title: Comparison of the effect of rose bengal- and eosin Y-mediated photodynamic inactivation on planktonic cells and biofilms of Candida albicans.
abstract: Candida albicans is an opportunistic yeast that can cause oral candidosis through the formation of a biofilm, an important virulence factor that compromises the action of antifungal agents. The objective of this study was to compare the effect of rose bengal (RB)- and eosin Y (EY)-mediated photodynamic inactivation (PDI) using a green light-emitting diode (LED; 532 ± 10 nm) on planktonic cells and biofilms of C. albicans (ATCC 18804). Planktonic cultures were treated with photosensitizers at concentrations ranging from 0.78 to 400 μM, and biofilms were treated with 200 μM of photosensitizers. The number of colony-forming unit per milliliter (CFU/mL) was compared by analysis of variance and Tukey's test (P ≤ 0.05). After treatment, one biofilm specimen of the control and PDI groups were examined by scanning electron microscopy. The photosensitizers (6.25, 25, 50, 200, and 400 μM of EY, and 6.25 μM of RB or higher) significantly reduced the number of CFU/mL in the PDI groups when compared to the control group. With respect to biofilm formation, RB- and EY-mediated PDI promoted reductions of 0.22 log10 and 0.45 log10, respectively. Scanning electron microscopy showed that the two photosensitizers reduced fungal structures. In conclusion, EY- and RB-mediated PDI using LED irradiation significantly reduced C. albicans planktonic cells and biofilms.
authors.affiliation: Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, UNESP - Universidade Estadual Paulista, Francisco José Longo 777, São Dimas, São José dos Campos, 12245-000, São Paulo, Brazil, fefreire21@hotmail.com.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Freire
authors.forename: Anna Carolina Borges Pereira
authors.initials: AC
authors.lastname: Costa
authors.forename: Cristiane Aparecida
authors.initials: CA
authors.lastname: Pereira
authors.forename: Milton
authors.initials: M
authors.lastname: Beltrame Junior
authors.forename: Juliana Campos
authors.initials: JC
authors.lastname: Junqueira
authors.forename: Antonio Olavo Cardoso
authors.initials: AO
authors.lastname: Jorge
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004801:Eosine Yellowish-(YS) / Q000737:chemistry / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology; D010933:Plankton / Q000166:cytology* / Q000187:drug effects*; D012395:Rose Bengal / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D017319:Photosensitizing Agents; D012395:Rose Bengal; D004801:Eosine Yellowish-(YS)