Diverse outcomes of Photodynamic Antimicrobial Chemotherapy on five Enterococcus faecalis strains

Author(s)

Silva, T. C. ^[1] ; Pereira, A. F. F. ^[2] ; Buzalaf, M. A. R. ^[3] ; Machado, M. A. A. M. ^[1] ; Crielaard, W. ^{[4, 5]} ; Deng, D. M. ^{[4, 5]}

Affiliation

^[1] Univ Sao Paulo, Bauru Sch Dent, Dept Pediat Dent Orthodont & Publ Hlth, BR-17012901 Bauru, SP - Brazil

^[2] Univ Sao Paulo, Bauru Sch Dent, Dept Speech Language Pathol & Audiol, BR-17012901 Bauru, SP - Brazil

^[3] Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, BR-17012901 Bauru, SP - Brazil

^[4] Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, Dept Prevent Dent, NL-1081 Amsterdam - Netherlands

^[5] Vrije Univ, NL-1081 Amsterdam - Netherlands

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 11, n. 3, p. 283-289, SEP 2014.
• Web of Science Citations: 9

Abstract

Objectives: In the present study, the effectiveness of Photodynamic Antimicrobial Chemotherapy (PACT) was evaluated on planktonic cells and biofilms of five Enterococcus faecalis clinical isolates. Methods: Planktonic cells and biofilms of E. faecalis E2, E3, ER3/2s, OS16 and AA-OR34 were grown in SDMY medium plus 0.4% glucose. Approximately 5.0 x 10(7) CFU planktonic cells and 24h biofilms were subjected to PACT using the combination of Light Emitting Diodes (LEDs, Biotable (R)) and Photogem (R). The metabolic activity of bacterial cells was evaluated by a resazurin assay. Biomass values of the biofilms were determined by a crystal violet assay. Results: Compared to the water-treated control group, gradual increases of light energy led to greater reduction of metabolic activity of planktonic cells and biofilms of E. faecalis when the combination of LEDs and Photogem (R) was applied. Photogem (R) alone significantly reduced the metabolic activity of planktonic cells, whereas LEDs or Photogem (R) alone did not result in biofilm viability changes. PACT yielded similar antimicrobial outcomes on planktonic cells of all tested E. faecalis strains, whereas biofilms of E. faecalis E3, ER3/2s and OS16 were more resistant to PACT than biofilms of E. faecalis E2 and AA-OR34. Conclusions: The efficacy of PACT on E. faecalis biofilms was strain dependent. PACT demonstrated its potential as an adjuvant antimicrobial treatment by killing of E. faecalis planktonic and biofilm cells. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 08/06969-5 - EFFECTS OF PHOTODYNAMIC THERAPY ON STREPTOCOCCUS MUTANS
• Grantee: Thiago Cruvinel da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate