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Harris DM, Sulewski JG. Photoinactivation and Photoablation of Porphyromonas gingivalis. Pathogens 2023; 12:1160. [PMID: 37764967 PMCID: PMC10535405 DOI: 10.3390/pathogens12091160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/31/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023] Open
Abstract
Several types of phototherapy target human pathogens and Porphyromonas gingivitis (Pg) in particular. The various approaches can be organized into five different treatment modes sorted by different power densities, interaction times, effective wavelengths and mechanisms of action. Mode 1: antimicrobial ultraviolet (aUV); mode 2: antimicrobial blue light (aBL); mode 3: antimicrobial selective photothermolysis (aSP); mode 4: antimicrobial vaporization; mode 5: antimicrobial photodynamic therapy (aPDT). This report reviews the literature to identify for each mode (a) the putative molecular mechanism of action; (b) the effective wavelength range and penetration depth; (c) selectivity; (d) in vitro outcomes; and (e) clinical trial/study outcomes as these elements apply to Porphyromonas gingivalis (Pg). The characteristics of each mode influence how each is translated into the clinic.
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Affiliation(s)
- David M. Harris
- Bio-Medical Consultants, Inc., Canandaigua, NY 14424, USA
- Department of Periodontics, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - John G. Sulewski
- Institute for Advanced Dental Technologies, Huntington Woods, MI 48070, USA
- Millennium Dental Technologies, Inc., Cerritos, CA 90703, USA
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Sinclair LG, Dougall LR, Ilieva Z, McKenzie K, Anderson JG, MacGregor SJ, Maclean M. Laboratory evaluation of the broad-spectrum antibacterial efficacy of a low-irradiance visible 405-nm light system for surface-simulated decontamination. HEALTH AND TECHNOLOGY 2023; 13:1-15. [PMID: 37363345 PMCID: PMC10264887 DOI: 10.1007/s12553-023-00761-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023]
Abstract
Purpose Lighting systems which use visible light blended with antimicrobial 405-nm violet-blue light have recently been developed for safe continuous decontamination of occupied healthcare environments. This paper characterises the optical output and antibacterial efficacy of a low irradiance 405-nm light system designed for environmental decontamination applications, under controlled laboratory conditions. Methods In the current study, the irradiance output of a ceiling-mounted 405-nm light source was profiled within a 3×3×2 m (18 m3) test area; with values ranging from 0.001-2.016 mWcm-2. To evaluate antibacterial efficacy of the light source for environmental surface decontamination, irradiance levels within this range (0.021-1 mWcm-2) at various angular (Δ ϴ=0-51.3) and linear (∆s=1.6-2.56 m) displacements from the source were used to generate inactivation kinetics, using the model organism, Staphylococcus aureus. Additionally, twelve bacterial species were surface-seeded and light-exposed at a fixed displacement below the source (1.5 m; 0.5 mWcm-2) to demonstrate broad-spectrum efficacy at heights typical of high touch surfaces within occupied settings. Results Results demonstrate that significant (P≤0.05) inactivation was successfully achieved at all irradiance values investigated, with spatial positioning from the source affecting inactivation, with greater times required for inactivation as irradiance decreased. Complete/near-complete (≥93.28%) inactivation of all bacteria was achieved following exposure to 0.5 mWcm-2 within exposure times realistic of those utilised practically for whole-room decontamination (2-16 h). Conclusion This study provides fundamental evidence of the efficacy, and energy efficiency, of low irradiance 405-nm light for bacterial inactivation within a controlled laboratory setting, further justifying its benefits for practical infection control applications.
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Affiliation(s)
- Lucy G Sinclair
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Laura R Dougall
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Zornitsa Ilieva
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Karen McKenzie
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - John G Anderson
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Scott J MacGregor
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Michelle Maclean
- The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic & Electrical Engineering, University of Strathclyde, Glasgow, UK
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
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Kuratli J, Leonard CA, Frohns A, Schoborg R, Piazena H, Borel N. Refinement of water-filtered infrared A (wIRA) irradiations of in vitro acute and persistent chlamydial infections. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 234:112533. [PMID: 35914465 DOI: 10.1016/j.jphotobiol.2022.112533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/23/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Water-filtered infrared A (wIRA) alone or in combination with visible light (VIS) exerts anti-chlamydial effects in vitro and in vivo in acute infection models. However, it has remained unclear whether reduced irradiation duration and irradiance would still maintain anti-chlamydial efficacy. Furthermore, efficacy of this non-chemical treatment option against persistent (chronic) chlamydial infections has not been investigated to date. To address this knowledge gap, we evaluated 1) irradiation durations of 5, 15 or 30 min in genital and ocular Chlamydia trachomatis acute infection models, 2) irradiances of 100, 150 or 200 mW/cm2 in the acute genital infection model and 3) anti-chlamydial activity of wIRA and VIS against C. trachomatis serovar B and E with amoxicillin (AMX)- or interferon γ (IFN-γ)-induced persistence. Reduction of irradiation duration reduced anti-chlamydial efficacy. Irradiances of 150 to 200 mW/cm2, but not 100 mW/cm2, induced anti-chlamydial effects. For persistent infections, wIRA and VIS irradiation showed robust anti-chlamydial activity independent of the infection status (persistent or recovering), persistence inducer (AMX or IFN-γ) or chlamydial strain (serovar B or E). This study clarifies the requirement of 30 min irradiation duration and 150 mW/cm2 irradiance to induce significant anti-chlamydial effects in vitro, supports the use of irradiation in the wIRA and VIS spectrum as a promising non-chemical treatment for chlamydial infections and provides important information for follow-up in vivo studies. Notably, wIRA and VIS exert anti-chlamydial effects on persistent chlamydiae which are known to be refractory to antibiotic treatment.
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Affiliation(s)
- Jasmin Kuratli
- Institute of Veterinary Pathology (IVPZ) and Center for Applied Biotechnology and Molecular Medicine (CABMM), Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 268, 8057 Zürich, Switzerland; Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Mittelstrasse 43, 3012 Bern, Switzerland.
| | - Cory Ann Leonard
- Institute of Veterinary Pathology (IVPZ) and Center for Applied Biotechnology and Molecular Medicine (CABMM), Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 268, 8057 Zürich, Switzerland.
| | - Antonia Frohns
- Plant membrane biophysics, Technical University of Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany
| | - Robert Schoborg
- Department of Medical Education and Center for Infectious Disease, Inflammation and Immunity, Quillen College in Medicine, East Tennessee State University, PO Box 70582, Johnson City, TN 37614, USA.
| | - Helmut Piazena
- Department of Anaesthesiology and Operative Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Corporative Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.
| | - Nicole Borel
- Institute of Veterinary Pathology (IVPZ) and Center for Applied Biotechnology and Molecular Medicine (CABMM), Vetsuisse Faculty, University of Zürich, Winterthurerstrasse 268, 8057 Zürich, Switzerland.
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Wang Y, Wang Y, Wang Y, Murray CK, Hamblin MR, Hooper DC, Dai T. Antimicrobial blue light inactivation of pathogenic microbes: State of the art. Drug Resist Updat 2017; 33-35:1-22. [PMID: 29145971 DOI: 10.1016/j.drup.2017.10.002] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/28/2017] [Accepted: 10/02/2017] [Indexed: 12/20/2022]
Abstract
As an innovative non-antibiotic approach, antimicrobial blue light in the spectrum of 400-470nm has demonstrated its intrinsic antimicrobial properties resulting from the presence of endogenous photosensitizing chromophores in pathogenic microbes and, subsequently, its promise as a counteracter of antibiotic resistance. Since we published our last review of antimicrobial blue light in 2012, there have been a substantial number of new studies reported in this area. Here we provide an updated overview of the findings from the new studies over the past 5 years, including the efficacy of antimicrobial blue light inactivation of different microbes, its mechanism of action, synergism of antimicrobial blue light with other angents, its effect on host cells and tissues, the potential development of resistance to antimicrobial blue light by microbes, and a novel interstitial delivery approach of antimicrobial blue light. The potential new applications of antimicrobial blue light are also discussed.
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Affiliation(s)
- Yucheng Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Cancer Center, Aviation General Hospital, Beijing, China; Department of Medical Oncology, Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, China
| | - Ying Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Laser Medicine, Chinese PLA General Hospital, Beijing, China
| | - Yuguang Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Center of Digital Dentistry, School and Hospital of Stomatology, Peking University, Beijing, China
| | - Clinton K Murray
- Infectious Disease Service, San Antonio Military Medical Center, JBSA-Fort Sam Houston, TX, USA
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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Leonard CA, Schoborg RV, Borel N. Productive and Penicillin-Stressed Chlamydia pecorum Infection Induces Nuclear Factor Kappa B Activation and Interleukin-6 Secretion In Vitro. Front Cell Infect Microbiol 2017; 7:180. [PMID: 28553623 PMCID: PMC5425588 DOI: 10.3389/fcimb.2017.00180] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/25/2017] [Indexed: 11/13/2022] Open
Abstract
Nuclear factor kappa B (NFκB) is an inflammatory transcription factor that plays an important role in the host immune response to infection. The potential for chlamydiae to activate NFκB has been an area of interest, however most work has focused on chlamydiae impacting human health. Given that inflammation characteristic of chlamydial infection may be associated with severe disease outcomes or contribute to poor overall fitness in farmed animals, we evaluated the ability of porcine chlamydiae to induce NFκB activation in vitro. C. pecorum infection induced both NFκB nuclear translocation and activation at 2 hours post infection (hpi), an effect strongly enhanced by suppression of host de novo protein synthesis. C. suis and C. trachomatis showed less capacity for NFκB activation compared to C. pecorum, suggesting a species-specific variation in NFκB activation. At 24 hpi, C. pecorum induced significant NFκB activation, an effect not abolished by penicillin (beta lactam)-induced chlamydial stress. C. pecorum-dependent secretion of interleukin 6 was also detected in the culture supernatant of infected cells at 24 hpi, and this effect, too, was unchanged by penicillin-induced chlamydial stress. Taken together, these results suggest that NFκB participates in the early inflammatory response to C. pecorum and that stressed chlamydiae can promote inflammation.
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Affiliation(s)
- Cory A Leonard
- Department of Pathobiology, Institute of Veterinary Pathology, University of ZurichZurich, Switzerland
| | - Robert V Schoborg
- Department of Biomedical Sciences, Center for Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State UniversityJohnson City, TN, USA
| | - Nicole Borel
- Department of Pathobiology, Institute of Veterinary Pathology, University of ZurichZurich, Switzerland
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Biener G, Masson-Meyers DS, Bumah VV, Hussey G, Stoneman MR, Enwemeka CS, Raicu V. Blue/violet laser inactivates methicillin-resistant Staphylococcus aureus by altering its transmembrane potential. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 170:118-124. [DOI: 10.1016/j.jphotobiol.2017.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/21/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022]
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Sommers C, Gunther NW, Sheen S. Inactivation of Salmonella spp., pathogenic Escherichia coli, Staphylococcus spp., or Listeria monocytogenes in chicken purge or skin using a 405-nm LED array. Food Microbiol 2016; 64:135-138. [PMID: 28213017 DOI: 10.1016/j.fm.2016.12.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 10/28/2016] [Accepted: 12/20/2016] [Indexed: 12/28/2022]
Abstract
Raw poultry are sometimes contaminated with foodborne pathogens, which can lead to illness in humans. In recent years research has focused on a variety of light technologies to decontaminate food and food contact surfaces during meat and poultry processing. In this study we evaluated the ability of 405-nm light generated from an LED array to inactivate multi-isolate cocktails of either Salmonella spp., pathogenic Escherichia coli, Staphylococcus spp., or Listeria monocytogenes suspended in chicken purge or skin. When exposed to 180 J/cm2 405-nm light at two separate light intensities (300 mW/cm2/s or 150 mW/cm2/s) the maximum pathogen reduction on chicken skin was ca. 0.4 log. When the pathogens were suspended in chicken purge the maximum log reductions ranged from 0.23 to 0.68 log (180 J/cm2; 150 mW/cm2/s) versus 0.69 to 1.01 log (180 J/cm2; 300 mW/cm2/s). Log reductions of each pathogen, when they were subjected to heat shock prior to 405-nm light treatment, were reduced, indicating that thermal effects accounted for much of the bacterial inactivation.
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Affiliation(s)
- Christopher Sommers
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
| | - Nereus W Gunther
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
| | - Shiowshuh Sheen
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
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Skwor TA, Klemm S, Zhang H, Schardt B, Blaszczyk S, Bork MA. Photodynamic inactivation of methicillin-resistant Staphylococcus aureus and Escherichia coli: A metalloporphyrin comparison. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 165:51-57. [DOI: 10.1016/j.jphotobiol.2016.10.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 12/18/2022]
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A New Proof of Concept in Bacterial Reduction: Antimicrobial Action of Violet-Blue Light (405 nm) in Ex Vivo Stored Plasma. JOURNAL OF BLOOD TRANSFUSION 2016; 2016:2920514. [PMID: 27774337 PMCID: PMC5059568 DOI: 10.1155/2016/2920514] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/28/2016] [Indexed: 11/17/2022]
Abstract
Bacterial contamination of injectable stored biological fluids such as blood plasma and platelet concentrates preserved in plasma at room temperature is a major health risk. Current pathogen reduction technologies (PRT) rely on the use of chemicals and/or ultraviolet light, which affects product quality and can be associated with adverse events in recipients. 405 nm violet-blue light is antibacterial without the use of photosensitizers and can be applied at levels safe for human exposure, making it of potential interest for decontamination of biological fluids such as plasma. As a pilot study to test whether 405 nm light is capable of inactivating bacteria in biological fluids, rabbit plasma and human plasma were seeded with bacteria and treated with a 405 nm light emitting diode (LED) exposure system (patent pending). Inactivation was achieved in all tested samples, ranging from low volumes to prebagged plasma. 99.9% reduction of low density bacterial populations (≤103 CFU mL−1), selected to represent typical “natural” contamination levels, was achieved using doses of 144 Jcm−2. The penetrability of 405 nm light, permitting decontamination of prebagged plasma, and the nonrequirement for photosensitizing agents provide a new proof of concept in bacterial reduction in biological fluids, especially injectable fluids relevant to transfusion medicine.
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Gunther NW, Phillips JG, Sommers C. The Effects of 405-nm Visible Light on the Survival of Campylobacter on Chicken Skin and Stainless Steel. Foodborne Pathog Dis 2016; 13:245-50. [DOI: 10.1089/fpd.2015.2084] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Nereus W. Gunther
- Molecular Characterization of Foodborne Pathogens Research Unit, Eastern Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania
| | - John G. Phillips
- Agricultural Research Service–Retired, Eastern Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania
| | - Christopher Sommers
- Food Safety and Intervention Technologies Research Unit, Eastern Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania
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Marti H, Blenn C, Borel N. The contribution of temperature, exposure intensity and visible light to the inhibitory effect of irradiation on acute chlamydial infection. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 153:324-33. [PMID: 26513384 DOI: 10.1016/j.jphotobiol.2015.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 10/02/2015] [Accepted: 10/15/2015] [Indexed: 01/05/2023]
Abstract
Water-filtered infrared A (wIRA) is radiation with a spectrum ranging from 780 to 1400 nm. Chlamydiaceae are obligate intracellular bacteria associated with various diseases in both animals and humans. A recent in vitro study demonstrated that wIRA combined with visible light (wIRA/VIS) has potential as a non-chemical method for the treatment of chlamydial infections without adversely affecting the cell viability. The aim of this study was to investigate the influence of various factors on the effect of wIRA/VIS on acute chlamydial infection, namely the impact of temperature, exposure intensity and infectious dose (multiplicity of infection) as well as the efficacy of the visible light component.We demonstrate that non-thermal effects contribute to the inhibition of acute chlamydial infection. Visible light enhances the inhibitory effect of wIRA on extracellular bacteria (elementary bodies or EBs).Moreover, the inhibitory effect of wIRA/VIS following treatment of EBs prior to infection correlated with increased irradiation intensity. The infectivity of mature chlamydial inclusions was significantly reduced upon wIRA/VIS exposure at all irradiation intensities investigated, suggesting the contribution of host cell factors to the anti-chlamydial effect of wIRA/VIS in the late stage of the developmental cycle. The effect of irradiation was not influenced by the infectious dose.
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Affiliation(s)
- Hanna Marti
- Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse, 268, 8057, Zurich, Switzerland.
| | - Christian Blenn
- Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse, 268, 8057, Zurich, Switzerland.
| | - Nicole Borel
- Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse, 268, 8057, Zurich, Switzerland.
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Bumah VV, Masson-Meyers DS, Cashin S, Enwemeka CS. Optimization of the antimicrobial effect of blue light on methicillin-resistant Staphylococcus aureus (MRSA) in vitro. Lasers Surg Med 2015; 47:266-72. [PMID: 25639752 DOI: 10.1002/lsm.22327] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND OBJECTIVE In previous studies, we showed that irradiation with 405 nm or 470 nm light suppresses up to 92% methicillin-resistant Staphylococcus aureus (MRSA) growth in vitro and that the remaining bacteria re-colonize. In this study, the aim was to develop a protocol that yields 100% MRSA growth suppression. MATERIALS AND METHODS We cultured 3 × 10(6) and 5 × 10(6) CFU/ml USA300 strain of MRSA and then irradiated each plate with varying fluences of 1-60 J/cm2 of 405 nm or 470 nm light, either once or twice at 6 hours intervals. Next, we plated 7 × 10(6) CFU/ml and irradiated it with 45, 50, 55, or 60 J/cm2 fluence, once, twice, or thrice at the same 6 hours intervals. In a third experiment, the same culture density was irradiated with 0, 165, 180, 220, or 240 J/cm(2) , either once, twice, or thrice. RESULTS Irradiation with either wavelength significantly reduced the bacterial colonies regardless of bacterial density (P < 0.05). At 3 × 10(6) CFU/ml density, nearly 40% and 50% growth of MRSA were suppressed with as little as 3 J/cm2 of 405 nm and 470 nm wavelengths, respectively. Moreover, 100% of the colonies were suppressed with a single exposure to 55 or 60 J/cm2 of 470 nm light or double treatment with 50, 55, or 60 J/cm2 of 405 nm wavelength. At 5 × 10(6) CFU/ml density, irradiating twice with 50, 55, or 60 J/cm2 of either wavelength suppressed bacterial growth completely, lower fluences did not. The denser 7 × 10(6) CFU/ml culture required higher doses to achieve 100% suppression, either one shot with 220 J/cm2 of 470 nm light or two shots of the same dose using 405 nm. CONCLUSION The bactericidal effect of blue light can be optimized to yield 100% bacterial growth suppression, but with relatively high fluences for dense bacterial cultures, such as 7 × 10(6) CFU/ml.
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Affiliation(s)
- Violet V Bumah
- College of Health Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, 53211
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Maclean M, McKenzie K, Anderson J, Gettinby G, MacGregor S. 405 nm light technology for the inactivation of pathogens and its potential role for environmental disinfection and infection control. J Hosp Infect 2014; 88:1-11. [DOI: 10.1016/j.jhin.2014.06.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 06/17/2014] [Indexed: 01/22/2023]
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Marti H, Koschwanez M, Pesch T, Blenn C, Borel N. Water-filtered infrared a irradiation in combination with visible light inhibits acute chlamydial infection. PLoS One 2014; 9:e102239. [PMID: 25019934 PMCID: PMC4096919 DOI: 10.1371/journal.pone.0102239] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 06/17/2014] [Indexed: 11/19/2022] Open
Abstract
New therapeutic strategies are needed to overcome drawbacks in treatment of infections with intracellular bacteria. Chlamydiaceae are Gram-negative bacteria implicated in acute and chronic diseases such as abortion in animals and trachoma in humans. Water-filtered infrared A (wIRA) is short wavelength infrared radiation with a spectrum ranging from 780 to 1400 nm. In clinical settings, wIRA alone and in combination with visible light (VIS) has proven its efficacy in acute and chronic wound healing processes. This is the first study to demonstrate that wIRA irradiation combined with VIS (wIRA/VIS) diminishes recovery of infectious elementary bodies (EBs) of both intra- and extracellular Chlamydia (C.) in two different cell lines (Vero, HeLa) regardless of the chlamydial strain (C. pecorum, C. trachomatis serovar E) as shown by indirect immunofluorescence and titration by subpassage. Moreover, a single exposure to wIRA/VIS at 40 hours post infection (hpi) led to a significant reduction of C. pecorum inclusion frequency in Vero cells and C. trachomatis in HeLa cells, respectively. A triple dose of irradiation (24, 36, 40 hpi) during the course of C. trachomatis infection further reduced chlamydial inclusion frequency in HeLa cells without inducing the chlamydial persistence/stress response, as ascertained by electron microscopy. Irradiation of host cells (HeLa, Vero) neither affected cell viability nor induced any molecular markers of cytotoxicity as investigated by Alamar blue assay and Western blot analysis. Chlamydial infection, irradiation, and the combination of both showed a similar release pattern of a subset of pro-inflammatory cytokines (MIF/GIF, Serpin E1, RANTES, IL-6, IL-8) and chemokines (IL-16, IP-10, ENA-78, MIG, MIP-1α/β) from host cells. Initial investigation into the mechanism indicated possible thermal effects on Chlamydia due to irradiation. In summary, we demonstrate a non-chemical reduction of chlamydial infection using the combination of water-filtered infrared A and visible light.
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Affiliation(s)
- Hanna Marti
- Institute of Veterinary Pathology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Maria Koschwanez
- Institute of Veterinary Pathology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Theresa Pesch
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Christian Blenn
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Nicole Borel
- Institute of Veterinary Pathology, University of Zurich-Vetsuisse, Zurich, Switzerland
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McKenzie K, Maclean M, Timoshkin IV, Endarko E, MacGregor SJ, Anderson JG. Photoinactivation of bacteria attached to glass and acrylic surfaces by 405 nm light: potential application for biofilm decontamination. Photochem Photobiol 2013; 89:927-35. [PMID: 23550978 DOI: 10.1111/php.12077] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 03/25/2013] [Indexed: 11/30/2022]
Abstract
Attachment of bacteria to surfaces and subsequent biofilm formation remains a major cause of cross-contamination capable of inducing both food-related illness and nosocomial infections. Resistance to many current disinfection technologies means facilitating their removal is often difficult. The aim of this study was to investigate the efficacy of 405 nm light for inactivation of bacterial attached as biofilms to glass and acrylic. Escherichia coli biofilms (10(3)-10(8) CFU mL(-1)) were generated on glass and acrylic surfaces and exposed for increasing times to 405 nm light (5-60 min) at ca 140 mW cm(-2). Successful inactivation of biofilms has been demonstrated, with results highlighting complete/near-complete inactivation (up to 5 log10 reduction on acrylic and 7 log10 on glass). Results also highlight that inactivation of bacterial biofilms could be achieved whether the biofilm was on the upper "directly exposed" surface or "indirectly exposed" underside surface. Statistically significant inactivation was also shown with a range of other microorganisms associated with biofilm formation (Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes). Results from this study have demonstrated significant inactivation of bacteria ranging from monolayers to densely populated biofilms using 405 nm light, highlighting that with further development this technology may have potential applications for biofilm decontamination in food and clinical settings.
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Affiliation(s)
- Karen McKenzie
- Department of Electronic and Electrical Engineering, ROLEST, University of Strathclyde, Glasgow, Scotland.
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