Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine (R) on MSSA and MRSA Strains

Author(s)

Nunes Souza, Beatriz Muller ^[1] ; Pinto, Juliana Guerra ^[1] ; Correia Pereira, Andre Henrique ^[1] ; Minan, Alejandro Guillermo ^[2] ; Ferreira-Strixino, Juliana ^[1]

Affiliation

^[1] Univ Vale Paraiba, Res & Dev Inst, Lab Photobiol Appl Hlth, BR-2911 Urbanova - Brazil

^[2] Univ Nacl La Plata, Inst Invest Fis Quim Teor & Aplicadas, Fac Ciencias Exactas, RA-1900 La Plata - Argentina

• Document type: Journal article
• Source: ANTIBIOTICS-BASEL; v. 10, n. 7 JUL 2021.
• Web of Science Citations: 0

Abstract

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine (R) (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm(2). The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains. (AU)

• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC