An in Vitro Study on the Effect of Combined Treatment with Photodynamic and Chemical Therapies on Candida albicans

Abstract

Candida albicans is the most commonly encountered human fungal pathogen, and it is traditionally treated with antimicrobial chemical agents. The antimicrobial effect of these agents is largely weakened by drug resistance and biofilm-associated virulence. Enhancement of the antimicrobial activity of existing agents is needed for effective candidiasis treatment. Our aim was to develop a therapy that combined biofilm disruption with existing antimicrobial agents. Photodynamic therapy (PDT) utilizing curcumin and blue light was tested as an independent therapy and in combination with fluconazole treatment. Viability assays and morphology analysis were used to assess the effectiveness of C. albicans treatment. Results showed that fluconazole treatment decreased the viability of planktonic C. albicans, but the decrease was not as pronounced in adherent C. albicans because its biofilm form was markedly more resistant to the antimicrobiotic. PDT effectively eradicated C. albicans biofilms, and when combined with fluconazole, PDT significantly inhibited C. albicans to a greater extent. This study suggests that the addition of PDT to fluconazole to treat C. albicans infection enhances its effectiveness and can potentially be used clinically.

Sequential Photodynamic Therapy with Phthalocyanine Encapsulated Chitosan-Tripolyphosphate Nanoparticles and Flucytosine Treatment against Candida tropicalis

“…However, the antimicrobial PDT effect in adherent C. tropicalis was a lot weaker than in planktonic C. tropicalis . Consistent with our previous study on C. albicans [25], this result fulfills our prediction that it is more difficult to eradicate C. tropicalis when it is forming biofilms.…”

“…As an alternative treatment, PDT is an efficient antitumor therapy. However, for antimicrobial therapies, the effect of PDT is limited, as has been previously reported [25,43], and this is confirmed in this work. One major problem in antimicrobial PDT is the poor solubility and limited cell penetration of photosensitizers [44].…”

“…Photodynamic therapy is a promising alternative treatment in cancers [22] and microbial diseases [23,24]. The combination of chemical treatment and photodynamic therapy (PDT) greatly enhances antimicrobial efficiency in C. albicans [25]. Many photosensitizers have been approved by the Food and Drug Administration in the US, including Photofrin, Levulan, Metvix, and Visudyne [26].…”

Antimicrobial efficacy of photodynamic therapy on the treatment of oral candidiasis in people living with hiv/aids

“…An experimental study with 21 PLWHA showed that fluconazole did not prevent recurrence of oral candidiasis when they were reevaluated within 30 days, whereas in patients receiving PDT, there was no recurrence of the lesion during the same reevaluation period 14 . The combination of PDT and fluconazole was effective in reducing C. albicans colonies in in vitro 10,11 and in vivo 12,13 studies. In this study, participants 015 and 018, respectively, received PDT/nystatin and PDT/ fluconazole exhibited a reduction in oral candidiasis severity ratings when reassessed after 14 days.…”

“…This technique has shown to be promising in reducing C. albicans colonies in in vitro [9][10][11] and in vivo 12,13 assays. PDT was also effective in the treatment of oral candidiasis in PLWHA, without causing side effects, both isolated 14 and when associated with topical antifungals 15 .…”