title: Photodynamic effects of antioxidant substituted porphyrin photosensitizers on gram-positive and -negative bacterial.
abstract: Photodynamic treatment of the gram-negative bacteria Escherichia coli B and Acinetobacter baumannii and the gram-positive bacterium Staphylococcus aureus was performed using two newly devised and synthesized antioxidant carrier photosensitizers (antioxidant carrier sensitizers-2 [ACS-2] and antioxidant carrier sensitizers-3 [ACS-3]), which are butyl hydroxy toluene and propyl gallate substituted haematoporphyrins, respectively. It was found that ACS-2 is less reactive than other photosensitizers previously used for the same purpose, whereas ACS-3 is very effective against the multidrug-resistant bacterium A. baumannii, causing its complete eradication at a low fluence (approximately 7.5 J/cm2) of blue light (407-420 nm) and a low concentration (10 microM). At a higher fluence (approximately 37.5 J/cm2) complete eradication of E. coli B can be obtained under the same conditions. Furthermore, X-ray microanalysis and ultrastructural changes indicate that ACS-3, especially in the case of photodynamic treatment of A. baumannii, interferes with membrane functions and causes the inactivation of the bacterium. ACS-3 may be suggested as a specific photosensitization agent for photoinactivation of gram-negative bacteria.
authors.affiliation: Health Sciences Research Center, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
authors.forename: Helena
authors.initials: H
authors.lastname: Ashkenazi
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Nitzan
authors.forename: Dezso
authors.initials: D
authors.lastname: Gál
mesh_terms: D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000648:ultrastructure; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000648:ultrastructure; D008854:Microscopy, Electron; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011166:Porphyrins / Q000494:pharmacology*
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins