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Allen GR, Benner KJ, Bahnfleth WP. Inactivation of Pathogens in Air Using Ultraviolet Direct Irradiation Below Exposure Limits. JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 2022; 126:126052. [PMID: 38469440 PMCID: PMC10046823 DOI: 10.6028/jres.126.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/05/2021] [Indexed: 03/13/2024]
Abstract
A method is described for inactivation of pathogens, especially airborne pathogens, using ultraviolet (UV) radiation emitted directly into occupied spaces and exposing occupants to a dose below the accepted actinic exposure limit (EL). This method is referred to as direct irradiation below exposure limits, or DIBEL. It is demonstrated herein that low-intensity UV radiation below exposure limits can achieve high levels of equivalent air changes per hour (ACHeq) and can be an effective component of efforts to combat airborne pathogens such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). An ACHeq of 4 h-¹ is presently achievable over a continuous 8 h period for the SARS-CoV-2 virus with UV-C light-emitting diodes (LEDs) having peak wavelength at 275 nm, and future improvements in LED technology and optics are anticipated to enable improvements up to 150 h-¹ in the coming decade. For example, the actinic EL is 60 J/m² at 254 nm, and human coronaviruses, including SARS-CoV-2, have a UV dose required for 90 % inactivation of about 5 J/m² at 254 nm. Irradiation by 254 nm UV-C at the EL is expected to provide 90 % inactivation of these organisms in air in about 40 min when the UV-C is delivered at a constant irradiance over 8 h, or in about 5 min if the UV-C is delivered at a constant irradiance over 1 h. Since the irradiation is continuous, the inactivation of initial contaminants accumulates to 99 % and then 99.9 %, and it also immediately begins inactivating any newly introduced (e.g., exhaled) pathogens at the same rate throughout the 8 h period. The efficacy for inactivating airborne pathogens with DIBEL may be expressed in terms of ACHeq, which may be compared with conventional ventilation-based methods for air disinfection. DIBEL may be applied in addition to other disinfection methods, such as upper room UV germicidal irradiation, and mechanical ventilation and filtration. The ACHeq of the separate methods is additive, providing enhanced cumulative disinfection rates. Conventional air disinfection technologies have typical ACHeq values of about 1 h-¹ to 5 h-¹ and maximum practical values of about 20 h-¹. UV-C DIBEL currently provides ACHeq values that are typically about 1 h-¹ to 10 h-¹, thus either complementing, or potentially substituting for, conventional technologies. UV-C DIBEL protocols are forecast herein to evolve to >100 ACHeq in a few years, potentially surpassing conventional technologies. UV-A (315 nm to 400 nm) and/or UV-C (100 nm to 280 nm) DIBEL is also efficacious at inactivating pathogens on surfaces. The relatively simple installation, low acquisition and operating costs, and unobtrusive aesthetic of DIBEL using UV LEDs contribute value in a layered, multi-agent disinfection strategy.
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Affiliation(s)
- Gary R Allen
- Gary Allen Consulting, Inc., Euclid, OH 44119, USA
| | - Kevin J Benner
- GE Current, a Daintree company, East Cleveland, OH 44112, USA
| | - William P Bahnfleth
- Department of Architectural Engineering The Pennsylvania State University State College, PA 16801, USA
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McSharry S, Koolman L, Whyte P, Bolton D. Inactivation of Listeria monocytogenes and Salmonella Typhimurium in beef broth and on diced beef using an ultraviolet light emitting diode (UV-LED) system. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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53
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Mukubesa N, Nguenha R, Hong HT, Seididamyeh M, Netzel ME, Sultanbawa Y. Curcumin-Based Photosensitization, a Green Treatment in Inactivating Aspergillus flavus Spores in Peanuts. Foods 2022; 11:foods11030354. [PMID: 35159505 PMCID: PMC8834325 DOI: 10.3390/foods11030354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/21/2022] [Accepted: 01/23/2022] [Indexed: 12/04/2022] Open
Abstract
Controlling microbial contamination in foods using effective clean and green technologies is important in producing food with less contaminants. This study investigates the effect of photosensitization treatment using naturally occurring curcumin on inactivating Aspergillus flavus spores on peanuts. Light dosages of 76.4 J/cm2 and 114.5 J/cm2 at 420 nm were employed in combination with curcumin concentrations from 25 to 100 μM. The inactivation efficiency of the treatment towards spores in suspension achieved a maximum 2 log CFU/mL reduction in viable spores with 75 μM of curcumin at a light dosage of 114.5 J/cm2 (p < 0.05). The in vivo study was then designed using the optimum conditions from the in vitro experiment. The photosensitization treatment at three different curcumin concentrations (50, 75, 100 μM) extended the shelf-life of raw peanuts by 7 days when treated with 75 μM of curcumin combined with a 114.5 J/cm2 light dosage and stored at 25 °C. The treatment effectively reduced average levels of aflatoxin B1 (AF-B1) on peanuts stored for 7 days at 25 °C from 9.65 mg/kg of untreated samples to 0.007 and 0.006 mg/kg for 75 and 100 μM curcumin (p < 0.05) respectively. The results show the potential use of curcumin-based photosensitization treatment in inactivating fungal growth and reducing AF-B1 concentration on raw peanuts.
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Affiliation(s)
- Nalukui Mukubesa
- The Ministry of Agriculture, Mulungushi House, Independence Avenue, Lusaka P.O. Box 50197, Zambia;
- School of Agriculture and Food Science, The University of Queensland, St. Lucia, QLD 4108, Australia;
| | - Rafael Nguenha
- School of Agriculture and Food Science, The University of Queensland, St. Lucia, QLD 4108, Australia;
- Faculdade de Agronomia e Engenharia Florestal, Universidade Eduardo Mondlane, Maputo 1102, Mozambique
| | - Hung T. Hong
- ARC Industrial Transformation Training Centre for Uniquely Australian Foods, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Indooroopilly, QLD 4068, Australia; (H.T.H.); (M.S.); (M.E.N.)
| | - Maral Seididamyeh
- ARC Industrial Transformation Training Centre for Uniquely Australian Foods, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Indooroopilly, QLD 4068, Australia; (H.T.H.); (M.S.); (M.E.N.)
| | - Michael E. Netzel
- ARC Industrial Transformation Training Centre for Uniquely Australian Foods, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Indooroopilly, QLD 4068, Australia; (H.T.H.); (M.S.); (M.E.N.)
| | - Yasmina Sultanbawa
- ARC Industrial Transformation Training Centre for Uniquely Australian Foods, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Indooroopilly, QLD 4068, Australia; (H.T.H.); (M.S.); (M.E.N.)
- Correspondence:
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54
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Greer A. Violet-blue Light Induces "Natural" Photodynamic Plasma Disinfection with Endogenous Sensitizers. Photochem Photobiol 2022; 98:513-515. [PMID: 35020199 DOI: 10.1111/php.13591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/09/2022] [Indexed: 11/29/2022]
Abstract
Naturally, endogenous porphyrins can provide sensitized disinfection power, and to photobiologists' delight, violet-blue light has potential virtues. But progress is needed before violet-blue light treatment can used for microbe treatment of blood samples, and yet safeguard against plasma protein photooxidation. A report by Maclean et al. in this issue of Photochemistry & Photobiology on microbe reduction of blood samples showing negligible competing protein photooxidation may bring that goal a step closer.
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Affiliation(s)
- Alexander Greer
- Department of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York, 11210, United States.,Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York, 10016, United States
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55
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Gomes ATPC, Faustino MAF, Neves MGPMS, Almeida A. Bioluminescent Models to Evaluate the Efficiency of Light-Based Antibacterial Approaches. Methods Mol Biol 2022; 2451:631-669. [PMID: 35505039 DOI: 10.1007/978-1-0716-2099-1_34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The emergence of microbial resistance to antimicrobials among several common pathogenic microbial strains is an increasing problem worldwide. Thus, it is urgent to develop not only new antimicrobial therapeutics to fight microbial infections, but also new effective, rapid, and inexpensive methods to monitor the efficacy of these new therapeutics. Antimicrobial photodynamic therapy (aPDT) and antimicrobial blue light (aBL) therapy are receiving considerable attention for their antimicrobial potential and represent realistic alternatives to antibiotics. To monitor the photoinactivation process provided by aPDT and aBL, faster and more effective methods are required instead of laborious conventional plating and overnight incubation procedures. Bioluminescent microbial models are very interesting in this context. Light emission from bioluminescent microorganisms is a highly sensitive indication of their metabolic activity and can be used to monitor, in real time, the effects of antimicrobial agents and therapeutics. This chapter reviews the efforts of the scientific community concerning the development of in vitro, ex vivo, and in vivo bioluminescent bacterial models and their potential to evaluate the efficiency of aPDT and aBL in the inactivation of bacteria.
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Affiliation(s)
- Ana T P C Gomes
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | - Maria A F Faustino
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Maria G P M S Neves
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Adelaide Almeida
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.
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KEYVAN E, KAHRAMAN HA, TUTUN H, DONMEZ S, SEN E, DEMIRTAS A, AKYUZ AO. Inactivation efficacy of 405 nm light emitting diodes (LEDs) on Salmonella Enteritidis at different illumination temperatures. FOOD SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1590/fst.08721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
| | | | | | | | - Erdi SEN
- Burdur Mehmet Akif Ersoy University, Turkey
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Resistance of Eupenicillium javanicum mold spores to the light-emitting diode (LED), LED-assisted thermal and thermal processing in strawberry and apple juices. Curr Res Food Sci 2022; 5:1524-1529. [PMID: 36132492 PMCID: PMC9483732 DOI: 10.1016/j.crfs.2022.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 08/29/2022] [Accepted: 09/09/2022] [Indexed: 11/23/2022] Open
Abstract
The use of light-emitting diode (LED) technology for the non-thermal processing of foods is a major topic of interest among various research groups. This study is aimed at inactivating the Eupenicillium javanicum ascospores present in strawberry and apple juices using a combination of a visible LED (vis-LED, 430–630 nm, 216–420 J/cm2) and 90 °C thermal treatment, as well as to compare the findings with the inactivation done using thermal-processes alone. The results showed that violet-blue LEDs within the range of 430 and 460 nm with an energy between 300 and 420 J/cm2 were better for the inactivation of E. javanicum ascospores than the green and red LEDs which were within the 550–630 nm region with an energy range from 216 to 264 J/cm2. Furthermore, the inactivation process conducted using vis-LED was affected by the juice's soluble solid contents and the calculated DLED-values were within the range of 116.3 J/cm2 to 277.8 J/cm2 in juices with a Brix scale value of 10–20°. Finally, the inactivation rate obtained from combining a violet-blue LED with a 90 °C thermal treatment was similar to the rate of using the thermal treatment alone. Effect of visible (vis-) LED treatment on inactivation E. javanicum spores was studied. Maximum log reduction was obtained with LED in the violet-blue region. E. javanicum spores showed higher LED resistance in apple juice than in strawberry juice. Soluble solid has an effect on E. javanicum inactivation by vis-LED. Similar thermal inactivation rates were observed between vis-LED + heat and heat alone.
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58
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SHIRAI AKIHIRO, YASUTOMO YUKO, KANNO YUKA. Effects of Violet-Blue Light-Emitting Diode on Controlling Bacterial Contamination in Boiled Young Sardine. Biocontrol Sci 2022; 27:9-19. [DOI: 10.4265/bio.27.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- AKIHIRO SHIRAI
- Department of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University
| | - YU-KO YASUTOMO
- Department of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University
| | - YUKA KANNO
- Department of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University
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59
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Abstract
Rhodopsins are light-activated proteins displaying an enormous versatility of function as cation/anion pumps or sensing environmental stimuli and are widely distributed across all domains of life. Even with wide sequence divergence and uncertain evolutionary linkages between microbial (type 1) and animal (type 2) rhodopsins, the membrane orientation of the core structural scaffold of both was presumed universal. This was recently amended through the discovery of heliorhodopsins (HeRs; type 3), that, in contrast to known rhodopsins, display an inverted membrane topology and yet retain similarities in sequence, structure, and the light-activated response. While no ion-pumping activity has been demonstrated for HeRs and multiple crystal structures are available, fundamental questions regarding their cellular and ecological function or even their taxonomic distribution remain unresolved. Here, we investigated HeR function and distribution using genomic/metagenomic data with protein domain fusions, contextual genomic information, and gene coexpression analysis with strand-specific metatranscriptomics. We bring to resolution the debated monoderm/diderm occurrence patterns and show that HeRs are restricted to monoderms. Moreover, we provide compelling evidence that HeRs are a novel type of sensory rhodopsins linked to histidine kinases and other two-component system genes across phyla. In addition, we also describe two novel putative signal-transducing domains fused to some HeRs. We posit that HeRs likely function as generalized light-dependent switches involved in the mitigation of light-induced oxidative stress and metabolic circuitry regulation. Their role as sensory rhodopsins is corroborated by their photocycle dynamics and their presence/function in monoderms is likely connected to the higher sensitivity of these organisms to light-induced damage. IMPORTANCE Heliorhodopsins are enigmatic, novel rhodopsins with a membrane orientation that is opposite to all known rhodopsins. However, their cellular and ecological functions are unknown, and even their taxonomic distribution remains a subject of debate. We provide evidence that HeRs are a novel type of sensory rhodopsins linked to histidine kinases and other two-component system genes across phyla boundaries. In support of this, we also identify two novel putative signal transducing domains in HeRs that are fused with them. We also observe linkages of HeRs to genes involved in mitigation of light-induced oxidative stress and increased carbon and nitrogen metabolism. Finally, we synthesize these findings into a framework that connects HeRs with the cellular response to light in monoderms, activating light-induced oxidative stress defenses along with carbon/nitrogen metabolic circuitries. These findings are consistent with the evolutionary, taxonomic, structural, and genomic data available so far.
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60
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Stewart CF, Tomb RM, Ralston HJ, Armstrong J, Anderson JG, MacGregor SJ, Atreya CD, Maclean M. Violet-blue 405-nm Light-based Photoinactivation for Pathogen Reduction of Human Plasma Provides Broad Antibacterial Efficacy Without Visible Degradation of Plasma Proteins. Photochem Photobiol 2021; 98:504-512. [PMID: 34935147 DOI: 10.1111/php.13584] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/15/2021] [Indexed: 11/28/2022]
Abstract
In transfusion medicine, bacterial contamination can occur in ex vivo stored blood plasma, and there are continued efforts to improve blood safety and reduce the risk of transfusion-transmitted infections. Visible 405-nm violet-blue light has demonstrated potential for in situ pathogen reduction in ex vivo stored plasma and platelet concentrates. This study investigates the broad-spectrum antibacterial efficacy and compatibility potential of 405-nm light for treatment of blood plasma. Human plasma seeded with bacteria at a range of densities (101 -103 , 104 -106 , 107 -108 CFU mL-1 ) was exposed to 360 J cm-2 405-nm light (1 h at 0.1 W cm-2 ), with this fixed dose selected based on the initial analysis of inactivation kinetics. One-dimensional protein mobility analysis and measurement of advanced oxidation protein products (AOPP) was conducted to evaluate compatibility of the antimicrobial dose with plasma proteins and, identify upper levels at which protein degradation can be detected. Broad-spectrum antibacterial efficacy was observed with a fixed treatment of 360 J cm-2 , with 98.9-100% inactivation achieved across all seeding densities for all organisms, except E. coli, which achieved 95.1-100% inactivation. At this dose (360 J cm-2 ), no signs of protein degradation occurred. Overall, 405-nm light shows promise for broad-spectrum bacterial inactivation in blood plasma, while preserving plasma protein integrity.
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Affiliation(s)
- Caitlin F Stewart
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Rachael M Tomb
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Heather J Ralston
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Jack Armstrong
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - John G Anderson
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Scott J MacGregor
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Chintamani D Atreya
- Office of Blood Research and Review, Center for Biologics Evaluation and Research (CBER), Food and Drug Administration, Silver Spring, MD
| | - Michelle Maclean
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK.,Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
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The effect of a geometric-shaped tool with blue led light on the activation of human dermal fibroblasts and cancer cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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62
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Wang D, Kuzma ML, Tan X, He TC, Dong C, Liu Z, Yang J. Phototherapy and optical waveguides for the treatment of infection. Adv Drug Deliv Rev 2021; 179:114036. [PMID: 34740763 PMCID: PMC8665112 DOI: 10.1016/j.addr.2021.114036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/11/2021] [Accepted: 10/28/2021] [Indexed: 02/07/2023]
Abstract
With rapid emergence of multi-drug resistant microbes, it is imperative to seek alternative means for infection control. Optical waveguides are an auspicious delivery method for precise administration of phototherapy. Studies have shown that phototherapy is promising in fighting against a myriad of infectious pathogens (i.e. viruses, bacteria, fungi, and protozoa) including biofilm-forming species and drug-resistant strains while evading treatment resistance. When administered via optical waveguides, phototherapy can treat both superficial and deep-tissue infections while minimizing off-site effects that afflict conventional phototherapy and pharmacotherapy. Despite great therapeutic potential, exact mechanisms, materials, and fabrication designs to optimize this promising treatment option are underexplored. This review outlines principles and applications of phototherapy and optical waveguides for infection control. Research advances, challenges, and outlook regarding this delivery system are rigorously discussed in a hope to inspire future developments of optical waveguide-mediated phototherapy for the management of infection and beyond.
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Affiliation(s)
- Dingbowen Wang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Michelle Laurel Kuzma
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xinyu Tan
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA; Academy of Orthopedics, Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong Province 510280, China
| | - Tong-Chuan He
- Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA; Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Cheng Dong
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Zhiwen Liu
- Department of Electrical Engineering, Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
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63
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The role of UV and blue light in photo-eradication of microorganisms. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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64
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Courrol LC, Vallim MA. Characterization of chicken meat contaminated with Salmonella by fluorescence spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 261:119986. [PMID: 34126394 DOI: 10.1016/j.saa.2021.119986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 03/08/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
Contaminated poultry products as eggs and meat are the primary vehicles of Salmonella infection. Conventional methods for microorganisms detections involve multiple steps, and despite its accuracy, these assays are time-consuming. Biosensing methods have shown great potential for the rapid detection of foodborne pathogens. Some of the biosensors are based on fluorescence. Various fluorophores such as collagen, elastin, NAD(P)H, and porphyrins can be used to evaluate possible chemical changes in meat. In this manuscript, the fluorescence properties of chicken meat contaminated with Salmonella enterica (ATCC 14028) cell suspensions (500; 5000; 50,000 and 500,000 cells/mL) were obtained and compared with non-contaminated control, for meat kept at 25 °C for 24 and 48 h. The effects of ambient light were also considered. Our results indicated that free NAD(P)H and coproporphyrin emission bands present in contaminated meat, increased over time, and can provide access to valuable information for the detection of Salmonella in chicken meat.
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Affiliation(s)
- Lilia Coronato Courrol
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Department of Physics, Federal University of Sao Paulo, Diadema, Sao Paulo, Brazil.
| | - Marcelo Afonso Vallim
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Department of Biology, Federal University of Sao Paulo, Diadema, Sao Paulo, Brazil
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65
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Wang D, Nambu T, Tanimoto H, Iwata N, Yoshikawa K, Okinaga T, Yamamoto K. Interdental Plaque Microbial Community Changes under In Vitro Violet LED Irradiation. Antibiotics (Basel) 2021; 10:antibiotics10111348. [PMID: 34827286 PMCID: PMC8614803 DOI: 10.3390/antibiotics10111348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 12/23/2022] Open
Abstract
Oral microbiome dysbiosis has important links to human health and disease. Although photodynamic therapy influences microbiome diversity, the specific effect of violet light irradiation remains largely unknown. In this study, we analyzed the effect of violet light-emitting diode (LED) irradiation on interdental plaque microbiota. Interdental plaque was collected from 12 human subjects, exposed to violet LED irradiation, and cultured in a specialized growth medium. Next-generation sequencing of the 16S ribosomal RNA genes revealed that α-diversity decreased, whereas β-diversity exhibited a continuous change with violet LED irradiation doses. In addition, we identified several operational taxonomic units that exhibited significant shifts during violet LED irradiation. Specifically, violet LED irradiation led to a significant reduction in the relative abundance of Fusobacterium species, but a significant increase in several species of oral bacteria, such as Veillonella and Campylobacter. Our study provides an overview of oral plaque microbiota changes under violet LED irradiation, and highlights the potential of this method for adjusting the balance of the oral microbiome without inducing antibiotic resistance.
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Affiliation(s)
- Dan Wang
- Department of Operative Dentistry, Graduate School of Dentistry, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan;
| | - Takayuki Nambu
- Department of Bacteriology, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan
- Correspondence: (T.N.); (T.O.)
| | - Hiroaki Tanimoto
- Department of Operative Dentistry, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan; (H.T.); (N.I.); (K.Y.); (K.Y.)
| | - Naohiro Iwata
- Department of Operative Dentistry, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan; (H.T.); (N.I.); (K.Y.); (K.Y.)
| | - Kazushi Yoshikawa
- Department of Operative Dentistry, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan; (H.T.); (N.I.); (K.Y.); (K.Y.)
| | - Toshinori Okinaga
- Department of Bacteriology, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan
- Correspondence: (T.N.); (T.O.)
| | - Kazuyo Yamamoto
- Department of Operative Dentistry, Osaka Dental University, 8-1, Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan; (H.T.); (N.I.); (K.Y.); (K.Y.)
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De Santis R, Luca V, Näslund J, Ehmann RK, De Angelis M, Lundmark E, Nencioni L, Faggioni G, Fillo S, Amatore D, Regalbuto E, Molinari F, Petralito G, Wölfel R, Stefanelli P, Rezza G, Palamara AT, Antwerpen M, Forsman M, Lista F. Rapid inactivation of SARS-CoV-2 with LED irradiation of visible spectrum wavelengths. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021; 8:100082. [PMID: 34729540 PMCID: PMC8552801 DOI: 10.1016/j.jpap.2021.100082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 12/29/2022] Open
Abstract
Difficulty in controlling SARS-CoV-2 transmission made the ability to inactivate viruses in aerosols and fomites to be an important and attractive risk reduction measure. Evidence that light frequencies have the ability to inhibit microorganisms has already been reported by many studies which, however, focused on ultraviolet (UV) wavelengths, which are known to induce potential injury in humans. In the present study, the effect on suspensions of SARS-CoV-2 of a Light Emitting Diode (LED) device capable of radiating frequencies in the non-hazardous visible light spectrum (VIS) was investigated. In order to evaluate the efficiency of viral inactivation, plaque assay and western blot of viral proteins were performed. The observed results showed a significant reduction in infectious particles that had been exposed to the LED irradiation of visible light. Furthermore, the analysis of the intracellular expression of viral proteins confirmed the inactivating effect of this irradiation technology. This in vitro study revealed for the first time the inactivation of SARS-CoV-2 through LED irradiation with multiple wavelengths of the visible spectrum. However additional and more in-depth studies can aim to demonstrate the data obtained during these experiments in different matrices, in mutable environmental conditions and on other respiratory viruses such as the influenza virus. The type of LED technology can decisively contribute on reducing virus transmission through the continuous sanitation of common environments without risks for humans and animals.
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Affiliation(s)
| | - Vincenzo Luca
- Scientific Department, Army Medical Center, Rome, Italy.,7th CBRN Defence Regiment "Cremona", Civitavecchia, Italy
| | - Jonas Näslund
- Department of CBRN Protection and Security, Swedish Defence Research Agency (FOI), Umeå, Sweden
| | - Rosina K Ehmann
- Section Viral and Intracellular Pathogens, Bundeswehr Institute of Microbiology, Munich, Germany
| | - Marta De Angelis
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, "Sapienza" University of Rome, Italy
| | - Eva Lundmark
- Department of CBRN Protection and Security, Swedish Defence Research Agency (FOI), Umeå, Sweden
| | - Lucia Nencioni
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, "Sapienza" University of Rome, Italy
| | | | - Silvia Fillo
- Scientific Department, Army Medical Center, Rome, Italy
| | | | | | | | | | - Roman Wölfel
- Section Viral and Intracellular Pathogens, Bundeswehr Institute of Microbiology, Munich, Germany
| | - Paola Stefanelli
- Department of Infectious Disease, National Institute of Health, Rome, Italy
| | - Gianni Rezza
- Department of Infectious Disease, National Institute of Health, Rome, Italy
| | - Anna Teresa Palamara
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Pasteur Italia-Fondazione Cenci Bolognetti, "Sapienza" University of Rome, Italy
| | - Markus Antwerpen
- Section Viral and Intracellular Pathogens, Bundeswehr Institute of Microbiology, Munich, Germany
| | - Mats Forsman
- Department of CBRN Protection and Security, Swedish Defence Research Agency (FOI), Umeå, Sweden
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67
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Wang D, Kyere E, Ahmed Sadiq F. New Trends in Photodynamic Inactivation (PDI) Combating Biofilms in the Food Industry-A Review. Foods 2021; 10:2587. [PMID: 34828868 PMCID: PMC8621587 DOI: 10.3390/foods10112587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/19/2021] [Accepted: 10/22/2021] [Indexed: 12/26/2022] Open
Abstract
Biofilms cause problems in the food industry due to their persistence and incompetent hygiene processing technologies. Interest in photodynamic inactivation (PDI) for combating biofilms has increased in recent years. This technique can induce microbial cell death, reduce cell attachment, ruin biofilm biomolecules and eradicate structured biofilms without inducing microbial resistance. This review addresses microbial challenges posed by biofilms in food environments and highlights the advantages of PDI in preventing and eradicating microbial biofilm communities. Current findings of the antibiofilm efficiencies of this technique are summarized. Additionally, emphasis is given to its potential mechanisms and factors capable of influencing biofilm communities, as well as promising hurdle strategies.
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Affiliation(s)
- Dan Wang
- School of Food and Advanced Technology, Massey University, Palmerston North 4410, New Zealand;
| | - Emmanuel Kyere
- School of Food and Advanced Technology, Massey University, Palmerston North 4410, New Zealand;
| | - Faizan Ahmed Sadiq
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China;
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68
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NIR Irradiation Based on Low-Power LED Drive Module Design for Fat Reduction. BIOMED RESEARCH INTERNATIONAL 2021; 2021:9992095. [PMID: 34423044 PMCID: PMC8378979 DOI: 10.1155/2021/9992095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022]
Abstract
In this study, we designed a low-power visible ray (V) drive module based on a light-emitting diode (LED) to initiate fat reduction using light source irradiation. A chemical phantom of muscle and fat was fabricated, and the performance of the proposed LED drive module was tested using this chemical phantom. The LED light source could reduce fat by irradiating the skin 4–5 cm deep. The device exhibits a negative feedback and parallel amplification to maintain a stable circuit based on low-power consumption. Muscles have a high-water content and low impedance, whereas fats have a low water content and significant salt content. Therefore, fat exhibits high impedance. Chemical phantoms were fabricated according to these impedance values, and the fat reduction effect using the LED circuits was analyzed. When the fat phantom was irradiated by the light source, the fat impedance lowered, and we confirmed that fat reduction could be obtained. This study is expected to be applicable to family medicine and weight management health care.
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69
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Enwemeka CS, Bumah VV, Mokili JL. Pulsed blue light inactivates two strains of human coronavirus. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 222:112282. [PMID: 34404018 PMCID: PMC8349404 DOI: 10.1016/j.jphotobiol.2021.112282] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/01/2021] [Accepted: 08/06/2021] [Indexed: 01/29/2023]
Abstract
Emerging evidence suggests that blue light has the potential to inactivate viruses. Therefore, we investigated the effect of 405 nm, 410 nm, 425 nm and 450 nm pulsed blue light (PBL) on human alpha coronavirus HCoV-229 E and human beta coronavirus HCoV-OC43, using Qubit fluorometry and RT-LAMP to quantitate the amount of nucleic acid in irradiated and control samples. Like SARS-CoV-2, HCoV-229E and HCoV-OC43 are single stranded RNA viruses transmitted by air and direct contact; they have similar genomic sizes as SARS-CoV-2, and are used as surrogates for SARS-CoV-2. Irradiation was carried out either at 32.4 J cm-2 using 3 mW cm-2 irradiance or at 130 J cm-2 using 12 mW cm-2 irradiance. Results: (1) At each wavelength tested, PBL was antiviral against both coronaviruses. (2) 405 nm light gave the best result, yielding 52.3% (2.37 log10) inactivation against HCoV-OC43 (p < .0001), and a significant 1.46 log 10 (44%) inactivation of HCoV-229E (p < .01). HCoV-OC43, which like SARS-CoV-2 is a beta coronavirus, was more susceptible to PBL irradiation than alpha coronavirus HCoV-229E. The latter finding suggests that PBL is potentially antiviral against multiple coronavirus strains, and that, while its potency may vary from one virus to another, it seems more antiviral against beta coronaviruses, such as HCoV-OC43. (3) Further, the antiviral effect of PBL was better at a higher irradiance than a lower irradiance, and this indicates that with further refinement, a protocol capable of yielding 100% inactivation of viruses is attainable.
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Affiliation(s)
- Chukuka S Enwemeka
- College of Health and Human Services, San Diego State University, San Diego, CA, USA.
| | - Violet V Bumah
- College of Health and Human Services, San Diego State University, San Diego, CA, USA
| | - John L Mokili
- Viral Information Institute, Department of Biology, College of Sciences, San Diego State University, San Diego, CA, USA
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70
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Zhang Y, Xie J. Effects of 405 nm light‐emitting diode treatment on microbial community on fresh‐cut pakchoi and antimicrobial action against
Pseudomonas reinekei
and
Pseudomonas palleroniana. J Food Saf 2021. [DOI: 10.1111/jfs.12920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuchen Zhang
- College of Food Science and Technology Shanghai Ocean University Shanghai China
- National Experimental Teaching Demonstration Center for Food Science and Engineering Shanghai Ocean University Shanghai China
| | - Jing Xie
- College of Food Science and Technology Shanghai Ocean University Shanghai China
- National Experimental Teaching Demonstration Center for Food Science and Engineering Shanghai Ocean University Shanghai China
- Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation Shanghai China
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71
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Lotfali H, Meshkini A. Synthesis and characterization of lysozyme-conjugated Ag.ZnO@HA nanocomposite: A redox and pH-responsive antimicrobial agent with photocatalytic activity. Photodiagnosis Photodyn Ther 2021; 35:102418. [PMID: 34197967 DOI: 10.1016/j.pdpdt.2021.102418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/04/2021] [Accepted: 06/24/2021] [Indexed: 12/30/2022]
Abstract
Hydroxyapatite (HA) is extensively used for implantable device coating; however, it lacks antibacterial property, leading to potential bacterial infection during orthopedic implantation surgery. Herein, to enhance the antibacterial activity of HA, a redox- and pH-responsive HA nanocomposite with photocatalytic activity was designed. A photosensitive heterostructure, zinc oxide/hydroxyapatite (ZnO.HA), was coated with Ag nanoparticles (AgNPs) with assisted gallic acid using the UV-irradiation method. An antibacterial enzyme, lysozyme, was then conjugated on the surface of the nanocomposite by a cleavable disulfide linker, resulting in a redox-sensitive nanoplatform. In comparison with bare HA, the designed nanocomposites as Lyso.CAGZ@HA displayed much higher antibacterial activity (> 5-fold) toward Escherichia coli (E. coli) owing to the synergistic antibacterial effects of ZnONPs, AgNPs, gallic acid, and lysozyme on the surface of the nanocomposite. However, antibacterial and antifouling effects are much more enhanced in Lyso.CAGZ@HA-treated bacteria as they were subjected to UVA irradiation. Moreover, the cellular uptake of nanocomposite and intracellular glutathione depletion enhanced in the presence of UVA light, resulting in reactive oxygen specious generation enhancement. Further, in vitro cytotoxicity experiments on mammalian cells (human foreskin fibroblast) revealed that nanocomposite has no cytotoxic effects. Hence, this study demonstrated that Lyso.CAGZ@HA could be considered as a potential therapeutic approach against bacterial infectious diseases.
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Affiliation(s)
- Hanieh Lotfali
- Biochemical Research center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P. O. Box 9177948974, Mashhad, Iran
| | - Azadeh Meshkini
- Biochemical Research center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P. O. Box 9177948974, Mashhad, Iran; Novel Diagnostics and Therapeutics Research Group, Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran.
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72
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Effect of Photosensitization Mediated by Curcumin on Carotenoid and Aflatoxin Content in Different Maize Varieties. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11135902] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Mycotoxins are naturally occurring toxins produced by certain types of fungi that contaminate food and feed, posing serious health risks to human and livestock. This study evaluated the combination of blue light with curcumin to inactivate Aspergillus flavus spores, its effect on aflatoxin B1 (AFB1) production and maintaining carotenoid content in three maize varieties. The study was first conducted in vitro, and the spore suspensions (104 CFU·mL−1) were treated with four curcumin concentrations (25 and 50 µM in ethanol, 1000 and 1250 µM in propylene glycol) and illuminated at different light doses from 0 to 130.3 J·cm−2. The photoinactivation efficiency was light-dose dependent with the highest photoinactivation of 2.3 log CFU·mL−1 achieved using 1000 µM curcumin at 104.2 J·cm−2. Scanning electron microscopy revealed cell wall deformations as well as less density in photosensitized cells. Photosensitization of maize kernels gave rise to a complete reduction in the viability of A. flavus and therefore inhibition of AFB1 production, while no significant (p > 0.05) effect was observed using either light or curcumin. Moreover, photosensitization did not affect the carotenoids in all the studied maize varieties. The results suggest that photosensitization is a green alternative preservation technique to decontaminate maize kernels and reduce consumer exposure to AFB1 without any effect on carotenoid content.
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73
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Antibacterial mechanism of riboflavin-mediated 460 nm light emitting diode illumination against Listeria monocytogenes in phosphate-buffered saline and on smoked salmon. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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74
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Hyun JE, Moon SK, Lee SY. Antibacterial activity and mechanism of 460–470 nm light-emitting diodes against pathogenic bacteria and spoilage bacteria at different temperatures. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107721] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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75
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Raza S, Matuła K, Karoń S, Paczesny J. Resistance and Adaptation of Bacteria to Non-Antibiotic Antibacterial Agents: Physical Stressors, Nanoparticles, and Bacteriophages. Antibiotics (Basel) 2021; 10:435. [PMID: 33924618 PMCID: PMC8070485 DOI: 10.3390/antibiotics10040435] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/02/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial resistance is a significant threat to human health worldwide, forcing scientists to explore non-traditional antibacterial agents to support rapid interventions and combat the emergence and spread of drug resistant bacteria. Many new antibiotic-free approaches are being developed while the old ones are being revised, resulting in creating unique solutions that arise at the interface of physics, nanotechnology, and microbiology. Specifically, physical factors (e.g., pressure, temperature, UV light) are increasingly used for industrial sterilization. Nanoparticles (unmodified or in combination with toxic compounds) are also applied to circumvent in vivo drug resistance mechanisms in bacteria. Recently, bacteriophage-based treatments are also gaining momentum due to their high bactericidal activity and specificity. Although the number of novel approaches for tackling the antimicrobial resistance crisis is snowballing, it is still unclear if any proposed solutions would provide a long-term remedy. This review aims to provide a detailed overview of how bacteria acquire resistance against these non-antibiotic factors. We also discuss innate bacterial defense systems and how bacteriophages have evolved to tackle them.
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Affiliation(s)
| | | | | | - Jan Paczesny
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland; (S.R.); (K.M.); (S.K.)
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76
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Galo IDC, Prado RP, Santos WGD. Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth. BRAZ J BIOL 2021; 82:e231742. [PMID: 33787710 DOI: 10.1590/1519-6984.231742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 07/29/2020] [Indexed: 01/21/2023] Open
Abstract
The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm2, 13.19 mW/cm2 and 603.44 J/cm2, 27.93 mW/cm2 respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.
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Affiliation(s)
- I D C Galo
- Universidade Federal de Jataí - UFJ, Laboratório de Genética e Biologia Molecular, Programa de Pós-graduação em Ciências Aplicadas à Saúde, Jataí, GO, Brasil
| | - R P Prado
- Universidade Federal de Catalão - UFCAT, Departamento de Medicina, Catalão, GO, Brasil
| | - W G Dos Santos
- Universidade Federal de Jataí - UFJ, Laboratório de Genética e Biologia Molecular, Programa de Pós-graduação em Ciências Aplicadas à Saúde, Jataí, GO, Brasil
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77
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Hoenes K, Bauer R, Spellerberg B, Hessling M. Microbial Photoinactivation by Visible Light Results in Limited Loss of Membrane Integrity. Antibiotics (Basel) 2021; 10:341. [PMID: 33807025 PMCID: PMC8005082 DOI: 10.3390/antibiotics10030341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/15/2021] [Accepted: 03/17/2021] [Indexed: 01/07/2023] Open
Abstract
Interest in visible light irradiation as a microbial inactivation method has widely increased due to multiple possible applications. Resistance development is considered unlikely, because of the multi-target mechanism, based on the induction of reactive oxygen species by wavelength specific photosensitizers. However, the affected targets are still not completely identified. We investigated membrane integrity with the fluorescence staining kit LIVE/DEAD® BacLight™ on a Gram positive and a Gram negative bacterial species, irradiating Staphylococcus carnosus and Pseudomonas fluorescens with 405 nm and 450 nm. To exclude the generation of viable but nonculturable (VBNC) bacterial cells, we applied an ATP test, measuring the loss of vitality. Pronounced uptake of propidium iodide was only observed in Pseudomonas fluorescens at 405 nm. Transmission electron micrographs revealed no obvious differences between irradiated samples and controls, especially no indication of an increased bacterial cell lysis could be observed. Based on our results and previous literature, we suggest that visible light photoinactivation does not lead to rapid bacterial cell lysis or disruption. However, functional loss of membrane integrity due to depolarization or inactivation of membrane proteins may occur. Decomposition of the bacterial envelope following cell death might be responsible for observations of intracellular component leakage.
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Affiliation(s)
- Katharina Hoenes
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, 89081 Ulm, Germany;
| | - Richard Bauer
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, 89081 Ulm, Germany; (R.B.); (B.S.)
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, 89081 Ulm, Germany; (R.B.); (B.S.)
| | - Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, 89081 Ulm, Germany;
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78
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Photoinactivation of Staphylococci with 405 nm Light in a Trachea Model with Saliva Substitute at 37 °C. Healthcare (Basel) 2021; 9:healthcare9030310. [PMID: 33799642 PMCID: PMC7998829 DOI: 10.3390/healthcare9030310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/28/2021] [Accepted: 03/04/2021] [Indexed: 02/03/2023] Open
Abstract
The globally observed rise in bacterial resistance against antibiotics has increased the need for alternatives to antibiotic treatments. The most prominent and important pathogen bacteria are the ESKAPE pathogens, which include among others Staphylococcus aureus, Klebsiella pneumoniae and Acinetobacter baumannii. These species cause ventilator-associated pneumonia (VAP), which accounts for 24% of all nosocomial infections. In this study we tested the efficacy of photoinactivation with 405 nm violet light under conditions comparable to an intubated patient with artificial saliva for bacterial suspension at 37 °C. A technical trachea model was developed to investigate the visible light photoinactivation of Staphylococcus carnosus as a non-pathogen surrogate of the ESKAPE pathogen S. aureus (MRSA). The violet light was coupled into the tube with a fiber optic setup. The performed tests proved, that photoinactivation at 37 °C is more effective with a reduction of almost 3 log levels (99.8%) compared to 25 °C with a reduction of 1.2 log levels. The substitution of phosphate buffered saline (PBS) by artificial saliva solution slightly increased the efficiency during the experimental course. The increased efficiency might be caused by a less favorable environment for bacteria due to for example the ionic composition.
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79
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Kim DK, Kang DH. Efficacy of light-emitting diodes emitting 395, 405, 415, and 425 nm blue light for bacterial inactivation and the microbicidal mechanism. Food Res Int 2021; 141:110105. [PMID: 33641972 DOI: 10.1016/j.foodres.2021.110105] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/15/2020] [Accepted: 01/02/2021] [Indexed: 11/18/2022]
Abstract
We investigated the bactericidal effects against Escherichia coli O157:H7 of light-emitting diodes (LEDs) emitting blue light of four different peak wavelengths ranging from 395 to 425 nm in water. Furthermore, we investigated inactivation in the presence of reactive oxygen species (ROS) scavengers to elucidate the contribution of bacterial inactivation. An aluminum chamber was constructed and coated in carbon to block exterior light, and a single blue light LED with a rear heat sink was attached to the chamber lid. Effective inactivation of the pathogen was observed for all blue light LED irradiation at 305, 405, 415, and 425 nm. The log-linear with shoulder and tail model and log-linear model described the survival of the bacteria after blue light LED treatments. Not just the effects of ROS but also photophysical effects were shown with the addition of mannitol, a ROS scavenger. The integrity of the cell membrane was damaged regardless of the presence of ROS, which indicates that photophysical effects were sufficient to induce damage to the cell membrane. In addition, activity of succinate-coenzyme Q reductase, which participates in respiratory metabolism to generate energy, decreased in the absence of ROS and decreased further in the presence of ROS.
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Affiliation(s)
- Do-Kyun Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong-Hyun Kang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, Republic of Korea.
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80
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Wang Z, Han L, Liu J, Yao M. Refrigeration temperature enhanced synergistic interaction of curcumin and 460 nm light-emitting diode against Staphylococcus saprophyticus at neutral pH. FOOD QUALITY AND SAFETY 2021. [DOI: 10.1093/fqsafe/fyaa029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Objectives
As considered highly resistant to antibiotics like mecillinam, the rise of Staphylococcus saprophyticus (S. saprophyticus) contamination of fresh foods and food processing environments necessitates the development of a new antimicrobial approach for food safety control. This study aimed to investigate the synergistic effect of food-grade curcumin (CUR) and blue light-emitting diode (LED) on S. saprophyticus.
Materials and Methods
S. saprophyticus was subjected to the synergistic treatment at 4 and 25 °C. The influence of parameters, including CUR concentration, light dose, and pH incubation time on the inactivation of S. saprophyticus was characterized through plate counting method.
Results:
The combined treatment of CUR and blue light irradiation significantly (P < 0.05) reduced bacterial counts and the antimicrobial effect was in a CUR concentration and light dose-dependent manner. Moreover, refrigeration temperature (4 °C) significantly (P < 0.05) enhanced the antibacterial effect at neutral pH condition (6.2–7.2), resulting in approximately 6.0 log reductions. Under acidic condition (pH 2.2–5.2), there was no significant difference in bacterial population reduction between treatments at both temperatures.
Conclusions
These findings proposed that synergistic interaction of CUR and 460 nm LED under refrigerated temperature could enhance the inactivation of S. saprophyticus at neutral pH condition.
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81
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Bhavya ML, Shewale SR, Rajoriya D, Hebbar HU. Impact of Blue LED Illumination and Natural Photosensitizer on Bacterial Pathogens, Enzyme Activity and Quality Attributes of Fresh-Cut Pineapple Slices. FOOD BIOPROCESS TECH 2021. [DOI: 10.1007/s11947-021-02581-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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82
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Hoenes K, Bauer R, Meurle T, Spellerberg B, Hessling M. Inactivation Effect of Violet and Blue Light on ESKAPE Pathogens and Closely Related Non-pathogenic Bacterial Species - A Promising Tool Against Antibiotic-Sensitive and Antibiotic-Resistant Microorganisms. Front Microbiol 2021; 11:612367. [PMID: 33519770 PMCID: PMC7838345 DOI: 10.3389/fmicb.2020.612367] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/11/2020] [Indexed: 01/20/2023] Open
Abstract
Due to the globally observed increase in antibiotic resistance of bacterial pathogens and the simultaneous decline in new antibiotic developments, the need for alternative inactivation approaches is growing. This is especially true for the treatment of infections with the problematic ESKAPE pathogens, which include Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, and often exhibit multiple antibiotic resistances. Irradiation with visible light from the violet and blue spectral range is an inactivation approach that does not require any additional supplements. Multiple bacterial and fungal species were demonstrated to be sensitive to this disinfection technique. In the present study, pathogenic ESKAPE organisms and non-pathogenic relatives are irradiated with visible blue and violet light with wavelengths of 450 and 405 nm, respectively. The irradiation experiments are performed at 37°C to test a potential application for medical treatment. For all investigated microorganisms and both wavelengths, a decrease in colony forming units is observed with increasing irradiation dose, although there are differences between the examined bacterial species. A pronounced difference can be observed between Acinetobacter, which prove to be particularly light sensitive, and enterococci, which need higher irradiation doses for inactivation. Differences between pathogenic and non-pathogenic bacteria of one genus are comparatively small, with the tendency of non-pathogenic representatives being less susceptible. Visible light irradiation is therefore a promising approach to inactivate ESKAPE pathogens with future fields of application in prevention and therapy.
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Affiliation(s)
- Katharina Hoenes
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
| | - Richard Bauer
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, Germany
| | - Tobias Meurle
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, Germany
| | - Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
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83
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Oliveira M, Tiwari BK, Duffy G. Emerging Technologies for Aerial Decontamination of Food Storage Environments to Eliminate Microbial Cross-Contamination. Foods 2020; 9:E1779. [PMID: 33266230 PMCID: PMC7759774 DOI: 10.3390/foods9121779] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 01/07/2023] Open
Abstract
Air is recognized as an important source of microbial contamination in food production facilities and has the potential to contaminate the food product causing food safety and spoilage issues for the food industry. Potential for aerial microbial contamination of food can be a particular issue during storage in cold rooms when the food is not packaged and is exposed to contaminated air over a prolonged period. Thus, there are potential benefits for the food industry for an aerial decontamination in cold storage facilities. In this paper, aerial decontamination approaches are reviewed and challenges encountered for their applications are discussed. It is considered that current systems may not be completely effective and environmentally friendly, therefore, it is of great significance to consider the development of nonresidual and verified decontamination technologies for the food industry and, in particular, for the cold storage rooms.
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Affiliation(s)
- Márcia Oliveira
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Ashtown, D15 KN3K Dublin, Ireland;
| | - Brijesh K. Tiwari
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Ashtown, D15 KN3K Dublin, Ireland;
| | - Geraldine Duffy
- Food Safety Department, Teagasc Food Research Centre, Ashtown, D15 KN3K Dublin, Ireland;
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84
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Jankowska KI, Nagarkatti R, Acharyya N, Dahiya N, Stewart CF, Macpherson RW, Wilson MP, Anderson JG, MacGregor SJ, Maclean M, Dey N, Debrabant A, Atreya CD. Complete Inactivation of Blood Borne Pathogen Trypanosoma cruzi in Stored Human Platelet Concentrates and Plasma Treated With 405 nm Violet-Blue Light. Front Med (Lausanne) 2020; 7:617373. [PMID: 33330577 PMCID: PMC7732587 DOI: 10.3389/fmed.2020.617373] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/02/2020] [Indexed: 12/05/2022] Open
Abstract
The introduction of pathogen reduction technologies (PRTs) to inactivate bacteria, viruses and parasites in donated blood components stored for transfusion adds to the existing arsenal toward reducing the risk of transfusion-transmitted infectious diseases (TTIDs). We have previously demonstrated that 405 nm violet-blue light effectively reduces blood-borne bacteria in stored human plasma and platelet concentrates. In this report, we investigated the microbicidal effect of 405 nm light on one important bloodborne parasite Trypanosoma cruzi that causes Chagas disease in humans. Our results demonstrated that a light irradiance at 15 mWcm−2 for 5 h, equivalent to 270 Jcm−2, effectively inactivated T. cruzi by over 9.0 Log10, in plasma and platelets that were evaluated by a MK2 cell infectivity assay. Giemsa stained T. cruzi infected MK2 cells showed that the light-treated parasites in plasma and platelets were deficient in infecting MK2 cells and did not differentiate further into intracellular amastigotes unlike the untreated parasites. The light-treated and untreated parasite samples were then evaluated for any residual infectivity by injecting the treated parasites into Swiss Webster mice, which did not develop infection even after the animals were immunosuppressed, further demonstrating that the light treatment was completely effective for inactivation of the parasite; the light-treated platelets had similar in vitro metabolic and biochemical indices to that of untreated platelets. Overall, these results provide a proof of concept toward developing 405 nm light treatment as a pathogen reduction technology (PRT) to enhance the safety of stored human plasma and platelet concentrates from bloodborne T. cruzi, which causes Chagas disease.
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Affiliation(s)
- Katarzyna I Jankowska
- Laboratory of Cellular Hematology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Rana Nagarkatti
- Laboratory of Emerging Pathogens, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Nirmallya Acharyya
- Laboratory of Emerging Pathogens, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Neetu Dahiya
- Laboratory of Cellular Hematology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Caitlin F Stewart
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Ruairidh W Macpherson
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Mark P Wilson
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - John G Anderson
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Scott J MacGregor
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Michelle Maclean
- The Robertson Trust Laboratory for Electronic Sterilization Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom.,Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom
| | - Neil Dey
- Canary, Inc., Acton, MA, United States
| | - Alain Debrabant
- Laboratory of Emerging Pathogens, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Chintamani D Atreya
- Laboratory of Cellular Hematology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
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85
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Hyun JE, Choi C, Lee SY. Synergistic effects of blue light-emitting diodes in combination with antimicrobials against Escherichia coli O157:H7 and their mode of action. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 213:112079. [PMID: 33202366 DOI: 10.1016/j.jphotobiol.2020.112079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/21/2020] [Accepted: 11/07/2020] [Indexed: 12/25/2022]
Abstract
This study was conducted to evaluate the antibacterial effect of 460-470 nm light-emitting diodes illumination (460/470 LED) combined with various antimicrobials at inactivating Escherichia coli O157:H7 and identify the antibacterial mechanisms. When carvacrol, thymol, citric acid, malic acid, citrus fruit extract, 3% NaCl, or 5% NaCl was combined with 460/470 LED, there was a higher reduction in E. coli O157:H7 compared to 460/470 LED treatment or antimicrobials alone at 4 °C. Particularly, a marked synergistic effect (>8.74 log10 CFU/ml) was observed when 460/470 LED was combined with carvacrol, malic acid, citrus fruit extract, or 3% NaCl. Levels of intracellular ROS and lipid peroxidation of E. coli O157:H7 were higher in the combination of 460/470 LED and antimicrobials compared to individual treatments. Moreover, the combination treatment increased depolarization of the cell membrane leading to membrane damage as well as the loss of DNA integrity. Thus, adding antimicrobial treatment to 460/470 LED could improve its efficacy against pathogenic bacteria such as E. coli O157:H7.
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Affiliation(s)
- Jeong-Eun Hyun
- Department of Food and Nutrition, Chung-Ang University, Anseong-si, Gyeonggi-do, Republic of Korea
| | - Changsun Choi
- Department of Food and Nutrition, Chung-Ang University, Anseong-si, Gyeonggi-do, Republic of Korea
| | - Sun-Young Lee
- Department of Food and Nutrition, Chung-Ang University, Anseong-si, Gyeonggi-do, Republic of Korea.
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86
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Hyun JE, Lee SY. Blue light-emitting diodes as eco-friendly non-thermal technology in food preservation. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2020.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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87
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Angarano V, Akkermans S, Smet C, Chieffi A, Van Impe JF. The potential of violet, blue, green and red light for the inactivation of P. fluorescens as planktonic cells, individual cells on a surface and biofilms. FOOD AND BIOPRODUCTS PROCESSING 2020. [DOI: 10.1016/j.fbp.2020.07.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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88
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Zhang L, Li Y, Zhang Q, Du N, Li X, Zhang Q, Yuan L, Dong F, Jiang Y, Tang J, Wang Y. Antimicrobial Activity of an Implantable Wireless Blue Light-Emitting Diode Against Root Canal Biofilm In Vitro. PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY 2020; 38:694-702. [PMID: 33103954 DOI: 10.1089/photob.2020.4821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Objective: We developed an implantable wireless blue micro light-emitting diode (micro-LED) device and evaluated the utility of continuous antimicrobial blue light (aBL) irradiation emitted from this micro-LED for root canal disinfection. Methods: An implantable wireless blue micro-LED device (peak wavelength: 410 nm, maximum power: 15 mW) was developed to be placed in the root canal. Optical transmission of the device in human dentin tissue was simulated using Monte Carlo ray-tracing method. The bactericidal effect of low-level aBL on planktonic root canal infection-related bacteria [Enterococcus faecalis, methicillin-resistant Streptococcus aureus (MRSA), and Prevotella intermedia] was evaluated by colony counting. The biocompatibility of continuous low-level aBL exposure was evaluated by infrared thermal imaging and cell viability tests. Thirty extracted intact human single-rooted teeth were prepared and the root canals were infected with E. faecalis for 14 days to form biofilm. The infected root canals were randomly divided into three groups (n = 10), and treated with normal saline (group NS), calcium hydroxide (group CH), and micro-LED device (group aBL) for 3 and 7 days. The bactericidal effect of each group was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Results: Monte Carlo simulation showed that blue light irradiation of the micro-LED device decreased exponentially with the light transmission distance through human dentin tissue. Planktonic E. faecalis, MRSA, and P. intermedia were significantly eliminated after irradiation with 432, 36, and 1.35 J/cm2 aBL, respectively (p < 0.05). Infrared thermal imaging and cell viability tests showed that continuous aBL exposure is biocompatible in vitro. CLSM and SEM analyses revealed that the micro-LED device had a greater antimicrobial effect than CH on E. faecalis biofilm in the root canal. Conclusions: The wireless blue micro-LED device is a promising and user-friendly approach for root canal disinfection that will facilitate infection control in the root canal using aBL.
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Affiliation(s)
- Ludan Zhang
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,NHC Key Laboratory of Digital Technology of Stomatology, Peking University, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China
| | - Yamin Li
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qian Zhang
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China
| | - Ning Du
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xuefen Li
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China
| | - Qianyi Zhang
- School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Lintian Yuan
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,NHC Key Laboratory of Digital Technology of Stomatology, Peking University, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China
| | - Fan Dong
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,NHC Key Laboratory of Digital Technology of Stomatology, Peking University, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China
| | - Yuxi Jiang
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,NHC Key Laboratory of Digital Technology of Stomatology, Peking University, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China
| | - Jun Tang
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yuguang Wang
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,NHC Key Laboratory of Digital Technology of Stomatology, Peking University, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University, Beijing, China.,National Clinical Research Center for Oral Diseases, Beijing, China
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89
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Kong D, Zhao W, Ma Y, Liang H, Zhao X. Effects of light‐emitting diode illumination on the quality of fresh‐cut cherry tomatoes during refrigerated storage. Int J Food Sci Technol 2020. [DOI: 10.1111/ijfs.14836] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Dehui Kong
- Food Science and Engineering College Beijing University of Agriculture Beijing100096China
- Vegetable Research Center Beijing Academy of Agriculture and Forestry Sciences Beijing Key Laboratory of Agricultural Products of Fruits and Vegetables Preservation and Processing Key Laboratory of Vegetable Postharvest Processing Ministry of Agriculture and Rural Affairs Beijing100097China
| | - Wenting Zhao
- Vegetable Research Center Beijing Academy of Agriculture and Forestry Sciences Beijing Key Laboratory of Agricultural Products of Fruits and Vegetables Preservation and Processing Key Laboratory of Vegetable Postharvest Processing Ministry of Agriculture and Rural Affairs Beijing100097China
| | - Yue Ma
- Vegetable Research Center Beijing Academy of Agriculture and Forestry Sciences Beijing Key Laboratory of Agricultural Products of Fruits and Vegetables Preservation and Processing Key Laboratory of Vegetable Postharvest Processing Ministry of Agriculture and Rural Affairs Beijing100097China
| | - Hao Liang
- Longda Food Group Company Limited Shandong265231China
| | - Xiaoyan Zhao
- Food Science and Engineering College Beijing University of Agriculture Beijing100096China
- Vegetable Research Center Beijing Academy of Agriculture and Forestry Sciences Beijing Key Laboratory of Agricultural Products of Fruits and Vegetables Preservation and Processing Key Laboratory of Vegetable Postharvest Processing Ministry of Agriculture and Rural Affairs Beijing100097China
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90
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Kasparova EA, Yang B, Bocharova YA, Novikov IA. [Application of visible longwave radiation for inactivation of microorganisms]. Vestn Oftalmol 2020; 136:42-49. [PMID: 33084278 DOI: 10.17116/oftalma202013606142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To perform a comparative assessment of the bactericidal and fungicidal effects of various parts of the radiation spectrum (Ultraviolet A, red, green and blue). MATERIAL AND METHODS The study included strains of the most clinically significant microorganisms, which are the most common causes of purulent keratitis - S. aureus, P. aeruginosa and fungi C. albicans. After populating the surface of Petri dishes uniformly with microorganisms of each culture, on four out of the five specimens the central zone of the surface with a diameter of 1 cm was irradiated with light of different spectrum - from ultraviolet to red, with a total radiation energy density of 5.4 J/cm2. One specimen remained as the control subject. After irradiation, scanning electron microscopy with lanthanides contrasting (SEMLC) was used to evaluate the total metabolic activity, the activity of the efflux systems and the morphological characteristics of the microorganisms. RESULTS The damaging effect of visible spectrum light and UVA radiation on S. aureus, P. aeruginosa and C. albicans cultures was proved by SEMLC. Green spectrum emission with a wavelength of 500 nm had the highest antimicrobial activity. It was manifested by a decrease in the overall level of metabolic activity (from 40-63 c.u. to 26-37 c.u. (S. aureus (p<0.01), P. aeruginosa (p<0.01) and C. albicans (p<0.05)), as well as a 2-fold increase in the proportion of S. aureus cells with active efflux systems. CONCLUSION SEMLC allows evaluation of parameters of the microorganisms` state: morphological (form and size) and functional (general metabolic activity, activation of efflux systems). Investigation of S. aureus, P. aeruginosa and C. albicans cultures using SEMLC demonstrated the antimicrobial activity of green spectrum radiation of 500 nm wavelength. This will serve as a basis for further research and development of a method of treating infectious keratitis using green light.
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Affiliation(s)
| | - Biao Yang
- Research Institute of Eye Diseases, Moscow, Russia
| | - Yu A Bocharova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - I A Novikov
- Research Institute of Eye Diseases, Moscow, Russia
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91
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Hessling M, Wenzel U, Meurle T, Spellerberg B, Hönes K. Photoinactivation results of Enterococcus moraviensis with blue and violet light suggest the involvement of an unconsidered photosensitizer. Biochem Biophys Res Commun 2020; 533:813-817. [PMID: 32993958 DOI: 10.1016/j.bbrc.2020.09.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 09/21/2020] [Indexed: 12/23/2022]
Abstract
Microorganisms can be photoinactivated with 405 and 450 nm irradiation, due to endogenous photosensitizers, which absorb light of these wavelengths and generate reactive oxygen species that destroy the cells from within. The photosensitizers assumed to be responsible are porphyrins in the spectral region around 405 nm and flavins at about 450 nm. The aim of this study was to investigate this hypothesis on enterococci, considering that they do not contain porphyrins. In photoinactivation experiments with Enterococcus moraviensis, 405 nm and 450 nm irradiation both led to a reduction of the bacterial concentration by several orders of magnitude with 405 nm irradiation being much more efficient. The measurement and analysis of the fluorescence spectra revealed no signs of porphyrins whereas flavins seemed to be rapidly converted to lumichrome by 405 nm radiation. Therefore, probably none of the usual suspects, porphyrins and flavins, was responsible for the photoinactivation of Enterococcus moraviensis during 405 nm irradiation. Fluorescence experiments revealed the spectra of lumichrome and NADH, which are both known photosensitizers. Presumably, one of them or both were actually involved here. As NADH and flavins (and therefore their photodegradation product lumichrome) are abundant in all microorganisms, they are probably also involved in 405 nm photoinactivation processes of other species.
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Affiliation(s)
- Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, 89081, Germany.
| | - Ulla Wenzel
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, 89081, Germany
| | - Tobias Meurle
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, 89081, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, 89081, Germany
| | - Katharina Hönes
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, 89081, Germany
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92
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Enhancement of Contact Lens Disinfection by Combining Disinfectant with Visible Light Irradiation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176422. [PMID: 32899295 PMCID: PMC7504152 DOI: 10.3390/ijerph17176422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 01/05/2023]
Abstract
Multiple use contact lenses have to be disinfected overnight to reduce the risk of infections. However, several studies demonstrated that not only microorganisms are affected by the disinfectants, but also ocular epithelial cells, which come into contact via residuals at reinsertion of the lens. Visible light has been demonstrated to achieve an inactivation effect on several bacterial and fungal species. Combinations with other disinfection methods often showed better results compared to separately applied methods. We therefore investigated contact lens disinfection solutions combined with 405 nm irradiation, with the intention to reduce the disinfectant concentration of ReNu Multiplus, OptiFree Express or AOSept while maintaining adequate disinfection results due to combination benefits. Pseudomonads, staphylococci and E. coli were studied with disk diffusion assay, colony forming unit (cfu) determination and growth delay. A log reduction of 4.49 was achieved for P. fluorescens in 2 h for 40% ReNu Multiplus combined with an irradiation intensity of 20 mW/cm2 at 405 nm. For AOSept the combination effect was so strong that 5% of AOSept in combination with light exhibited the same result as 100% AOSept alone. Combination of disinfectants with visible violet light is therefore considered a promising approach, as a reduction of potentially toxic ingredients can be achieved.
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93
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Sicks B, Hönes K, Spellerberg B, Hessling M. Blue LEDs in Endotracheal Tubes May Prevent Ventilator-Associated Pneumonia. PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY 2020. [DOI: 10.1089/photob.2020.4842] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Ben Sicks
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
| | - Katharina Hönes
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, Germany
| | - Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
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94
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Ahmed E, El-Gendy AO, Moniem Radi NA, Mohamed T. The bactericidal efficacy of femtosecond laser-based therapy on the most common infectious bacterial pathogens in chronic wounds: an in vitro study. Lasers Med Sci 2020; 36:641-647. [PMID: 32725427 DOI: 10.1007/s10103-020-03104-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/22/2020] [Indexed: 12/29/2022]
Abstract
We investigated the influence of femtosecond laser irradiation on the growth of the two most common infectious bacterial pathogens in wounds; Staphylococcus aureus and Pseudomonas aeruginosa as an attempt to validate optimum parameters for a laser-based bactericidal modality to be used clinically. Bacterial cultures were exposed to femtosecond laser irradiation at different wavelengths, exposure times, and laser powers. The source of femtosecond laser was INSPIRE HF100 laser system, Spectra-Physics, which is pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP, Spectra-Physics. After irradiation, bacterial cells' survival was monitored by observing the clear zones of inhibition in cultured agar plates. Results for all strains indicated that the exposure to femtosecond laser irradiation with a wavelength ranging from ultraviolet (λ > 350 nm) to blue laser light (λ < 480 nm), for a period above 20 min and with a power density of ≈ 0.063 W/cm2, was enough to inhibit both bacterial pathogens with the results maintained for 1 week following irradiation.
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Affiliation(s)
- Esraa Ahmed
- Laser Institute for Research and Applications LIRA, Beni-Suef University, Beni-Suef, 62511, Egypt
| | - Ahmed O El-Gendy
- Laser Institute for Research and Applications LIRA, Beni-Suef University, Beni-Suef, 62511, Egypt.,Faculty of Pharmacy, Department of Microbiology and Immunology, Beni-Suef University, Beni-Suef, 62514, Egypt
| | - Naglaa A Moniem Radi
- Faculty of Medicine, Department of Microbiology and Immunology, Beni-Suef University, Beni-Suef, 62514, Egypt
| | - Tarek Mohamed
- Laser Institute for Research and Applications LIRA, Beni-Suef University, Beni-Suef, 62511, Egypt.
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95
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Rhee KY, Chawla R, Lele PP. Protein expression-independent response of intensity-based pH-sensitive fluorophores in Escherichia coli. PLoS One 2020; 15:e0234849. [PMID: 32555627 PMCID: PMC7302705 DOI: 10.1371/journal.pone.0234849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 12/02/2022] Open
Abstract
Fluorescent proteins that modulate their emission intensities when protonated serve as excellent probes of the cytosolic pH. Since the total fluorescence output fluctuates significantly due to variations in the fluorophore levels in cells, eliminating the dependence of the signal on protein concentration is crucial. This is typically accomplished with the aid of ratiometric fluorescent proteins such as pHluorin. However, pHluorin is excited by blue light, which can complicate pH measurements by adversely impacting bacterial physiology. Here, we characterized the response of intensity-based, pH-sensitive fluorescent proteins that excite at longer wavelengths where the blue light effect is diminished. The pH-response was interpreted in terms of an analytical model that assumed two emission states for each fluorophore: a low intensity protonated state and a high intensity deprotonated state. The model suggested a scaling to eliminate the dependence of the signal on the expression levels as well as on the illumination and photon-detection settings. Experiments successfully confirmed the scaling predictions. Thus, the internal pH can be readily determined with intensity-based fluorophores with appropriate calibrations irrespective of the fluorophore concentration and the signal acquisition setup. The framework developed in this work improves the robustness of intensity-based fluorophores for internal pH measurements in E. coli, potentially extending their applications.
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Affiliation(s)
- Kathy Y. Rhee
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Ravi Chawla
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Pushkar P. Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
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96
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Yeor-Davidi E, Zverzhinetsky M, Krivitsky V, Patolsky F. Real-time monitoring of bacterial biofilms metabolic activity by a redox-reactive nanosensors array. J Nanobiotechnology 2020; 18:81. [PMID: 32448291 PMCID: PMC7247256 DOI: 10.1186/s12951-020-00637-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/16/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bacterial biofilms are communities of surface-associated microorganisms living in cellular clusters or micro-colonies, encapsulated in a complex matrix composed of an extracellular polymeric substance, separated by open water channels that act as a circulatory system that enable better diffusion of nutrients and easier removal of metabolic waste products. The monitoring of biofilms can provide important information on fundamental biofilm-related processes. That information can shed light on the bacterial processes and enable scientists to find ways of preventing future bacterial infections. Various approaches in use for biofilm analysis are based on microscopic, spectrochemical, electrochemical, and piezoelectrical methods. All these methods provide significant progress in understanding the bio-process related to biofilm formation and eradication, nevertheless, the development of novel approaches for the real-time monitoring of biochemical, in particular metabolic activity, of bacterial species during the formation, life and eradication of biofilms is of great potential importance. RESULTS Here, detection and monitoring of the metabolic activity of bacterial biofilms in high-ionic-strength solutions were enabled as a result of novel surface modification by an active redox system, composed of 9,10-dihydroxyanthracene/9,10-anthraquinone, on the oxide layer of the SiNW, yielding a chemically-gated FET array. With the use of enzymatic reactions of oxidases, metabolites can be converted to H2O2 and monitored by the nanosensors. Here, the successful detection of glucose metabolites in high-ionic-strength solutions, such as bacterial media, without pre-processing of small volume samples under different conditions and treatments, has been demonstrated. The biofilms were treated with antibiotics differing in their mechanisms of action and were compared to untreated biofilms. Further examination of biofilms under antibiotic treatment with SiNW-FET devices could shed light on the bioprocess that occurs within the biofilm. Moreover, finding proper treatment that eliminates the biofilm could be examined by the novel nanosensor as a monitoring tool. CONCLUSIONS To summarize, the combination of redox-reactive SiNW-FET devices with micro-fluidic techniques enables the performance of rapid, automated, and real-time metabolite detection with the use of minimal sample size, noninvasively and label-free. This novel platform can be used as an extremely sensitive tool for detection and establishing medical solutions for bacterial-biofilm eradication and for finding a proper treatment to eliminate biofilm contaminations. Moreover, the sensing system can be used as a research tool for further understanding of the metabolic processes that occur within the bacterial biofilm population.
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Affiliation(s)
- Ella Yeor-Davidi
- School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Marina Zverzhinetsky
- School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Vadim Krivitsky
- School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.
| | - Fernando Patolsky
- School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman, Faculty of Engineering, Tel Aviv University, 69978, Tel Aviv, Israel.
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97
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Enwemeka CS, Bumah VV, Masson-Meyers DS. Light as a potential treatment for pandemic coronavirus infections: A perspective. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 207:111891. [PMID: 32388486 PMCID: PMC7194064 DOI: 10.1016/j.jphotobiol.2020.111891] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022]
Abstract
The recent outbreak of COVID-19, which continues to ravage communities with high death tolls and untold psychosocial and catastrophic economic consequences, is a vivid reminder of nature's capacity to defy contemporary healthcare. The pandemic calls for rapid mobilization of every potential clinical tool, including phototherapy—one of the most effective treatments used to reduce the impact of the 1918 “Spanish influenza” pandemic. This paper cites several studies showing that phototherapy has immense potential to reduce the impact of coronavirus diseases, and offers suggested ways that the healthcare industry can integrate modern light technologies in the fight against COVID-19 and other infections. The evidence shows that violet/blue (400–470 nm) light is antimicrobial against numerous bacteria, and that it accounts for Niels Ryberg Finsen's Nobel-winning treatment of tuberculosis. Further evidence shows that blue light inactivates several viruses, including the common flu coronavirus, and that in experimental animals, red and near infrared light reduce respiratory disorders, similar to those complications associated with coronavirus infection. Moreover, in patients, red light has been shown to alleviate chronic obstructive lung disease and bronchial asthma. These findings call for urgent efforts to further explore the clinical value of light, and not wait for another pandemic to serve as a reminder. The ubiquity of inexpensive light emitting lasers and light emitting diodes (LEDs), makes it relatively easy to develop safe low-cost light-based devices with the potential to reduce infections, sanitize equipment, hospital facilities, emergency care vehicles, homes, and the general environment as pilot studies have shown.
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Affiliation(s)
- Chukuka Samuel Enwemeka
- College of Health and Human Services, San Diego State University, 5500 Campanile Dr, San Diego, CA 92182, USA.
| | - Violet Vakunseh Bumah
- College of Health and Human Services, San Diego State University, 5500 Campanile Dr, San Diego, CA 92182, USA; Department of Chemistry and Biochemistry, College of Sciences, 5500 Campanile Dr, San Diego, CA 92182, USA.
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98
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Angarano V, Smet C, Akkermans S, Watt C, Chieffi A, Van Impe JF. Visible Light as an Antimicrobial Strategy for Inactivation of Pseudomonas fluorescens and Staphylococcus epidermidis Biofilms. Antibiotics (Basel) 2020; 9:E171. [PMID: 32290162 PMCID: PMC7235755 DOI: 10.3390/antibiotics9040171] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
The increase of antimicrobial resistance is challenging the scientific community to find solutions to eradicate bacteria, specifically biofilms. Light-Emitting Diodes (LED) represent an alternative way to tackle this problem in the presence of endogenous or exogenous photosensitizers. This work adds to a growing body of research on photodynamic inactivation using visible light against biofilms. Violet (400 nm), blue (420 nm), green (570 nm), yellow (584 nm) and red (698 nm) LEDs were used against Pseudomonas fluorescens and Staphylococcus epidermidis. Biofilms, grown on a polystyrene surface, were irradiated for 4 h. Different irradiance levels were investigated (2.5%, 25%, 50% and 100% of the maximum irradiance). Surviving cells were quantified and the inactivation kinetic parameters were estimated. Violet light could successfully inactivate P. fluorescens and S. epidermidis (up to 6.80 and 3.69 log10 reduction, respectively), while blue light was effective only against P. fluorescens (100% of maximum irradiance). Green, yellow and red irradiation neither increased nor reduced the biofilm cell density. This is the first research to test five different wavelengths (each with three intensities) in the visible spectrum against Gram-positive and Gram-negative biofilms. It provides a detailed study of the potential of visible light against biofilms of a different Gram-nature.
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Affiliation(s)
- Valeria Angarano
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Cindy Smet
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Simen Akkermans
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Charlotte Watt
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Andre Chieffi
- Procter & Gamble, Newcastle Innovation Center, Newcastle NE12 9TS, UK;
| | - Jan F.M. Van Impe
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
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99
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Turner ER, Luo Y, Buchanan RL. Microgreen nutrition, food safety, and shelf life: A review. J Food Sci 2020; 85:870-882. [PMID: 32144769 DOI: 10.1111/1750-3841.15049] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 11/15/2019] [Accepted: 12/16/2019] [Indexed: 02/02/2023]
Abstract
Microgreens have gained increasing popularity as food ingredients in recent years because of their high nutritional value and diverse sensorial characteristics. Microgreens are edible seedlings including vegetables and herbs, which have been used, primarily in the restaurant industry, to embellish cuisine since 1996. The rapidly growing microgreen industry faces many challenges. Microgreens share many characteristics with sprouts, and while they have not been associated with any foodborne illness outbreaks, they have recently been the subject of seven recalls. Thus, the potential to carry foodborne pathogens is there, and steps can and should be taken during production to reduce the likelihood of such incidents. One major limitation to the growth of the microgreen industry is the rapid quality deterioration that occurs soon after harvest, which keeps prices high and restricts commerce to local sales. Once harvested, microgreens easily dehydrate, wilt, decay and rapidly lose certain nutrients. Research has explored preharvest and postharvest interventions, such as calcium treatments, modified atmopsphere packaging, temperature control, and light, to maintain quality, augment nutritional value, and extend shelf life. However, more work is needed to optimize both production and storage conditions to improve the safety, quality, and shelf life of microgreens, thereby expanding potential markets.
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Affiliation(s)
- Ellen R Turner
- Food Quality Laboratory, Agricultural Research Service, U.S. Dept. of Agriculture, Beltsville, MD, 20705, U.S.A.,Environmental Microbiology and Food Safety Laboratory, Agricultural Research Service, U.S. Dept. of Agriculture, Beltsville, MD, 20705, U.S.A.,Dept. of Nutrition and Food Science, Univ. of Maryland, College Park, MD, 20740, U.S.A
| | - Yaguang Luo
- Food Quality Laboratory, Agricultural Research Service, U.S. Dept. of Agriculture, Beltsville, MD, 20705, U.S.A.,Environmental Microbiology and Food Safety Laboratory, Agricultural Research Service, U.S. Dept. of Agriculture, Beltsville, MD, 20705, U.S.A
| | - Robert L Buchanan
- Dept. of Nutrition and Food Science, Univ. of Maryland, College Park, MD, 20740, U.S.A.,Center for Food Safety and Security Systems, Univ. of Maryland, College Park, MD, 20742, U.S.A
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Huang J, Chen B, Li H, Zeng QH, Wang JJ, Liu H, Pan Y, Zhao Y. Enhanced antibacterial and antibiofilm functions of the curcumin-mediated photodynamic inactivation against Listeria monocytogenes. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106886] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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