title: Photodynamic inactivation of Candida albicans mediated by a low density of light energy.
abstract: Shorter times and lower energies of application of light sources are desirable to use photodynamic antimicrobial chemotherapy (PACT) to the clinical control of candidiasis, especially among babies and children. Light energies ranging from 39.5 to 100 J/cm(2) were previously applied to kill Candida albicans by PACT. The present study evaluated the efficacy of a combination of 0.05 mg/mL toluidine blue O (TBO) and a short time of application (60 s) and a low density of light energy (18 J/cm(2)) of a red light-emitting diode (LED) in killing C. albicans planktonic cells. Standard suspensions of C. albicans were randomly assigned for four treatment groups: control (L-P-), LED alone (L+P-), TBO alone (L-P+), and PACT (L+P+). After treatments, serial dilutions of suspensions were prepared and streaked on Sabouraud dextrose agar to determine colony-forming units of C. albicans per milliliter (CFU/mL). The results were analyzed by ANOVA and Tukey's post-hoc test (P < 0.05). PACT significantly reduced CFUs of C. albicans in comparison to other three treatments. Our results demonstrated a fungicidal effect of PACT mediated by a shorter time of application of LED on C. albicans planktonic cells. Further in vivo studies are needed to elucidate the efficacy of PACT to treat human fungal infections.
authors.affiliation: Discipline of Pediatric Dentistry, Bauru School of Dentistry, University of Sao Paulo, Bauru, Sao Paolo, Brazil, gasalles@gmail.com.
authors.forename: Gabriel Salles
authors.initials: GS
authors.lastname: Barbério
authors.forename: Soraia Veloso
authors.initials: SV
authors.lastname: da Costa
authors.forename: Mariana
authors.initials: M
authors.lastname: dos Santos Silva
authors.forename: Thaís Marchini
authors.initials: TM
authors.lastname: de Oliveira
authors.forename: Thiago Cruvinel
authors.initials: TC
authors.lastname: Silva
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: de Andrade Moreira Machado
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D054023:Lasers, Semiconductor; D008826:Microbial Sensitivity Tests; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000494:pharmacology*; D014048:Tolonium Chloride / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D017319:Photosensitizing Agents; D014048:Tolonium Chloride