Successive applications of Antimicrobial Photodynamic Therapy effects the susceptibility of Candida albicans grown in medium with or without fluconazole

Author(s)

Dias, Luana Mendonca ^[1] ; Klein, Marlise Inez ^[1] ; Jordao, Claudia Carolina ^[1] ; Carmello, Juliana Cabrini ^[1] ; Bellini, Amanda ^[1] ; Pavarina, Ana Claudia ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Sch Dent, Dept Dent Mat & Prosthodont, Humaita St 1680, BR-14801903 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 32, DEC 2020.
• Web of Science Citations: 0

Abstract

Antimicrobial Photodynamic Therapy (aPDT) was introduced as a therapy due to resistance that microorganisms have developed to conventional drugs. The study aimed to evaluate the potential of successive applications of aPDT in effecting Candida albicans susceptibility and also whether the presence of fluconazole effected the recovery of the fungi in the culture medium. Planktonic cultures and biofilm were subjected to successive applications of Photodithazine-mediated (25 mg/L) LED-associated aPDT (660 nm, 34 mW/cm(2)). Plating was performed on Sabouraud Dextrose Agar supplemented or not with fluconazole to recover colony-forming units per milliliter (CFU/mL). Surviving cells were recovered, recultivated, and again exposed to the treatment. The treatments were performed until not enough colonies were available for recultivation and continuation of the protocol. The complete inactivation of the fungus was obtained after three and five applications for planktonic culture and biofilm, respectively. A reduction of 6.3 log(10) was observed after third applications in the planktonic cultures grown on medium without fluconazole, while there was a 7 log(10) reduction of these cultures grown on fluconazole medium. However, a reduction of 6.1 log(10) occurred for biofilms after fifth applications for cultures grown on medium without fluconazole, while a reduction of 6.7 log(10) was observed for cultures grown on medium with the antifungal. Thus, aPDT was potentiated by fluconazole. C. albicans in planktonic and biofilm cultures are susceptible to successive applications of PDZ-mediated aPDT, and tolerance to aPDT is higher in the biofilm. (AU)

• FAPESP's process: 16/13868-7 - Evaluation of the fototoxic and fotobiomodulador effects of different wavelengths of Light Emitting Diode (led) radiation on human cells and micro-organims
• Grantee: Juliana Cabrini Carmello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/14874-6 - Potential of antimicrobial photodynamic therapy in the development of resistance in Candida albicans
• Grantee: Luana Mendonça Dias Santana
• Support Opportunities: Scholarships in Brazil - Master