TITLE:
In Vitro Effects of Photodynamic Therapy with Three Photosensitizers on Candida spp from Complicated Vulvovaginitis and Asymptomatic Women
AUTHORS:
Humberto Fabio Boatto, Maria Sayonara de Moraes, Alexandre Paulo Machado, Manoel João Batista Castelo Girão, Gilglécia Novaes Pereira Santana, Fernanda Aparecida Vieira Fernandes, Orion Sant’anna Motter Borba, Olga Fischman Gompertz
KEYWORDS:
Photodynamic Therapy, Photosensitizers, Candida albicans, Species Non-Albicans, Complicated Fungal Vulvovaginitis
JOURNAL NAME:
Open Journal of Medical Microbiology,
Vol.11 No.4,
November
2,
2021
ABSTRACT: Aim: To evaluate photodynamic therapy (PDT) in vitro to reduce the growth of Candida spp, and its synergy with the antifungals fluconazole and
ketoconazole for inhibition of resistant, DDS and susceptible isolates from
asymptomatic carriers and with complicated vulvovaginitis. Methods: Between 2017 and 2020, we evaluated 230 women with vulvovaginal candidiasis and 400 asymptomatic.
We obtained 130 positive cultures for Candida spp from vulvovaginitis and 94 asymptomatic. Yeasts were characterized by
classical and molecular tests. Sensitivity to fluconazole and ketoconazole was
evaluated by E-test. We used photodynamic light through blue LED, wavelengths
between 450 to 470 nm, power of 260 mW, energy fluence
of 270 J/cm2, for 15 minutes over all colonies of Candida spp. Methylene
blue (MB) at 450 mg/mL, 2% gentian violet (VG) and 50 μM
curcumin (CR) were used in association or not with LED irradiation. Suspensions
of Candida spp of 106 CFU/mL, subjected to the different assays, were introduced in 96-well
microplates, incubated for 48 hours at 35˚C and the readings at 530 nm. The
samples were finally cultivated in Petri plates containing Sabouraud dextrose
agar to assess the growth inhibition. All procedures were in triplicate. Results: C. albicans was prevalent in vulvovaginal
candidiasis, however, we also isolated non-albicans species such as C. glabrata, C. tropicalis and C. parapsilosis. There was a substantial reduction (66.6% to 83.8%)
of the CFU/mL of the isolates treated with FDT. Gentian violet at 2% alone
reduced the growth of CFU/ml of Candida spp from 69% to 75%. Among isolates of vaginitis and asymptomatic carriers,
after using FDT, we found a reduction in resistant phenotypes and DDS for
fluconazole in percentages from 20% to 100% for C. albicans, from 50% to 100% C.
glabrata, 33.3% to 100% C.
parapsilosis and 100% C. tropicalis.
For ketoconazole in the same isolates, there was a reduction in phenotypes with
MIC > 16 μg/mL of up to 50% in C.
albicans, 50% to 100% C. glabrata,
50% to 100% C. tropicalis. Conclusions: PDT with MB, GV and CR revealed efficacy in
vitro in reducing the growth of C.
albicans and non-albicans,
especially due to chronic recurrent vulvovaginitis.