Photodynamic inactivation of a multispecies biofilm using Photodithazine® and LED light after one and three successive applications
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In this investigation, the effectiveness of successive applications of antimicrobial photodynamic inactivation (API) mediated by Photodithazine® (PDZ) and LED light was evaluated against a multispecies biofilm formed by Candida albicans, Candida glabrata, and Streptococcus mutans on denture base acrylic resin. Standard cell suspensions (bacteria and yeast) were inoculated on acrylic resin samples, and the biofilm was grown for 48 h (37 °C/75 rpm). API was performed by the administration of PDZ (175 and 200 mg/L) and exposure to 37.5 J/cm2 of LED light (660 nm). Additional samples were treated with PDZ or LED light only. Untreated control samples were not submitted to light or PDZ. The conditions described were applied once or in three consecutive applications for all groups. Cell viability was determined by colony counts (CFU/mL), metabolic activity, total biomass, and confocal laser scanning microscopy (CLSM). Data were analyzed by a nonparametric two-way ANOVA and Tukey tests (α = 0.05). The results obtained demonstrated a significant effect (p < 0.05) of number of applications and treatment groups for CFU/mL, and S. mutans showed the highest susceptibility to API. The metabolic activity of the multispecies biofilm was significantly reduced (p < 0.05) after API for both numbers of applications, which were also significantly different (p < 0.05) between them. The total biomass of the biofilm was significantly different (p < 0.05) only between groups submitted to one and three API applications. CLSM showed a visual increase of dead cells after API. API-mediated PDZ was effective in reducing the cell viability of multispecies biofilm. Three consecutive applications of API were more effective for reducing the cell viability and the total biomass of multispecies biofilm.
KeywordsBiofilm Candida albicans Candida glabrata Streptococcus mutans Acrylic resin Photodynamic therapy
This work was supported by the São Paulo Research Foundation—FAPESP (grant 2011/09054), Centro de Pesquisa em Óptica e Fotônica—CEPOF-CEPID (grant 13/07276-1), and Fundação para o Desenvolvimento da UNESP—FUNDUNESP (grant 878/11-DFP).
Conflict of interest
The authors declare that they have no conflict of interest.
- 5.Baena-Monroy T, Moreno-Maldonado V, Franco-Martínez F, Aldape-Barrios B, Quindós G, Sánchez-Vargas LO (2005) Candida albicans, Staphylococcus aureus and Streptococcus mutans colonization in patients wearing dental prosthesis. Med Oral Patol Oral Cir Bucal 10:27–39Google Scholar
- 15.Banting DW, Greenhorn PA, McMinn JG (1995) Effectiveness of a topical antifungal regimen for the treatment of oral candidiasis in older, chronically ill, institutionalized, adults. J Can Dent Assoc 61(199–200):203–205Google Scholar
- 28.Strackhovskaya MG, Belenikina NS, Ivanova EV, Chemeris YK, Stranadko EF (2002) The photodynamic inactivation of the yeast Candida guilliermondii in the presence of photodithazine. Microbiol 71:345–48Google Scholar
- 29.Hakimiha N, Khoei F, Bahador A, Fekrazad R (2014) The susceptibility of Streptococcus mutans to antibacterial photodynamic therapy: a comparison of two different photosensitizers and light sources. J Appl Oral Sci22:804.Google Scholar
- 30.Fekrazad R, Khoei F, Hakimiha N, Bahador A. Photoelimination of Streptococcus mutans with two methods of photodynamic and photothermal therapy. Photodiagnosis Photodyn Ther. Dec;10(4):62631Google Scholar
- 31.Fekrazad R, Bargrizan M, Sajadi S, Sajadi S (2013) Evaluation of the effect of photoactivated disinfection with Radachlorin(®) against Streptococcus mutans (an in vitro study). Photodiagnosis Photodyn Ther 8:24953Google Scholar