Effectiveness of photodynamic therapy on Candida species isolated from oral samples of children exposed and not exposed to HIV

Abstract

Objective: Identify yeast species isolated from unexposed, exposed and HIV-carrier children, and verify the effectiveness of low power laser photodynamic therapy (PDT) on the yeasts species belonging to the Candida genus. Methods: Fifty children assisted by the Public Health Program of the city of Vitória da Conquista, Bahia, were selected and divided into three groups: unexposed to HIV, exposed to HIV during pregnancy, and HIV-carrier. Saliva samples were collected in a disposable sterile universal container and were plated to Sabouraud dextrose agar supplemented with 0.1 mg/mL chloramphenicol. The plates were incubated at 37°C for 48 h. Three strains of each patient were identified by using an API 20 C AUX system. The strains were submitted to photodynamic therapy (PDT) with a 660 nm low power laser and methylene blue dye at different times of irradiation (90, 180 and 282 sec.). Results: The results showed that the most prevalent species was Candida albicans followed by Candida famata (second most prevalent in unexposed to HIV and HIV carriers)) and Candida parapsilosis (second most prevalent in exposed to HIV group). The CFU/mL of Candida spp. decreased significantly (p<0,05) in all groups treated with PDT compared to the controls. Photodynamic therapy treatments at different exposure times (e.g., PS+L90+, PS+L180+, PS+L282+) revealed that the exposure time of 282 sec. gave the highest reduction of the mean logarithmic CFU/mL. Conclusion: Candida albicans was the most prevalent Candida species in these three groups and Candida non-albicans species, when combined, amounted to a significant percentage of Candida isolates. Photodynamic therapy was effective in inactivating the Candida spp. isolated from the oral cavity of children not exposed to HIV, exposed to HIV and HIV-carriers, with the best photodynamic therapy irradiation time being 282 sec.

Antibacterial Effect of Three Kinds of Methylene Blue Photosensitizers Mediated Photodynamic Therapy on Streptococcus Mutans

“…The oxygen molecules that receive the energy undergo a series of photochemical reactions to produce singlet oxygen and a variety of reactive oxygen species with strong oxidation [4]. Studies have shown that PDT-mediated treatment of periodontal disease can eliminate plaque formation without involving normal periodontal mucosal tissue [5]. It has also been reported that by culturing Streptococcus mutans in vitro and pretreating them with PDT method, the growth and proliferation of bacteria can be effectively inhibited [6].…”

Laserterapia de baixa intensidade com terapia fotodinâmica no tratamento de onicomicose [Low intensity laser therapy with photodynamic therapy in the treatment of onychomycosis] [Terapia láser de baja intensidad con terapia fotodinámica en el tratamiento de la onicomicosis]

“…O tratamento das infecções fúngicas com agentes fotossensibilizantes têm ganhado atenção como uma alternativa viável aos tratamentos convencionais, visto que a TFD com o laser de baixa potência é eficaz na inativação dos fungos 22 .…”

Evaluation of the Effects of Photodynamic Therapy With Methylene Blue on Different Candida Species In Vitro

“…Most previous studies have evaluated the effects of photodynamic therapy on C. albicans in animal models or in vitro. [9][10][11][12][13][14][15] Since there is no study on the effectiveness of photodynamic therapy and laser therapy in eradicating resistant Candida species, including C. glabrata, C. tropicalis, and C. krusei, this study aimed to investigate the effects of photodynamic therapy on the growth of these resistant Candida species in vitro.…”