title: Overall biochemical changes in bacteria photosensitized with cationic porphyrins monitored by infrared spectroscopy.
abstract: Photodynamic inactivation of micro-organisms is a promising nonantibiotic multitarget approach to treat localized and superficial infections through oxidative stress. Herein, the changes occurring on major cellular components of Escherichia coli and Staphylococcus warneri, induced by photosensitization with cationic porphyrins (Tri-Py(+)-Me-PF and Tetra-Py(+)-Me) and white light, were monitored by infrared spectroscopy.
  
  
  
  In E. coli, most of the changes occurred on proteins and lipids, suggesting a key effect on lipopolysaccharides in the first irradiation times. In S. warneri, proteins were the major molecular targets of oxidative damage but phospholipids and polysaccharides were also affected.
  
  
  
  Infrared spectroscopy is a very interesting tool to monitor biochemical changes induced by photosensitization in bacteria and also to infer on its mechanism of action.
authors.affiliation: Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Eliana
authors.initials: E
authors.lastname: Alves
authors.affiliation: Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Moreirinha
authors.affiliation: Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Maria Af
authors.initials: MA
authors.lastname: Faustino
authors.affiliation: Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Ângela
authors.initials: Â
authors.lastname: Cunha
authors.affiliation: Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Delgadillo
authors.affiliation: Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Maria Gpms
authors.initials: MG
authors.lastname: Neves
authors.affiliation: Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Adelaide
authors.initials: A
authors.lastname: Almeida
mesh_terms: D002412:Cations; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000378:metabolism; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D011166:Porphyrins / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013210:Staphylococcus / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects
chemical_list: D002412:Cations; D010743:Phospholipids; D017319:Photosensitizing Agents; D011135:Polysaccharides, Bacterial; D011166:Porphyrins
keywords: Escherichia coli; Staphylococcus warneri; lipopolysaccharides; oxidative damage; photodynamic; photosensitizer