title: Titanium dioxide nanoparticles enhance mortality of fish exposed to bacterial pathogens.
abstract: Nano-TiO2 is immunotoxic to fish and reduces the bactericidal function of fish neutrophils. Here, fathead minnows (Pimephales promelas) were exposed to low and high environmentally relevant concentration of nano-TiO2 (2 ng g(-1) and 10 μg g(-1) body weight, respectively), and were challenged with common fish bacterial pathogens, Aeromonas hydrophila or Edwardsiella ictaluri. Pre-exposure to nano-TiO2 significantly increased fish mortality during bacterial challenge. Nano-TiO2 concentrated in the kidney and spleen. Phagocytosis assay demonstrated that nano-TiO2 has the ability to diminish neutrophil phagocytosis of A. hydrophila. Fish injected with TiO2 nanoparticles displayed significant histopathology when compared to control fish. The interplay between nanoparticle exposure, immune system, histopathology, and infectious disease pathogenesis in any animal model has not been described before. By modulating fish immune responses and interfering with resistance to bacterial pathogens, manufactured nano-TiO2 has the potential to affect fish survival in a disease outbreak.
authors.affiliation: Chair for Fish Diseases and Fisheries Biology, Faculty of Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany; Center for Nanoscience (CeNS), LMU, Munich, Germany. Electronic address: nanoaquatox@gmail.com.
authors.forename: Boris
authors.initials: B
authors.lastname: Jovanović
authors.affiliation: Pathogenesis, LLC, Gainesville, FL, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Whitley
authors.affiliation: Center for Food Security and Public Health, Iowa State University, Ames, IA, USA.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Kimura
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Crumpton
authors.affiliation: Chair for Fish Diseases and Fisheries Biology, Faculty of Veterinary Medicine, Ludwig Maximilian University of Munich, Munich, Germany. Electronic address: d.palic@fisch.vetmed.uni-muenchen.de.
authors.forename: Dušan
authors.initials: D
authors.lastname: Palić
mesh_terms: D000333:Aeromonas / Q000502:physiology*; D000818:Animals; D003530:Cyprinidae / Q000276:immunology / Q000378:metabolism; D060467:Disease Resistance; D020610:Edwardsiella ictaluri / Q000502:physiology*; D005393:Fish Diseases; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D053758:Nanoparticles / Q000633:toxicity*; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects; D013154:Spleen / Q000378:metabolism; D014025:Titanium / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: Bacteria; Disease resistance; Fish; Histopathology; Immune response; Nanoparticles; Titanium dioxide