title: ZnO nanoparticles impose a panmetabolic toxic effect along with strong necrosis, inducing activation of the envelope stress response in Salmonella enterica serovar Enteritidis.
abstract: In this study, we tested the antimicrobial activity of three metal nanoparticles (NPs), ZnO, MgO, and CaO NPs, against Salmonella enterica serovar Enteritidis in liquid medium and on solid surfaces. Out of the three tested metal NPs, ZnO NPs exhibited the most significant antimicrobial effect both in liquid medium and when embedded on solid surfaces. Therefore, we focused on revealing the mechanisms of surface-associated ZnO biocidal activity. Using the global proteome approach, we report that a great majority (79%) of the altered proteins in biofilms formed by Salmonella enterica serovar Enteritidis were downregulated, whereas a much smaller fraction (21%) of proteins were upregulated. Intriguingly, all downregulated proteins were enzymes involved in a wide range of the central metabolic pathways, including translation; amino acid biosynthetic pathways; nucleobase, nucleoside, and nucleotide biosynthetic processes; ATP synthesis-coupled proton transport; the pentose phosphate shunt; and carboxylic acid metabolic processes, indicating that ZnO NPs exert a panmetabolic toxic effect on this prokaryotic organism. In addition to their panmetabolic toxicity, ZnO NPs induced profound changes in cell envelope morphology, imposing additional necrotic effects and triggering the envelope stress response of Salmonella serovar Enteritidis. The envelope stress response effect activated periplasmic chaperones and proteases, transenvelope complexes, and regulators, thereby facilitating protection of this prokaryotic organism against ZnO NPs.
authors: Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
authors: Sinisa
authors: S
authors: Vidovic
authors: Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
authors: Jeff
authors: J
authors: Elder
authors: Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
authors: Prabhakara
authors: P
authors: Medihala
authors: Environment Canada, Saskatoon, SK, Canada.
authors: John R
authors: JR
authors: Lawrence
authors: Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, SK, Canada Prairie Swine Centre Inc., Saskatoon, SK, Canada.
authors: Bernardo
authors: B
authors: Predicala
authors: National Research Council of Canada, Saskatoon, SK, Canada.
authors: Haixia
authors: H
authors: Zhang
authors: Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada darren.korber@usask.ca.
authors: Darren R
authors: DR
authors: Korber
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D012481:Salmonella Infections, Animal / Q000382:microbiology; D012477:Salmonella enteritidis / Q000187:drug effects*; D015034:Zinc Oxide / Q000494:pharmacology*
chemical_list: D015034:Zinc Oxide