Study in vivo of photodynamic therapy mediated by Photodithazione and led light on Candida albicans fluconazole-resistant

Abstract

Oral candidiasis is the most common opportunistic infection of the oral cavity. The fungal species of the gender Candida, particularly C.albicans, are the main agent of disease. Despite these micro-organisms are commonly found in the oral cavity in relation to commensalism, this type of fungus has the ability to change their morphology, causing infection of the oral tissues. Treatments directed to oral candidiasis may include topical antifungal therapy and / or systemic, in addition to oral hygiene care. However, the use of antimicrobial drugs has resulted development of resistance of microorganisms. In this context, Photodynamic therapy has been studied as an alternative method of treatment of infectious diseases. This study will evaluate the effect of photodynamic therapy (PDT) mediated by Photodithazine ® (PDZ) and LED light in the inactivation of C. albicans fluconazole-resistant candidosis induced in mice. In addition, will assess the effect of PDT on the virulence factors of Candida albicans resistant to fluconazole. In Study 1, will be used 40 female mice of approximately 6 weeks. The mice will be immunosupressed with subcutaneous injections of prednisolone, and subsequently inoculated with the microorganism evaluated. Then the animals will be treated with PDT pipetting 50µL of PDZ at concentrations of 100 mg / L (saline or hydrogel) in the oral cavity and, after 20min, the tongue dorsum will be illuminated with LED (37.5 J / cm ²). Additional animals will be treated with LED, others only with the PDZ, others will not receive any treatment, moreover, another group of healthy mice, i.e., not contaminated, will receive treatment with PDT (n = 5). Then, the tongue dorsum will be swabbed with a cotton pad of each animal and aliquots will be cultured in Sabouraud Dextrose Agar. After 48 hours at 37 ° C, the colonies will be counted (ufc/ mL). For evaluation of virulence factors (Study 2) two colonies per plate will be isolated and resssuspended in PBS. Standardization of cell concentration will be performed spectrophotometrically according to the parameters required in each of the methods used. The virulence factors evaluated in samples exposed or not PDT will be: capacity for adhesion and biofilm formation on abiotic surfaces, the ability to synthesize specific degradative enzymes (protease and phospholipase) and formation of germ tubes and pseudo-hyphae. The control group consisted of suspensions that will be not receive either PDZ or light. The data will be analyzed according to appropriate statistical method. (AU)