Maclean, M. and MacGregor, S.J. and Anderson, J.G. and Woolsey, G.A. (2008) The role of oxygen in the visible-light inactivation of Staphylococcus aureus. Journal of Photochemistry and Photobiology B: Biology, 92 (3). pp. 180-184. ISSN 1011-1344Full text not available in this repository. (Request a copy from the Strathclyde author)
Exposure to visible-light causes the photoinactivation of certain bacteria by a process that is believed to involve the photo-stimulation of endogenous intracellular porphyrins. Studies with some bacterial species have reported that this process is oxygen-dependent. This study examines the role of oxygen in the visible-light inactivation of Staphylococcus aureus. Suspensions of S. aureus were exposed to broadband visible-light under both oxygen depletion and oxygen enhancement conditions to determine whether these environmental modifications had any effect on the staphylococcal inactivation rate. Oxygen enhancement was achieved by flowing oxygen over the surface of the bacterial sample during light inactivation and results demonstrated an increased rate of staphylococcal inactivation, with approximately 3.5 times less specific dose being required for inactivation compared to that for a non-enhanced control. Oxygen depletion, achieved through the addition of oxygen scavengers to the S. aureus suspension, further demonstrated the essential role of oxygen in the light inactivation process, with significantly reduced staphylococcal inactivation being observed in the presence of oxygen scavengers. The results of the present study demonstrate that the presence of oxygen is important for the visible-light inactivation of S. aureus, thus providing supporting evidence that the nature of the mechanism occurring within the visible-light-exposed staphylococci is photodynamic inactivation through the photo-excitation of intracellular porphyrins.
|Keywords:||photodynamic inactivation, visible-light, Oxygen depletion, Oxygen enhancement, Staphylococcus aureus, Electrical engineering. Electronics Nuclear engineering, Electrical and Electronic Engineering|
|Subjects:||Technology > Electrical engineering. Electronics Nuclear engineering|
|Department:||Faculty of Engineering > Electronic and Electrical Engineering|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||08 Jun 2010 14:04|
|Last modified:||25 Nov 2016 03:17|