title: Photoinactivation of Staphylococcus aureus using protoporphyrin IX: the role of haem-regulated transporter HrtA.
abstract: Light- and photosensitiser-based antimicrobial photodynamic therapy is a very promising approach to the control of microbial infections. How the phenotypic features of a microorganism affect its response to photosensitiser-based photokilling represents an area of substantial research interest. To understand the mechanisms governing the phenomenon of a strain-dependent response to photodynamic inactivation (PDI), we analysed the possible role of the membrane-located haem transporter HrtA in Staphylococcus aureus. We used a S. aureus strains with an inactivated component of the haem-regulated transporter, HrtA, along with its wild-type counterpart to determine differences in PDI outcome and photosensitiser uptake between the studied isogenic strains. We observed that a lack of HrtA protein potentiates the phototoxic effect towards S. aureus but only when extracellular protoporphyrin IX is used. The observed effect may depend on the function of the HrtA transporter but is likely to result from changed membrane properties following the absence of the protein in the membrane. This indicates that disturbing the membrane properties is an attractive method for improving the efficacy of the photodynamic inactivation of microorganisms.
authors.affiliation: Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822, Gdansk, Poland. joanna.nakonieczna@biotech.ug.edu.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Nakonieczna
authors.affiliation: Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822, Gdansk, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Kossakowska-Zwierucho
authors.affiliation: Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822, Gdansk, Poland.|Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland.
authors.forename: Michalina
authors.initials: M
authors.lastname: Filipiak
authors.affiliation: Faculty of Chemistry, Gdansk University of Technology, Gabriela Narutowicza 11/12, Gdansk, Poland.
authors.forename: Weronika
authors.initials: W
authors.lastname: Hewelt-Belka
authors.affiliation: Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822, Gdansk, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Grinholc
authors.affiliation: Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822, Gdansk, Poland.
authors.forename: Krzysztof Piotr
authors.initials: KP
authors.lastname: Bielawski
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000528:radiation effects; D006418:Heme / Q000378:metabolism*; D008027:Light; D050296:Microbial Viability / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000378:metabolism*; D011524:Protoporphyrins / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D006418:Heme; C028025:protoporphyrin IX; D000251:Adenosine Triphosphatases; C529956:HrtA protein, Staphylococcus aureus
keywords: Lipid content; Membrane fluidity; Photoinactivation; Protoporphyrin IX; Staphylococcus aureus