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The antibacterial effect of sinoporphyrin sodium photodynamic therapy on Staphylococcus aureus planktonic and biofilm cultures
Author(s) -
Mai Bingjie,
Wang Xiaobing,
Liu Quanhong,
Leung Albert Wingnang,
Wang Xinliang,
Xu Chuanshan,
Wang Pan
Publication year - 2016
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.22468
Subject(s) - photodynamic therapy , biofilm , staphylococcus aureus , photosensitizer , microbiology and biotechnology , bacteria , lysis , chemistry , flow cytometry , reactive oxygen species , biology , photochemistry , biochemistry , genetics , organic chemistry
Background and Objectives Staphylococcus aureus ( S. aureus ) are important causes of nosocomial and medical‐device‐related infections. Photodynamic treatment (PDT) has been proposed as an alternative approach for the inactivation of bacteria. Sinoporphyrin sodium (DVDMS) is a newly identified photosensitizer and has high photo‐sensitivity when used in PDT. This study aims to evaluate the antibacterial effect of DVDMS mediated PDT on S. aureus planktonic and biofilm cultures. Study Design/Materials and Methods The uptake of DVDMS in S. aureus was evaluated according to photometry after alkali lysis. Then bacteria were incubated with DVDMS and exposed to light treatment. After PDT treatment, counting colony‐forming units (CFU) was applied to estimate the bactericidal effect. Intracellular reactive oxygen species (ROS) production was detected by flow cytometry. Scanning electron microscope (SEM) was performed to assess the disruption of biofilm. Results With the incubation time increased, the relative fluorescence intensity of DVDMS in bacteria increased and reached peak at 75 minutes. DVDMS alone did not produce significant toxicity compared with the untreated group, while, remarkable survival decrease was observed in PDT groups in a dose‐dependent manner. More than 90% of the bacteria were effectively killed by the combined treatment of 2 µM DVDMS with 10 J/cm 2 light irradiation, and 4‐log reduction in CFU was observed after 5 µM DVDMS treatment followed by 100 J/cm 2 light irradiation. Intracellular ROS level was significantly enhanced after PDT treatment. The disruption of biofilm was confirmed by SEM, suggesting DVDMS‐PDT effectively damaged the biofilm. Conclusion These results indicate DVDMS‐PDT presents significant bactericidal activity. Lasers Surg. Med. 48:400–408, 2016. © 2016 Wiley Periodicals, Inc.