title: A novel study of antibacterial activity of copper iodide nanoparticle mediated by DNA and membrane damage.
abstract: In this article potential activity of nanoparticles (NPs) of copper iodide (CuI) as an antibacterial agent has been presented. The nano particles are synthesized by co-precipitation method with an average size of 8 nm as determined by Transmission Electron Microscope (TEM). The average charge of the NPs is -21.5 mV at pH 7 as obtained by zeta potential measurement and purity is determined by XRD. These NPs are able to kill both gram positive and gram negative bacteria. Among the bacteria tested, DH5α is more sensitive but Bacillus subtilis is more resistant to NPs of CuI. Consequently, the MIC and MBC values of DH5α is least (0.066 mg/ml and 0.083 mg/ml respectively) and B. subtilis is highest (0.15 mg/ml and 0.18 mg/ml respectively) among the tested bacterial strains. From our studies it is inferred that CuI NPs produce reactive oxygen species (ROS) in both gram negative and gram positive bacteria and it also causes ROS mediated DNA damage for the suppression of transcription as revealed by reporter gene assay. Probably ROS is formed on the surface of NPs of CuI in presence of amine functional groups of various biological molecules. Furthermore they induce membrane damage as determined by atomic force microscopy (AFM). Thus production of ROS and membrane damage are major mechanisms of the bactericidal activity of these NPs of CuI.
authors.affiliation: Department of Life Science and Biotechnology, Jadavpur University, 188 Raja SC Mallick Road, Kolkata, West Bengal 700032, India.
authors.forename: Arindam
authors.initials: A
authors.lastname: Pramanik
authors.forename: Dipranjan
authors.initials: D
authors.lastname: Laha
authors.forename: Debalina
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: Panchanan
authors.initials: P
authors.lastname: Pramanik
authors.forename: Parimal
authors.initials: P
authors.lastname: Karmakar
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects*; D003300:Copper / Q000737:chemistry*; D004249:DNA Damage; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D007454:Iodides / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D007454:Iodides; D017382:Reactive Oxygen Species; D003300:Copper