405 nm light technology for the inactivation of pathogens and its potential role for environmental disinfection and infection control

Maclean, Michelle; McKenzie, Karen; Anderson, John G.; Gettinby, G.; MacGregor, S.J.

doi:10.1016/j.jhin.2014.06.004

Cited by 122 publications

(110 citation statements)

References 76 publications

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“…Visible light has been explored as an antimicrobial treatment in numerous studies, with effectiveness demonstrated against a diverse range of medically important bacteria and fungi (for reviews, see references [22][23][24]. In most cases, high-intensity violet-blue light (405 nm) has been used (25)(26)(27)(28).…”

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confidence: 99%

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799

O'Donoghue

NicAogáin

Bennett

et al. 2016

Appl Environ Microbiol

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Listeria monocytogenes senses blue light via the flavin mononucleotide-containing sensory protein Lmo0799, leading to activation of the general stress response sigma factor SigB ( B ). In this study, we investigated the physiological response of this foodborne pathogen to blue light. We show that blue light (460 to 470 nm) doses of 1.5 to 2 mW cm ؊2 cause inhibition of growth on agar-based and liquid culture media. The inhibitory effects are dependent on cell density, with reduced effects evident when high cell numbers are present. The addition of 20 mM dimethylthiourea, a scavenger of reactive oxygen species, or catalase to the medium reverses the inhibitory effects of blue light, suggesting that growth inhibition is mediated by the formation of reactive oxygen species. A mutant strain lacking B (⌬sigB) was found to be less inhibited by blue light than the wild type, likely indicating the energetic cost of deploying the general stress response. When a lethal dose of light (8 mW cm ؊2 ) was applied to cells, the ⌬sigB mutant displayed a marked increase in sensitivity to light compared to the wild type. To investigate the role of the bluelight sensor Lmo0799, mutants were constructed that either had a deletion of the gene (⌬lmo0799) or alteration in a conserved cysteine residue at position 56, which is predicted to play a pivotal role in the photocycle of the protein (lmo0799 C56A). Both mutants displayed phenotypes similar to the ⌬sigB mutant in the presence of blue light, providing genetic evidence that residue 56 is critical for light sensing in L. monocytogenes. Taken together, these results demonstrate that L. monocytogenes is inhibited by blue light in a manner that depends on reactive oxygen species, and they demonstrate clear light-dependent phenotypes associated with B and the blue-light sensor Lmo0799. IMPORTANCEListeria monocytogenes is a bacterial foodborne pathogen that can cause life-threatening infections in humans. It is known to be able to sense and respond to visible light. In this study, we examine the effects of blue light on the growth and survival of this pathogen. We show that growth can be inhibited at comparatively low doses of blue light, and that at higher doses, L. monocytogenes cells are killed. We present evidence suggesting that blue light inhibits this organism by causing the production of reactive oxygen species, such as hydrogen peroxide. We help clarify the mechanism of light sensing by constructing a "blind" version of the blue-light sensor protein. Finally, we show that activation of the general stress response by light has a negative effect on growth, probably because cellular resources are diverted into protective mechanisms rather than growth.

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confidence: 99%

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799

O'Donoghue

NicAogáin

Bennett

et al. 2016

Appl Environ Microbiol

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“…The high-intensity narrow-spectrum (HINS) light environmental decontamination system (EDS) is a visible light based system which uses low-irradiance violet-blue light, focused on 405nm, to provide continuous environmental decontamination, a technology that was recently reviewed [56]. Unlike, UVC and chemical-based systems, the EDS is designed for use in occupied environments, providing continuous decontamination of the air and all exposed surfaces in occupied environments.…”

Section: Nm Violet-blue Lightmentioning

confidence: 99%

Decontamination of the Hospital Environment: New Technologies for Infection Control

Maclean

McKenzie

Moorhead

et al. 2015

Curr Treat Options Infect Dis

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“…6 Blue light has been reported to have significant antimicrobial activity against a broad range of bacterial and fungal pathogens. 6,7 The rate of emergence of antibiotic resistance has increased dramatically due to antibiotic misuse, the failure of some patients to comply with their treatment regimen, and the high capability of bacteria to mutate. As a result, antibiotic resistance leads to the failure of treatment of life-threatening bacterial infections and increases costs due to longer stay in health care settings.…”

Section: Introductionmentioning

confidence: 99%

In vitro and in vivo antimicrobial activity of combined therapy of silver nanoparticles and visible blue light against Pseudomonas aeruginosa

Din¹,

El-Tayeb

Abou-Aisha³

et al. 2016

IJN

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Silver nanoparticles (AgNPs) have been used as potential antimicrobial agents against resistant pathogens. We investigated the possible therapeutic use of AgNPs in combination with visible blue light against a multidrug resistant clinical isolate of Pseudomonas aeruginosa in vitro and in vivo. The antibacterial activity of AgNPs against P. aeruginosa (1×10 5 colony forming unit/mL) was investigated at its minimal inhibitory concentration (MIC) and sub-MIC, alone and in combination with blue light at 460 nm and 250 mW for 2 hours. The effect of this combined therapy on the treated bacteria was then visualized using transmission electron microscope. The therapy was also assessed in the prevention of biofilm formation by P. aeruginosa on AgNP-impregnated gelatin biopolymer discs. Further, in vivo investigations were performed to evaluate the efficacy of the combined therapy to prevent burn-wound colonization and sepsis in mice and, finally, to treat a real infected horse with antibiotic-unresponsive chronic wound. The antimicrobial activity of AgNPs and visible blue light was significantly enhanced ( P <0.001) when both agents were combined compared to each agent alone when AgNPs were tested at MIC, 1/2, or 1/4 MIC. Transmission electron microscope showed significant damage to the cells that were treated with the combined therapy compared to other cells that received either the AgNPs or blue light. In addition, the combined treatment significantly ( P <0.001) inhibited biofilm formation by P. aeruginosa on gelatin discs compared to each agent individually. Finally, the combined therapy effectively treated a horse suffering from a chronic wound caused by mixed infection, where signs of improvement were observed after 1 week, and the wound completely healed after 4 weeks. To our knowledge, this combinatorial therapy has not been investigated before. It was proved efficient and promising in managing infections caused by multidrug resistant bacteria and could be used as an alternative to conventional antibiotic therapy.

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405 nm light technology for the inactivation of pathogens and its potential role for environmental disinfection and infection control

Cited by 122 publications

References 76 publications

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799

Decontamination of the Hospital Environment: New Technologies for Infection Control

In vitro and in vivo antimicrobial activity of combined therapy of silver nanoparticles and visible blue light against Pseudomonas aeruginosa

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405 nm light technology for the inactivation of pathogens and its potential role for environmental disinfection and infection control

Cited by 122 publications

References 76 publications

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ B and the Blue-Light Sensor Lmo0799

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ B and the Blue-Light Sensor Lmo0799

Decontamination of the Hospital Environment: New Technologies for Infection Control

In vitro and in vivo antimicrobial activity of combined therapy of silver nanoparticles and visible blue light against Pseudomonas aeruginosa

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Product

Resources

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Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799

Blue-Light Inhibition of Listeria monocytogenes Growth Is Mediated by Reactive Oxygen Species and Is Influenced by σ ^B and the Blue-Light Sensor Lmo0799