Abstract
Bacteria subjected to antiseptic or antibiotic stress often develop tolerance, a trait that can lead to permanent resistance. To determine whether photodynamic agents could be used to counter tolerance, we evaluated three non-iron hemin analogs (M-PpIX; M = Al, Ga, In) as targeted photosensitizers for antimicrobial photodynamic inactivation (aPDI) following exposure to sublethal H2O2. Al-PpIX is an active producer of ROS whereas Ga- and In-PpIX are more efficient at generating singlet oxygen. Al- and Ga-PpIX are highly potent aPDI agents against S. aureus and methicillin-resistant strains (MRSA) with antimicrobial activity (3 log reduction in colony-forming units) at nanomolar concentrations. The aPDI activities of Al- and Ga-PpIX against S. aureus were tested in the presence of 1 mM H2O2 added at different stages of growth. Bacteria exposed to H2O2 during log-phase growth were less susceptible to aPDI but bacteria treated with H2O2 in their postgrowth phase exhibited aPDI hypersensitivity, with no detectable colony growth after treatment with 15 nM Ga-PpIX.
Date of this Version
5-3-2024
Recommended Citation
Sivasubramaniam, Badhu Prashanthika; Washer, Benjamin M.; Watanabe, Yuichiro; Ragheb, Kathryn E.; Robinson, J. Paul; and Wei, Alexander, "Photodynamic treatment of Staphylococcus aureus with non-iron hemin analogs in the presence of hydrogen peroxide" (2024). Department of Chemistry Faculty Publications. Paper 26.
https://docs.lib.purdue.edu/chempubs/26
Comments
This is the publisher PDF of Sivasubramaniam, B; Washer, B; Watanabe, Y; Ragheb, K; Robinson, J; and Wei, A. (2024) Photodynamic treatment of Staphylococcus aureus with non-iron hemin analogs in the presence of hydrogen peroxide. RSC Medicinal Chemistry, 15, 2138-2145. The version of record is available at DOI: 10.1039/D4MD00148F, and it is published CC-BY.