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. Results: 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. Conclusion: 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.
keywords
PHOTODYNAMIC INACTIVATION; ESCHERICHIA-COLI; FTIR SPECTROSCOPY; TOLUIDINE BLUE; MEMBRANE PHOSPHOLIPIDS; STAPHYLOCOCCUS-WARNERI; METHYLENE-BLUE; MECHANISMS; OXIDATION; PROTEINS
subject category
Pharmacology & Pharmacy
authors
Moreirinha, C; Alves, E; Faustino, MAF; Cunha, A; Delgadillo, I; Neves, MGPMS; Almeida, A
our authors
Catarina Moreirinha
Post-Doc Fellowshipacknowledgements
The authors are thankful to the University of Aveiro, to FCT/MEC for the financial support to the QOPNA research unit (FCT UID/QUI/00062/2013) and Centre for Environmental and Marine Studies (CESAM) associated laboratory (project Pest-C/MAR/LA0017/2013), through national funds and, where applicable, cofinanced by the FEDER, within the PT2020 Partnership Agreement, and also to the Portuguese NMR Network. Eliana Alves (SFRH/BD/41806/2007) and Catarina Moreirinha (SFRH/BD/71512/2010) are grateful to FCT for their doctoral grants. The authors also thank Sara Moreirinha for the artwork. E Alves' current affiliation is Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro, Portugal. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.