Antimicrobial photodynamic therapy and its applicability in aquaculture systems and aquatic animal health management: An overview

Global aquaculture production in 2012 touched new high of 90.4 million tonnes including 66.6 million tonnes of food fish and 23.8 million tonnes of aquatic algae providing 19.2 kg per capita food fish suppy. Aquaculture is reported to suffer heavy production and financial losses due to fish infections caused by microbial pathogens. Therefore in order to make aquaculture industry more sustainable, effective strategies to control fish infections are urgently needed. Antimicrobial Photodynamic Therapy (aPDT) is an emerging, low-cost anti-microbial approach to the treatment of locally occurring infections and also for the treatment of aquaculture water and waste waters. Already proven effective in various medical and clinical applications, it utilizes three vital components: a photosensitizing agent (PS), a light source of an appropriate wave length and oxygen. aPDT has got a potential of being a preferred choice over antibiotics in aquaculture systems because of its non-target specificity, few side effects, lack of the pathogenicity reversal and re-growth of the micro-organism after treatment and the lack of development of resistance mechanisms. The technique has been proved effective in vitro against bacteria (including drug-resistant strains), yeasts, fungi, viruses, parasites and even the stubborn biofilms. Although preliminary results indicate that this technology has a high potential to disinfect waters in aquaculture system and also in hatcheries and seed production units, but it clearly needs more deep knowledge and multi-dimenstional approach.

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Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine® on MSSA and MRSA Strains

Antibiotics ◽

10.3390/antibiotics10070869 ◽

2021 ◽

Vol 10 (7) ◽

pp. 869

Author(s):

Beatriz Müller Nunes Souza ◽

Juliana Guerra Pinto ◽

André Henrique Correia Pereira ◽

Alejandro Guillermo Miñán ◽

Juliana Ferreira-Strixino

Keyword(s):

Staphylococcus Aureus ◽

Photodynamic Therapy ◽

Antimicrobial Photodynamic Therapy ◽

Bacterial Inactivation ◽

Bacterial Reduction ◽

Complete Inactivation ◽

Opportunistic Bacteria ◽

Significant Difference ◽

Mrsa Strains

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

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Photodynamic Therapy Combined with Antibiotics or Antifungals against Microorganisms That Cause Skin and Soft Tissue Infections: A Planktonic and Biofilm Approach to Overcome Resistances

Pharmaceuticals ◽

10.3390/ph14070603 ◽

2021 ◽

Vol 14 (7) ◽

pp. 603

Author(s):

Vanesa Pérez-Laguna ◽

Isabel García-Luque ◽

Sofía Ballesta ◽

Antonio Rezusta ◽

Yolanda Gilaberte

Keyword(s):

Photodynamic Therapy ◽

Soft Tissues ◽

Combined Treatment ◽

Resistance Pattern ◽

Antimicrobial Photodynamic Therapy ◽

Antimicrobial Drugs ◽

Bacteria And Fungi ◽

High Level ◽

Selection Of

The present review covers combination approaches of antimicrobial photodynamic therapy (aPDT) plus antibiotics or antifungals to attack bacteria and fungi in vitro (both planktonic and biofilm forms) focused on those microorganisms that cause infections in skin and soft tissues. The combination can prevent failure in the fight against these microorganisms: antimicrobial drugs can increase the susceptibility of microorganisms to aPDT and prevent the possibility of regrowth of those that were not inactivated during the irradiation; meanwhile, aPDT is effective regardless of the resistance pattern of the strain and their use does not contribute to the selection of antimicrobial resistance. Additive or synergistic antimicrobial effects in vitro are evaluated and the best combinations are presented. The use of combined treatment of aPDT with antimicrobials could help overcome the difficulty of fighting high level of resistance microorganisms and, as it is a multi-target approach, it could make the selection of resistant microorganisms more difficult.

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Efficacy of Toluidine Blue—Mediated Antimicrobial Photodynamic Therapy on Candida spp. A Systematic Review

Antibiotics ◽

10.3390/antibiotics10040349 ◽

2021 ◽

Vol 10 (4) ◽

pp. 349

Author(s):

Rafał Wiench ◽

Dariusz Skaba ◽

Jacek Matys ◽

Kinga Grzech-Leśniak

Keyword(s):

Photodynamic Therapy ◽

Toluidine Blue ◽

Randomized Clinical Trials ◽

Oral Candidiasis ◽

In Vitro Studies ◽

Cochrane Central Register ◽

Antimicrobial Photodynamic Therapy ◽

Candida Spp ◽

Denture Stomatitis

The effectiveness of antimicrobial photodynamic therapy (aPDT) in the treatment of oral yeast infections was examined many times in recent years. The authors of this review tried to address the question: “Should TBO (toluidine blue ortho)-mediated aPDT be considered a possible alternative treatment for oral candidiasis?”. PubMed/Medline and the Cochrane Central Register of Controlled Trials (CEN-TRAL) databases were searched from 1997 up to the 27th of October 2020 using a combination of the following keywords: (Candida OR Candidiasis oral OR Candidosis oral OR denture stomatitis) AND (toluidine blue OR photodynamic therapy OR aPDT OR photodynamic antimicrobial chemotherapy OR PACT OR photodynamic inactivation OR PDI). Animal studies or in vitro studies involving Candida albicans (C. albicans) and/or nonalbicans stain, randomized clinical trials (RCT) involving patients with oral candidiasis or denture stomatitis published solely in English language were included. Candida elimination method in animal, in vitro studies and RCT used was TBO-mediated aPDT. Exactly 393 studies were taken into consideration. Then, after analyzing titles and abstracts of said studies, 361 were excluded. Only 32 studies ended up being selected for in-depth screening, after which 21 of them were included in this study. All studies reported the antifungal effectiveness of aPDT with TBO against C. albicans and non-albicans Candida. In studies conducted with planktonic cells, only one study showed eradication of C. albicans. All others showed partial elimination and only one of them was not statistically significant. Experiments on yeast biofilms, in all cases, showed partial, statistically significant cell growth inhibition and weight reduction (a reduction in the number of cells—mainly hyphae) and the mass of extracellular polymeric substance (EPS). In vivo aPDT mediated by TBO exhibits antifungal effects against oral Candida spp.; however, its clinical effectiveness as a potent therapeutic strategy for oral yeast infections requires further investigation.

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Antimicrobial Photodynamic Therapy and Dental Plaque: A Systematic Review of the Literature

The Scientific World JOURNAL ◽

10.1155/2014/824538 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 20

Author(s):

G. C. Santin ◽

D. S. B. Oliveira ◽

R. Galo ◽

M. C. Borsatto ◽

S. A. M. Corona

Keyword(s):

Systematic Review ◽

Photodynamic Therapy ◽

Data Extraction ◽

Antimicrobial Photodynamic Therapy ◽

Review Of The Literature ◽

Eligibility Criteria ◽

Dental Biofilm ◽

Quality Assessments

Background. The aim of this study was to perform a systematic review of the literature on the efficacy of antimicrobial photodynamic therapy (PDTa) on cariogenic dental biofilm.Types of Studies Reviewed. Studiesin vivo,in vitro, andin situwere included. Articles that did not address PDTa, those that did not involve cariogenic biofilm, those that used microorganisms in the plankton phase, and reviews were excluded. Data extraction and quality assessments were performed independently by two raters using a scale.Results. Two hundred forty articles were retrieved; only seventeen of them met the eligibility criteria and were analyzed in the present review. Considerable variability was found regarding the methodologies and application protocols for antimicrobial PDTa. Two articles reported unfavorable results.Practical Implications. The present systematic review does not allow drawing any concrete conclusions regarding the efficacy of antimicrobial PDTa, although this method seems to be a promising option.

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