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.

High power and high efficiency blue light emitting diode on freestanding semipolar (101¯1¯) bulk GaN substrate

2007 ◽  
Vol 90 (23) ◽  
pp. 233504 ◽  
Author(s):  
Hong Zhong ◽  
Anurag Tyagi ◽  
Natalie N. Fellows ◽  
Feng Wu ◽  
Roy B. Chung ◽  
...  
Keyword(s):  
Blue Light ◽  
High Power ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Bulk Gan

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 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.

Deep blue light-emitting diode based on high molecular weight poly(9,9-dioctylfluorene) with high efficiency and color stability

2008 ◽  
Vol 9 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Shin-Rong Tseng ◽  
Shiuan-Yi Li ◽  
Hsin-Fei Meng ◽  
Yi-Hsiang Yu ◽  
Chia-Ming Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Blue Light ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Color Stability ◽  
Light Emitting ◽  
Deep Blue ◽  
High Molecular Weight Poly

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 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.

A high efficiency blue-light-emitting diode based on novel ladder poly(p-phenylene)s

1994 ◽  
Vol 6 (10) ◽  
pp. 748-752 ◽  
Author(s):  
Johannes Grüner ◽  
Peter J. Hamer ◽  
Richard H. Friend ◽  
Hans-Joachim Huber ◽  
Ullrich Scherf ◽  
...  
Keyword(s):  
Blue Light ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting
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