NÚÑEZ MONTOYA SUSANA CAROLINA
Congresos y reuniones científicas
Título:
Searching for new strategies against Candida tropicalis biofilm: Natural photosensitizing anthraquinones in combination with Amphotericin B
Autor/es:
MARIONI J; CABRERA JL; PARAJE MG; NÚÑEZ MONTOYA SC
Lugar:
Villa Carlos Paz
Reunión:
Encuentro; XIII ENCUENTRO LATINOAMERICANO DE FOTOQUÍMICA Y FOTOBIOLOGÍA (XIII ELAFOT); 2017
Institución organizadora:
Grupo Argentino de Fotobiología
Resumen:
Candida tropicalis is increasingly becoming one of the most commonly isolated pathogens in fungal infections, with a significant decrease in its susceptibility to antimicrobial agents, apparently due to its capacity for biofilms formation [1, 2]. Among the different postulated strategies for the treatment of biofilms, combination of drugs has achieved to improve results [3]. Another estrategy in development is the antimicrobial photodynamic therapy (aPDT), especially to combat infectious agents that have developed resistance to classical treatments. This theraphy inactivates microorganisms by means a biological photo-oxidation mediated by reactive oxygen species (ROS) [4]. Previously, we have demonstrated the in vitro photodynamic effect of two natural photosensitising anthraquinones (AQ), rubiadin (AQ1) and rubiadin 1-methyl ether (AQ2), over C. tropicalis biofilms. AQ1 produced a 63.5% of reduction (%R) in the biofilm biomass of C. tropicalis NCPF 3111 at 1.96 µg/ml, and AQ2 achieved a 47 %R of the the biomass at 15.6 µg/ml. It was also established that this effect was related to an increase in the oxidative and nitrosative stress [5].In this work, we have studied different strategies to improve the antibiofim activity of AQs. In this sense, the effect of consecutive irradiation periods on biofilms trated with each photosensitintizing AQ was assessed. In addition, the combination of each AQ with Amphotericin B (AMB), and the combination of both AQ with each other, even under different irradiation conditions, was evaluated. Generation of reactive oxygen species (ROS) and reactive nitrogen intermediate (RNI) was also measured, studying the activation of superoxide dismutase enzyme (SOD) and the total antioxidant system response.