title: Study of photodynamic therapy in the control of isolated microorganisms from infected wounds--an in vitro study.
abstract: The effective treatment of infected wounds continues to be a serious challenge, mainly due to the rise of antibiotic-resistant bacteria. Photodynamic therapy (PDT) refers to the topical or systemic administration of a non-toxic, photosensitizing agent (PS), followed by irradiation with visible light of a suitable wavelength. The possibility of applying the PDT locally is what makes it so favorable to the treatment of infected wounds. The goal of this study was to evaluate the action of the PDT in the inactivation in vitro of microorganisms coming from infected wounds, using methylene blue (MB) and photodithazine (PDZ) as the PS and comparing the efficacy of these two compounds for PDT on bacteria. For the application of PDT, isolated microorganisms identified from material collected from wounds were suspended in a saline solution containing 10(6) viable cells/ml. Each isolated microorganism was submitted to PDT with MB and with PDZ in accordance with the following treatment groups: N/T--no treatment; T1--PDT with PDZ; T2--PDT with MB; T3--irradiation without PS; T4--treatment with PDZ without light; and T5--treatment with MB without light. As a light source, an LED-based device was used (Biopdi/Irrad-Lead 660), composed of 54 LEDs, each with 70 mW of power in the 660 nm region of the electromagnetic spectrum. Each tray of 96 wells was irradiated with an intensity of 25 mW/cm(2) and a dose of light of 50 J/cm(3) for 33 min. All the tests were made in duplicate. It was then concluded that the PDT with PDZ was capable of inhibiting the growth of gram-positive bacteria samples, however it did not have the same effect on gram-negative bacteria, which showed growth greater than 100,000 CFU; the PDT with MB showed an effectiveness on gram-positive as well as gram-negative bacteria, for it was able to inhibit bacterial growth in both cases.
authors: Laboratory of Photodynamic Therapy, LEVB-Institute of Research & Development-Univap, University of Vale do Paraíba/Faculty of Health Sciences/IP&D, Av. Shishima Hifumi, 2911, Urbanova São José dos Campos, 12244, São Paulo, Brazil.
authors: Denise
authors: D
authors: Pereira de Lima Carvalho
authors: Juliana
authors: J
authors: Guerra Pinto
authors: Camila
authors: C
authors: Di Paula Costa Sorge
authors: Fabiana Regis
authors: FR
authors: Rodrigues Benedito
authors: Sonia
authors: S
authors: Khouri
authors: Juliana
authors: J
authors: Ferreira Strixino
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D004754:Enterobacter / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D005944:Glucosamine / Q000031:analogs & derivatives / Q000627:therapeutic use; D006801:Humans; D066298:In Vitro Techniques; D008751:Methylene Blue / Q000627:therapeutic use; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011513:Proteus mirabilis / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013210:Staphylococcus / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D014946:Wound Infection / Q000188:drug therapy* / Q000382:microbiology*
chemical_list: D017319:Photosensitizing Agents; C047635:N-methylglucosamine; D005944:Glucosamine; D008751:Methylene Blue