Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis.
OBJECTIVE
In vivo studies of antimicrobial PDT in animal models of oral candidosis are scarce and the association of porphyrin and LED light has not been evaluated for in vivo photoinactivation of Candida. In this study the effectiveness of photodynamic therapy (PDT) on the inactivation of Candida albicans in vivo was evaluated.


METHODS
Seventy-one 6-week-old female Swiss mice were immunosuppressed, provided tetracycline to their drinking water, then orally swabbed with a suspension of C. albicans (10(7) CFU/mL). Four days after oral inoculation, PDT was performed on the dorsum of the tongue after topical administration of Photogem at 400, 500, or 1000 mg/L and followed 30 minutes later by illumination with LED light (305 J/cm(2)) at 455 or 630 nm (n = 5 each). After swabbing to recover yeast from the tongue, the number of surviving yeast cells was determined (CFU/mL) and analyzed by ANOVA and Holm-Sidak tests (P < .05). Animals were humanely killed, and the tongues surgically removed and processed for histological evaluation of presence of yeast and inflammatory reaction.


RESULTS
PDT resulted in a significant reduction in C. albicans recovered from the tongue (P < .001) when compared with mice from the positive control group. There was no difference between the concentrations of Photogem and LED light wavelengths used. Histological evaluation of the tongue revealed that PDT causes no significant adverse effects to the local mucosa.


CONCLUSIONS
PDT promoted significant reduction in the viability of C. albicans biofilm without harming the tongue tissue.
Mima
Ewerton Garcia de Oliveira
EG
Dentistry School, São Francisco University-USF, Bragança Paulista, SP, Brazil.
Pavarina
Ana Cláudia
AC
Dovigo
Lívia Nordi
LN
Vergani
Carlos Eduardo
CE
Costa
Carlos Alberto de Souza
CA
Kurachi
Cristina
C
Bagnato
Vanderlei Salvador
VS
D000704:Analysis of Variance; D000818:Animals; D002176:Candida albicans / Q000187:drug effects / Q000528:radiation effects*; D002180:Candidiasis, Oral / Q000188:drug therapy* / Q000382:microbiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006415:Hematoporphyrins / Q000008:administration & dosage; D051379:Mice; D010778:Photochemotherapy / Q000295:instrumentation / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D014059:Tongue / Q000187:drug effects / Q000382:microbiology* / Q000528:radiation effects
D006415:Hematoporphyrins; D017319:Photosensitizing Agents