Photodynamic fungicidal efficacy of hypericin and dimethyl methylene blue against azole-resistant Candida albicans strains.
Mycoses
; 57(1): 35-42, 2014 Jan.
Article
em En
| MEDLINE
| ID: mdl-23905682
ABSTRACT
Antimicrobial photodynamic therapy (aPDT) is an emerging alternative to treat infections based on the use of photosensitisers (PSs) and visible light. To investigate the fungicidal effect of PDT against azole-resistant Candida albicans strains using two PSs with a different mechanism of action, hypericin (HYP) and 1,9-dimethyl methylene blue (DMMB), comparing their efficacy and the reactive oxygen species (ROS) species involved in their cytotoxicity. Azole-resistant and the azole-susceptible C. albicans strains were used. Solutions of 0.5 and 4 McFarland inoculum of each Candida strain were treated with different concentrations of each PS, and exposed to two light-emitting diode light fluences (18 and 37 J cm⻲). Mechanistic insight was gained using several ROS quenchers. The minimal fungicidal concentration of HYP for ≥3 log10 CFU reduction (0.5 McFarland) was 0.62 µmol l⻹ for most strains, whereas for DMMB it ranged between 1.25 and 2.5 µmol l⻹. Increasing the fluence to 37 J cm⻲ allowed to reduce the DMMB concentration. Higher concentrations of both PSs were required to reach a 6 log10 reduction (4 McFarland). H2O2 was the main phototoxic species involved in the fungicidal effect of HYP-aPDT whereas ¹O2 was more important for DMMB-based treatments. aPDT with either HYP or DMMB is effective in killing of C. albicans strains independent of their azole resistance pattern. HYP was more efficient at low fungal concentration and DMMB at higher concentrations.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Perileno
/
Azóis
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Candida albicans
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Fármacos Fotossensibilizantes
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Farmacorresistência Fúngica
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Azul de Metileno
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Antifúngicos
Limite:
Humans
Idioma:
En
Revista:
Mycoses
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Espanha