title: Photo-catalytic inactivation of an Enterococcus biofilm: the anti-microbial effect of sulphated and europium-doped titanium dioxide nanopowders.
abstract: The control and prevention of biofilm-related infections is an important public healthcare issue. Given the increasing antibiotic resistance among bacteria and fungi that cause serious infections in humans, promotion of new strategies combating microorganisms has been essential. One attractive approach to inactivate microorganisms is the use of semiconductor photo-catalysis, which has become the subject of extensive research. In this study, the bactericidal properties of four photo-catalysts, TiO₂, TiO₂-S, TiO₂-Eu and TiO₂-Eu-S, were investigated against established 24, 48, 72 and 96 h biofilms of Enterococcus The exposure of biofilms to the catalysts induced the production of superoxide radical anions. The best photo-catalytic inactivation was achieved with the TiO₂-Eu-S and TiO₂-S nanopowders and 24 h biofilms. Transmission electron microscopy images showed significant changes in the structure of the biofilm cells following photo-inactivation. The results suggest that doping with europium and modifying the surface with sulphate groups enhanced the bactericidal activity of the TiO₂ nanoparticles against enterococcal biofilms.
authors.affiliation: Department of Microbiology, Wrocław Medical University, 50-368 Wrocław, Poland ewa.dworniczek@umed.wroc.pl.
authors.forename: Ewa
authors.initials: E
authors.lastname: Dworniczek
authors.affiliation: Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia.
authors.forename: Gustav
authors.initials: G
authors.lastname: Plesch
authors.affiliation: Department of Microbiology, Wrocław Medical University, 50-368 Wrocław, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Seniuk
authors.affiliation: Institute of Genetics and Microbiology, University of Wrocław, 51-148 Wrocław, Poland.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Adamski
authors.affiliation: Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia.
authors.forename: Róbert
authors.initials: R
authors.lastname: Michal
authors.affiliation: Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia.
authors.forename: Mária
authors.initials: M
authors.lastname: Čaplovičová
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002384:Catalysis; D016983:Enterococcus / Q000187:drug effects* / Q000648:ultrastructure; D005063:Europium / Q000737:chemistry / Q000494:pharmacology; D049408:Luminescent Agents / Q000737:chemistry / Q000494:pharmacology; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017319:Photosensitizing Agents / Q000494:pharmacology*; D013431:Sulfates / Q000737:chemistry; D013481:Superoxides / Q000378:metabolism; D014025:Titanium / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D049408:Luminescent Agents; D017319:Photosensitizing Agents; D013431:Sulfates; D013481:Superoxides; C009495:titanium dioxide; D005063:Europium; D014025:Titanium
keywords: Enterococcus; biofilms; europium-doped titanium dioxide; photo-catalysis