Susceptibility of Candida Species to Photodynamic Effects of Photofrin (original) (raw)
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Sensitivity of Candida albicans Germ Tubes and Biofilms to Photofrin-Mediated Phototoxicity
Antimicrobial Agents and Chemotherapy, 2005
Treatment of mucocutaneous and cutaneous Candida albicans infections with photosensitizing agents and light, termed photodynamic therapy (PDT), offers an alternative to conventional treatments. Initial studies using the clinically approved photosensitizer Photofrin demonstrated the susceptibility of C. albicans to its photodynamic effects. In the present study, we have further refined parameters for Photofrin-mediated pho- todynamic action against C. albicans and examined
Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology, 2011
Objective. This study evaluated the effects of photodynamic therapy on pathogenicity of Candida albicans. Study design. Fifty-six rats were submitted to development of candidiasis on the tongue dorsum by C. albicans inoculations. After 5 days, different treatments were administered: laser and photosynthesizer methylene blue (LϩPϩ); laser only (LϩPϪ); photosensitizer only (LϪPϩ); and physiologic solution only (LϪPϪ). Samples of the oral cavity were collected for a count of colony-forming units per mL. Colonies were isolated for evaluation of proteinase and phospholipase activities. The rats were killed for microscopic analysis of the tongue dorsum. The data were analyzed by analysis of variance, Kruskal-Wallis, and Bonferroni tests. Results. The number of C. albicans recovered from the oral cavity of the rats was similar between the groups (P ϭ .106). The LϩPϩ group showed fewer microscopic lesions of candidiasis than the LϪPϪ group (P ϭ .001). The LϩPϩ group presented lower proteinase activity compared with the other groups, with significant difference between the groups LϩPϩ and LϪPϩ (P ϭ .018). Conclusions. Photodynamic therapy reduced the microscopic lesions of experimental candidiasis in rats and inhibited the proteinase activity of C.
Effect of photodynamic therapy with two photosensitizers on Candida albicans
Journal of Photochemistry and Photobiology B: Biology, 2016
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights of this study are the application of in In vivo and reduction of pathogen microorganisms in oral cavity with use of this technic.
New Applications of Photodynamic Therapy in the Management of Candidiasis
Journal of Fungi
The most important aetiological agent of opportunistic mycoses worldwide is Candida spp. These yeasts can cause severe infections in the host, which may be fatal. Isolates of Candida albicans occur with greater frequency and variable resistance patterns. Photodynamic therapy (PDT) has been recognised as an alternative treatment to kill pathogenic microorganisms. PDT utilises a photosensitizer, which is activated at a specific wavelength and oxygen concentration. Their reaction yields reactive oxygen species that kill the infectious microorganism. A systematic review of new applications of PDT in the management of candidiasis was performed. Of the 222 studies selected for in-depth screening, 84 were included in this study. All the studies reported the antifungal effectiveness, toxicity and dosimetry of treatment with antimicrobial PDT (aPDT) with different photosensitizers against Candida spp. The manuscripts that are discussed reveal the breadth of the new applications of aPDT again...
Photodynamic inactivation of oropharyngeal Candida strains
Phytomedicine, 2014
Oropharyngeal candidiasis (OPC) is an infection frequent in immunocompromised patients. Photodynamic therapy is an alternative to conventional treatments, based on the utilization of compounds that inhibit or kill microorganisms only under the effect of light, process known as Photodynamic Inactivation (PDI). In the present study, PDI of Candida spp. by the natural product ␣-terthienyl (␣-T) was investigated following the guidelines of CLSI M27-A3, under UV-A light irradiation. The optimal values of two variables, exposure irradiation time (ET) and distance to the irradiation source (DIS) were established by employing Design Expert Software (DES). For this purpose, a panel of Candida strains isolated from OPC (C. albicans, C. tropicalis, C. parapsilosis and C. krusei) was employed and optimal values were 5 min (ET) and between 6.06 and 6.43 cm (DIS) with a desirability factor of 0.989. ␣-T plus UV-A light in the optimal conditions caused a complete reduction in viable cells in 5 min which was demonstrated by viable cells reduction assays and confocal microscopy after vital staining (propidium iodide/fluorescein diacetate). The germ tube formation of C. albicans was inhibited by ␣-T at sub-inhibitory concentrations. Results showed that ␣-T plus UV-A light could constitute an alternative for OPC treatments at the optimal conditions determined here.
Photodynamic therapy of oral Candida infection in a mouse model
Journal of Photochemistry and Photobiology B: Biology, 2016
Species of the fungal genus Candida, can cause oral candidiasis especially in immunosuppressed patients. Many studies have investigated the use of photodynamic therapy (PDT) to kill fungi in vitro, but this approach has seldom been reported in animal models of infection. This study investigated the effects of PDT on Candida albicans as biofilms grown in vitro and also in an immunosuppressed mouse model of oral candidiasis infection. We used a luciferase-expressing strain that allowed noninvasive monitoring of the infection by bioluminescence imaging. The phenothiazinium salts, methylene blue (MB) and new methylene blue (NMB) were used as photosensitizers (PS), combined or not with potassium iodide (KI), and red laser (660 nm) at four different light doses (10J, 20J, 40J and 60J). The best in vitro log reduction of CFU/ml on biofilm grown cells was: MB plus KI with 40J (2.31 log; p < 0.001); and NMB without KI with 60J (1.77 log; p < 0.001). These conditions were chosen for treating the in vivo model of oral Candida infection. After 5 days of treatment the disease was practically eradicated, especially using MB plus KI with 40J. This study suggests that KI can potentiate PDT of fungal infection using MB (but not NMB) and could be a promising new approach for the treatment of oral candidiasis.
Lasers in medical science, 2017
This study evaluated the effects of antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine® (PDZ) and LED light on the virulence factors of fluconazole-susceptible (CaS) and fluconazole-resistant (CaR) Candida albicans. Standardized suspensions of strains were prepared (10(7)), and after 48 h of biofilm formation, these strains were incubated with PDZ (100 mg/L) for 20 min and exposed to LED light (660 nm, 37.5 J/cm(2)). Additional samples were treated with PDZ or light only, and the control consisted of biofilms that received no treatment. After aPDT, the cells were recovered and the virulence factors were evaluated. To analyze the capacity of adhesion, cells were recovered after aPDT and submitted to the adhesion process in the bottom of a 96-well plate. After this, metabolic activity tests (XTT assay) and cell viability (colony forming units per milliliter, CFU/mL) were applied. To evaluate the biofilm-forming ability after aPDT, the cells recovered were submitted t...
BMC Microbiology, 2013
Background Candida spp. are recognized as a primary agent of severe fungal infection in immunocompromised patients, and are the fourth most common cause of bloodstream infections. Our study explores treatment with photodynamic therapy (PDT) as an innovative antimicrobial technology that employs a nontoxic dye, termed a photosensitizer (PS), followed by irradiation with harmless visible light. After photoactivation, the PS produces either singlet oxygen or other reactive oxygen species (ROS) that primarily react with the pathogen cell wall, promoting permeabilization of the membrane and cell death. The emergence of antifungal-resistant Candida strains has motivated the study of antimicrobial PDT (aPDT) as an alternative treatment of these infections. We employed the invertebrate wax moth Galleria mellonella as an in vivo model to study the effects of aPDT against C. albicans infection. The effects of aPDT combined with conventional antifungal drugs were also evaluated in G. mellonell...
In Vitro Fungicidal Photodynamic Effect of Hypericin on Candida Species†
Photochemistry and Photobiology, 2012
Hypericin is a natural photosensitizer considered for the new generation of photodynamic therapy (PDT) drugs. The aim of this study was to evaluate the in vitro fungicidal effect of hypericin PDT on various Candida spp., assessing its photocytotoxicity to keratinocytes (HaCaT) and dermal fibroblasts (hNDF) to determine possible side effects. A 3 log fungicidal effect was observed at 0.5 McFarland for two Candida albicans strains, Candida parapsilosis and Candida krusei with hypericin concentrations of 0.625, 1.25, 2.5 and 40 lm, respectively, at a fluence of 18 J cm)2 (LED lamp emitting at 602 ± 10 nm). To obtain a 6 log reduction, significantly higher hypericin concentrations and light doses were needed (C. albicans 5 lM M, C. parapsilosis 320 lM and C. krusei 320 lM; light dose 37 J cm)2). Keratinocytes and fibroblasts can be preserved by keeping the hypericin concentration below 1 lm and the light dose below 37 J cm)2. C. albicans appears to be suitable for treatment with hypericin PDT without significant damage to cutaneous cells.