title: Mechanisms of antibacterial activity of MgO: non-ROS mediated toxicity of MgO nanoparticles towards Escherichia coli.
abstract: The toxicity of metal oxide nanomaterials and their antimicrobial activity is attracting increasing attention. Among these materials, MgO is particularly interesting as a low cost, environmentally-friendly material. The toxicity of MgO, similar to other metal oxide nanomaterials, is commonly attributed to the production of reactive oxygen species (ROS). We investigated the toxicity of three different MgO nanoparticle samples, and clearly demonstrated robust toxicity towards Escherichia coli bacterial cells in the absence of ROS production for two MgO nanoparticle samples. Proteomics data also clearly demonstrate the absence of oxidative stress and indicate that the primary mechanism of cell death is related to the cell membrane damage, which does not appear to be due to lipid peroxidation.
authors.affiliation: Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yu Hang
authors.initials: YH
authors.lastname: Leung
authors.forename: Alan M C
authors.initials: AM
authors.lastname: Ng
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Xu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Shen
authors.forename: Lee A
authors.initials: LA
authors.lastname: Gethings
authors.forename: Mabel Ting
authors.initials: MT
authors.lastname: Wong
authors.forename: Charis M N
authors.initials: CM
authors.lastname: Chan
authors.forename: Mu Yao
authors.initials: MY
authors.lastname: Guo
authors.forename: Yip Hang
authors.initials: YH
authors.lastname: Ng
authors.forename: Aleksandra B
authors.initials: AB
authors.lastname: Djurišić
authors.forename: Patrick K H
authors.initials: PK
authors.lastname: Lee
authors.forename: Wai Kin
authors.initials: WK
authors.lastname: Chan
authors.forename: Li Hong
authors.initials: LH
authors.lastname: Yu
authors.forename: David Lee
authors.initials: DL
authors.lastname: Phillips
authors.forename: Angel P Y
authors.initials: AP
authors.lastname: Ma
authors.forename: Frederick C C
authors.initials: FC
authors.lastname: Leung
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000528:radiation effects / Q000648:ultrastructure; D063990:Gene Ontology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008277:Magnesium Oxide / Q000633:toxicity*; D008565:Membrane Proteins / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000528:radiation effects; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000633:toxicity* / Q000648:ultrastructure; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D008277:Magnesium Oxide
keywords: MgO nanoparticles; antibacterial activity; proteomics; toxicity