Genomic Epidemiology of Complex, Multispecies, Plasmid-Borne bla KPC Carbapenemase in Enterobacterales in the United Kingdom from 2009 to 2014.

Carbapenem resistance in Enterobacterales is a public health threat. Klebsiella pneumoniae carbapenemase (encoded by alleles of the bla KPC family) is one of the most common transmissible carbapenem resistance mechanisms worldwide. The dissemination of bla KPC historically has been associated with distinct K. pneumoniae lineages (clonal group 258 [CG258]), a particular plasmid family (pKpQIL), and a composite transposon (Tn4401). In the United Kingdom, bla KPC has represented a large-scale, persistent management challenge for some hospitals, particularly in North West England. The dissemination of bla KPC has evolved to be polyclonal and polyspecies, but the genetic mechanisms underpinning this evolution have not been elucidated in detail; this study used short-read whole-genome sequencing of 604 bla KPC-positive isolates (Illumina) and long-read assembly (PacBio)/polishing (Illumina) of 21 isolates for characterization. We observed the dissemination of bla KPC (predominantly bla KPC-2; 573/604 [95%] isolates) across eight species and more than 100 known sequence types. Although there was some variation at the transposon level (mostly Tn4401a, 584/604 [97%] isolates; predominantly with ATTGA-ATTGA target site duplications, 465/604 [77%] isolates), bla KPC spread appears to have been supported by highly fluid, modular exchange of larger genetic segments among plasmid populations dominated by IncFIB (580/604 isolates), IncFII (545/604 isolates), and IncR (252/604 isolates) replicons. The subset of reconstructed plasmid sequences (21 isolates, 77 plasmids) also highlighted modular exchange among non-bla KPC and bla KPC plasmids and the common presence of multiple replicons within bla KPC plasmid structures (>60%). The substantial genomic plasticity observed has important implications for our understanding of the epidemiology of transmissible carbapenem resistance in Enterobacterales for the implementation of adequate surveillance approaches and for control

Communication. Antimicrobial activity in thin films of pseudobrookite-structured titanium oxynitride under UV irradiation observed for Escherichia coli

It has been possible to observe a 99.98% reduction in the viable count of colonies of E. coli on a film of titanium oxynitride when exposed to 365 nm light. This film of the recently discovered Ti(2.85)O(4)N, isostructural to pseudobrookite, was grown on a glass substrate using atmospheric pressure chemical vapour deposition (APCVD)

White light induced photocatalytic activity of sulfur-doped TiO2 thin films and their potential for antibacterial application

Sulfur-doped titania thin films were prepared by atmospheric pressure chemical vapour deposition (APCVD) for the first time using titanium tetrachloride, ethyl acetate and carbon disulfide. The films were compared to two industrial self-cleaning products: Activ™ and BIOCLEAN™, and shown to be superior in both photocatalysis and photo-induced superhydrophilicity, two preferential properties of effective self-cleaning coatings. X-Ray diffraction showed the films have the anatase TiO2 structure. XPS and EDX analysis shows changes in S : Ti ratio with preparative conditions indicating that sulfur has indeed been incorporated into the lattice. S-Doped TiO2 films were found to be effective agents for killing the bacterium Escherichia coli using light sources commonly found in UK hospitals

Nanoparticulate silver coated-titania thin films—Photo-oxidative destruction of stearic acid under different light sources and antimicrobial effects under hospital lighting conditions

Antimicrobial films containing silver nanoparticles on a titania substrate were prepared and shown to have marked visible light photocatalytic properties. The films could be transformed from purple (silver oxide) to orange (silver) by 254 nm, 365 nm or white light radiation and the process reversed when the films were stored in air and in the dark. The films were characterized by XRD, Raman, AFM, SEM, EDX, UV-Vis spectroscopy and XPS as well as tested for functionality using a range of techniques including water contact angle measurement, the photo-destruction of stearic acid to a range of light sources and antimicrobial activity against MRSA and Escherichia coil bacteria under hospital lighting conditions. XRD and Raman indicated that the films were anatase. X-ray photoelectron measurements confirmed the presence of silver loading on the titania surface and EDX showed silver doping in the TiO2 layer. There appears to be an interaction between the phonon resonance of the silver nanoparticles and the band onset of the titania leading to significant visible light photo-oxidation of stearic acid as well as visible light induced superhydrophilicity. Samples were tested for photo-degradation of stearic acid under three different lighting conditions: UVA - 365 nm, white light (commonly found in UK hospitals) and UVA filtered white light. The Ag oxide-titania films were seen to be active photocatalysts under visible light conditions as well as displaying white light induced superhydrophilicity. These surfaces demonstrated a 99.996% reduction in the number of viable E. coli bacteria due to the silver ion presence and a 99.99% reduction in the number of MRSA bacteria due to the enhanced photocatalysis in a double pronged approach to antimicrobial mechanisms consisting of a synergistic relationship between the photocatalyst (TiO2) and the surface bound silver nanoparticles