151
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Trivellin N, Buffolo M, Onelia F, Pizzolato A, Barbato M, Orlandi VT, Del Vecchio C, Dughiero F, Zanoni E, Meneghesso G, Crisanti A, Meneghini M. Inactivating SARS-CoV-2 Using 275 nm UV-C LEDs through a Spherical Irradiation Box: Design, Characterization and Validation. Materials (Basel) 2021; 14:ma14092315. [PMID: 33946929 PMCID: PMC8125165 DOI: 10.3390/ma14092315] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/02/2021] [Accepted: 04/16/2021] [Indexed: 11/16/2022]
Abstract
We report on the design, characterization and validation of a spherical irradiation system for inactivating SARS-CoV-2, based on UV-C 275 nm LEDs. The system is designed to maximize irradiation intensity and uniformity and can be used for irradiating a volume of 18 L. To this aim: (i) several commercially available LEDs have been acquired and analyzed; (ii) a complete optical study has been carried out in order to optimize the efficacy of the system; (iii) the resulting prototype has been characterized optically and tested for the inactivation of SARS-CoV-2 for different exposure times, doses and surface types; (iv) the result achieved and the efficacy of the prototype have been compared with similar devices based on different technologies. Results indicate that a 99.9% inactivation can be reached after 1 min of treatment with a dose of 83.1 J/m2.
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Affiliation(s)
- Nicola Trivellin
- Department of Industrial Engineering, University of Padova, Via Gradenigo 6A, 35131 Padova, Italy;
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
- Correspondence:
| | - Matteo Buffolo
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
| | - Francesco Onelia
- Department of Molecular Medicine, University of Padova, Via Gabelli 63, 35121 Padova, Italy; (F.O.); (C.D.V.); (A.C.)
| | | | - Marco Barbato
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
- LightCube SRL, Viale Navigazione Interna 51, 35129, Padova, Italy;
| | | | - Claudia Del Vecchio
- Department of Molecular Medicine, University of Padova, Via Gabelli 63, 35121 Padova, Italy; (F.O.); (C.D.V.); (A.C.)
| | - Fabrizio Dughiero
- Department of Industrial Engineering, University of Padova, Via Gradenigo 6A, 35131 Padova, Italy;
| | - Enrico Zanoni
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
| | - Gaudenzio Meneghesso
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
| | - Andrea Crisanti
- Department of Molecular Medicine, University of Padova, Via Gabelli 63, 35121 Padova, Italy; (F.O.); (C.D.V.); (A.C.)
| | - Matteo Meneghini
- Department of Information Engineering, University of Padova, Via Gradenigo 6B, 35131 Padova, Italy; (M.B.); (M.B.); (E.Z.); (G.M.); (M.M.)
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152
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Anderson ER, Hughes GL, Patterson EI. Inactivation of SARS-CoV-2 on surfaces and in solution with Virusend (TX-10), a novel disinfectant. Access Microbiol 2021; 3:000228. [PMID: 34151178 PMCID: PMC8208756 DOI: 10.1099/acmi.0.000228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/03/2021] [Indexed: 12/24/2022] Open
Abstract
Until an effective vaccine against SARS-CoV-2 is available on a widespread scale, the control of the COVID-19 pandemic is reliant upon effective pandemic control measures. The ability of SARS-CoV-2 to remain viable on surfaces and in aerosols, means indirect contact transmission can occur and there is an opportunity to reduce transmission using effective disinfectants in public and communal spaces. Virusend (TX-10), a novel disinfectant, has been developed as a highly effective disinfectant against a range of microbial agents. Here we investigate the ability of Virusend to inactivate SARS-CoV-2. Using surface and solution inactivation assays, we show that Virusend is able to reduce SARS-CoV-2 viral titre by 4 log10 p.f.u. ml-1 within 1 min of contact. Ensuring disinfectants are highly effective against SARS-CoV-2 is important in eliminating environmental sources of the virus to control the COVID-19 pandemic.
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Affiliation(s)
- Enyia R. Anderson
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Grant L. Hughes
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Edward I. Patterson
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- Department of Biological Sciences, Brock University, St. Catharines L2S 3A1, ON, Canada
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153
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Zhu Y, Chang J, Tan K, Huang SK, Liu X, Wang X, Cao M, Zhang H, Li S, Duan X, Chang Y, Fan Y, Cao P. Clioquinol Attenuates Pulmonary Fibrosis through Inactivation of Fibroblasts via Iron Chelation. Am J Respir Cell Mol Biol 2021; 65:189-200. [PMID: 33861690 DOI: 10.1165/rcmb.2020-0279oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Strict control of iron homeostasis is critical for the maintenance of normal lung function. Iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (PF), but the characteristics of iron metabolism in the pathogenesis of PF and related targeting therapeutics are not well studied. In this study, we investigated the cellular and molecular characteristics of iron metabolism in fibrotic lungs and further explored the efficacy of clioquinol (CQ) for the treatment of PF as well as its functional mechanism. Iron aggregates accumulated in the lungs of patients with idiopathic PF, and FTL (ferritin light chain) transcripts were increased in their pulmonary fibroblasts. In the bleomycin (BLM)-induced PF (BLM-PF) mouse model, pulmonary iron accumulation is a very early and concomitant event of PF. Labile iron pool levels in both fibroblasts and macrophages from the BLM-PF model were elevated, and iron metabolism was dysregulated. CQ attenuated PF induced by BLM and FITC, and iron-saturated CQ did not alleviate BLM-PF. Furthermore, CQ inhibited the activation of fibroblasts, including proliferation, fibrotic differentiation, proinflammatory cytokine secretion, and migration. In conclusion, our study demonstrated that CQ, acting as an iron chelator, attenuates experimental PF through inactivation of fibroblasts, providing support for targeting iron metabolism as a basis for PF treatment.
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Affiliation(s)
- Yumeng Zhu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Jing Chang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Ke Tan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Steven K Huang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, University of Michigan, Ann Arbor, Michigan; and
| | - Xin Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Xiaofan Wang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Mengshu Cao
- Department of Respiratory and Critical Care Medicine, Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital, Nanjing, Jiangsu, China
| | - Hongmin Zhang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Shuxin Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Xianglin Duan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Yanzhong Chang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Yumei Fan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Pengxiu Cao
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
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154
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Colás-Medà P, Nicolau-Lapeña I, Viñas I, Neggazi I, Alegre I. Bacterial Spore Inactivation in Orange Juice and Orange Peel by Ultraviolet-C Light. Foods 2021; 10:foods10040855. [PMID: 33920777 PMCID: PMC8103511 DOI: 10.3390/foods10040855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/04/2021] [Accepted: 04/12/2021] [Indexed: 11/16/2022] Open
Abstract
Spore-forming bacteria are a great concern for fruit juice processors as they can resist the thermal pasteurization and the high hydrostatic pressure treatments that fruit juices receive during their processing, thus reducing their microbiological quality and safety. In this context, our objective was to evaluate the efficacy of Ultraviolet-C (UV-C) light at 254 nm on reducing bacterial spores of Alicyclobacillus acidoterrestris, Bacillus coagulans and Bacillus cereus at two stages of orange juice production. To simulate fruit disinfection before processing, the orange peel was artificially inoculated with each of the bacterial spores and submitted to UV-C light (97.8-100.1 W/m2) with treatment times between 3 s and 10 min. The obtained product, the orange juice, was also tested by exposing the artificially inoculated juice to UV-C light (100.9-107.9 W/m2) between 5 and 60 min. A three-minute treatment (18.0 kJ/m2) reduced spore numbers on orange peel around 2 log units, while more than 45 min (278.8 kJ/m2) were needed to achieve the same reduction in orange juice for all evaluated bacterial spores. As raw fruits are the main source of bacterial spores in fruit juices, reducing bacterial spores on fruit peels could help fruit juice processors to enhance the microbiological quality and safety of fruit juices.
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155
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Siciliano RA, Reale A, Mazzeo MF, Morandi S, Silvetti T, Brasca M. Paraprobiotics: A New Perspective for Functional Foods and Nutraceuticals. Nutrients 2021; 13:1225. [PMID: 33917707 PMCID: PMC8068161 DOI: 10.3390/nu13041225] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 12/15/2022] Open
Abstract
Probiotics are live microorganisms that confer health benefits on the host. However, in recent years, several concerns on their use have been raised. In particular, industrial processing and storage of probiotic products are still technological challenges as these could severely impair cell viability. On the other hand, safety of live microorganisms should be taken into account, especially when administered to vulnerable people, such as the elderly and immunodeficient individuals. These drawbacks have enhanced the interest toward new products based on non-viable probiotics such as paraprobiotics and postbiotics. In particular, paraprobiotics, defined as "inactivated microbial cells (non-viable) that confer a health benefit to the consumer," hold the ability to regulate the adaptive and innate immune systems, exhibit anti-inflammatory, antiproliferative and antioxidant properties and exert antagonistic effect against pathogens. Moreover, paraprobiotics can exhibit enhanced safety, assure technological and practical benefits and can also be used in products suitable for people with weak immunity and the elderly. These features offer an important opportunity to prompt the market with novel functional foods or nutraceuticals that are safer and more stable. This review provides an overview of central issues on paraprobiotics and highlights the urgent need for further studies aimed at assessing safety and efficacy of these products and their mechanisms of action in order to support decisions of regulatory authorities. Finally, a definition is proposed that unambiguously distinguishes paraprobiotics from postbiotics.
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Affiliation(s)
- Rosa Anna Siciliano
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Anna Reale
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Maria Fiorella Mazzeo
- Institute of Food Sciences, National Research Council (CNR-ISA), Via Roma 64, 83100 Avellino, Italy; (R.A.S.); (A.R.)
| | - Stefano Morandi
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
| | - Tiziana Silvetti
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.)
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156
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Nyhan L, Przyjalgowski M, Lewis L, Begley M, Callanan M. Investigating the Use of Ultraviolet Light Emitting Diodes (UV-LEDs) for the Inactivation of Bacteria in Powdered Food Ingredients. Foods 2021; 10:797. [PMID: 33917815 PMCID: PMC8068219 DOI: 10.3390/foods10040797] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 11/16/2022] Open
Abstract
The addition of contaminated powdered spices and seasonings to finished products which do not undergo further processing represents a significant concern for food manufacturers. To reduce the incidence of bacterial contamination, seasoning ingredients should be subjected to a decontamination process. Ultraviolet light emitting diodes (UV-LEDs) have been suggested as an alternative to UV lamps for reducing the microbial load of foods, due to their increasing efficiency, robustness and decreasing cost. In this study, we investigated the efficacy of UV-LED devices for the inactivation of four bacteria (Listeria monocytogenes, Escherichia coli, Bacillus subtilis and Salmonella Typhimurium) on a plastic surface and in four powdered seasoning ingredients (onion powder, garlic powder, cheese and onion powder and chilli powder). Surface inactivation experiments with UV mercury lamps, UVC-LEDs and UVA-LEDs emitting at wavelengths of 254 nm, 270 nm and 365 nm, respectively, revealed that treatment with UVC-LEDs were comparable to, or better than those observed using the mercury lamp. Bacterial reductions in the seasoning powders with UVC-LEDs were less than in the surface inactivation experiments, but significant reductions of 0.75-3 log10 colony forming units (CFU) were obtained following longer (40 s) UVC-LED exposure times. Inactivation kinetics were generally nonlinear, and a comparison of the predictive models highlighted that microbial inactivation was dependent on the combination of powder and microorganism. This study is the first to report on the efficacy of UV-LEDs for the inactivation of several different bacterial species in a variety of powdered ingredients, highlighting the potential of the technology as an alternative to the traditional UV lamps used in the food industry.
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Affiliation(s)
- Laura Nyhan
- Department of Biological Sciences, Munster Technological University, T12 P928 Cork, Ireland; (L.N.); (M.B.)
| | - Milosz Przyjalgowski
- Centre for Advanced Photonics and Process Analysis, Munster Technological University, T12 P928 Cork, Ireland; (M.P.); (L.L.)
| | - Liam Lewis
- Centre for Advanced Photonics and Process Analysis, Munster Technological University, T12 P928 Cork, Ireland; (M.P.); (L.L.)
| | - Máire Begley
- Department of Biological Sciences, Munster Technological University, T12 P928 Cork, Ireland; (L.N.); (M.B.)
| | - Michael Callanan
- Department of Biological Sciences, Munster Technological University, T12 P928 Cork, Ireland; (L.N.); (M.B.)
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157
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Perkins DJ, Nofchissey RA, Ye C, Donart N, Kell A, Foo-Hurwitz I, Muller T, Bradfute SB. COVID-19 global pandemic planning: Dry heat incubation and ambient temperature fail to consistently inactivate SARS-CoV-2 on N95 respirators. Exp Biol Med (Maywood) 2021; 246:952-959. [PMID: 33342283 PMCID: PMC7750684 DOI: 10.1177/1535370220977819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/10/2020] [Indexed: 11/25/2022] Open
Abstract
The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.
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Affiliation(s)
- Douglas J Perkins
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Robert A Nofchissey
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Chunyan Ye
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Nathan Donart
- Office of Research, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Alison Kell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Ivy Foo-Hurwitz
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Timothy Muller
- Office of Research, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Steven B Bradfute
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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158
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Abbas F, Vinberg F. Transduction and Adaptation Mechanisms in the Cilium or Microvilli of Photoreceptors and Olfactory Receptors From Insects to Humans. Front Cell Neurosci 2021; 15:662453. [PMID: 33867944 PMCID: PMC8046925 DOI: 10.3389/fncel.2021.662453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/02/2021] [Indexed: 12/11/2022] Open
Abstract
Sensing changes in the environment is crucial for survival. Animals from invertebrates to vertebrates use both visual and olfactory stimuli to direct survival behaviors including identification of food sources, finding mates, and predator avoidance. In primary sensory neurons there are signal transduction mechanisms that convert chemical or light signals into an electrical response through ligand binding or photoactivation of a receptor, that can be propagated to the olfactory and visual centers of the brain to create a perception of the odor and visual landscapes surrounding us. The fundamental principles of olfactory and phototransduction pathways within vertebrates are somewhat analogous. Signal transduction in both systems takes place in the ciliary sub-compartments of the sensory cells and relies upon the activation of G protein-coupled receptors (GPCRs) to close cyclic nucleotide-gated (CNG) cation channels in photoreceptors to produce a hyperpolarization of the cell, or in olfactory sensory neurons open CNG channels to produce a depolarization. However, while invertebrate phototransduction also involves GPCRs, invertebrate photoreceptors can be either ciliary and/or microvillar with hyperpolarizing and depolarizing responses to light, respectively. Moreover, olfactory transduction in invertebrates may be a mixture of metabotropic G protein and ionotropic signaling pathways. This review will highlight differences of the visual and olfactory transduction mechanisms between vertebrates and invertebrates, focusing on the implications to the gain of the transduction processes, and how they are modulated to allow detection of small changes in odor concentration and light intensity over a wide range of background stimulus levels.
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Affiliation(s)
- Fatima Abbas
- Vinberg Lab, Department of Ophthalmology and Visual Science, John A. Moran Center, University of Utah, Salt Lake City, UT, United States
| | - Frans Vinberg
- Vinberg Lab, Department of Ophthalmology and Visual Science, John A. Moran Center, University of Utah, Salt Lake City, UT, United States
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159
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Fang T, Wu Y, Xie Y, Sun L, Qin X, Liu Y, Li H, Dong Q, Wang X. Inactivation and Subsequent Growth Kinetics of Listeria monocytogenes After Various Mild Bactericidal Treatments. Front Microbiol 2021; 12:646735. [PMID: 33815335 PMCID: PMC8017141 DOI: 10.3389/fmicb.2021.646735] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/01/2021] [Indexed: 01/09/2023] Open
Abstract
This study was carried out to investigate the effects of mild heat, lactic acid, benzalkonium chloride and nisin treatments on the inactivation, sublethal injury, and subsequent growth of Listeria monocytogenes. Results showed that the Bigelow model successfully described the thermal inactivation kinetics, while the Log-linear model with tail consistently offered the most accurate fit to LA, BC, and nisin inactivation curves of cells. Differential plating indicated that percentage of sublethal injury for nisin treated cells was significantly higher than that for the other three treatments. Compared to non-treated cells, significant extension of lag time was observed for all treated cells. The longer exposures to heat treatment contributed to the extended lag time of the survivors. While for LA, BC and nisin treated cells, the longest lag time was not observed at the most severe treatment conditions. The correlation analysis of sublethal injury percentage on the duration of lag time revealed that only heat treatment showed the significant correlation. Overall, the lag time analysis could evaluate a wide range of bacterial injury. Lag time of treated cells was significantly influenced by stress treatments and temperatures of recovery, however, there were not any significant changes in the maximum specific growth rate between treated and non-treated cells under isothermal recovery conditions. The information generated from this study is valuable for utilizing intervention strategies in the elimination or growth inhibition of L. monocytogenes.
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Affiliation(s)
- Taisong Fang
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Yufan Wu
- Research Centre of Analysis and Test, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Yani Xie
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Linjun Sun
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Xiaojie Qin
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Yangtai Liu
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Hongmei Li
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Qingli Dong
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Xiang Wang
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
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160
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Lewis AH, Grandl J. Inactivation Kinetics and Mechanical Gating of Piezo1 Ion Channels Depend on Subdomains within the Cap. Cell Rep 2021; 30:870-880.e2. [PMID: 31968259 PMCID: PMC7021530 DOI: 10.1016/j.celrep.2019.12.040] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/05/2019] [Accepted: 12/12/2019] [Indexed: 01/06/2023] Open
Abstract
Piezo1 ion channels are activated by mechanical stimuli and mediate the sensing of blood flow. Although cryo-electron microscopy (cryo-EM) structures have revealed the overall architecture of Piezo1, the precise domains involved in activation and subsequent inactivation have remained elusive. Here, we perform a targeted chimeric screen between Piezo1 and the closely related isoform Piezo2 and use electrophysiology to characterize their inactivation kinetics during mechanical stimulation. We identify three small subdomains within the extracellular cap that individually can confer the distinct kinetics of inactivation of Piezo2 onto Piezo1. We further show by cysteine crosslinking that conformational flexibility of these subdomains is required for mechanical activation to occur and that electrostatic interactions functionally couple the cap to the extensive blades, which have been proposed to function as sensors of membrane curvature and tension. This study provides a demonstration of internal gating motions involved in mechanotransduction by Piezo1. Lewis and Grandl combine a chimeric screen and cysteine crosslinking to identify small subdomains of the cap of mechanically activated Piezo1 ion channels that must have conformational flexibility for mechanical gating. They further show that electrostatic interactions couple one of these domains to the channel blade.
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Affiliation(s)
- Amanda H Lewis
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jörg Grandl
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
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161
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Jureka AS, Williams CG, Basler CF. Pulsed Broad-Spectrum UV Light Effectively Inactivates SARS-CoV-2 on Multiple Surfaces and N95 Material. Viruses 2021; 13:460. [PMID: 33799842 PMCID: PMC7998866 DOI: 10.3390/v13030460] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/02/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
The ongoing SARS-CoV-2 pandemic has resulted in an increased need for technologies capable of efficiently disinfecting public spaces as well as personal protective equipment. UV light disinfection is a well-established method for inactivating respiratory viruses. Here, we have determined that broad-spectrum, pulsed UV light is effective at inactivating SARS-CoV-2 on multiple surfaces in vitro. For hard, non-porous surfaces, we observed that SARS-CoV-2 was inactivated to undetectable levels on plastic and glass with a UV dose of 34.9 mJ/cm2 and stainless steel with a dose of 52.5 mJ/cm2. We also observed that broad-spectrum, pulsed UV light is effective at reducing SARS-CoV-2 on N95 respirator material to undetectable levels with a dose of 103 mJ/cm2. We included UV dosimeter cards that provide a colorimetric readout of UV dose and demonstrated their utility as a means to confirm desired levels of exposure were reached. Together, the results presented here demonstrate that broad-spectrum, pulsed UV light is an effective technology for the in vitro inactivation of SARS-CoV-2 on multiple surfaces.
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Affiliation(s)
| | | | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA; (A.S.J.); (C.G.W.)
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162
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Kumar R, Kolloli A, Subbian S. Inactivation and Elimination of SARS-CoV-2 in Biosamples Using Simple Fixatives and Ultrafiltration. Methods Protoc 2021; 4:18. [PMID: 33673589 DOI: 10.3390/mps4010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 12/24/2022] Open
Abstract
The Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) causes Coronavirus disease-2019 (COVID-19), which is an ongoing pandemic that has significantly affected the health, economy, and socio-economic status of individuals worldwide. Laboratory research using in vitro, ex vivo and in vivo models has been accelerated to understand the pathogenesis of SARS-CoV-2 infection. However, such experimental research involving SARS-CoV-2 is restricted to biocontainment/safety level-3 (BSL-3) settings, due to the high pathogenicity of this virus. Since many of the downstream analyses of SARS-CoV-2-infected biological samples need to be conducted in a non-BSL3 setting, it is important to ensure that the samples are fully decontaminated and safe for subsequent analysis. Here, we report the effectiveness of standard procedures used to fix cells and tissues for pathological analysis, including 2% or 4% paraformaldehyde, 50%–70% ethanol, 10% neutral buffered formalin and ultrafiltration using membranes with a molecular weight cut-off (MWCO) ranging from 3 to 30 kDa, for inactivating or eliminating SARS-CoV-2. We validated these methods in experimental laboratory samples, such as viral inoculum in cell culture media, SARS-CoV-2 infected host cells and animal tissue lysates. We found that 15 minutes’ treatment of viral inoculum (105 plaque-forming units; PFU) or SARS-CoV-2 infected cells with paraformaldehyde or 70% ethanol resulted in complete inactivation of the virus. The treatment of infected hamster lung tissues with 10% neutral buffered formalin also fully inactivated the virus. However, only 3 kDa ultracentrifuge filter was effective in eliminating the virus to an undetectable limit in the filtrate. Our validated methods are useful for decontaminating biological samples to reduce infection risk and safe handling in BSL2 facilities.
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163
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Dähnert L, Schlosser J, Fast C, Fröhlich A, Gröner A, Lange E, Roth NJ, Schäfer W, Schröder C, Eiden M, Groschup MH. Hepatitis E virus: Efficacy of pasteurization of plasma-derived VWF/FVIII concentrate determined by pig bioassay. Transfusion 2021; 61:1266-1277. [PMID: 33605455 DOI: 10.1111/trf.16298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hepatitis E virus (HEV) is the leading cause of acute hepatitis throughout the world. Increasing blood component transfusion-associated HEV infections highlight the need for reliable virus inactivation procedures for plasma derivatives from pooled plasma donations. STUDY DESIGN AND METHODS An animal infection study was conducted to evaluate the efficiency of HEV inactivation by pasteurization during the manufacturing process of the von Willebrand Factor/Factor VIII (VWF/FVIII) concentrate Haemate P/Humate-P (CSL Behring, Marburg, Germany). For this purpose, groups of pigs were inoculated with stabilized VWF/FVIII intermediate spiked with HEV-positive liver homogenate and exposed to increasing incubation times of 0, 3, 6, and 10 h at 60°C. Animals were evaluated for virus replication over 27 days and in a subsequent trial over 92 days. RESULTS Virus replication was detected in animals up to the 6-h pasteurization group. In contrast, pasteurization for 10 h did not reveal virus detection when the observation period was 27 days. In an additional experiment using the 10-h pasteurized material, two individuals started virus excretion and seroconverted when the observation period was extended to 92 days. Based on the total infection rate (2 of 12) of the animals inoculated with the sample pasteurized for 10 h, a virus reduction factor of at least 4.7 log10 is calculated. CONCLUSION This study demonstrates that pasteurization at 60°C for 10 h of an HEV-positive plasma derivative leads to the effective reduction of infectivity, resulting in a VWF/FVIII product with an appropriate margin of safety for HEV.
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Affiliation(s)
- Lisa Dähnert
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Josephine Schlosser
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Germany.,Department of Veterinary Medicine, Freie Universität Berlin, Institute of Immunology, Berlin, Germany
| | - Christine Fast
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Andreas Fröhlich
- Institute of Epidemiology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | | | - Elke Lange
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Nathan J Roth
- Global Pathogen Safety, CSL Behring AG, Bern, Switzerland
| | | | - Charlotte Schröder
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Martin Eiden
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Martin H Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Germany
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164
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Liu X, Zhang M, Meng X, He X, Zhao W, Liu Y, He Y. Inactivation and Membrane Damage Mechanism of Slightly Acidic Electrolyzed Water on Pseudomonas deceptionensis CM2. Molecules 2021; 26:molecules26041012. [PMID: 33672940 PMCID: PMC7917946 DOI: 10.3390/molecules26041012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 11/16/2022] Open
Abstract
Pseudomonas is considered as the specific spoilage bacteria in meat and meat products. The purpose of this study was to evaluate the inactivation efficiency and mechanisms of slightly acidic electrolyzed water (SAEW) against Pseudomonas deceptionensis CM2, a strain isolated from spoiling chicken breast. SAEW caused time-dependent inactivation of P. deceptionensis CM2 cells. After exposure to SAEW (pH 5.9, oxidation-reduction potential of 945 mV, and 64 mg/L of available chlorine concentration) for 60 s, the bacterial populations were reduced by 5.14 log reduction from the initial load of 10.2 log10 CFU/mL. Morphological changes in P. deceptionensis CM2 cells were clearly observed through field emission-scanning electron microscopy as a consequence of SAEW treatment. SAEW treatment also resulted in significant increases in the extracellular proteins and nucleic acids, and the fluorescence intensities of propidium iodide and n-phenyl-1-napthylamine in P. deceptionensis CM2 cells, suggesting the disruption of cytoplasmic and outer membrane integrity. These findings show that SAEW is a promising antimicrobial agent.
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Affiliation(s)
- Xiao Liu
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China; (X.L.); (M.Z.); (X.M.); (X.H.); (W.Z.)
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450001, China
| | - Mingli Zhang
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China; (X.L.); (M.Z.); (X.M.); (X.H.); (W.Z.)
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450001, China
| | - Xi Meng
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China; (X.L.); (M.Z.); (X.M.); (X.H.); (W.Z.)
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450001, China
| | - Xiangli He
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China; (X.L.); (M.Z.); (X.M.); (X.H.); (W.Z.)
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450001, China
| | - Weidong Zhao
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China; (X.L.); (M.Z.); (X.M.); (X.H.); (W.Z.)
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, China
- Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou 450001, China
| | - Yongji Liu
- Department of Nutrition, Henry Fok School of Food Science and Engineering, Shaoguan University, Shaoguan 512000, China
- Correspondence: (Y.L.); (Y.H.)
| | - Yu He
- College of Food and Biotechnology Engineering, Xuzhou University of Technology, Xuzhou 221018, China
- Correspondence: (Y.L.); (Y.H.)
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165
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Criscuolo E, Diotti RA, Ferrarese R, Alippi C, Viscardi G, Signorelli C, Mancini N, Clementi M, Clementi N. Fast inactivation of SARS-CoV-2 by UV-C and ozone exposure on different materials. Emerg Microbes Infect 2021; 10:206-210. [PMID: 33399524 PMCID: PMC7872580 DOI: 10.1080/22221751.2021.1872354] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The extremely rapid spread of the SARS-CoV-2 has already resulted in more than 1 million reported deaths of coronavirus disease 2019 (COVID-19). The ability of infectious particles to persist on environmental surfaces is potentially considered a factor for viral spreading. Therefore, limiting viral diffusion in public environments should be achieved with correct disinfection of objects, tissues, and clothes. This study proves how two widespread disinfection systems, short-wavelength ultraviolet light (UV-C) and ozone (O3), are active in vitro on different commonly used materials. The development of devices equipped with UV-C, or ozone generators, may prevent the virus from spreading in public places.
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Affiliation(s)
- Elena Criscuolo
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy
| | - Roberta A Diotti
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy
| | - Roberto Ferrarese
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy
| | - Cesare Alippi
- Dipartimento di Elettronica e Informazione, WEMSY Lab, Politecnico di Milano, Italy
| | - Gabriele Viscardi
- Dipartimento di Elettronica e Informazione, WEMSY Lab, Politecnico di Milano, Italy
| | - Carlo Signorelli
- School of Medicine, Vita-Salute San Raffaele University, Milan, Italy
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy.,Laboratory of Microbiology and Virology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy.,Laboratory of Microbiology and Virology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy.,Laboratory of Microbiology and Virology, IRCCS San Raffaele Scientific Institute, Milan, Italy
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166
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Jelsma T, Wijnker JJ, van der Poel WHM, Wisselink HJ. Intestinal Viral Loads and Inactivation Kinetics of Livestock Viruses Relevant for Natural Casing Production: a Systematic Review and Meta-Analysis. Pathogens 2021; 10:pathogens10020173. [PMID: 33557372 PMCID: PMC7915499 DOI: 10.3390/pathogens10020173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/15/2021] [Accepted: 01/29/2021] [Indexed: 01/26/2023] Open
Abstract
Animal intestines are the source of edible sausage casings, which are traded worldwide and may come from areas where notifiable infectious animal diseases are prevalent. To estimate the risks of virus contamination, knowledge about the quantity of virus and decimal reduction values of the standard preservation method by salting is of great importance. A literature search, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was performed in search engine CAB Abstracts to determine the viral load of 14 relevant animal viruses in natural casings or intestines. Only a very limited number of scientific publications per virus were found and viral loads in the intestines varied from high for ASFV (five publications), BVDV (3), CSFV (6), PPRV (3), RPV (2) and TGEV (3) to moderate for PEDV (2) and SVDV (3), low for HEV (2) and FMDV (5), very low for VESV (1) and negative for PrV (2) and VSV (1). PRRSV was found in intestines, however, viral titers were not published. Three viruses (BVDV, CSFV and PPRV) with high viral loads were selected to search for their inactivation kinetics. For casings, no inactivation data were found, however, thermal inactivation data of these viruses were available, but differed in quantity, quality and matrices. In conclusion, important data gaps still exist when it comes to the quantitative inactivation of viruses in sausage casings or livestock intestines.
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Affiliation(s)
- Tinka Jelsma
- Department of Virology, Wageningen Bioveterinary Research (WBVR) Part of Wageningen University & Research (WUR), P.O. Box 65, 8200 AB Lelystad, The Netherlands;
- Correspondence:
| | - Joris J. Wijnker
- Department of Population Health Sciences, Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80178, 3508 TD Utrecht, The Netherlands;
| | - Wim H. M. van der Poel
- Department of Virology, Wageningen Bioveterinary Research (WBVR) Part of Wageningen University & Research (WUR), P.O. Box 65, 8200 AB Lelystad, The Netherlands;
| | - Henk J. Wisselink
- Department of Infection Biology, Wageningen Bioveterinary Research (WBVR) Part of Wageningen University & Research (WUR), P.O. Box 65, 8200 AB Lelystad, The Netherlands;
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167
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Wigginton KR, Arts PJ, Clack HL, Fitzsimmons WJ, Gamba M, Harrison KR, LeBar W, Lauring AS, Li L, Roberts WW, Rockey NC, Torreblanca J, Young C, Anderegg LG, Cohn AM, Doyle JM, Meisenhelder CM, Raskin L, Love NG, Kaye KS. Validation of N95 Filtering Facepiece Respirator Decontamination Methods Available at a Large University Hospital. Open Forum Infect Dis 2021; 8:ofaa610. [PMID: 33575418 DOI: 10.1101/2020.04.28.20084038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/09/2020] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND Due to unprecedented shortages in N95 filtering facepiece respirators, healthcare systems have explored N95 reprocessing. No single, full-scale reprocessing publication has reported an evaluation including multiple viruses, bacteria, and fungi along with respirator filtration and fit. METHODS We explored reprocessing methods using new 3M 1860 N95 respirators, including moist (50%-75% relative humidity [RH]) heat (80-82°C for 30 minutes), ethylene oxide (EtO), pulsed xenon UV-C (UV-PX), hydrogen peroxide gas plasma (HPGP), and hydrogen peroxide vapor (HPV). Respirator samples were analyzed using 4 viruses (MS2, phi6, influenza A virus [IAV], murine hepatitis virus [MHV)]), 3 bacteria (Escherichia coli, Staphylococcus aureus, Geobacillus stearothermophilus spores, and vegetative bacteria), and Aspergillus niger. Different application media were tested. Decontaminated respirators were evaluated for filtration integrity and fit. RESULTS Heat with moderate RH most effectively inactivated virus, resulting in reductions of >6.6-log10 MS2, >6.7-log10 Phi6, >2.7-log10 MHV, and >3.9-log10 IAV and prokaryotes, except for G stearothermohphilus. Hydrogen peroxide vapor was moderately effective at inactivating tested viruses, resulting in 1.5- to >4-log10 observable inactivation. Staphylococcus aureus inactivation by HPV was limited. Filtration efficiency and proper fit were maintained after 5 cycles of heat with moderate RH and HPV. Although it was effective at decontamination, HPGP resulted in decreased filtration efficiency, and EtO treatment raised toxicity concerns. Observed virus inactivation varied depending upon the application media used. CONCLUSIONS Both moist heat and HPV are scalable N95 reprocessing options because they achieve high levels of biological indicator inactivation while maintaining respirator fit and integrity.
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Affiliation(s)
- Krista R Wigginton
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter J Arts
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Herek L Clack
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William J Fitzsimmons
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Mirko Gamba
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine R Harrison
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William LeBar
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Adam S Lauring
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Lucinda Li
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan Health System, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Nicole C Rockey
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Jania Torreblanca
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Carol Young
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Loïc G Anderegg
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts, USA
| | - Amy M Cohn
- Department of Industrial & Operations Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts, USA
| | | | - Lutgarde Raskin
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Nancy G Love
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
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168
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Wigginton KR, Arts PJ, Clack HL, Fitzsimmons WJ, Gamba M, Harrison KR, LeBar W, Lauring AS, Li L, Roberts WW, Rockey NC, Torreblanca J, Young C, Anderegg LG, Cohn AM, Doyle JM, Meisenhelder CM, Raskin L, Love NG, Kaye KS. Validation of N95 Filtering Facepiece Respirator Decontamination Methods Available at a Large University Hospital. Open Forum Infect Dis 2021; 8:ofaa610. [PMID: 33575418 PMCID: PMC7863868 DOI: 10.1093/ofid/ofaa610] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Due to unprecedented shortages in N95 filtering facepiece respirators, healthcare systems have explored N95 reprocessing. No single, full-scale reprocessing publication has reported an evaluation including multiple viruses, bacteria, and fungi along with respirator filtration and fit. METHODS We explored reprocessing methods using new 3M 1860 N95 respirators, including moist (50%-75% relative humidity [RH]) heat (80-82°C for 30 minutes), ethylene oxide (EtO), pulsed xenon UV-C (UV-PX), hydrogen peroxide gas plasma (HPGP), and hydrogen peroxide vapor (HPV). Respirator samples were analyzed using 4 viruses (MS2, phi6, influenza A virus [IAV], murine hepatitis virus [MHV)]), 3 bacteria (Escherichia coli, Staphylococcus aureus, Geobacillus stearothermophilus spores, and vegetative bacteria), and Aspergillus niger. Different application media were tested. Decontaminated respirators were evaluated for filtration integrity and fit. RESULTS Heat with moderate RH most effectively inactivated virus, resulting in reductions of >6.6-log10 MS2, >6.7-log10 Phi6, >2.7-log10 MHV, and >3.9-log10 IAV and prokaryotes, except for G stearothermohphilus. Hydrogen peroxide vapor was moderately effective at inactivating tested viruses, resulting in 1.5- to >4-log10 observable inactivation. Staphylococcus aureus inactivation by HPV was limited. Filtration efficiency and proper fit were maintained after 5 cycles of heat with moderate RH and HPV. Although it was effective at decontamination, HPGP resulted in decreased filtration efficiency, and EtO treatment raised toxicity concerns. Observed virus inactivation varied depending upon the application media used. CONCLUSIONS Both moist heat and HPV are scalable N95 reprocessing options because they achieve high levels of biological indicator inactivation while maintaining respirator fit and integrity.
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Affiliation(s)
- Krista R Wigginton
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter J Arts
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Herek L Clack
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William J Fitzsimmons
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Mirko Gamba
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine R Harrison
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William LeBar
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Adam S Lauring
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Lucinda Li
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan Health System, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Nicole C Rockey
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Jania Torreblanca
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Carol Young
- Department of Pathology, Clinical Microbiology, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Loïc G Anderegg
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts, USA
| | - Amy M Cohn
- Department of Industrial & Operations Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts, USA
| | | | - Lutgarde Raskin
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Nancy G Love
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
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169
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Tomita K, Miyauchi S, Katagiri Y, Yoneyama S, Dongze L, Chiba Y, Hirata TI, Ichijo T, Yasuda HA, Hikono H, Murakami K. Effectiveness of on-farm continuous flow high-temperature short-time pasteurization for inactivation of bovine leukemia virus in milk. Anim Sci J 2021; 91:e13495. [PMID: 33372705 DOI: 10.1111/asj.13495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/21/2020] [Accepted: 11/30/2020] [Indexed: 11/27/2022]
Abstract
The effectiveness of on-farm continuous flow high-temperature short-time (HTST) pasteurization (i.e., 72°C for 15 s) for the inactivation of bovine leukemia virus (BLV) in milk was investigated with a sheep bioassay. Four sheep that had been inoculated with completely pasteurized milk containing approximately 3.4 × 107 BLV-infected peripheral blood mononuclear cells (PBMC) and treated by either HTST pasteurization or laboratory-scale low-temperature long-time (LTLT) pasteurization (i.e., 60°C for 30 min), remained negative for BLV for at least 17 weeks after inoculation. In contrast, all sheep inoculated with unpasteurized or inadequately pasteurized milk containing the same number of BLV-infected PBMC were tested positive for BLV and anti-BLV antibodies within 3 weeks after inoculation. These results suggest that on-farm continuous flow HTST pasteurization was equivalent value with inactivated BLV on the LTLT procedure and can effectively inactivate BLV in the milk. Therefore, on-farm HTST pasteurization of the pooled colostrum or milk used in automated feeding systems is likely to protect group-housed preweaned calves from BLV infection, thereby improving animal health on dairy farms.
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Affiliation(s)
- Keisuke Tomita
- Graduate School of Veterinary Sciences, Iwate University, Iwate, Japan
| | - Sonoko Miyauchi
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Yuzuru Katagiri
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Syuji Yoneyama
- Graduate School of Veterinary Sciences, Iwate University, Iwate, Japan
| | - Leng Dongze
- Graduate School of Veterinary Sciences, Iwate University, Iwate, Japan
| | - Yusuke Chiba
- Graduate School of Veterinary Sciences, Iwate University, Iwate, Japan
| | - Toh-Ichi Hirata
- Field Science Center, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Toshihiro Ichijo
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Hajime A Yasuda
- Research Faculty of Agriculture, Hokkaido University, Hokkaido, Japan
| | - Hirokazu Hikono
- Department of Animal Sciences, Teikyo University of Science, Tokyo, Japan
| | - Kenji Murakami
- Graduate School of Veterinary Sciences, Iwate University, Iwate, Japan.,Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate, Japan
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170
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Abstract
Green tea extracts effectively inactivated SARS-CoV-2 in vitro in a dose-dependent manner. Serially 10-fold diluted solutions of catechin mixture reagent from green tea were mixed with the viral culture fluid at a volume ratio of nine to one, respectively, and kept at room temperature for 5 min. The solution of 10 mg/mL catechin reagent reduced the viral titer by 4.2 log and 1.0 mg/mL solution reduced only by one log. Pre-infection treatment of the cells with the reagent alone did not affect the viral growth. In addition, cells treated with only the reagent was assayed for host-cell viability using the WST-8 system and almost no host-cell damage by the treatment was observed. These findings suggested that the direct treatment of virus with the reagent before inoculation decreased the viral activity and that catechins might have a potential to suppress the SARS-CoV-2 infection.
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Affiliation(s)
- Hidekazu Nishimura
- Virus Research Center, Clinical Research Division, Sendai Medical Center, Japan
| | - Michiko Okamoto
- Department of Virology, Tohoku University Graduate School of Medicine, Japan
| | - Isolde Dapat
- Virus Research Center, Clinical Research Division, Sendai Medical Center, Japan
| | | | - Hitoshi Oshitani
- Department of Virology, Tohoku University Graduate School of Medicine, Japan
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171
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Jacq-Bailly A, Benvenuti M, Payne N, Kpebe A, Felbek C, Fourmond V, Léger C, Brugna M, Baffert C. Electrochemical Characterization of a Complex FeFe Hydrogenase, the Electron-Bifurcating Hnd From Desulfovibrio fructosovorans. Front Chem 2021; 8:573305. [PMID: 33490032 PMCID: PMC7820892 DOI: 10.3389/fchem.2020.573305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/10/2020] [Indexed: 12/02/2022] Open
Abstract
Hnd, an FeFe hydrogenase from Desulfovibrio fructosovorans, is a tetrameric enzyme that can perform flavin-based electron bifurcation. It couples the oxidation of H2 to both the exergonic reduction of NAD+ and the endergonic reduction of a ferredoxin. We previously showed that Hnd retains activity even when purified aerobically unlike other electron-bifurcating hydrogenases. In this study, we describe the purification of the enzyme under O2-free atmosphere and its biochemical and electrochemical characterization. Despite its complexity due to its multimeric composition, Hnd can catalytically and directly exchange electrons with an electrode. We characterized the catalytic and inhibition properties of this electron-bifurcating hydrogenase using protein film electrochemistry of Hnd by purifying Hnd aerobically or anaerobically, then comparing the electrochemical properties of the enzyme purified under the two conditions via protein film electrochemistry. Hydrogenases are usually inactivated under oxidizing conditions in the absence of dioxygen and can then be reactivated, to some extent, under reducing conditions. We demonstrate that the kinetics of this high potential inactivation/reactivation for Hnd show original properties: it depends on the enzyme purification conditions and varies with time, suggesting the coexistence and the interconversion of two forms of the enzyme. We also show that Hnd catalytic properties (Km for H2, diffusion and reaction at the active site of CO and O2) are comparable to those of standard hydrogenases (those which cannot catalyze electron bifurcation). These results suggest that the presence of the additional subunits, needed for electron bifurcation, changes neither the catalytic behavior at the active site, nor the gas diffusion kinetics but induces unusual rates of high potential inactivation/reactivation.
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Affiliation(s)
| | | | - Natalie Payne
- CNRS, Aix Marseille University, BIP, Marseille, France
| | - Arlette Kpebe
- CNRS, Aix Marseille University, BIP, Marseille, France
| | | | | | | | - Myriam Brugna
- CNRS, Aix Marseille University, BIP, Marseille, France
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172
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Govaris A, Pexara A. Inactivation of Foodborne Viruses by High-Pressure Processing (HPP). Foods 2021; 10:215. [PMID: 33494224 DOI: 10.3390/foods10020215] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 12/25/2022] Open
Abstract
High-pressure processing (HPP) is an innovative non-thermal food preservation method. HPP can inactivate microorganisms, including viruses, with minimal influence on the physicochemical and sensory properties of foods. The most significant foodborne viruses are human norovirus (HuNoV), hepatitis A virus (HAV), human rotavirus (HRV), hepatitis E virus (HEV), human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV), and enterovirus (EV), which have also been implicated in foodborne outbreaks in various countries. The HPP inactivation of foodborne viruses in foods depends on high-pressure processing parameters (pressure, temperature, and duration time) or non-processing parameters such as virus type, food matrix, water activity (aw), and the pH of foods. HPP was found to be effective for the inactivation of foodborne viruses such as HuNoV, HAV, HAstV, and HuAdV in foods. HPP treatments have been found to be effective at eliminating foodborne viruses in high-risk foods such as shellfish and vegetables. The present work reviews the published data on the effect of HPP processing on foodborne viruses in laboratory media and foods.
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173
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Soni A, Choi J, Brightwell G. Plasma-Activated Water (PAW) as a Disinfection Technology for Bacterial Inactivation with a Focus on Fruit and Vegetables. Foods 2021; 10:foods10010166. [PMID: 33467523 PMCID: PMC7830122 DOI: 10.3390/foods10010166] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/11/2022] Open
Abstract
Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.
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Affiliation(s)
- Aswathi Soni
- Food Assurance, AgResearch, Palmerston North 4442, New Zealand;
- Correspondence: ; Tel.: +64-21-0860-7979
| | - Jonghyun Choi
- The New Zealand Institute for Plant and Food Research Ltd., Private Bag 3230, Waikato Mail Centre, Hamilton 3240, New Zealand;
| | - Gale Brightwell
- Food Assurance, AgResearch, Palmerston North 4442, New Zealand;
- New Zealand Food Safety Science Research Centre, Palmerston North 4474, New Zealand
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174
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Dijkema FM, Nordentoft MK, Didriksen AK, Corneliussen AS, Willemoës M, Winther JR. Flash properties of Gaussia luciferase are the result of covalent inhibition after a limited number of cycles. Protein Sci 2021; 30:638-649. [PMID: 33426745 DOI: 10.1002/pro.4023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 01/15/2023]
Abstract
Luciferases are widely used as reporters for gene expression and for sensitive detection systems. The luciferase (GLuc) from the marine copepod Gaussia princeps, has gained popularity, primarily because it is secreted and displays a very high light intensity. While firefly luciferase is characterized by kinetic behavior which is consistent with conventional steady-state Michaelis-Menten kinetics, GLuc displays what has been termed "flash" kinetics, which signify a burst in light emission followed by a rapid decay. As the mechanistic background for this behavior was unclear, we decided to decipher this in more detail. We show that decay in light signal is not due to depletion of substrate, but rather is caused by the irreversible inactivation of the enzyme. Inactivation takes place after between 10 and 200 reaction cycles, depending on substrate concentration and can be described by the sum of two exponentials with associated rate constants. The dominant of these increases linearly with substrate concentration while the minor is substrate-concentration independent. In terms of rate of initial luminescence reaction, this increases with the substrate concentration to the power of 1.5 and shows no signs of saturation up to 10 μM coelenterazine. Finally, we find that the inactivated form of the enzyme has a larger apparent size in both size exclusion chromatography and SDS-PAGE analysis and shows a fluorescence peak at 410 nm when excited at 333 nm. These findings indicate that the "flash" kinetics in Gaussia luciferase are caused by an irreversible covalent binding to a substrate derivative during catalysis.
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Affiliation(s)
- Fenne Marjolein Dijkema
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Matilde Knapkøien Nordentoft
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anders Krøll Didriksen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anders Svaerke Corneliussen
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin Willemoës
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jakob R Winther
- Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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175
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Barrow KA, Rich LM, Vanderwall ER, Reeves SR, Rathe JA, White MP, Debley JS. Inactivation of Material from SARS-CoV-2-Infected Primary Airway Epithelial Cell Cultures. Methods Protoc 2021; 4:mps4010007. [PMID: 33430421 PMCID: PMC7839057 DOI: 10.3390/mps4010007] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/25/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022] Open
Abstract
Given that the airway epithelium is the initial site of infection, study of primary human airway epithelial cells (AEC) infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will be crucial to improved understanding of viral entry factors and innate immune responses to the virus. Centers for Disease Control and Prevention (CDC) guidance recommends work with live SARS-CoV-2 in cell culture be conducted in a Biosafety Level 3 (BSL-3) laboratory. To facilitate downstream assays of materials from experiments there is a need for validated protocols for SARS-CoV-2 inactivation to facilitate safe transfer of material out of a BSL-3 laboratory. We propagated stocks of SARS-CoV-2, then evaluated the effectiveness of heat (65 °C) or ultraviolet (UV) light inactivation. We infected differentiated human primary AECs with SARS-CoV-2, then tested protocols designed to inactivate SARS-CoV-2 in supernatant, protein isolate, RNA, and cells fixed for immunohistochemistry by exposing Vero E6 cells to materials isolated/treated using these protocols. Heating to 65 °C for 10 min or exposing to UV light fully inactivated SARS-CoV-2. Furthermore, we found in SARS-CoV-2-infected primary AEC cultures that treatment of supernatant with UV light, isolation of RNA with Trizol®, isolation of protein using a protocol including sodium dodecyl sulfate (SDS) 0.1% and Triton X100 1%, and fixation of AECs using 10% formalin and Triton X100 1%, each fully inactivated SARS-CoV-2.
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Affiliation(s)
- Kaitlyn A. Barrow
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
| | - Lucille M. Rich
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
| | - Elizabeth R. Vanderwall
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
| | - Stephen R. Reeves
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
- Department of Pediatrics, Division of Pulmonary and Sleep Medicine, Seattle Children’s Hospital, University of Washington, Seattle, WA 98101, USA
| | - Jennifer A. Rathe
- Department of Pediatrics, Division of Infectious Disease, Seattle Children’s Hospital, University of Washington, Seattle, WA 98101, USA;
| | - Maria P. White
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
| | - Jason S. Debley
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (K.A.B.); (L.M.R.); (E.R.V.); (S.R.R.); (M.P.W.)
- Department of Pediatrics, Division of Pulmonary and Sleep Medicine, Seattle Children’s Hospital, University of Washington, Seattle, WA 98101, USA
- Correspondence:
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176
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Berlansky S, Humer C, Sallinger M, Frischauf I. More Than Just Simple Interaction between STIM and Orai Proteins: CRAC Channel Function Enabled by a Network of Interactions with Regulatory Proteins. Int J Mol Sci 2021; 22:E471. [PMID: 33466526 PMCID: PMC7796502 DOI: 10.3390/ijms22010471] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/29/2020] [Accepted: 12/29/2020] [Indexed: 12/27/2022] Open
Abstract
The calcium-release-activated calcium (CRAC) channel, activated by the release of Ca2+ from the endoplasmic reticulum (ER), is critical for Ca2+ homeostasis and active signal transduction in a plethora of cell types. Spurred by the long-sought decryption of the molecular nature of the CRAC channel, considerable scientific effort has been devoted to gaining insights into functional and structural mechanisms underlying this signalling cascade. Key players in CRAC channel function are the Stromal interaction molecule 1 (STIM1) and Orai1. STIM1 proteins span through the membrane of the ER, are competent in sensing luminal Ca2+ concentration, and in turn, are responsible for relaying the signal of Ca2+ store-depletion to pore-forming Orai1 proteins in the plasma membrane. A direct interaction of STIM1 and Orai1 allows for the re-entry of Ca2+ from the extracellular space. Although much is already known about the structure, function, and interaction of STIM1 and Orai1, there is growing evidence that CRAC under physiological conditions is dependent on additional proteins to function properly. Several auxiliary proteins have been shown to regulate CRAC channel activity by means of direct interactions with STIM1 and/or Orai1, promoting or hindering Ca2+ influx in a mechanistically diverse manner. Various proteins have also been identified to exert a modulatory role on the CRAC signalling cascade although inherently lacking an affinity for both STIM1 and Orai1. Apart from ubiquitously expressed representatives, a subset of such regulatory mechanisms seems to allow for a cell-type-specific control of CRAC channel function, considering the rather restricted expression patterns of the specific proteins. Given the high functional and clinical relevance of both generic and cell-type-specific interacting networks, the following review shall provide a comprehensive summary of regulators of the multilayered CRAC channel signalling cascade. It also includes proteins expressed in a narrow spectrum of cells and tissues that are often disregarded in other reviews of similar topics.
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Affiliation(s)
| | | | | | - Irene Frischauf
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (S.B.); (C.H.); (M.S.)
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177
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Fan J, Zhang L, He J, Zhao M, Loh B, Leptihn S, Yu Y, Hua X. Plasmid Dynamics of mcr-1-Positive Salmonella spp. in a General Hospital in China. Front Microbiol 2020; 11:604710. [PMID: 33414775 PMCID: PMC7782425 DOI: 10.3389/fmicb.2020.604710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/02/2020] [Indexed: 12/18/2022] Open
Abstract
Salmonella is an important food pathogen that can cause severe gastroenteritis with more than 600,000 deaths globally every year. Colistin (COL), a last-resort antibiotic, is ineffective in bacteria that carry a functional mcr-1 gene, which is often spread by conjugative plasmids. Our work aimed to understand the prevalence of the mcr-1 gene in clinical isolates of Salmonella, as the frequency of occurrence of the mcr-1 gene is increasing globally. Therefore, we analyzed 689 clinical strains, that were isolated between 2009 and late 2018. The mcr-1 gene was found in six strains, which we analyzed in detail by whole genome sequencing and antibiotic susceptibility testing, while we also provide the clinical information on the patients suffering from an infection. The genomic analysis revealed that five strains had plasmid-encoded mcr-1 gene located in four IncHI2 plasmids and one IncI2 plasmid, while one strain had the chromosomal mcr-1 gene originated from plasmid. Surprisingly, in two strains the mcr-1 genes were inactive due to disruption by insertion sequences (ISs): ISApl1 and ISVsa5. A detailed analysis of the plasmids revealed a multitude of ISs, most commonly IS26. The IS contained genes that meditate broad resistance toward most antibiotics underlining their importance of the mobile elements, also with respect to the spread of the mcr-1 gene. Our study revealed potential reservoirs for the transmission of COL resistance and offers insights into the evolution of the mcr-1 gene in Salmonella.
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Affiliation(s)
- Jianzhong Fan
- Department of Laboratory Medicine, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Linghong Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jintao He
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Maoying Zhao
- Department of Laboratory Medicine, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, China
| | - Belinda Loh
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China
| | - Sebastian Leptihn
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University, Haining, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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178
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Abstract
The voltage-gated sodium channel Nav1.8 mediates the tetrodotoxin-resistant (TTX-R) Na+ current in nociceptive primary sensory neurons, which has an important role in the transmission of painful stimuli. Here, we describe the functional modulation of the human Nav1.8 α-subunit in Xenopus oocytes by auxiliary β subunits. We found that the β3 subunit down-regulated the maximal Na+ current amplitude and decelerated recovery from inactivation of hNav1.8, whereas the β1 and β2 subunits had no such effects. The specific regulation of Nav1.8 by the β3 subunit constitutes a potential novel regulatory mechanism of the TTX-R Na+ current in primary sensory neurons with potential implications in chronic pain states. In particular, neuropathic pain states are characterized by a down-regulation of Nav1.8 accompanied by increased expression of the β3 subunit. Our results suggest that these two phenomena may be correlated, and that increased levels of the β3 subunit may directly contribute to the down-regulation of Nav1.8. To determine which domain of the β3 subunit is responsible for the specific regulation of hNav1.8, we created chimeras of the β1 and β3 subunits and co-expressed them with the hNav1.8 α-subunit in Xenopus oocytes. The intracellular domain of the β3 subunit was shown to be responsible for the down-regulation of maximal Nav1.8 current amplitudes. In contrast, the extracellular domain mediated the effect of the β3 subunit on hNav1.8 recovery kinetics.
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Affiliation(s)
- S T Nevin
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - N Lawrence
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - A Nicke
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia.,Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - R J Lewis
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia
| | - D J Adams
- School of Biomedical Sciences and the Institute for Molecular Bioscience, The University of Queensland , Brisbane, Australia.,Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong , Wollongong, Australia
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179
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Abstract
The spread of novel coronavirus disease 2019 (COVID-19) infections worldwide has raised concerns about the prevention and control of SARS-CoV-2. Devices that rapidly inactivate viruses can reduce the chance of infection through aerosols and contact transmission. This in vitro study demonstrated that irradiation with a deep ultraviolet light-emitting diode (DUV-LED) of 280 ± 5 nm wavelength rapidly inactivates SARS-CoV-2 obtained from a COVID-19 patient. Development of devices equipped with DUV-LED is expected to prevent virus invasion through the air and after touching contaminated objects.
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Affiliation(s)
- Hiroko Inagaki
- M&N Collaboration Research Laboratory, Department of Medical Environment Innovation, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Akatsuki Saito
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
- Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan
| | - Hironobu Sugiyama
- M&N Collaboration Research Laboratory, Department of Medical Environment Innovation, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
- Nikkiso Co., LTD, Tokyo, Japan
| | - Tamaki Okabayashi
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
- Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan
| | - Shouichi Fujimoto
- Department of Hemovascular Medicine and Artificial Organs, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
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180
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Abstract
Sesamin is a major lignan in sesame seeds, and a recent meta-analysis of controlled trials indicated that sesamin intake decreases blood pressure. The antihypertensive effect of sesamin has been suggested to be due to sesamin-mediated suppression of 20-hydroxyeicosatetraenoic acid production catalyzed by CYP4F2. However, the detailed mechanism underlying inhibition of CYP4F2 function by sesamin remains unclear. In this study, the effects of sesamin on catalytic activity of CYP4F2 were investigated in vitro. Sesamin inhibited luciferin-4F2/3 O-dealkylase activity of recombinant human CYP4F2 with an IC50 value of 0.381 µM. When preincubated in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH) for 20 min, sesamin potentiated the inhibition of CYP4F2 activity. Moreover, kinetic analysis of the inactivation revealed that sesamin showed a preincubation time- and concentration-dependent inhibition of CYP4F2 activity yielding a maximal inactivation rate constant (kinact) value of 0.354 min-1 and half-maximal inhibitory concentration (KI) value of 1.12 µM. The inactivation of CYP4F2 by sesamin required NADPH. These results indicated that sesamin is a mechanism-based inactivator of human CYP4F2.
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Affiliation(s)
- Hiroaki Watanabe
- Department of Pharmacy, Shinshu University Hospital.,Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University
| | - Satoshi Yamaori
- Department of Pharmacy, Shinshu University Hospital.,Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University
| | - Shinobu Kamijo
- Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University
| | - Kaori Aikawa
- Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University
| | - Shigeru Ohmori
- Department of Pharmacy, Shinshu University Hospital.,Department of Biochemical Pharmacology and Toxicology, Graduate School of Medicine, Shinshu University
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181
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Nasir A, Ashok S, Shim JY, Park S, Yoo TH. Recent Progress in the Understanding and Engineering of Coenzyme B 12-Dependent Glycerol Dehydratase. Front Bioeng Biotechnol 2020; 8:500867. [PMID: 33224925 PMCID: PMC7674605 DOI: 10.3389/fbioe.2020.500867] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 09/17/2020] [Indexed: 01/21/2023] Open
Abstract
Coenzyme B12-dependent glycerol dehydratase (GDHt) catalyzes the dehydration reaction of glycerol in the presence of adenosylcobalamin to yield 3-hydroxypropanal (3-HPA), which can be converted biologically to versatile platform chemicals such as 1,3-propanediol and 3-hydroxypropionic acid. Owing to the increased demand for biofuels, developing biological processes based on glycerol, which is a byproduct of biodiesel production, has attracted considerable attention recently. In this review, we will provide updates on the current understanding of the catalytic mechanism and structure of coenzyme B12-dependent GDHt, and then summarize the results of engineering attempts, with perspectives on future directions in its engineering.
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Affiliation(s)
- Abdul Nasir
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | | | - Jeung Yeop Shim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Tae Hyeon Yoo
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea.,Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, South Korea
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182
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Sakudo A, Yamashiro R, Harata C. Effect of Non-Concentrated and Concentrated Vaporized Hydrogen Peroxide on Scrapie Prions. Pathogens 2020; 9:pathogens9110947. [PMID: 33202870 PMCID: PMC7696461 DOI: 10.3390/pathogens9110947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 11/16/2022] Open
Abstract
To date, there have been no studies on the sterilization of prions by non-concentrated and concentrated vaporized hydrogen peroxide (VHP) applied by the same instrument. Here, the effect of the two types of VHP applied using an ES-700 sterilizer on prions was investigated. Brain homogenate from scrapie (Chandler) prion-infected mice was spotted on a cover glass and subjected to ES-700 treatment in soft (non-concentrated VHP from 59% hydrogen peroxide) or standard (concentrated VHP from 80% hydrogen peroxide) mode. Proteinase K-resistant prion protein (PrPres), an indicator of the abnormal isoform of prion protein (PrPSc), was reduced by ES-700 treatment under several conditions: SFT1/4 (soft mode, quarter cycle), SFT1/2 (soft mode, half cycle), SFT1 (soft mode, full cycle), and STD1/2 (standard mode, half cycle). PrPres was detected after the first and second rounds of protein misfolding cyclic amplification (PMCA) of untreated samples, but was undetectable in SFT1/4, SFT1/2, SFT1, and STD1/2 treated samples. In a mouse bioassay, SFT1/2 and STD1/2 treatment of prions significantly prolonged survival time, suggesting that prion infectivity is reduced after ES-700 treatment. In summary, both non-concentrated and concentrated VHP inactivate prions and may be useful for the low-temperature sterilization of prion-contaminated medical devices.
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Affiliation(s)
- Akikazu Sakudo
- School of Veterinary Medicine, Okayama University of Science, Imabari, Ehime 794-8555, Japan
- Laboratory of Biometabolic Chemistry, School of Health Sciences, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan;
- Correspondence:
| | - Risa Yamashiro
- Laboratory of Biometabolic Chemistry, School of Health Sciences, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan;
| | - Chihiro Harata
- Canon Lifecare Solutions Inc., Minato-ku, Tokyo 108-0075, Japan;
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183
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Boiteux C, Posson DJ, Allen TW, Nimigean CM. Selectivity filter ion binding affinity determines inactivation in a potassium channel. Proc Natl Acad Sci U S A 2020; 117:29968-78. [PMID: 33154158 DOI: 10.1073/pnas.2009624117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Potassium channels can become nonconducting via inactivation at a gate inside the highly conserved selectivity filter (SF) region near the extracellular side of the membrane. In certain ligand-gated channels, such as BK channels and MthK, a Ca2+-activated K+ channel from Methanobacterium thermoautotrophicum, the SF has been proposed to play a role in opening and closing rather than inactivation, although the underlying conformational changes are unknown. Using X-ray crystallography, identical conductive MthK structures were obtained in wide-ranging K+ concentrations (6 to 150 mM), unlike KcsA, whose SF collapses at low permeant ion concentrations. Surprisingly, three of the SF's four binding sites remained almost fully occupied throughout this range, indicating high affinities (likely submillimolar), while only the central S2 site titrated, losing its ion at 6 mM, indicating low K+ affinity (∼50 mM). Molecular simulations showed that the MthK SF can also collapse in the absence of K+, similar to KcsA, but that even a single K+ binding at any of the SF sites, except S4, can rescue the conductive state. The uneven titration across binding sites differs from KcsA, where SF sites display a uniform decrease in occupancy with K+ concentration, in the low millimolar range, leading to SF collapse. We found that ions were disfavored in MthK's S2 site due to weaker coordination by carbonyl groups, arising from different interactions with the pore helix and water behind the SF. We conclude that these differences in interactions endow the seemingly identical SFs of KcsA and MthK with strikingly different inactivating phenotypes.
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184
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Abstract
The COVID-19 pandemic has brought about a consideration of our understanding of transmission of the causal agent, SARS-CoV-2 to humans and its potential effect on food safety and food security. The main routes of transmission are reported to be person-to-person, by respiratory droplets and to a lesser degree, by fomites. Concerns have been raised on the possibility of transmission via food and food packaging and whether the virus poses a risk to food safety. The current contribution provides an exposé of updated literature and reports applicable to various components of food safety and its linkage to SARS-CoV-2. The article focuses on SARS-CoV-2 survival in food, on food contact materials and food packaging, and its categorization as a foodborne vs. respiratory virus, the possibility of fecal-oral transmission and the likelihood of infection via the gastro-intestinal system. The survival and inactivation of SARS-CoV-2 in food through thermal and non-thermal inactivation methods as well as the survival and inactivation on inanimate surfaces and effective disinfection of food contact surfaces, are discussed. Ultimately, the article endeavors to add to the body of knowledge pertaining to the role of SARS-CoV-2 in food safety and thereby contribute to an agile and robust fraternity that is equipped to absorb and weather the ongoing effects of the pandemic on the food sector.
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Affiliation(s)
- Lucia E. C. M. Anelich
- Centre for Applied Food Sustainability- and Biotechnology, Central University of Technology, Bloemfontein, South Africa
| | - Ryk Lues
- Centre for Applied Food Sustainability- and Biotechnology, Central University of Technology, Bloemfontein, South Africa
| | - Jeffrey M. Farber
- Department of Food Science, University of Guelph, Guelph, ON, Canada
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185
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Yang G, Shi Y, Zhao Z, Zhong M, Jin T, Shi C, Zhang C, Xia X. Comparison of Inactivation Effect of Slightly Acidic Electrolyzed Water and Sodium Hypochlorite on Bacillus cereus Spores. Foodborne Pathog Dis 2020; 18:192-201. [PMID: 33121277 DOI: 10.1089/fpd.2020.2811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Bacillus cereus spores are concerns for food spoilage and foodborne disease in food industry due to their high resistance to heat and various disinfectants. The aim of this study was to investigate the inactivation of B. cereus spores by slightly acidic electrolyzed water (SAEW) in comparison to sodium hypochlorite (NaClO) with same available chlorine content (ACC). In this study, the efficacy of SAEW with different concentrations of ACC (40, 60, 80, 100, and 120 mg/L) on the inactivation of B. cereus spores, and the effect of SAEW combined with mild heat treatment (60°C), was examined in pure culture suspensions. Heat resistance and pyridine-2,6-dicarboxylic acid (DPA) release of the spores were also determined. The results showed that the sporicidal effect of the SAEW was significantly higher compared with the NaClO with the same concentration of ACC. Furthermore, the inactivation efficacy was largely dependent on ACC and treatment time. Moreover, the sporicidal activity of the SAEW was significantly improved when combined with a mild heat treatment (60°C). The majority of the DPA was released from spores, and the spores exhibited less resistance to heat after SAEW treatment for 30 min. These findings indicate that SAEW could effectively inactivate B. cereus spores, making it a promising and environmentally friendly decontamination technology for application in the food industry.
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Affiliation(s)
- Gaoji Yang
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yiqi Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Zhiyi Zhao
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Mengyao Zhong
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Tong Jin
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Chao Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Chunling Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xiaodong Xia
- College of Food Science and Engineering, Northwest A&F University, Yangling, China.,School of Food Science and Technology, National Engineering Research Center of Seafood, Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, China.,Technical Center, Jiangsu Ecolovo Food Group Co., Ltd., Suqian, China
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186
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van Bockel D, Munier CML, Turville S, Badman SG, Walker G, Stella AO, Aggarwal A, Yeang M, Condylios A, Kelleher AD, Applegate TL, Vallely A, Whiley D, Rawlinson W, Cunningham P, Kaldor J, Guy R. Evaluation of Commercially Available Viral Transport Medium (VTM) for SARS-CoV-2 Inactivation and Use in Point-of-Care (POC) Testing. Viruses 2020; 12:E1208. [PMID: 33114233 PMCID: PMC7690900 DOI: 10.3390/v12111208] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/16/2020] [Accepted: 10/21/2020] [Indexed: 01/14/2023] Open
Abstract
Critical to facilitating SARS-CoV-2 point-of-care (POC) testing is assurance that viruses present in specimens are inactivated onsite prior to processing. Here, we conducted experiments to determine the virucidal activity of commercially available Viral Transport Mediums (VTMs) to inactivate SARS-CoV-2. Independent testing methods for viral inactivation testing were applied, including a previously described World Health Organization (WHO) protocol, in addition to a buffer exchange method where the virus is physically separated from the VTM post exposure. The latter method enables sensitive detection of viral viability at higher viral titre when incubated with VTM. We demonstrate that VTM formulations, Primestore® Molecular Transport Medium (MTM) and COPAN eNAT™ completely inactivate high-titre SARS-CoV-2 virus (>1 × 107 copies/mL) and are compatible with POC processing. Furthermore, full viral inactivation was rapidly achieved in as little as 2 min of VTM exposure. We conclude that adding certain VTM formulations as a first step post specimen collection will render SARS-CoV-2 non-infectious for transport, or for further in-field POC molecular testing using rapid turnaround GeneXpert platforms or equivalent.
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Affiliation(s)
- David van Bockel
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - C. Mee Ling Munier
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Stuart Turville
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Steven G. Badman
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Gregory Walker
- NSW Health Pathology, Prince of Wales Hospital, Randwick, NSW 2052, Australia; (G.W.); (M.Y.); (A.C.); (W.R.)
| | - Alberto Ospina Stella
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Anupriya Aggarwal
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Malinna Yeang
- NSW Health Pathology, Prince of Wales Hospital, Randwick, NSW 2052, Australia; (G.W.); (M.Y.); (A.C.); (W.R.)
| | - Anna Condylios
- NSW Health Pathology, Prince of Wales Hospital, Randwick, NSW 2052, Australia; (G.W.); (M.Y.); (A.C.); (W.R.)
| | - Anthony D. Kelleher
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Tanya L. Applegate
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Andrew Vallely
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - David Whiley
- NSW State Reference Laboratory for HIV-AIDS/St Vincent’s Hospital Sydney, St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital Sydney Limited, Darlinghurst, NSW 2010, Australia;
- Australia Pathology Queensland, Royal Brisbane and Women’s Hospital, Herston, QLD 4006, Australia
| | - William Rawlinson
- NSW Health Pathology, Prince of Wales Hospital, Randwick, NSW 2052, Australia; (G.W.); (M.Y.); (A.C.); (W.R.)
| | - Phillip Cunningham
- Centre for Clinical Research, The University of Queensland, Royal Brisbane and Women’s Hospital Campus, Herston, QLD 4006, Australia;
| | - John Kaldor
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
| | - Rebecca Guy
- Kirby Institute for Infection and Immunity in Society, UNSW Medicine, UNSW Sydney, Kensington, NSW 2052, Australia; (C.M.L.M.); (S.T.); (S.G.B.); (A.O.S.); (A.A.); (A.D.K.); (T.L.A.); (A.V.); (J.K.); (R.G.)
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187
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Rockey N, Arts PJ, Li L, Harrison KR, Langenfeld K, Fitzsimmons WJ, Lauring AS, Love NG, Kaye KS, Raskin L, Roberts WW, Hegarty B, Wigginton KR. Humidity and Deposition Solution Play a Critical Role in Virus Inactivation by Heat Treatment of N95 Respirators. mSphere 2020. [PMID: 33087516 DOI: 10.1101/2020.06.22.20137448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
Supply shortages of N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic have motivated institutions to develop feasible and effective N95 respirator reuse strategies. In particular, heat decontamination is a treatment method that scales well and can be implemented in settings with variable or limited resources. Prior studies using multiple inactivation methods, however, have often focused on a single virus under narrowly defined conditions, making it difficult to develop guiding principles for inactivating emerging or difficult-to-culture viruses. We systematically explored how temperature, humidity, and virus deposition solutions impact the inactivation of viruses deposited and dried on N95 respirator coupons. We exposed four virus surrogates across a range of structures and phylogenies, including two bacteriophages (MS2 and phi6), a mouse coronavirus (murine hepatitis virus [MHV]), and a recombinant human influenza A virus subtype H3N2 (IAV), to heat treatment for 30 min in multiple deposition solutions across several temperatures and relative humidities (RHs). We observed that elevated RH was essential for effective heat inactivation of all four viruses tested. For heat treatments between 72°C and 82°C, RHs greater than 50% resulted in a >6-log10 inactivation of bacteriophages, and RHs greater than 25% resulted in a >3.5-log10 inactivation of MHV and IAV. Furthermore, deposition of viruses in host cell culture media greatly enhanced virus inactivation by heat and humidity compared to other deposition solutions, such as phosphate-buffered saline, phosphate-buffered saline with bovine serum albumin, and human saliva. Past and future heat treatment methods must therefore explicitly account for deposition solutions as a factor that will strongly influence observed virus inactivation rates. Overall, our data set can inform the design and validation of effective heat-based decontamination strategies for N95 respirators and other porous surfaces, especially for emerging viruses that may be of immediate and future public health concern.IMPORTANCE Shortages of personal protective equipment, including N95 respirators, during the coronavirus (CoV) disease 2019 (COVID-19) pandemic have highlighted the need to develop effective decontamination strategies for their reuse. This is particularly important in health care settings for reducing exposure to respiratory viruses, like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19. Although several treatment methods are available, a widely accessible strategy will be necessary to combat shortages on a global scale. We demonstrate that the combination of heat and humidity inactivates a range of RNA viruses, including both viral pathogens and common viral pathogen surrogates, after deposition on N95 respirators and achieves the necessary virus inactivation detailed by the U.S. Food and Drug Administration guidelines to validate N95 respirator decontamination technologies. We further demonstrate that depositing viruses onto surfaces when suspended in culture media can greatly enhance observed inactivation, adding caution to how heat and humidity treatment methods are validated.
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Affiliation(s)
- Nicole Rockey
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter J Arts
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Lucinda Li
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine R Harrison
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Kathryn Langenfeld
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William J Fitzsimmons
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Adam S Lauring
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Nancy G Love
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Lutgarde Raskin
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan Health System, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Bridget Hegarty
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Krista R Wigginton
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
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188
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Welch SR, Davies KA, Buczkowski H, Hettiarachchi N, Green N, Arnold U, Jones M, Hannah MJ, Evans R, Burton C, Burton JE, Guiver M, Cane PA, Woodford N, Bruce CB, Roberts ADG, Killip MJ. Analysis of Inactivation of SARS-CoV-2 by Specimen Transport Media, Nucleic Acid Extraction Reagents, Detergents, and Fixatives. J Clin Microbiol 2020; 58:e01713-20. [PMID: 32839250 DOI: 10.1128/JCM.01713-20] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/20/2020] [Indexed: 12/17/2022] Open
Abstract
The COVID-19 pandemic has necessitated a multifaceted rapid response by the scientific community, bringing researchers, health officials, and industry together to address the ongoing public health emergency. To meet this challenge, participants need an informed approach for working safely with the etiological agent, the novel human coronavirus SARS-CoV-2. Work with infectious SARS-CoV-2 is currently restricted to high-containment laboratories, but material can be handled at a lower containment level after inactivation. The COVID-19 pandemic has necessitated a multifaceted rapid response by the scientific community, bringing researchers, health officials, and industry together to address the ongoing public health emergency. To meet this challenge, participants need an informed approach for working safely with the etiological agent, the novel human coronavirus SARS-CoV-2. Work with infectious SARS-CoV-2 is currently restricted to high-containment laboratories, but material can be handled at a lower containment level after inactivation. Given the wide array of inactivation reagents that are being used in laboratories during this pandemic, it is vital that their effectiveness is thoroughly investigated. Here, we evaluated a total of 23 commercial reagents designed for clinical sample transportation, nucleic acid extraction, and virus inactivation for their ability to inactivate SARS-CoV-2, as well as seven other common chemicals, including detergents and fixatives. As part of this study, we have also tested five filtration matrices for their effectiveness at removing the cytotoxic elements of each reagent, permitting accurate determination of levels of infectious virus remaining following treatment. In addition to providing critical data informing inactivation methods and risk assessments for diagnostic and research laboratories working with SARS-CoV-2, these data provide a framework for other laboratories to validate their inactivation processes and to guide similar studies for other pathogens.
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189
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Rockey N, Arts PJ, Li L, Harrison KR, Langenfeld K, Fitzsimmons WJ, Lauring AS, Love NG, Kaye KS, Raskin L, Roberts WW, Hegarty B, Wigginton KR. Humidity and Deposition Solution Play a Critical Role in Virus Inactivation by Heat Treatment of N95 Respirators. mSphere 2020; 5:e00588-20. [PMID: 33087516 PMCID: PMC7580954 DOI: 10.1128/msphere.00588-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/07/2020] [Indexed: 12/29/2022] Open
Abstract
Supply shortages of N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic have motivated institutions to develop feasible and effective N95 respirator reuse strategies. In particular, heat decontamination is a treatment method that scales well and can be implemented in settings with variable or limited resources. Prior studies using multiple inactivation methods, however, have often focused on a single virus under narrowly defined conditions, making it difficult to develop guiding principles for inactivating emerging or difficult-to-culture viruses. We systematically explored how temperature, humidity, and virus deposition solutions impact the inactivation of viruses deposited and dried on N95 respirator coupons. We exposed four virus surrogates across a range of structures and phylogenies, including two bacteriophages (MS2 and phi6), a mouse coronavirus (murine hepatitis virus [MHV]), and a recombinant human influenza A virus subtype H3N2 (IAV), to heat treatment for 30 min in multiple deposition solutions across several temperatures and relative humidities (RHs). We observed that elevated RH was essential for effective heat inactivation of all four viruses tested. For heat treatments between 72°C and 82°C, RHs greater than 50% resulted in a >6-log10 inactivation of bacteriophages, and RHs greater than 25% resulted in a >3.5-log10 inactivation of MHV and IAV. Furthermore, deposition of viruses in host cell culture media greatly enhanced virus inactivation by heat and humidity compared to other deposition solutions, such as phosphate-buffered saline, phosphate-buffered saline with bovine serum albumin, and human saliva. Past and future heat treatment methods must therefore explicitly account for deposition solutions as a factor that will strongly influence observed virus inactivation rates. Overall, our data set can inform the design and validation of effective heat-based decontamination strategies for N95 respirators and other porous surfaces, especially for emerging viruses that may be of immediate and future public health concern.IMPORTANCE Shortages of personal protective equipment, including N95 respirators, during the coronavirus (CoV) disease 2019 (COVID-19) pandemic have highlighted the need to develop effective decontamination strategies for their reuse. This is particularly important in health care settings for reducing exposure to respiratory viruses, like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19. Although several treatment methods are available, a widely accessible strategy will be necessary to combat shortages on a global scale. We demonstrate that the combination of heat and humidity inactivates a range of RNA viruses, including both viral pathogens and common viral pathogen surrogates, after deposition on N95 respirators and achieves the necessary virus inactivation detailed by the U.S. Food and Drug Administration guidelines to validate N95 respirator decontamination technologies. We further demonstrate that depositing viruses onto surfaces when suspended in culture media can greatly enhance observed inactivation, adding caution to how heat and humidity treatment methods are validated.
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Affiliation(s)
- Nicole Rockey
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter J Arts
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Lucinda Li
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine R Harrison
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Kathryn Langenfeld
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William J Fitzsimmons
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Adam S Lauring
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Nancy G Love
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Lutgarde Raskin
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Roberts
- Department of Urology, University of Michigan Health System, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Bridget Hegarty
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Krista R Wigginton
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
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190
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Abd-Elghaffar AA, Rashed ME, Ali AE, Amin MA. In-Vitro Inactivation of Sabin-Polioviruses for Development of Safe and Effective Polio Vaccine. Vaccines (Basel) 2020; 8:E601. [PMID: 33066050 DOI: 10.3390/vaccines8040601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/02/2020] [Indexed: 11/25/2022] Open
Abstract
After years of global collaboration; we are steps away from a polio-free world. However, the currently conventional inactivated polio vaccine (cIPV) is suboptimal for the post eradication era. cIPV production cost and biosafety hazards hinder its availability and coverage of the global demands. Production of IPV from the attenuated Sabin strains (sIPV) was an ideal solution and scientists work extensively to perfect a safe, effective and affordable sIPV. This study investigated the ability of hydrogen peroxide (H2O2), ascorbic acid (AA) and epigallocatechin-3-gallate (EGCG) as alternatives for Formaldehyde (HCHO) to inactivate Sabin-polioviruses strains for sIPV production. Sabin-polioviruses vaccine strains were individually treated with AA, EGCG or H2O2 and were compared to HCHO. This was investigated by determination of the inactivation kinetics on HEP2C cells, testing of D-antigen preservation by ELISA and the immune response in Wistar rats of the four vaccine preparations. H2O2, AA and EGCG were able to inactivate polioviruses within 24 h while HCHO required 96 h. Significant high D-antigen levels were observed using AA, EGCG and H2O2 compared to HCHO. Rat sera tested for neutralizing antibodies showed comparable results. These findings support the idea of using these inactivating agents as safe and time- saving alternatives for HCHO to produce sIPV.
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Kumar S, Koehn JT, Gonzalez-Juarrero M, Crans DC, Crick DC. Mycobacterium tuberculosis Survival in J774A.1 Cells Is Dependent on MenJ Moonlighting Activity, Not Its Enzymatic Activity. ACS Infect Dis 2020; 6:2661-2671. [PMID: 32866371 DOI: 10.1021/acsinfecdis.0c00312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MenJ, a flavoprotein oxidoreductase, is responsible for the saturation of the β-isoprene unit of mycobacterial menaquinone, resulting in the conversion of menaquinone with nine isoprene units (MK-9) to menaquinone with nine isoprene units where the double bond in the second unit is reduced [MK-9(II-H2)]. The hydrogenation of MK-9 increases the efficiency of the mycobacterial electron transport system, whereas the deletion of MenJ results in decreased survival of the bacteria inside J774A.1 macrophage-like cells but is not required for growth in culture. Thus, it was suggested that MenJ may represent a contextual drug target in M. tuberculosis, that is, a drug target that is valid only in the context of an infected macrophage. However, it was unclear if the conversion of MK-9 to MK-9(II-H2) or the MenJ protein itself was responsible for bacterial survival. In order to resolve this issue, a plasmid expressing folded, full-length, inactive MenJ was engineered. Primary sequence analysis data revealed that MenJ shares conserved FAD binding, NADH binding, and catalytic and C-terminal motifs with archaeal geranylgeranyl reductases. A MenJ mutant deficient in any one of these motifs is devoid of reductase activity. Therefore, point mutations of highly conserved amino acids in the conserved motifs were generated and the recombinant proteins were monitored for conformational changes by circular dichroism and oxidoreductase activity. The mutational analysis indicates that amino acids tryptophan 215 (W215) and cysteine 46 (C46) of M. tuberculosis MenJ, conserved in known archaeal geranylgeranyl reductases and putative menaquinone saturases, are essential to the hydrogenation of MK-9. The mutation of either C46 to serine (C46S) or W215 to leucine (W215L) in MenJ completely abolishes the catalytic activity in vitro, and menJ knockout strains of M. tuberculosis expressing either the C46S or W215L mutant protein are unable to convert MK-9 to MK-9(II-H2) but survive inside the J774A.1 cells. Thus, surprisingly, the survival of M. tuberculosis in J774A.1 cells is dependent on the expression of MenJ rather than its oxidoreductase activity, the conversion of MK-9 to MK-9(II-H2) as previously hypothesized. Overall, the current data suggest that MenJ is a moonlighting protein.
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192
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Sakudo A, Imanishi Y, Hirata A, Koga Y, Shintani H. Effect of Nitrogen Gas Plasma Generated by a Fast-Pulsed Power Supply Using a Static Induction Thyristor on Scrapie Prion. Pathogens 2020; 9:pathogens9100819. [PMID: 33036274 PMCID: PMC7599630 DOI: 10.3390/pathogens9100819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 11/16/2022] Open
Abstract
Previous studies show that nitrogen gas plasma generated by a fast-pulsed power supply using a static induction thyristor has both virucidal and bactericidal effects. In this study, nitrogen gas plasma was further evaluated for its potential effects on prions, which are well known to be the most resistant pathogen to both chemical and physical inactivation. Aliquots (10 μL) of mouse brain homogenate infected with Chandler scrapie prion were spotted onto cover glasses and subjected to nitrogen gas plasma. Treated samples were recovered and subjected to further analyses. Control prion samples were prepared in exactly the same way but without plasma treatment. Protein misfolding cyclic amplification (PMCA) showed that nitrogen gas plasma treatment at 1.5 kilo pulse per second for 15 or 30 min caused a reduction in the in vitro propagation level of PrPres (proteinase K-resistant prion protein), which was used as an index of abnormal prion protein (PrPSc). Moreover, mice injected with prion treated with plasma for 30 min showed longer survival than mice injected with control prion, indicating that nitrogen gas plasma treatment decreased prion infectivity. Altogether, these results suggest that nitrogen gas plasma treatment can inactivate scrapie prions by decreasing the propagation activity and infectivity of PrPSc.
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Affiliation(s)
- Akikazu Sakudo
- School of Veterinary Medicine, Okayama University of Science, Imabari, Ehime 794-8555, Japan
- Laboratory of Biometabolic Chemistry, School of Health Sciences, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan
- Correspondence:
| | - Yuichiro Imanishi
- NGK Insulators Ltd., Nagoya, Aichi 467-8530, Japan;
- Energy Support Corporation, Inuyama, Aichi 484-8505, Japan
| | - Azumi Hirata
- Department of Anatomy and Cell Biology, Faculty of Medicine, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan;
| | - Yuichi Koga
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan;
| | - Hideharu Shintani
- Department of Science and Engineering, Chuo University, Tokyo 112-8551, Japan;
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193
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Berchtikou A, Sokullu E, Nahar S, Tijssen P, Gauthier MA, Ozaki T. Comparative study on the inactivation of MS2 and M13 bacteriophages using energetic femtosecond lasers. J Biophotonics 2020; 13:e202000109. [PMID: 32701195 DOI: 10.1002/jbio.202000109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Femtosecond (fs) laser irradiation techniques are emerging tools for inactivating viruses that do not involve ionizing radiation. In this work, the inactivation of two bacteriophages representing protective capsids with different geometric constraints, that is, the near-spherical MS2 (with a diameter of 27 nm) and the filamentous M13 (with a length of 880 nm) is compared using energetic visible and near-infrared fs laser pulses with various energies, pulse durations, and exposure times. Intriguingly, the results show that inactivation using 400 nm lasers is substantially more efficient for MS2 compared to M13. In contrast, using 800 nm lasers, M13 was slightly more efficiently inactivated. For both viruses, the genome was exposed to a harmful environment upon fs-laser irradiation. However, in addition to the protection of the genome, the metastable capsids differ in many properties required for stepwise cell entry that may explain their dissimilar behavior after (partial) disassembly. For MS2, the dominant mechanism of fs-laser inactivation was the aggregation of the viral capsid proteins, whereas aggregation did not affect M13 inactivation, suggesting that the dominant mechanism of M13 inactivation was related to breaking of secondary protein links.
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Affiliation(s)
- Aziz Berchtikou
- INRS - Centre Énergie Matériaux Télécommunications, Varennes, Québec, Canada
| | - Esen Sokullu
- INRS - Centre Énergie Matériaux Télécommunications, Varennes, Québec, Canada
| | - Sharifun Nahar
- INRS - Centre Énergie Matériaux Télécommunications, Varennes, Québec, Canada
| | - Peter Tijssen
- INRS - Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada
| | - Marc A Gauthier
- INRS - Centre Énergie Matériaux Télécommunications, Varennes, Québec, Canada
| | - Tsuneyuki Ozaki
- INRS - Centre Énergie Matériaux Télécommunications, Varennes, Québec, Canada
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Patterson EI, Prince T, Anderson ER, Casas-Sanchez A, Smith SL, Cansado-Utrilla C, Solomon T, Griffiths MJ, Acosta-Serrano Á, Turtle L, Hughes GL. Methods of Inactivation of SARS-CoV-2 for Downstream Biological Assays. J Infect Dis 2020; 222:1462-1467. [PMID: 32798217 PMCID: PMC7529010 DOI: 10.1093/infdis/jiaa507] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/06/2020] [Indexed: 12/29/2022] Open
Abstract
The scientific community has responded to the coronavirus disease 2019 (COVID-19) pandemic by rapidly undertaking research to find effective strategies to reduce the burden of this disease. Encouragingly, researchers from a diverse array of fields are collectively working towards this goal. Research with infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is undertaken in high-containment laboratories; however, it is often desirable to work with samples at lower-containment levels. To facilitate the transfer of infectious samples from high-containment laboratories, we have tested methods commonly used to inactivate virus and prepare the sample for additional experiments. Incubation at 80°C, a range of detergents, Trizol reagents, and UV energies were successful at inactivating a high titer of SARS-CoV-2. Methanol and paraformaldehyde incubation of infected cells also inactivated the virus. These protocols can provide a framework for in-house inactivation of SARS-CoV-2 in other laboratories, ensuring the safe use of samples in lower-containment levels.
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Affiliation(s)
- Edward I Patterson
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Tessa Prince
- National Institute for Health Research Health Protection Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, United Kingdom
| | - Enyia R Anderson
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Aitor Casas-Sanchez
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Shirley L Smith
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Cintia Cansado-Utrilla
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Tom Solomon
- National Institute for Health Research Health Protection Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, United Kingdom
- Walton Centre NHS Foundation Trust, Liverpool, United Kingdom
| | - Michael J Griffiths
- National Institute for Health Research Health Protection Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, United Kingdom
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
- Department of Neurology, Alder Hey Children’s NHS Trust, Liverpool, United Kingdom
| | - Álvaro Acosta-Serrano
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lance Turtle
- National Institute for Health Research Health Protection Unit in Emerging and Zoonotic Infections, Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, United Kingdom
- Tropical and Infectious Disease Unit, Liverpool University Hospitals Foundation NHS Trust, Liverpool, United Kingdom
| | - Grant L Hughes
- Department of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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195
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Djebbi-Simmons D, Alhejaili M, Janes M, King J, Xu W. Survival and inactivation of human norovirus GII.4 Sydney on commonly touched airplane cabin surfaces. AIMS Public Health 2020; 7:574-586. [PMID: 32968679 PMCID: PMC7505796 DOI: 10.3934/publichealth.2020046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/13/2020] [Indexed: 02/04/2023] Open
Abstract
Human norovirus (HuNoV) is one of the leading causes of acute gastroenteritis globally. HuNoV outbreaks have been recently reported during air travels. Contaminated surfaces are known as a critical transmission route at various settings. The aim of this study was to provide key information about the survival and the decontamination of HuNoV on three commonly touched airplane cabin surfaces. In this study, we monitored the survival of HuNoV on seat leather, plastic tray table, and seatbelt for 30 days, with and without additional organic load (simulated gastric fluid). The efficacy of two EPA registered anti-norovirus disinfectants were also evaluated. Results showed that HuNoV was detected at high titers (>4 log10 genomic copy number) for up to 30 days when additional organic load was present. Both tested disinfectants were found highly ineffective against HuNoV when the surface was soiled. The study showed that when the organic load was present, HuNoV was highly stable and resistant against disinfectants. Findings from this study indicated that appropriate procedures should be developed by airline companies with the help of public health authorities to decrease passengers' exposure risk to HuNoV.
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Affiliation(s)
- Dorra Djebbi-Simmons
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
| | - Mohammed Alhejaili
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
| | - Marlene Janes
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
| | - Joan King
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
| | - Wenqing Xu
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
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196
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Soni A, Smith J, Archer R, Gardner A, Tong K, Brightwell G. Development of Bacterial Spore Pouches as a Tool to Evaluate the Sterilization Efficiency-A Case Study with Microwave Sterilization Using Clostridium sporogenes and Geobacillus stearothermophilus. Foods 2020; 9:E1342. [PMID: 32977443 PMCID: PMC7598248 DOI: 10.3390/foods9101342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/18/2020] [Accepted: 09/20/2020] [Indexed: 11/16/2022] Open
Abstract
In this study, novel spore pouches were developed using mashed potato as a food model inoculated with either Geobacillus stearothermophilus or Clostridium sporogenes spores. These spore pouches were used to evaluate the sterilization efficiency of Coaxially induced microwave pasteurization and sterilization (CiMPAS) as a case study. CiMPAS technology combines microwave energy (915 MHz) along with hot water immersion to sterilize food in polymeric packages. The spore pouches were placed at pre-determined specific locations, especially cold spots in each food tray before being processed using two regimes (R-121 and R-65), which consisted of 121 °C and 65 °C at 12 and 22 kW, respectively, followed by recovery and enumeration of the surviving spores. To identify cold spots or the location for inoculation, mashed potato was spiked with Maillard precursors and processed through CiMPAS, followed by measurement of lightness values (*L-values). Inactivation equivalent to of 1-2 Log CFU/g and >6 Log CFU/g for Geobacillus stearothermophilus and Clostridium sporogenes spores, respectively was obtained on the cold spots using R-121, which comprised of a total processing time of 64.2 min. Whereas, inactivation of <1 and 2-3 Log CFU/g for G. stearothermophilus and C. sporogenes spores, respectively on the cold spots was obtained using R-65 (total processing time of 68.3 min), whereas inactivation of 1-3 Log CFU/g of C. sporogenes spores was obtained on the sides of the tray. The results were reproducible across three processing replicates for each regime and inactivation at the specific locations were clearly distinguishable. The study indicated a strong potential to use spore pouches as a tool for validation studies of microwave-induced sterilization.
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Affiliation(s)
- Aswathi Soni
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
| | - Jeremy Smith
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Richard Archer
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Amanda Gardner
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
| | - Kris Tong
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Gale Brightwell
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
- New Zealand Food Safety Science Research Centre, Palmerston North 4410, New Zealand
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197
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Meister TL, Brüggemann Y, Todt D, Conzelmann C, Müller JA, Groß R, Münch J, Krawczyk A, Steinmann J, Steinmann J, Pfaender S, Steinmann E. Virucidal Efficacy of Different Oral Rinses Against Severe Acute Respiratory Syndrome Coronavirus 2. J Infect Dis 2020; 222:1289-1292. [PMID: 32726430 PMCID: PMC7454736 DOI: 10.1093/infdis/jiaa471] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/24/2020] [Indexed: 01/14/2023] Open
Abstract
The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic creates a significant threat to global health. Recent studies suggested the significance of throat and salivary glands as major sites of virus replication and transmission during early coronavirus disease 2019, thus advocating application of oral antiseptics. However, the antiviral efficacy of oral rinsing solutions against SARS-CoV-2 has not been examined. Here, we evaluated the virucidal activity of different available oral rinses against SARS-CoV-2 under conditions mimicking nasopharyngeal secretions. Several formulations with significant SARS-CoV-2 inactivating properties in vitro support the idea that oral rinsing might reduce the viral load of saliva and could thus lower the transmission of SARS-CoV-2.
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Affiliation(s)
- Toni Luise Meister
- Department for Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Yannick Brüggemann
- Department for Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Daniel Todt
- Department for Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- European Virus Bioinformatics Center, Jena, Germany
| | - Carina Conzelmann
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Janis A Müller
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Rüdiger Groß
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Adalbert Krawczyk
- Department of Infectious Diseases, West German Centre of Infectious Diseases, Universitätsmedizin Essen, University Duisburg-Essen, Essen, Germany
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Jörg Steinmann
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, General Hospital Nürnberg, Paracelsus Medical University, Nuremberg, Germany
- Institute of Medical Microbiology, University Hospital of Essen, Essen, Germany
| | - Jochen Steinmann
- Dr. Brill + Partner GmbH Institute for Hygiene and Microbiology, Bremen, Germany
| | - Stephanie Pfaender
- Department for Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Eike Steinmann
- Department for Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
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198
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Colnago LA, Trevisol IM, Voss Rech D, Forato LA, Igreja do Nascimento Mitre C, Gagliardi Leite JP, Giglioti R, Okino CH. Simple, Low-Cost and Long-Lasting Film for Virus Inactivation Using Avian Coronavirus Model as Challenge. Int J Environ Res Public Health 2020; 17:E6456. [PMID: 32899803 PMCID: PMC7558860 DOI: 10.3390/ijerph17186456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/28/2022]
Abstract
The COVID-19 infection, caused by SARS-CoV-2, is inequitably distributed and more lethal among populations with lower socioeconomic status. Direct contact with contaminated surfaces has been among the virus sources, as it remains infective up to days. Several disinfectants have been shown to inactivate SARS-CoV-2, but they rapidly evaporate, are flammable or toxic and may be scarce or inexistent for vulnerable populations. Therefore, we are proposing simple, easy to prepare, low-cost and efficient antiviral films, made with a widely available dishwashing detergent, which can be spread on hands and inanimate surfaces and is expected to maintain virucidal activity for longer periods than the current sanitizers. Avian coronavirus (ACoV) was used as model of the challenge to test the antivirus efficacy of the proposed films. Polystyrene petri dishes were covered with a thin layer of detergent formula. After drying, the films were exposed to different virus doses for 10 min and virus infectivity was determined using embryonated chicken eggs, and RNA virus quantification in allantoic fluids by RT-qPCR. The films inactivated the ACoV (ranging from 103.7 to 106.7 EID50), which is chemically and morphologically similar to SARS-CoV-2, and may constitute an excellent alternative to minimize the spread of COVID-19.
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Affiliation(s)
| | - Iara Maria Trevisol
- Embrapa Suínos e Aves, Rodovia BR-153 Km 110, Concórdia 89715-899, Brazil; (I.M.T.); (D.V.R.)
| | - Daiane Voss Rech
- Embrapa Suínos e Aves, Rodovia BR-153 Km 110, Concórdia 89715-899, Brazil; (I.M.T.); (D.V.R.)
| | | | | | - José Paulo Gagliardi Leite
- Laboratório de Virologia Comparada e Ambiental, Instituto Oswaldo Cruz, Fiocruz, Avenida Brasil, 4365, Rio de Janeiro 21040-360, Brazil;
| | - Rodrigo Giglioti
- Instituto de Zootecnia-IZ, Centro de Pesquisa de Genética e Reprodução Animal, Rua Heitor Penteado n.56, Nova Odessa 13380-011, Brazil;
| | - Cintia Hiromi Okino
- Embrapa Pecuária Sudeste, Rodovia Washington Luiz Km 234 s/n, São Carlos 13560-970, Brazil
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199
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Morán P. Exercise to explain X-chromosome inactivation in humans. Biochem Mol Biol Educ 2020; 48:499-501. [PMID: 32770862 DOI: 10.1002/bmb.21417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/21/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Distance learning requires the combined use of techniques because it is more complicated to keep the students' attention. This exercise is designed to explain the inactivation of the x-chromosome in humans and is intended to complement the theoretical explanations. It is estimated that it lasts two hours and makes use of different web resources. It is intended for students familiar with the use of BLAST tools.
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Affiliation(s)
- Paloma Morán
- Departamento de Bioquímica, Genética e Inmunología y Centro de Investigación Mariña (CIM-UVIGO), Universidade de Vigo, Vigo, Spain
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200
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Abstract
Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is classified as a Risk Group 3 pathogen; propagative work with this live virus should be conducted in biosafety level-3 (BSL-3) laboratories. However, inactivated virus can be safely handled in BSL-2 laboratories. Gamma irradiation is one of the methods used to inactivate a variety of pathogens including viruses. Objective To determine the radiation dose required to inactivate SARS-CoV-2 and its effect, if any, on subsequent polymerase chain reaction (PCR) assay. Methods Aliquots of SARS-CoV-2 virus culture were subjected to increasing doses of gamma radiation to determine the proper dose required to inactivate the virus. Real-time quantitative polymerase chain reaction (RT-qPCR) data from irradiated samples was compared with that of the non-irradiated samples to assess the effect of gamma radiation on PCR assay. Results A radiation dose of 1 Mrad was required to completely inactivate 106.5 TCID50/ml of SARS-CoV-2. The influence of gamma radiation on PCR sensitivity was inversely related and dose-dependent up to 0.5 Mrad with no further reduction thereafter. Conclusion Gamma irradiation can be used as a reliable method to inactivate SARS-CoV-2 with minimal effect on subsequent PCR assay.
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Affiliation(s)
- Anders Leung
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Kaylie Tran
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Jonathan Audet
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Sherisse Lavineway
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Nathalie Bastien
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Jay Krishnan
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
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