scholarly journals Comparison of standard light-emitting diode (LED) and 385 nm ultraviolet A LED (UVA-LED) for disinfection of Escherichia coli

2017 ◽  
Vol 13 (4-2) ◽  
pp. 430-437 ◽  
Author(s):  
Sameen Ahmed Malik ◽  
Tan Tian Swee ◽  
Nik Ahmad Nizam Nik Malek ◽  
Mohammed Rafiq Abdul Kadir ◽  
Takahiro Emoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Human Life ◽  
Light Emitting ◽  
Led Light ◽  
E Coli ◽  
Wide Range ◽  
Uva Light ◽  
Uv Lamps

UV light has become an integral part of human life especially in performing wide range of disinfection. Most of the research on UVLEDs is limited to UVC region because of comparison with mercury based UV lamps which work typically at 254 nm. Limited research is found on the use of UVA-LEDs for inactivation of microorganisms in healthcare. In this study a standard 3 mm LED has been compared with 385 nm UVA-LED for inactivation of Escherichia coli.  E. coli strains were swabbed on control, LED and UVA-LED petri dishes using cotton bud. The LED and UVA-LED samples were exposed to standard LED light and UVA light respectively for 1 h. The analysis of bacteria by determining Colony forming units (CFU) and log inactivation were carried out to calculate the number of colonies present in each sample. Result showed negligible to none disinfection properties in standard LED light. LED samples had  CFU/ml colonies compared to control which is  CFU/ml. UVA-LED samples achieved maximum inactivation and only had  CFU/ml. Log inactivation results showed that LED samples observed 0.1-log inactivation whereas the UVA-LED had significant inactivation of 3.8-log inactivation corresponding to approximately 99.99 % E. coli reduction. The results demonstrate that UVA-LED at 385 nm is capable of efficiently providing inactivation of bacteria E. coli. 

scholarly journals POTENCIAL ANTIBACTERIANO DO ÓLEO ESSENCIAL DE LIPPIA ALBA MILL. ASSOCIADO A LUZES DE LED

2021 ◽  
Vol 33 (2) ◽  
pp. 188
Author(s):  
Vitoria Ruana Sales Santos ◽  
Dárcio Luiz de Sousa Júnior ◽  
Jailson De Castro Freitas ◽  
Pedro Everson Alexandre de Aquino ◽  
Maria Karollyna Do Nascimento Silva Leandro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Led Light ◽  
E Coli ◽  
Lippia Alba

Lippia alba Mill., também conhecida como erva cidreira, é um subarbusto aromático que ocorre em todo território brasileiro. Seu óleo essencial possui muitas atividades, mas ainda são escassos estudos do seu uso associado à fototerapia. O objetivo desse estudo foi avaliar a atividade antibacteriana do óleo essencial de Lippia alba (OEL) associado a luzes de LED (Light Emitting Diode) azul, vermelha e amarela contra cepas de Staphylococcus aureus e Escherichia coli. O óleo foi extraído pelo método de hidrodestilação. A atividadeantibacteriana e moduladora foi avaliada pelo método de contato gasoso utilizando o óleo, luzes de LED e antibióticos, os quais foram realizados em triplicata. O OEL possui um potencial antibacteriano frente todas as cepas testadas tendo um resultado mais expressivo na cepa multirresistente de E. coli quando associado a luzes de LED. Na modulação da resistência bacteriana, tanto nas combinações do óleo + antibiótico + luzes de LED como óleo + antibióticos, houve sinergismo frente às linhagens multirresistentes de ambas as cepas testadas. Os resultados obtidos no presente estudo mostraram que o óleo essencial de Lippia alba associado às luzes de LED possui efeito antibacteriano e modulador pelo método de contato gasoso. Estes dados obtidos poderão colaborar com pesquisas futuras que visem o desenvolvimento de novas estratégias terapêuticas no combate de microrganismos resistentes.

scholarly journals Fundamental Characteristics of Deep-UV Light-Emitting Diodes and Their Application To Control Foodborne Pathogens

2015 ◽  
Vol 82 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Joo-Yeon Shin ◽  
Soo-Ji Kim ◽  
Do-Kyun Kim ◽  
Dong-Hyun Kang
Keyword(s):  
Foodborne Pathogens ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Bacterial Inactivation ◽  
Content Type ◽  
Light Emitting ◽  
E Coli ◽  
Deep Uv ◽  
Uv Lamps ◽  
Uv C

ABSTRACTLow-pressure mercury UV (LP-UV) lamps have long been used for bacterial inactivation, but due to certain disadvantages, such as the possibility of mercury leakage, deep-UV-C light-emitting diodes (DUV-LEDs) for disinfection have recently been of great interest as an alternative. Therefore, in this study, we examined the basic spectral properties of DUV-LEDs and the effects of UV-C irradiation for inactivating foodborne pathogens, includingEscherichia coliO157:H7,Salmonella entericaserovar Typhimurium, andListeria monocytogenes, on solid media, as well as in water. As the temperature increased, DUV-LED light intensity decreased slightly, whereas LP-UV lamps showed increasing intensity until they reached a peak at around 30°C. As the irradiation dosage and temperature increased,E. coliO157:H7 andS. Typhimurium experienced 5- to 6-log-unit reductions.L. monocytogeneswas reduced by over 5 log units at a dose of 1.67 mJ/cm2. At 90% relative humidity (RH), onlyE. coliO157:H7 experienced inactivation significantly greater than at 30 and 60% RH. In a water treatment study involving a continuous system, 6.38-, 5.81-, and 3.47-log-unit reductions were achieved inE. coliO157:H7,S. Typhimurium, andL. monocytogenes, respectively, at 0.5 liter per minute (LPM) and 200 mW output power. The results of this study suggest that the use of DUV-LEDs may compensate for the drawbacks of using LP-UV lamps to inactivate foodborne pathogens.

scholarly journals Effects of 462 nm Light-Emitting Diode on the Inactivation of Escherichia coli and a Multidrug-Resistant by Tetracycline Photoreaction

2018 ◽  
Vol 7 (9) ◽  
pp. 278 ◽  
Author(s):  
Shiuh-Tsuen Huang ◽  
Chun-Yi Wu ◽  
Nan‐Yao Lee ◽  
Chien-Wei Cheng ◽  
Meei-Ju Yang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Blue Light ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Phosphate Buffer Solution ◽  
Multidrug Resistant ◽  
Molecular Formula ◽  
Light Illumination ◽  
Light Emitting ◽  
E Coli

The adaptability of bacterial resistance to antibiotics contributes to its high efficiency during evolution. Tetracycline (TC) is a broad-spectrum antimicrobial agent. Chromatographic analyses and mass spectrometry were used to study the effects of the light illumination of a 462 nm light-emitting diode (LED) on the conformational changes of TC in a phosphate buffer solution (PBS, pH 7.8). Especially, the inactivation of superoxide anion radicals (O2•−) and Escherichia coli (E. coli), including that of a multidrug-resistant E. coli (MDR E. coli), were investigated during the photolysis of TC. A photolysis product of TC (PPT) was generated in an alkaline solution after the illumination of a blue light. The mass spectra of PPT had characteristic ion signals in m/z 459, 445, and 249.1 Da. The PPT has the molecular formula of C22H22N2O9, and the exact mass is 458.44 g/mol. The inactivation of MDR E. coli is not significant with TC treatment. The drug-resistant ability of MDR E. coli has a less significant effect on PPT, and the changed conformation of TC retained the inactivation ability of MDR E. coli upon blue light photoreaction. With TC, illuminated by a blue light in a pH 7.8 PBS, O2•− was generated from TC photolysis, which enhanced the inactivation of E. coli and MDR E. coli. A 96.6% inactivation rate of MDR E. coli was reached with TC under 2.0 mW/cm2 blue light illumination at 25 ± 3 °C for 120 min, and the effects of the TC-treated photoreaction on MDR E. coli viability repressed the growth of MDR E. coli by 4 to 5 logs. The present study of the blue light photoreaction of TC offers a new approach to the inactivation of MDR E. coli.

scholarly journals Inactivation of Escherichia Coli and Salmonella Using 365 and 395 nm High Intensity Pulsed Light Emitting Diodes

Foods ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 679 ◽  
Author(s):  
Amritha Prasad ◽  
Michael Gänzle ◽  
M. S. Roopesh
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
High Intensity ◽  
Light Exposure ◽  
Light Emitting Diode ◽  
Antibacterial Efficacy ◽  
Pulsed Light ◽  
Light Emitting ◽  
E Coli ◽  
Novel Approach

High intensity pulsed light emitting diode (LED) treatment is a novel approach to inactivate foodborne pathogens. The objective of this study was to evaluate the antibacterial potential of high intensity 365 (UV-A) and 395 nm (NUV-Vis) LED treatments against Escherichia coli and Salmonella enterica at high and low water activity (aw) conditions, and to understand the influence of different process parameters on their antibacterial efficacy. Bacteria at high (in phosphate buffer saline, PBS) and low aw (aw = 0.75) conditions were treated with both the LEDs with specific doses at a fixed distance from the LEDs. The 365 nm LED showed more effectiveness in reducing the dried bacteria compared to 395 nm LED. The dry E. coli showed more resistance to LED treatments compared to Salmonella. The 365 and 395 nm LED treatments with ~658 J/cm2 dose resulted in reductions of 0.79 and 1.76 log CFU/g of Salmonella, respectively, on 0.75 aw pet foods. The LED treatments increased the surface temperature, resulting in water loss in the treated samples. This study showed that the dose, duration of light exposure, bacterial strain, and aw played a major role in the antibacterial efficacy of the 365 and 395 nm LEDs.

scholarly journals Demonstration and evaluation of germicidal UV-LEDs for point-of-use water disinfection

2010 ◽  
Vol 8 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Christie Chatterley ◽  
Karl Linden
Keyword(s):  
Uv Irradiation ◽  
Uv Light ◽  
Low Pressure ◽  
Water Disinfection ◽  
Light Emitting ◽  
E Coli ◽  
Point Of Use ◽  
One Year ◽  
Uv Lamps ◽  
Uv Leds

Ultraviolet (UV) irradiation is a common disinfection option for water treatment in the developed world. There are a few systems installed in developing countries for point-of-use treatment, but the low-pressure mercury lamps currently used as the UV irradiation source have a number of sustainability issues including a fragile envelope, a lifetime of approximately one year, and they contain mercury. UV light emitting diodes (LEDs) may offer solutions to many of the sustainability issues presented by current UV systems. LEDs are small, efficient, have long lifetimes, and do not contain mercury. Germicidal UV LEDs emitting at 265 nm were evaluated for inactivation of E. coli in water and compared to conventional low-pressure UV lamps. Both systems provided an equivalent level of treatment. A UV-LED prototype was developed and evaluated as a proof-of-concept of this technology for a point-of-use disinfection option, and the economics of UV-LEDs were evaluated.

scholarly journals Extended spectrum β-lactamase (ESBL)-producing Escherichia coli inactivation by UVA-LED irradiation system in a Japanese hospital

2019 ◽  
Author(s):  
Maria Ulfa ◽  
Momoyo Azuma ◽  
Masami Sato ◽  
Takaaki Shimohata ◽  
Shiho Fukushima ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Light Emitting Diode ◽  
Minimum Energy ◽  
University Hospital ◽  
Healthcare Facilities ◽  
Light Emitting ◽  
E Coli ◽  
Irradiation System ◽  
Extended Spectrum ◽  
Led Irradiation

Abstract Background: The prevalence of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing rapidlyand spreading worldwide, particularly in Asia compared to other regions. In the last 10 years, in our hospital, in particular, there has been <30% increase. To prevent the spread of ESBL in hospitals and in the community, the ultraviolet (UV) A-light-emitting diode (LED) irradiation device was used to inactivate ESBL- E. coli in human livestock and the environment . Methods: ESBL- E. coli and E. coli bacterial samples were collected from patients at Tokushima University Hospital (Tokushima City, Japan). The UVA-LED irradiation system had 365 nm single wavelength, and the current of the circuit was set to 0.23 or 0.50 A consistently. Results: Results demonstrated that UVA-LED was useful for the inactivation of ESBL- E. coli and E. coli . The minimum energy dosage required to inactivate ESBL- E. coli and E. coli was 40.75 J/cm 2 (45 min) in the first type of UVA-LED and 38.85 J/cm 2 (5 min) in the second type. There were no significant differences between ESBL- E. coli and E. coli . The inactivation of ESBL- E. coli was dependent on energy. Conclusions: These findings suggest that UVA-LED with 365 nm single wavelength could be useful for surface decontamination in healthcare facilities.

Inactivation of Nonpathogenic Escherichia coli, Escherichia coli O157:H7, Salmonella enterica Typhimurium, and Listeria monocytogenes in Ice Using a UVC Light-Emitting Diode

2017 ◽  
Vol 80 (7) ◽  
pp. 1198-1203 ◽  
Author(s):  
Suguru Murashita ◽  
Shuso Kawamura ◽  
Shigenobu Koseki
Keyword(s):  
Escherichia Coli ◽  
Food Industry ◽  
Light Emitting Diode ◽  
Microbial Inactivation ◽  
Distilled Water ◽  
Light Emitting ◽  
E Coli ◽  
Uv Lamp ◽  
Uv Dose ◽  
Led Irradiation

ABSTRACT Ice, widely used in the food industry, is a potential cause of food poisoning resulting from microbial contamination. Direct microbial inactivation of ice is necessary because microorganisms may have been present in the source water used to make it and/or may have been introduced due to poor hygiene during production or handling of the ice. Nonthermal and nondestructive microbial inactivation technologies are needed to control microorganisms in ice. We evaluated the applicability of a UVC light-emitting diode (UVC-LED) for microbial inactivation in ice. The effects of UV intensity and UV dose of the UVC-LED on Escherichia coli ATCC 25922 and a comparison of UVC-LED with a conventional UV lamp for effective bacterial inactivation in distilled water and ice cubes were investigated to evaluate the performance of the UVC-LED. Finally, we assessed the effects of the UVC-LED on pathogens such as E. coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in ice cubes. The results indicated that UVC-LED effectiveness depended on the UV dose at all UV intensity conditions (0.084, 0.025, 0.013, 0.007, and 0.005 mW/cm2) in ice and that UVC-LED could more efficiently inactivate E. coli ATCC 25922 in distilled water and ice than the UV lamp. At a UV dose of 2.64 mJ/cm2, E. coli in distilled water was decreased by 0.90 log CFU/mL (UV lamp) and by more than 7.0 log CFU/mL (UVC-LED). At 15.2 mJ/cm2, E. coli in ice was decreased by 3.18 log CFU/mL (UV lamp) and by 4.45 CFU/mL (UVC-LED). Furthermore, UVC-LED irradiation reduced the viable number of pathogens by 6 to 7 log cycles at 160 mJ/cm2, although the bactericidal effect was somewhat dependent on the type of bacteria. L. monocytogenes in ice was relatively more sensitive to UVC irradiation than were E. coli O157:H7 and Salmonella Typhimurium. These results demonstrate that UVC-LED irradiation could contribute to the safety of ice in the food industry.

scholarly journals Operation of LED Light as Emergency Lighting Resource DC with Charger Control Based Arduino Uno ATmega

2017 ◽  
Vol 1 (2) ◽  
pp. 13
Author(s):  
I Wayan Rinas ◽  
I Made Suartika ◽  
Anak Agung Maharta Pemayun ◽  
I G. A. P. Raka Agung
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Human Life ◽  
Life Time ◽  
Power Source ◽  
Light Emitting ◽  
Dc Voltage ◽  
Led Light ◽  
Arduino Uno ◽  
Dc Current

Lighting is very important to support the activities of human life. To maintain the continuity of lighting can use power source from genset or battery. Now many manufactured LED (light emitting diode) bulb type which is energy saving with life time up to 50.000 hours. LEDs of this type can be operated with AC and DC current. The design control charger based Arduino Uno ATmega micro controller is used as a control system for charging and turning on LED lights. In this research the measurement of light intensity is done at 220 volt AC as reference, then measured the intensity of light for operation on some variation of DC voltage. The measurement results at DC voltage, LED Osram can be operated at 115 volt DC has reached the same light intensity with 220 volt AC. This selection aims to reduce the amount of battery usage as a DC power source.

Evaluation of parameters governing dark and photorepair in UVC-irradiated Escherichia coli

2022 ◽  
Author(s):  
Mostafa Maghsoodi ◽  
Grace Lowry ◽  
Ian Smith ◽  
Samuel Snow
Keyword(s):  
Escherichia Coli ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Uv Exposure ◽  
Uv Disinfection ◽  
Light Emitting ◽  
Recent Advances ◽  
Evaluation Of Parameters

After decades of UV disinfection practice and numerous studies on the potential for pathogens to undergo dark or photo-repair after UV exposure, recent advances in UV light emitting diode (LED)...

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