /CuO grown by atmospheric pressure thermal (APT)CVD are investigated for activity against multiple antibiotic-resistant pathogens namely, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, vancomycin-resistant enterococci (VRE), and a recent isolate of methicillin-resistant Staphylococcus aureus (MRSA), that have been shown to persist in the hospital environment. The bacteria are killed by UVA irradiation of the photocatalyst with a >5 log kill within 4-6 h except for the MRSA where a 2-3 log kill is obtained after 6 h increasing to >5 log after 24 h. There is antimicrobial activity in the dark which is enhanced by irradiation with fluorescent light. There is also activity at 5 8C under UVA, but activity is lower when fluorescent light is used for illumination.

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