title: Antimicrobial action from a novel porphyrin derivative in photodynamic antimicrobial chemotherapy in vitro.
abstract: Efforts to identify improved treatments for corneal infection include the development of photodynamic antimicrobial chemotherapy (PACT). We evaluated the antimicrobial effect of PACT with a novel porphyrin derivative, TONS 504, and a novel light system on methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). Bacteria were irradiated with a light-emitting diode (LED) at energies of 10, 20, or 30 J/cm(2) in the presence of various concentrations of TONS 504. Bacterial viability was assessed at 30 min and 24 h after irradiation by determination of colony formation on agar plates. PACT inhibited the growth of both MSSA and MRSA as early as 30 min after light exposure. Complete inhibition of bacterial growth was apparent at 24 h after irradiation at a TONS 504 concentration of 1 mg/L and LED energies of ≥10 J/cm(2) or a TONS 504 concentration of 0.5 mg/L and LED energies of ≥20 J/cm(2) for MSSA, and at a TONS 504 concentration of 10 mg/L and LED energies of ≥10 J/cm(2) or of a TONS 504 concentration of 1 mg/L and LED energies of ≥20 J/cm(2) for MRSA. Bacterial growth was unaffected by TONS 504 in the absence of irradiation or by irradiation in the absence of TONS 504. Our results thus demonstrate the antimicrobial efficacy of PACT with TONS 504 and a LED against both MSSA and MRSA in vitro, and they therefore provide a basis for further investigation of this system as a potential treatment for corneal infection.
authors.affiliation: Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8551, Japan.
authors.forename: Miftahul Akhyar
authors.initials: MA
authors.lastname: Latief
authors.forename: Taiichiro
authors.initials: T
authors.lastname: Chikama
authors.forename: Momoko
authors.initials: M
authors.lastname: Shibasaki
authors.forename: Takaaki
authors.initials: T
authors.lastname: Sasaki
authors.forename: Ji-Ae
authors.initials: JA
authors.lastname: Ko
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiuchi
authors.forename: Takemasa
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Obana
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011166:Porphyrins / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000188:drug therapy
chemical_list: D000900:Anti-Bacterial Agents; D017319:Photosensitizing Agents; D011166:Porphyrins