scholarly journals Effects of Combined Aerosolization with Ultraviolet C Light-Emitting Diode on Enterohemorrhagic Escherichia coli and Staphylococcus aureus Attached to Soft Fresh Produce

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1834
Author(s):  
Chae-Lim Lee ◽  
Geun-Hyang Kim ◽  
Ki-Sun Yoon
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Light Emitting Diode ◽  
Fresh Produce ◽  
Combined Treatment ◽  
Enterohemorrhagic Escherichia Coli ◽  
Light Emitting ◽  
Ultraviolet C ◽  
And Staphylococcus Aureus ◽  
Led Irradiation

Washing soft fresh produce such as strawberries, baby leaves, and sliced onions with sanitizing agents is challenging due to their fragile texture. Thus, treatments like aerosolization using slightly acidic electrolyzed water (SAEW) and ultraviolet C light-emitting diode (UVC LED) irradiation may be good alternatives. In the present study, the reduction effects of a combined treatment of aerosolization using SAEW and UVC LED irradiation on enterohemorrhagic Escherichia coli (EHEC) and Staphylococcus aureus attached to strawberries, baby leaves, and sliced onions were investigated. The behaviours of EHEC and S. aureus, moisture loss, colour measurement, and visual appearance were also analyzed at 10 and 15 °C for 7 days. The reduction effect of the combined treatment with 100 SAEW and UVC LED was higher (0.53–0.92 log CFU g−1) than a single aerosolization treatment (0.11–0.41 log CFU g−1), regardless of samples or pathogens. A greater effect on EHEC and S. aureus reduction was observed in strawberries (0.74 and 0.92 log CFU g−1) than in baby leaves (0.62 and 0.53 log CFU g−1) and sliced onions (0.55 and 0.62 log CFU g−1). The combined treatment further reduced the EHEC and S. aureus populations in strawberries during 7 days of storage at 10 and 15 °C. However, the EHEC and S. aureus populations were maintained in baby leaves and sliced onions at 10 °C for 7 days. Additionally, the greatest effect on the maintenance of colour and appearance was obtained in the combined treatment. Since the combined treatment reduces EHEC and S. aureus populations and preserves visual quality, it could be expected to extend the shelf life of soft fresh produce at the retailer stage of the supply chain.

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.

Inhibitory Effects of Combinations of Chemicals on Escherichia coli, Bacillus cereus, and Staphylococcus aureus Biofilms during the Clean-in-Place Process at an Experimental Dairy Plant

2020 ◽  
Vol 83 (8) ◽  
pp. 1302-1306
Author(s):  
EUN-SEON LEE ◽  
JONG-HUI KIM ◽  
MI-HWA OH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Citric Acid ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Combined Treatment ◽  
Food Additives ◽  
Inhibitory Effects ◽  
E Coli ◽  
And Staphylococcus Aureus

ABSTRACT In dairy plants, clean-in-place (CIP) equipment cannot be disassembled, making it difficult to clean the inner surface of pipes. In this study, the inhibitory effects of chemical agents on biofilms formed by three foodborne pathogens, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, was evaluated in a dairy CIP system. The experiment was conducted on a laboratory scale. Each of the three bacteria (200 μL) was inoculated onto stainless steel (SS) chips (25 by 25 mm), and the effect of single cleaning agents was evaluated. Individual treatments with NaClO (30, 50, 100, and 200 ppm), NaOH (0.005, 0.01, 0.05, and 0.1%), citric acid (1, 3, 5, and 7%), and nisin (5, 10, 25, 50, 100, and 200 ppm) were used to clean the SS chip for 10 min. The most effective concentration of each solution was selected for further testing in a commercial plant. Simultaneous cleaning with 200 ppm of NaClO (10 min) and 7% citric acid (10 min) reduced the biofilms of B. cereus, E. coli, and S. aureus by 6.9, 7.0, and 8.0 log CFU/cm2, respectively. Both 7% citric acid and 0.1% NaOH were optimal treatments for E. coli. NaClO and citric acid are approved for use as food additives in the Republic of Korea. Our results revealed that a combined treatment with NaClO and citric acid is the most effective approach for reducing biofilms formed by common foodborne pathogens on CIP equipment. These findings can contribute to the production of safe dairy products. HIGHLIGHTS

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.

Comparison of the Effects of Silver in Nanostructured and Ultrahigh Diluted Form on Growth and Volatile Compounds Produced by Escherichia coli and Staphylococcus aureus

2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Life Cycles ◽  
Gas Chromatography Mass Spectrometry ◽  
Untreated Sample ◽  
E Coli ◽  
Volatile Metabolites ◽  
Octyl Acetate ◽  
Volatile Organic ◽  
And Staphylococcus Aureus

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).

Penggunaan Limbah Logam Tembaga yang Didaur Ulang untuk Antibakteri dan Degradasi Metil Merah Secara Fotolisis

2019 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Ariyetti Ariyetti ◽  
Muhammad Nasir ◽  
Safni Safni ◽  
Syukri Darajat
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Silver Nitrate ◽  
Copper Sulfate ◽  
Bacterial Growth ◽  
Methyl Red ◽  
Copper Metal ◽  
Sulfate Hydrate ◽  
Red Dye ◽  
And Staphylococcus Aureus

<p><em>Metil merah merupakan salah satu zat warna golongan azo yang sering digunakan dalam industri dan laboratorium. Penggunaan metil merah dapat menimbulkan efek terhadap kesehatan dan lingkungan. Oleh sebab itu dilakukan metode fotodegradasi dengan menggunakan semikonduktor dan radiasi sinar tampak. Semikonduktor yang digunakan yaitu berbahan dasar tembaga sulfat hidrat dan perak nitrat. Prekusor tembaga sulfat hidrat dibuat dari pengolahan limbah logam tembaga hasil pemotongan tembaga yang ada di bengkel Lembaga Ilmu Pengetahuan Indonesia (LIPI) Bandung. Bahan semikonduktor juga memiliki kemampuan dalam menghambat pertumbuhan bakteri. Hasil optimum yang didapatkan dalam proses fotodegradasi dan antibakteri merupakan gabungan antara kedua prekusor tembaga sulfat hidrat dan perak nitrat dengan bantuan penyinaran. Kemampuan dalam menghambat pertumbuhan bakteri didapatkan persentase kematian 100 % untuk masing-masing bakteri, yaitu Escherichia coli dan Staphylococcus aureus. Aktifitas fotokatalitiknya dengan konsentrasi semikonduktor 10 ppm untuk mendegradasi zat warna metil merah 5 ppm, selama 23 jam, dimana persentase degradasi yang didapatkan dengan penyinaran lebih tinggi dibandingkan dengan tanpa penyinaran. Pengaruh pH larutan terhadap degradasi metil merah yaitu optimum pada pH 12 (basa).</em></p><p><em><br /></em></p><p><em>Methyl red is one of the azo group dyes that is often used in industry and laboratories. The use of methyl red can have an effect on health and the environment. Therefore photodegradation method is done by using semiconductor and visible light radiation. The semiconductor used is based on copper sulfate hydrate and silver nitrate. The copper sulphate hydrate precursor is made from the processing of copper-cut copper metal waste in the workshop of the Indonesian Institute of Sciences (LIPI) in Bandung. Semiconductor materials also have the ability to inhibit bacterial growth. The optimum results obtained in the photodegradation and antibacterial process are a combination of both copper sulfate hydrate precursor and silver nitrate with the help of irradiation. The ability to inhibit bacterial growth obtained 100% mortality for each bacterium, namely Escherichia coli and Staphylococcus aureus. Photocatalytic activity with 10 ppm semiconductor concentration to degrade methyl red dye 5 ppm, for 23 hours, where the percentage of degradation obtained by irradiation is higher than without irradiation. The effect of pH of the solution on the degradation of methyl red is optimum at pH 12 (base).</em></p>

scholarly journals Sulfaquinoxaline Oxidation and Toxicity Reduction by Photo-Fenton Process

2021 ◽  
Vol 18 (3) ◽  
pp. 1005
Author(s):  
Vanessa Ribeiro Urbano ◽  
Milena Guedes Maniero ◽  
José Roberto Guimarães ◽  
Luis J. del Valle ◽  
Montserrat Pérez-Moya
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pilot Plant ◽  
Environmental Water ◽  
Fenton Process ◽  
Experimental Conditions ◽  
Laboratory Bench ◽  
Degradation Rates ◽  
Bacterial Growth Inhibition ◽  
And Staphylococcus Aureus

Sulfaquinoxaline (SQX) has been detected in environmental water samples, where its side effects are still unknown. To the best of our knowledge, its oxidation by Fenton and photo-Fenton processes has not been previously reported. In this study, SQX oxidation, mineralization, and toxicity (Escherichia coli and Staphylococcus aureus bacteria) were evaluated at two different setups: laboratory bench (2 L) and pilot plant (15 L). The experimental design was used to assess the influence of the presence or absence of radiation source, as well as different H2O2 concentrations (94.1 to 261.9 mg L−1). The experimental conditions of both setups were: SQX = 25 mg L−1, Fe(II) = 10 mg L−1, pH 2.8 ± 0.1. Fenton and photo-Fenton were suitable for SQX oxidation and experiments resulted in higher SQX mineralization than reported in the literature. For both setups, the best process was the photo-Fenton (178.0 mg L−1 H2O2), for which over 90% of SQX was removed, over 50% mineralization, and bacterial growth inhibition less than 13%. In both set-ups, the presence or absence of radiation was equally important for sulfaquinoxaline oxidation; however, the degradation rates at the pilot plant were between two to four times higher than the obtained at the laboratory bench.

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