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

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

Novel antibacterial silver-silica surface coatings prepared by chemical vapour deposition for infection control

Aims: Environmental contamination plays an important role in the transmission of infections, especially healthcare-associated infections. Disinfection transiently reduces contamination, but surfaces can rapidly become re-contaminated. Antimicrobial surfaces may partially overcome that limitation. The antimicrobial activity of novel surface coatings containing silver and silica prepared using a flame-assisted chemical vapour deposition method on both glass and ceramic tiles was investigated. Methods and Results: Antimicrobial activity against a variety of bacteria including recent clinical isolates was investigated based on the BS ISO 22196:2007 Plastics – Measurement of antibacterial activity on plastics surfaces, British Standards Institute, London, method. Activity on natural contamination in an in use test in a toilet facility was also determined. Activity on standard test strains gave a log10 reduction of five after 1–4 h. The hospital isolates were more resistant, but MRSA was reduced by a log10 reduction factor of >5 after 24 h. Activity was maintained after simulated ageing and washing cycles. Contamination in situ was reduced by >99�9% after 4 months. Activity was inhibited by protein, but, although this could be overcome by increasing the amount of silver in the films, this reduced the hardness of the coating. Conclusions: The coatings had a good activity against standard test strains. Clinical isolates were killed more slowly but were still sensitive. The optimum composition for use therefore needs to be a balance between activity and durability. Significance and Impact of the Study: The coatings may have applications in health care by maintaining a background antimicrobial activity between standard cleaning and disinfection regimes. They may also have applications in other areas where reduction in microbial contamination is important, for example, in the food industry

Antimicrobial activity against hospital-related pathogens of dual layer CuO/TiO2 coatings prepared by CVD

Photocatalytically active films of TiO2/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

Amyloid-β and Astrocytes Interplay in Amyloid-β Related Disorders

Amyloid-β (Aβ) pathology is known to promote chronic inflammatory responses in the brain. It was thought previously that Aβ is only associated with Alzheimer’s disease and Down syndrome. However, studies have shown its involvement in many other neurological disorders. The role of astrocytes in handling the excess levels of Aβ has been highlighted in the literature. Astrocytes have a distinctive function in both neuronal support and protection, thus its involvement in Aβ pathological process may tip the balance toward chronic inflammation and neuronal death. In this review we describe the involvement of astrocytes in Aβ related disorders including Alzheimer’s disease, Down syndrome, cerebral amyloid angiopathy, and frontotemporal dementia