Grinholc M1, Rodziewicz A2, Forys K2, Rapacka-Zdonczyk A2, Kawiak A3,4, Domachowska A3, Golunski G5, Wolz C6, Mesak L7, Becker K8, Bielawski KP2.
Appl Microbiol Biotechnol. 2015 Nov;99(21):9161-76. doi: 10.1007/s00253-015-6863-z. Epub 2015 Aug 8.Bacterial cell envelope is generally accepted as the primary target for a photo-induced oxidative stress. It is plausible that DNA damage occurs during the antimicrobial photoinactivation. Here we investigate the correlation between DNA damage and photoinactivation by evaluating the level of RecA-based DNA repair system in Staphylococcus aureus. By using exogenous photosensitizers (new methylene blue (NMB), toluidine blue O (TBO), 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP), zinc phthalocyanine (ZnPc), Rose Bengal (RB)) and ALA-induced endogenous porphyrin-dependent blue light (405 nm), several outcomes were observed: (i) an increase of DNA damage (from gel electrophoresis in DNA damage assay), (ii) an increase of recA expression (luminescence assay in recA-lux strain), and (iii) an increase of RecA protein level (Western blotting). Read More