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Bhutkar S, Brandão TRS, Silva CLM, Miller FA. Application of Ultrasound Treatments in the Processing and Production of High-Quality and Safe-to-Drink Kiwi Juice. Foods 2024; 13:328. [PMID: 38275695 PMCID: PMC10815408 DOI: 10.3390/foods13020328] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
This study explores the potential of thermosonication as an alternative to traditional heat treatments, such as pasteurization, in the processing of fruit juices. Conventional methods often lead to undesirable quality changes in fruit juices, whereas thermosonication offers promising results regarding microbial inactivation and quality preservation. This work focused on the inactivation kinetics of Listeria innocua 2030c, a surrogate for pathogenic L. monocytogenes, in kiwifruit juice using thermosonication at 45 °C, 50 °C, and 55 °C. These treatments were compared with equivalent heat treatments. Quality attributes of the juice were also evaluated to assess process efficiency. Survival data of L. innocua were fitted with the Weibull model, estimating first decimal reduction times (δ) and shape parameters (n). The results reveal temperature and process dependencies on δ, while n remains mostly temperature and treatment independent. Thermosonication outperforms heat treatment, achieving higher L. innocua reductions while retaining quality attributes like pH, soluble solid content, and total phenolics and chlorophylls. Thermosonication at 55 °C stands out, providing a 6.2-log-cycle reduction in just 3 min with superior quality retention. These findings highlight the synergistic effect of temperature and ultrasound, making mild heat processes feasible while enhancing product quality. Thermosonication, particularly at 55 °C, emerges as an effective alternative to traditional thermal treatments for fruit juices, offering improved microbial safety without compromising product quality.
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Affiliation(s)
| | | | | | - Fátima A. Miller
- CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal; (S.B.); (T.R.S.B.); (C.L.M.S.)
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Cong W, Pike A, Gonçalves K, Shisler JL, Mariñas BJ. Inactivation Kinetics and Replication Cycle Inhibition of Coxsackievirus B5 by Free Chlorine. Environ Sci Technol 2023; 57:18690-18699. [PMID: 36946773 DOI: 10.1021/acs.est.2c09269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The kinetics of coxsackievirus serotype B5 (CVB5) inactivation with free chlorine is characterized over a range of pH and temperature relevant to drinking water treatment with the primary goal of selecting experimental conditions used for assessing inactivation mechanisms. The inactivation kinetics identified in our study is similar to or slower than experimental data reported in the literature and thus provides a conservative representation of the kinetics of CVB5 inactivation for free chlorine that could be useful in developing future regulations for waterborne viral pathogens including adequate disinfection treatment for CVB5. Untreated and free chlorine-treated viruses, and host cells synchronized-infected with these viruses, are analyzed by a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method with the goal of quantitatively investigating the effect of free chlorine exposure on viral genome integrity, attachment to host cell, and viral genome replication. The inactivation kinetics observed results from a combination of hindering virus attachment to the host cell, inhibition of one or more subsequent steps of the replication cycle, and possibly genome damage.
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Salazar JK, Fay ML, Khouja BA, Chavda NJ, Patil GR, Ingram DT. Effect of dehydration on the inactivation of Listeria monocytogenes and Salmonella enterica on enoki and wood ear mushrooms. Front Microbiol 2023; 14:1257053. [PMID: 38029214 PMCID: PMC10644103 DOI: 10.3389/fmicb.2023.1257053] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Foodborne illness outbreaks in the U.S. associated with consumption of both fresh and dried specialty mushrooms have recently occurred. Dried wood ear mushrooms were implicated in a salmonellosis outbreak in 2020, while fresh enoki mushrooms were associated with two listeriosis outbreaks in 2020 and 2023. These specialty mushrooms are commercially available in both their fresh and dried states. Due to the short shelf life of mushrooms, dehydration is a common method used in both industry and by consumers to extend the shelf life and preserve quality. Therefore, the aim of this study was to evaluate the use of dehydration on the inactivation kinetics of both Listeria monocytogenes and Salmonella enterica on enoki and wood ear mushrooms. Fresh mushrooms were inoculated with four strain cocktails of either L. monocytogenes or S. enterica and dried at ambient conditions for 10 min. Following drying of the inoculum, mushrooms were placed into food dehydrators preheated to 70, 80, or 90°C and treated for up to 24 h. At treatment intervals, mushrooms were removed from the dehydrators for pathogen enumeration. Inactivation kinetics for both pathogens were modeled using the Weibull, log-linear with tail, and log-linear with shoulder models. Pathogen reductions of >4 log CFU/g were achieved on both enoki and wood ear mushrooms during dehydration at 90°C after only 2-4 h. At 70 and 80°C, log reductions of >4 log CFU/g were observed on wood ear mushrooms after 4-8 h. On enoki mushrooms, a tailing effect was observed with residual populations (>2 log CFU/g) of L. monocytogenes and S. enterica remaining even after 24 h of treatment at both 70 and 80°C. This study emphasizes the need for an individualized dehydration strategy for each mushroom type to ensure the effectiveness of dehydration as a process to reduce pathogen populations. Results of this study will aid in informing proper time and temperature combinations for dehydration of specialty mushrooms to ensure product safety.
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Affiliation(s)
- Joelle K. Salazar
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, United States
| | - Megan L. Fay
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, United States
| | - Bashayer A. Khouja
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, United States
| | - Nirali J. Chavda
- Department of Food Science and Nutrition, Illinois Institute of Technology, Bedford Park, IL, United States
| | - Gayatri R. Patil
- Department of Food Science and Nutrition, Illinois Institute of Technology, Bedford Park, IL, United States
| | - David T. Ingram
- Division of Produce Safety, U. S. Food and Drug Administration, College Park, MD, United States
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Choi JM, D'Souza DH. Inactivation of Tulane virus and feline calicivirus by aqueous ozone. J Food Sci 2023; 88:4218-4229. [PMID: 37680092 DOI: 10.1111/1750-3841.16755] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/30/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023]
Abstract
Ongoing challenges with reproducible human norovirus cultivable assays necessitate the use of surrogates, such as feline calicivirus (FCV-F9) and Tulane virus (TV), during inactivation studies. Chlorine alternates used as control strategies include aqueous and gaseous ozone. This study aimed at determining the inactivation of FCV-F9 and TV by a portable ozone-generating device. FCV-F9 (∼8 log PFU/mL) or TV (∼6 log PFU/mL) in sterile-low-organic matter-containing-water was treated for 0-5 min, or in sterile-water containing newborn calf serum (high-organic matter/protein) for 0-38 min with ∼1 ppm ozone (pH 7-6). Infectivity was determined from triplicate treatments using plaque assays. FCV-F9 titers significantly decreased by 6.07 log PFU/mL after 5 min in ozonated low-organic-matter-containing-water and was non-detectable (≤2 log PFU/mL) after 36 min treatments in high-organic-matter-containing water (p < 0.05). TV titers decreased by 4.18 log PFU/mL after 4 min in ozonated low-organic-matter water (non-detectable after 4.5 min) and were non-detectable after 22.5 min treatments of high-organic-matter-containing water (p < 0.05). Overall, ∼1 ppm aqueous ozone significantly decreased FCV-F9 by >6 log PFU/mL after 5 min, TV to non-detectable levels (≤2 log PFU/mL) after 4.5 min and required longer treatments (>32 and >20 min, respectively) for ≥4 log reduction in high-organic-matter-containing water (p < 0.05). For ozone treatment of both viruses, the linear and Weibull models were similar for low-organic-load water, though the Weibull model was better for the high-organic load water. Prior filtration or organic load removal is recommended before ozonation for increased viral inactivation with decreased treatment-time.
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Affiliation(s)
- Joseph Moon Choi
- Department of Food Science, University of Tennessee, Knoxville, Tennessee, USA
| | - Doris H D'Souza
- Department of Food Science, University of Tennessee, Knoxville, Tennessee, USA
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Schöbel H, Diem G, Kiechl J, Chistè D, Bertacchi G, Mayr A, Wilflingseder D, Lass-Flörl C, Posch W. Antimicrobial efficacy and inactivation kinetics of a novel LED based UV-irradiation technology. J Hosp Infect 2023; 135:11-17. [PMID: 36754288 PMCID: PMC10041887 DOI: 10.1016/j.jhin.2022.12.023] [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: 10/03/2022] [Revised: 12/06/2022] [Accepted: 12/15/2022] [Indexed: 02/09/2023]
Abstract
BACKGROUND UV light emitting diodes (UV-LEDs) are energy efficient and of special interest for the inactivation of microorganisms. In context of the current pandemic, novel UV technologies can offer a powerful alternative of effective infection prevention and control (IPC). METHODS We here assessed the antimicrobial efficacy of UV-C LEDs on Escherichia coli, Pseudomonas fluorescens and Listeria innocua as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus 1 (HIV-1) and murine norovirus (MNV) dried on inanimate surfaces based on the European standard EN 17272. RESULTS We found an inactivation rate of 90% for the tested bacteria at a mean UV-C dose, averaged over all three investigated UV-C wavelengths, of 1.7 mJ cm-2 for E. coli, 1.9 mJ cm-2 for P. fluorescens and 1.5 mJ cm-2 for L. innocua. For the tested viruses, a 90% inactivation rate at UV doses less than 15 mJ cm-2 for applied UV wavelengths at 255 nm and 265 nm were found. Exposure of viruses to longer UV wavelengths such as 275 nm and 285 nm, required much higher doses up to 120 mJ cm-2 for inactivation. Regarding inactivation, non-enveloped MNV required much higher UV doses for all tested wavelengths compared to SARS-CoV-2 or HIV-1. CONCLUSION Overall, our data recommend the use of LEDs emitting at shorter wavelengths of the UV-C spectrum to inactivate bacteria as well as enveloped and non-enveloped viruses by exposure to the appropriate UV-dose. However, low availability and excessive production costs of shortwave UV-C LEDs restricts the implementation currently and supports the use of longwave UV-C LEDs in combination with higher irradiation doses.
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Affiliation(s)
- Harald Schöbel
- Department Biotechnology and Food Engineering, MCI - the Entrepreneurial School, 6020 Innsbruck, Austria
| | - Gabriel Diem
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Julia Kiechl
- Department Biotechnology and Food Engineering, MCI - the Entrepreneurial School, 6020 Innsbruck, Austria
| | - Daniela Chistè
- Department Biotechnology and Food Engineering, MCI - the Entrepreneurial School, 6020 Innsbruck, Austria
| | - Giulia Bertacchi
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Astrid Mayr
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, 6020 Innsbruck, Austria.
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Khan A, Heng W, Imran K, Zhu G, Ji J, Zhang Y, Guan X, Ge G, Wei DQ. Discovery of Isojacareubin as a covalent inhibitor of SARS-CoV-2 main protease using structural and experimental approaches. J Med Virol 2023; 95:e28542. [PMID: 36727647 DOI: 10.1002/jmv.28542] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/25/2023] [Accepted: 01/30/2023] [Indexed: 02/03/2023]
Abstract
The ongoing pandemic with the emergence of immune evasion potential and, particularly, the current omicron subvariants intensified the situation further. Although vaccines are available, the immune evasion capabilities of the recent variants demand further efficient therapeutic choices to control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Hence, considering the necessity of the small molecule inhibitor, we target the main protease (3CLpro), which is an appealing target for the development of antiviral drugs against SARS-CoV-2. High-throughput molecular in silico screening of South African natural compounds database reported Isojacareubin and Glabranin as the potential inhibitors for the main protease. The calculated docking scores were reported to be -8.47 and -8.03 kcal/mol, respectively. Moreover, the structural dynamic assessment reported that Isojacareubin in complex with 3CLpro exhibit a more stable dynamic behavior than Glabranin. Inhibition assay indicated that Isojacareubin could inhibit SARS-CoV-2 3CLpro in a time- and dose-dependent manner, with half maximal inhibitory concentration values of 16.00 ± 1.35 μM (60 min incubation). Next, the covalent binding sites of Isojacareubin on SARS-CoV-2 3CLpro was identified by biomass spectrometry, which reported that Isojacareubin can covalently bind to thiols or Cysteine through Michael addition. To evaluate the inactivation potency of Isojacareubin, the inactivation kinetics was further investigated. The inactivation kinetic curves were plotted according to various concentrations with gradient-ascending incubation times. The KI value of Isojacareubin was determined as 30.71 μM, whereas the Kinact value was calculated as 0.054 min-1 . These results suggest that Isojacareubin is a covalent inhibitor of SARS-CoV-2 3CLpro .
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Affiliation(s)
- Abbas Khan
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P.R. China
- Zhongjing Research and Industrialization Institute of Chinese Medicine, Zhongguancun Scientific Park, Meixi, Nayang, Henan, P.R., China
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P.R., China
| | - Wang Heng
- International School of Cosmetics, School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai, P.R., China
| | - Kashif Imran
- Services Institute of Medical Sciences, Lahore, Punjab, Pakistan
| | - Guanghao Zhu
- Shanghai Frontiers Science Center for Chinese Medicine Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jun Ji
- Henan Provincial Engineering and Technology Center of Health Products for Livestock and Poultry, Henan Provincial Engineering and Technology Center of Animal Disease Diagnosis and Integrated Control, Nanyang Normal University, Nanyang, P.R., China
| | - Yani Zhang
- Peng Cheng Laboratory, Vanke Cloud City, Nashan District, Shenzhen, Guangdong, P.R., China
| | - Xiaoqing Guan
- Shanghai Frontiers Science Center for Chinese Medicine Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Guangbo Ge
- Shanghai Frontiers Science Center for Chinese Medicine Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Dong-Qing Wei
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P.R. China
- Zhongjing Research and Industrialization Institute of Chinese Medicine, Zhongguancun Scientific Park, Meixi, Nayang, Henan, P.R., China
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P.R., China
- Peng Cheng Laboratory, Vanke Cloud City, Nashan District, Shenzhen, Guangdong, P.R., China
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McEvoy B, Maksimovic A, Rowan NJ. Geobacillus stearothermophilus and Bacillus atrophaeus spores exhibit linear inactivation kinetic performance when treated with an industrial scale vaporized hydrogen peroxide (VH2O2) sterilization process. J Appl Microbiol 2023; 134:6947817. [PMID: 36626777 DOI: 10.1093/jambio/lxac028] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/05/2022] [Accepted: 10/20/2022] [Indexed: 01/12/2023]
Abstract
AIMS This study aims to determine the inactivation kinetics of Geobacillus stearothermophilus and Bacillus atrophaeus biological indicators, treated with vaporized hydrogen peroxide (VH2O2) at an industrial scale. There is an assumption that sterilization processes generate linear kinetic plots of treated biological indicators that are used for informing probability-based decision-making by the MedTech industry for effective sterilization treatments; however, this has not been reported for sterilization using VH2O2. METHODS AND RESULTS Survivor curves were generated, and sterilization performances were separately determined using G. stearothermophilus and B. atrophaeus biological indicators following the development of appropriate process challenge devices (PCDs). Regression analysis revealed that the inactivation kinetics for VH2O2-treated microorganisms exhibited log linear profiles. The use of scanning electron microscope (SEM) revealed no significant topographical changes in the outer surface of these VH2O2-treated spores. CONCLUSIONS Both biological indicators exhibited log linear inactivation kinetics when treated with an industrial scale vaporized hydrogen peroxide (VH2O2) sterilization process. Therefore, this novel finding corroborates and proves the appropriateness of using VH2O2 as a sterilization method in accordance with applicable ISO standards.
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Affiliation(s)
- Brian McEvoy
- Applied Sterilization Technologies, IDA Business and Technology Park, Tullamore, R35 X865, Ireland.,Bioscience Research Institute, Technological University of the Shannon Midlands Midwest, Athlone Campus, N37 HD68, Ireland
| | - Ana Maksimovic
- Applied Sterilization Technologies, IDA Business and Technology Park, Tullamore, R35 X865, Ireland
| | - Neil J Rowan
- Bioscience Research Institute, Technological University of the Shannon Midlands Midwest, Athlone Campus, N37 HD68, Ireland
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Yuan Y, Liu Q, Huang Y, Qi M, Yan H, Li W, Zhuang H. Antibacterial Efficacy and Mechanisms of Curcumin-Based Photodynamic Treatment against Staphylococcus aureus and Its Application in Juices. Molecules 2022; 27:molecules27207136. [PMID: 36296729 PMCID: PMC9612228 DOI: 10.3390/molecules27207136] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/18/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial Photodynamic Treatment (aPDT) is a non-thermal sterilization technology, which can inactivate common foodborne pathogens. In the present study, photodynamic inactivation on Staphylococcus aureus (S. aureus) with different concentrations of curcumin and light dose was evaluated and the mechanisms were also investigated. The results showed that curcumin-based aPDT could inactivate S. aureus cells by 6.9 log CFU/mL in phosphate buffered saline (PBS). Moreover, the modified Gompertz model presented a good fit at the inactivation data of S. aureus. Photodynamic treatment caused cell membrane damage as revealed by analyzing scanning electron microscopy (SEM) images. Leakage of intracellular constituents further indicated that cell membrane permeability was changed. Flow cytometry with double staining demonstrated that cell membrane integrity and the activity of nonspecific esterase were destroyed. Compared with the control group, intracellular reactive oxygen species (ROS) levels caused by photodynamic treatment significantly increased. Furthermore, curcumin-based aPDT reduced S. aureus by 5 log CFU/mL in juices. The color of the juices was also tested using a Chromatic meter, and it was found that b* values were the most markedly influenced by photodynamic treatment. Overall, curcumin-based aPDT had strong antibacterial activity against S. aureus. This approach has the potential to remove foodborne pathogens from liquid food.
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Zhou J, Sheng L, Lv R, Liu D, Ding T, Liao X. Application of a 360-Degree Radiation Thermosonication Technology for the Inactivation of Staphylococcus aureus in Milk. Front Microbiol 2021; 12:771770. [PMID: 34803991 PMCID: PMC8602915 DOI: 10.3389/fmicb.2021.771770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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] [Received: 09/07/2021] [Accepted: 10/01/2021] [Indexed: 11/17/2022] Open
Abstract
Milk is easy to be contaminated by microorganisms due to its abundant nutrients. In this study, a 360-degree radiation thermosonication (TS) system was developed and utilized for the inactivation of Staphylococcus aureus in milk. The 360-degree radiation TS system-induced inactivation kinetics of S. aureus was fitted best by the Weibull model compared with biphasic and linear models. The treatment time, the exposure temperature, and the applied ultrasound power was found to affect the bactericidal efficacy of the 360-degree radiation TS system. Additionally, the TS condition of 200 W and 63°C for 7.5 min was successfully applied to achieve complete microbial inactivation (under the limit of detection value) in raw milk. The treatment of 360-degree radiation TS can enhance the zeta potential and decrease the average particle size of milk. It also exhibited better retainment of the proteins in milk compared with the ultrahigh temperature and conventional pasteurization processing. Therefore, the 360-degree radiation TS system developed in this study can be used as an alternative technology to assure the microbiological safety and retain the quality of milk, and the Weibull model could be applied for the prediction of the inactivation levels after exposure to this technology.
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Affiliation(s)
- Jianwei Zhou
- School of Mechanical and Energy Engineering, Ningbotech University, Ningbo, China
| | - Lele Sheng
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
| | - Ruiling Lv
- Ningbo Research Institute, Zhejiang University, Ningbo, China
| | - Donghong Liu
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
- Ningbo Research Institute, Zhejiang University, Ningbo, China
| | - Tian Ding
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
- Ningbo Research Institute, Zhejiang University, Ningbo, China
| | - Xinyu Liao
- School of Mechanical and Energy Engineering, Ningbotech University, Ningbo, China
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
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Foo NP, Liu YF, Wu PC, Hsing CH, Huang BM, So EC. Midazolam's Effects on Delayed-Rectifier K + Current and Intermediate-Conductance Ca 2+-Activated K + Channel in Jurkat T-lymphocytes. Int J Mol Sci 2021; 22:7198. [PMID: 34281255 DOI: 10.3390/ijms22137198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022] Open
Abstract
Midazolam (MDZ) could affect lymphocyte immune functions. However, the influence of MDZ on cell’s K+ currents has never been investigated. Thus, in the present study, the effects of MDZ on Jurkat T lymphocytes were studied using the patch-clamp technique. Results showed that MDZ suppressed the amplitude of delayed-rectifier K+ current (IK(DR)) in concentration-, time-, and state-dependent manners. The IC50 for MDZ-mediated reduction of IK(DR) density was 5.87 μM. Increasing MDZ concentration raised the rate of current-density inactivation and its inhibitory action on IK(DR) density was estimated with a dissociation constant of 5.14 μM. In addition, the inactivation curve of IK(DR) associated with MDZ was shifted to a hyperpolarized potential with no change on the slope factor. MDZ-induced inhibition of IK(DR) was not reversed by flumazenil. In addition, the activity of intermediate-conductance Ca2+-activated K+ (IKCa) channels was suppressed by MDZ. Furthermore, inhibition by MDZ on both IK(DR) and IKCa-channel activity appeared to be independent from GABAA receptors and affected immune-regulating cytokine expression in LPS/PMA-treated human T lymphocytes. In conclusion, MDZ suppressed current density of IK(DR) in concentration-, time-, and state-dependent manners in Jurkat T-lymphocytes and affected immune-regulating cytokine expression in LPS/PMA-treated human T lymphocytes.
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Sivakumar K, Lehmann R, Rachmadi AT, Augsburger N, Zaouri N, Tegner J, Hong PY. Elucidating the Role of Virulence Traits in the Survival of Pathogenic E. coli PI-7 Following Disinfection. Front Bioeng Biotechnol 2021; 8:614186. [PMID: 33415102 PMCID: PMC7783314 DOI: 10.3389/fbioe.2020.614186] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/03/2020] [Indexed: 11/13/2022] Open
Abstract
Reuse and discharge of treated wastewater can result in dissemination of microorganisms into the environment. Deployment of disinfection strategies is typically proposed as a last stage remediation effort to further inactivate viable microorganisms. In this study, we hypothesize that virulence traits, including biofilm formation, motility, siderophore, and curli production along with the capability to internalize into mammalian cells play a role in survival against disinfectants. Pathogenic E. coli PI-7 strain was used as a model bacterium that was exposed to diverse disinfection strategies such as chlorination, UV and solar irradiation. To this end, we used a random transposon mutagenesis library screening approach to generate 14 mutants that exhibited varying levels of virulence traits. In these 14 isolated mutants, we observed that an increase in virulence traits such as biofilm formation, motility, curli production, and internalization capability, increased the inactivation half-lives of mutants compared to wild-type E. coli PI-7. In addition, oxidative stress response and EPS production contributed to lengthening the lag phase duration (defined as the time required for exposure to disinfectant prior to decay). However, traits related to siderophore production did not help with survival against the tested disinfection strategies. Taken together, the findings suggested that selected virulence traits facilitate survival of pathogenic E. coli PI-7, which in turn could account for the selective enrichment of pathogens over the non-pathogenic ones after wastewater treatment. Further, the study also reflected on the effectiveness of UV as a more viable disinfection strategy for inactivation of pathogens.
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Affiliation(s)
- Krishnakumar Sivakumar
- Computational Bioscience Research Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Robert Lehmann
- Living Systems Laboratory, Environmental Epigenetic Program, Biological and Environmental Science and Engineering Division, Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Andri Taruna Rachmadi
- Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Nicolas Augsburger
- Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Noor Zaouri
- Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Jesper Tegner
- Living Systems Laboratory, Environmental Epigenetic Program, Biological and Environmental Science and Engineering Division, Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Pei-Ying Hong
- Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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Chang WT, Liu PY, Wu SN. Actions of FTY720 (Fingolimod), a Sphingosine-1-Phosphate Receptor Modulator, on Delayed-Rectifier K + Current and Intermediate-Conductance Ca 2+-Activated K + Channel in Jurkat T-Lymphocytes. Molecules 2020; 25:E4525. [PMID: 33023219 DOI: 10.3390/molecules25194525] [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: 09/05/2020] [Revised: 09/25/2020] [Accepted: 09/30/2020] [Indexed: 01/01/2023] Open
Abstract
FTY720 (fingolimod), a modulator of sphingosine-1-phosphate receptors, is known to produce the immunomodulatory actions and to be beneficial for treating the relapsing multiple sclerosis. However, whether it exerts any effects on membrane ion currents in immune cells remains largely unknown. Herein, the effects of FTY720 on ionic currents in Jurkat T-lymphocytes were investigated. Cell exposure to FTY720 suppressed the amplitude of delayed-rectifier K+ current (IK(DR)) in a time- and concentration-dependent manner with an IC50 value of 1.51 μM. Increasing the FTY720 concentration not only decreased the IK(DR) amplitude but also accelerated the inactivation time course of the current. By using the minimal reaction scheme, the effect of FTY720 on IK(DR) inactivation was estimated with a dissociation constant of 3.14 μM. FTY720 also shifted the inactivation curve of IK(DR) to a hyperpolarized potential with no change in the slope factor, and recovery from IK(DR) became slow during the exposure to this compound. Cumulative inactivation for IK(DR) in response to repetitive depolarizations was enhanced in the presence of FTY720. In SEW2871-treated cells, FTY720-induced inhibition of IK(DR) was attenuated. This compound also exerted a stimulatory action on the activity of intermediate-conductance Ca2+-activated K+ channels in Jurkat T-lymphocytes. However, in NSC-34 neuronal cells, FTY720 did not modify the inactivation kinetics of KV3.1-encoded IK(DR), although it suppressed IK(DR) amplitude in these cells. Collectively, the perturbations by FTY720 on different types of K+ channels may contribute to the functional activities of immune cells, if similar findings appear in vivo.
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Angarano V, Smet C, Akkermans S, Watt C, Chieffi A, Van Impe JF. Visible Light as an Antimicrobial Strategy for Inactivation of Pseudomonas fluorescens and Staphylococcus epidermidis Biofilms. Antibiotics (Basel) 2020; 9:E171. [PMID: 32290162 PMCID: PMC7235755 DOI: 10.3390/antibiotics9040171] [Citation(s) in RCA: 16] [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: 03/12/2020] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
The increase of antimicrobial resistance is challenging the scientific community to find solutions to eradicate bacteria, specifically biofilms. Light-Emitting Diodes (LED) represent an alternative way to tackle this problem in the presence of endogenous or exogenous photosensitizers. This work adds to a growing body of research on photodynamic inactivation using visible light against biofilms. Violet (400 nm), blue (420 nm), green (570 nm), yellow (584 nm) and red (698 nm) LEDs were used against Pseudomonas fluorescens and Staphylococcus epidermidis. Biofilms, grown on a polystyrene surface, were irradiated for 4 h. Different irradiance levels were investigated (2.5%, 25%, 50% and 100% of the maximum irradiance). Surviving cells were quantified and the inactivation kinetic parameters were estimated. Violet light could successfully inactivate P. fluorescens and S. epidermidis (up to 6.80 and 3.69 log10 reduction, respectively), while blue light was effective only against P. fluorescens (100% of maximum irradiance). Green, yellow and red irradiation neither increased nor reduced the biofilm cell density. This is the first research to test five different wavelengths (each with three intensities) in the visible spectrum against Gram-positive and Gram-negative biofilms. It provides a detailed study of the potential of visible light against biofilms of a different Gram-nature.
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Affiliation(s)
- Valeria Angarano
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Cindy Smet
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Simen Akkermans
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Charlotte Watt
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
| | - Andre Chieffi
- Procter & Gamble, Newcastle Innovation Center, Newcastle NE12 9TS, UK;
| | - Jan F.M. Van Impe
- BioTeC+, Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, 9000 Gent, Belgium; (V.A.); (C.S.); (S.A.); (C.W.)
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Mutz YS, Rosario DKA, Bernardes PC, Paschoalin VMF, Conte-Junior CA. Modeling Salmonella Typhimurium Inactivation in Dry-Fermented Sausages: Previous Habituation in the Food Matrix Undermines UV-C Decontamination Efficacy. Front Microbiol 2020; 11:591. [PMID: 32322246 PMCID: PMC7156554 DOI: 10.3389/fmicb.2020.00591] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 01/10/2020] [Accepted: 03/18/2020] [Indexed: 01/12/2023] Open
Abstract
The effects of previous Salmonella Typhimurium habituation to an Italian-style salami concerning pathogen resistance against ultraviolet-C light (UV-C) treatment were modeled in order to establish treatment feasibility for the decontamination of dry-fermented sausage. S. Typhimurium following 24 h habituation in fermented sausage (habituated cells) or non-habituation (non-habituated cells) were exposed to increasing UV-C radiation treatment times. The Weibull model was the best fit for describing S. Typhimurium UV-C inactivation. Heterogeneity in UV-C treatment susceptibilities within the S. Typhimurium population was observed, revealing intrinsic persistence in a sub-population. UV-C radiation up to 1.50 J/cm2 was a feasible treatment for dry-fermented sausage decontamination, as the matrices retained instrumental color and lipid oxidation physiochemical characteristics. However, habituation in the sausage matrix led to a 14-fold increase in the UV-C dose required to achieve the first logarithm reduction (δ value) in S. Typhimurium population. The results indicate that, although UV-C radiation might be considered an efficient method for dry-fermented sausage decontamination, effective doses should be reconsidered in order to reach desirable food safety parameters while preserving matrix quality.
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Affiliation(s)
- Yhan S. Mutz
- Post Graduate Program in Food Science, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Analytical and Molecular Laboratory Center, Faculty of Veterinary Medicine, Fluminense Federal University, Niterói, Brazil
- Center for Food Analysis, Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Denes K. A. Rosario
- Post Graduate Program in Food Science, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Analytical and Molecular Laboratory Center, Faculty of Veterinary Medicine, Fluminense Federal University, Niterói, Brazil
- Center for Food Analysis, Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia C. Bernardes
- Department of Food Engineering, Federal University of Espirito Santo, Alto Universitário, Alegre, Brazil
| | - Vania M. F. Paschoalin
- Post Graduate Program in Food Science, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos A. Conte-Junior
- Post Graduate Program in Food Science, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Analytical and Molecular Laboratory Center, Faculty of Veterinary Medicine, Fluminense Federal University, Niterói, Brazil
- Center for Food Analysis, Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Health Quality Control, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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15
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Velasco-Hernández A, Saucedo-Veloz C, Ramírez-Guzmán ME, Chávez-Franco SH, Valle-Guadarrama S, Saucedo-Reyes D. Effect of moderate thermal treatments on the inactivation of a strain of Listeria monocytogenes and physicochemical properties of soursop pulp. FOOD SCI TECHNOL INT 2020; 26:535-548. [PMID: 32223432 DOI: 10.1177/1082013220913357] [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] [Indexed: 11/16/2022]
Abstract
Soursop (Annona muricata L.) is a commercially important tropical fruit, whether fresh or processed as a pasteurized or frozen pulp used to prepare juice, drinks, nectar, ice cream, popsicles, and desserts. Besides preserving quality, another preoccupation in the processing of fruit pulps is product safety. Several studies show the association between pulp processing and the development of various microorganisms; however, few have focused on the association between L. monocytogenes and the pulp of sour fruits. The objective was to evaluate the effect of moderate thermal treatments on the inactivation of L. monocytogenes and the physicochemical properties in soursop pulp in order to determine the best processing conditions that will allow to maintain quality as well as to achieve an adequate level of safety. Thermal inactivation kinetics were obtained for L. monocytogenes inoculated in soursop pulp at five levels of temperature (50, 52.5, 55, 57.5, and 60 ℃) and different exposure times (0-60 min). The survival curves did not suggest a log-linear relationship, and were, consequently, fitted to the modified Gompertz equation. The results indicated that the modified Gompertz equation provided an acceptable goodness of fit. Five-log10 cycles reductions of L. monocytogenes were achieved at 50 ℃/60 min, 52.5 ℃/16 min, 55 ℃/10 min, 57.5 ℃/5 min, and 60 ℃/1.25 min. These 5-log10 treatments applied to the soursop pulp indicated that the soursop pulp showed changes in the color parameters and a decrease in the content of total sugars, reducing sugars, ascorbic acid, total phenols, and pH.
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Hossain MS, Tanaka T, Hayashi J, Takagi K, Takeda Y, Wakayama M. Characterization and Thermal Denaturation Kinetic Analysis of Recombinant l-Amino Acid Ester Hydrolase from Stenotrophomonas maltophilia. J Agric Food Chem 2018; 66:11064-11072. [PMID: 30277765 DOI: 10.1021/acs.jafc.8b04573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Stenotrophomonas maltophilia HS1 exhibits l-amino acid ester hydrolase (SmAEH) activity, which can synthesize dipeptides such as Ile-Trp, Val-Gly, and Trp-His from the corresponding amino acid methyl esters and amino acids. The gene encoding SmAEH was cloned and expressed in Escherichia coli and was purified and characterized. SmAEH shared 77% sequence identity with a known amino acid ester hydrolase (AEH) from Xanthomonas citri, which belongs to a class of β-lactam antibiotic acylases. The thermal stability of SmAEH was evaluated using various mathematical models to assess its industrial potential. First-order kinetics provided the best description for the inactivation of the enzyme over a temperature range of 35-50 °C. Decimal reduction time ranged from 212.76 to 3.44 min, with a z value of 8.06 °C, and the deactivation energy was 204.1 kJ mol-1.
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Affiliation(s)
- Md Saddam Hossain
- Department of Biotechnology, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
| | - Takahiro Tanaka
- Department of Biotechnology, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
| | - Junji Hayashi
- Department of Biotechnology, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
| | - Kazuyoshi Takagi
- Department of Applied Chemistry, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
| | - Yoichi Takeda
- Department of Biotechnology, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
| | - Mamoru Wakayama
- Department of Biotechnology, College of Life Sciences , Ritsumeikan University , Kusatsu , Shiga 525-8577 , Japan
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17
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Del Mármol JI, Touhara KK, Croft G, MacKinnon R. Piezo1 forms a slowly-inactivating mechanosensory channel in mouse embryonic stem cells. eLife 2018; 7:33149. [PMID: 30132757 PMCID: PMC6128688 DOI: 10.7554/elife.33149] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [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: 10/26/2017] [Accepted: 08/21/2018] [Indexed: 01/24/2023] Open
Abstract
Piezo1 is a mechanosensitive (MS) ion channel with characteristic fast-inactivation kinetics. We found a slowly-inactivating MS current in mouse embryonic stem (mES) cells and characterized it throughout their differentiation into motor-neurons to investigate its components. MS currents were large and slowly-inactivating in the stem-cell stage, and became smaller and faster-inactivating throughout the differentiation. We found that Piezo1 is expressed in mES cells, and its knockout abolishes MS currents, indicating that the slowly-inactivating current in mES cells is carried by Piezo1. To further investigate its slow inactivation in these cells, we cloned Piezo1 cDNA from mES cells and found that it displays fast-inactivation kinetics in heterologous expression, indicating that sources of modulation other than the aminoacid sequence determine its slow kinetics in mES cells. Finally, we report that Piezo1 knockout ES cells showed a reduced rate of proliferation but no significant differences in other markers of pluripotency and differentiation.
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Affiliation(s)
- Josefina Inés Del Mármol
- Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, Howard Hughes Medical Institute, New York, United States
| | - Kouki K Touhara
- Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, Howard Hughes Medical Institute, New York, United States
| | - Gist Croft
- Laboratory of Stem Cell Biology and Molecular Embryology, Rockefeller University, New York, United States
| | - Roderick MacKinnon
- Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, Howard Hughes Medical Institute, New York, United States
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18
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Buzrul S. Evaluation of Different Dose-Response Models for High Hydrostatic Pressure Inactivation of Microorganisms. Foods 2017; 6:E79. [PMID: 28880255 PMCID: PMC5615291 DOI: 10.3390/foods6090079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 07/05/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 11/17/2022] Open
Abstract
Modeling of microbial inactivation by high hydrostatic pressure (HHP) requires a plot of the log microbial count or survival ratio versus time data under a constant pressure and temperature. However, at low pressure and temperature values, very long holding times are needed to obtain measurable inactivation. Since the time has a significant effect on the cost of HHP processing it may be reasonable to fix the time at an appropriate value and quantify the inactivation with respect to pressure. Such a plot is called dose-response curve and it may be more beneficial than the traditional inactivation modeling since short holding times with different pressure values can be selected and used for the modeling of HHP inactivation. For this purpose, 49 dose-response curves (with at least 4 log10 reduction and ≥5 data points including the atmospheric pressure value (P = 0.1 MPa), and with holding time ≤10 min) for HHP inactivation of microorganisms obtained from published studies were fitted with four different models, namely the Discrete model, Shoulder model, Fermi equation, and Weibull model, and the pressure value needed for 5 log10 (P₅) inactivation was calculated for all the models above. The Shoulder model and Fermi equation produced exactly the same parameter and P₅ values, while the Discrete model produced similar or sometimes the exact same parameter values as the Fermi equation. The Weibull model produced the worst fit (had the lowest adjusted determination coefficient (R²adj) and highest mean square error (MSE) values), while the Fermi equation had the best fit (the highest R²adj and lowest MSE values). Parameters of the models and also P₅ values of each model can be useful for the further experimental design of HHP processing and also for the comparison of the pressure resistance of different microorganisms. Further experiments can be done to verify the P₅ values at given conditions. The procedure given in this study can also be extended for enzyme inactivation by HHP.
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Affiliation(s)
- Sencer Buzrul
- Auditing Department, Tütün ve Alkol Piyasası Düzenleme Kurumu (TAPDK), 06520 Ankara, Turkey.
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19
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Bevilacqua A, Speranza B, Sinigaglia M, Corbo MR. A Focus on the Death Kinetics in Predictive Microbiology: Benefits and Limits of the Most Important Models and Some Tools Dealing with Their Application in Foods. Foods 2015; 4:565-580. [PMID: 28231222 PMCID: PMC5224560 DOI: 10.3390/foods4040565] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [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: 07/28/2015] [Revised: 09/29/2015] [Accepted: 10/06/2015] [Indexed: 11/17/2022] Open
Abstract
Predictive Microbiology (PM) deals with the mathematical modeling of microorganisms in foods for different applications (challenge test, evaluation of microbiological shelf life, prediction of the microbiological hazards connected with foods, etc.). An interesting and important part of PM focuses on the use of primary functions to fit data of death kinetics of spoilage, pathogenic, and useful microorganisms following thermal or non-conventional treatments and can also be used to model survivors throughout storage. The main topic of this review is a focus on the most important death models (negative Gompertz, log-linear, shoulder/tail, Weibull, Weibull+tail, re-parameterized Weibull, biphasic approach, etc.) to pinpoint the benefits and the limits of each model; in addition, the last section addresses the most important tools for the use of death kinetics and predictive microbiology in a user-friendly way.
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Affiliation(s)
- Antonio Bevilacqua
- Department of the Science of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.
| | - Barbara Speranza
- Department of the Science of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.
| | - Milena Sinigaglia
- Department of the Science of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.
| | - Maria Rosaria Corbo
- Department of the Science of Agriculture, Food and Environment, University of Foggia, Via Napoli 25, 71122 Foggia, Italy.
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20
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March JK, Pratt MD, Lowe CW, Cohen MN, Satterfield BA, Schaalje B, O'Neill KL, Robison RA. The differential effects of heat-shocking on the viability of spores from Bacillus anthracis, Bacillus subtilis, and Clostridium sporogenes after treatment with peracetic acid- and glutaraldehyde-based disinfectants. Microbiologyopen 2015; 4:764-73. [PMID: 26185111 PMCID: PMC4618609 DOI: 10.1002/mbo3.277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 01/26/2015] [Revised: 06/13/2015] [Accepted: 06/23/2015] [Indexed: 01/11/2023] Open
Abstract
This study investigated (1) the susceptibility of Bacillus anthracis (Ames strain), Bacillus subtilis (ATCC 19659), and Clostridium sporogenes (ATCC 3584) spores to commercially available peracetic acid (PAA)- and glutaraldehyde (GA)-based disinfectants, (2) the effects that heat-shocking spores after treatment with these disinfectants has on spore recovery, and (3) the timing of heat-shocking after disinfectant treatment that promotes the optimal recovery of spores deposited on carriers. Suspension tests were used to obtain inactivation kinetics for the disinfectants against three spore types. The effects of heat-shocking spores after disinfectant treatment were also determined. Generalized linear mixed models were used to estimate 6-log reduction times for each spore type, disinfectant, and heat treatment combination. Reduction times were compared statistically using the delta method. Carrier tests were performed according to AOAC Official Method 966.04 and a modified version that employed immediate heat-shocking after disinfectant treatment. Carrier test results were analyzed using Fisher's exact test. PAA-based disinfectants had significantly shorter 6-log reduction times than the GA-based disinfectant. Heat-shocking B. anthracis spores after PAA treatment resulted in significantly shorter 6-log reduction times. Conversely, heat-shocking B. subtilis spores after PAA treatment resulted in significantly longer 6-log reduction times. Significant interactions were also observed between spore type, disinfectant, and heat treatment combinations. Immediately heat-shocking spore carriers after disinfectant treatment produced greater spore recovery. Sporicidal activities of disinfectants were not consistent across spore species. The effects of heat-shocking spores after disinfectant treatment were dependent on both disinfectant and spore species. Caution must be used when extrapolating sporicidal data of disinfectants from one spore species to another. Heat-shocking provides a more accurate picture of spore survival for only some disinfectant/spore combinations. Collaborative studies should be conducted to further examine a revision of AOAC Official Method 966.04 relative to heat-shocking.
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Affiliation(s)
- Jordon K March
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Michael D Pratt
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Chinn-Woan Lowe
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Marissa N Cohen
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Benjamin A Satterfield
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Bruce Schaalje
- Department of Statistics, 230 TMCB, Brigham Young University, Provo, Utah, 84602
| | - Kim L O'Neill
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
| | - Richard A Robison
- Department of Microbiology and Molecular Biology, 4007-B LSB, Brigham Young University, Provo, Utah, 84602
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21
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Lenz CA, Reineke K, Knorr D, Vogel RF. High pressure thermal inactivation of Clostridium botulinum type E endospores - kinetic modeling and mechanistic insights. Front Microbiol 2015; 6:652. [PMID: 26191048 PMCID: PMC4490342 DOI: 10.3389/fmicb.2015.00652] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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] [Received: 04/17/2015] [Accepted: 06/15/2015] [Indexed: 12/03/2022] Open
Abstract
Cold-tolerant, neurotoxigenic, endospore forming Clostridium (C.) botulinum type E belongs to the non-proteolytic physiological C. botulinum group II, is primarily associated with aquatic environments, and presents a safety risk for seafood. High pressure thermal (HPT) processing exploiting the synergistic effect of pressure and temperature can be used to inactivate bacterial endospores. We investigated the inactivation of C. botulinum type E spores by (near) isothermal HPT treatments at 300–1200 MPa at 30–75°C for 1 s to 10 min. The occurrence of heat and lysozyme susceptible spore fractions after such treatments was determined. The experimental data were modeled to obtain kinetic parameters and represented graphically by isoeffect lines. In contrast to findings for spores of other species and within the range of treatment parameters applied, zones of spore stabilization (lower inactivation than heat treatments alone), large heat susceptible (HPT-induced germinated) or lysozyme-dependently germinable (damaged coat layer) spore fractions were not detected. Inactivation followed first order kinetics. Dipicolinic acid release kinetics allowed for insights into possible inactivation mechanisms suggesting a (poorly effective) physiologic-like (similar to nutrient-induced) germination at ≤450 MPa/≤45°C and non-physiological germination at >500 MPa/>60–70°C. Results of this study support the existence of some commonalities in the HPT inactivation mechanism of C. botulinum type E spores and Bacillus spores although both organisms have significantly different HPT resistance properties. The information presented here contributes to closing the gap in knowledge regarding the HPT inactivation of spore formers relevant to food safety and may help industrial implementation of HPT processing. The markedly lower HPT resistance of C. botulinum type E spores compared with the resistance of spores from other C. botulinum types could allow for the implementation of milder processes without endangering food safety.
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Affiliation(s)
- Christian A Lenz
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München Freising, Germany
| | - Kai Reineke
- Quality and Safety of Food and Feed, Leibniz Institute for Agricultural Engineering (ATB), Potsdam Germany ; Department of Food Biotechnology and Food Process Engineering, Technische Universität Berlin Berlin, Germany
| | - Dietrich Knorr
- Department of Food Biotechnology and Food Process Engineering, Technische Universität Berlin Berlin, Germany
| | - Rudi F Vogel
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München Freising, Germany
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22
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Bastarrachea LJ, Goddard JM. Antimicrobial coatings with dual cationic and N-halamine character: characterization and biocidal efficacy. J Agric Food Chem 2015; 63:4243-4251. [PMID: 25871333 DOI: 10.1021/acs.jafc.5b00445] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A method to prepare an antimicrobial coating for food-handling materials is reported. Alternating layers of branched polyethylenimine and styrene maleic anhydride copolymer were applied onto the surface of polypropylene. The resulting coatings had low surface energy and presented enhanced antimicrobial character due to the presence of both cationic and N-halamine forming structures. In its unchlorinated form, the coating inactivated Listeria monocytogenes by ∼3 logarithmic cycles. In the form of N-halamines >5 logarithmic cycles were reached. Microbial inactivation kinetics showed a Weibullian behavior when the coating was unchlorinated and a sigmoidal behavior when chlorinated. Microscopy confirmed that the reduction in the microbial load was due to biocidal effects of the coating and not bacterial adhesion onto the modified surface. The modified surface was able to be repeatedly rechlorinated. Such rechargeable antimicrobial coatings may support improving food safety by reducing cross-contamination of microorganisms from food-processing equipment.
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Affiliation(s)
- Luis J Bastarrachea
- Department of Food Science, University of Massachusetts, 102 Holdsworth Way, Amherst, Massachusetts 01003, United States
| | - Julie M Goddard
- Department of Food Science, University of Massachusetts, 102 Holdsworth Way, Amherst, Massachusetts 01003, United States
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23
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Torres EF, González-M G, Klotz B, Rodrigo D. Effects of high hydrostatic pressure and temperature increase on Escherichia coli spp. and pectin methyl esterase inactivation in orange juice. FOOD SCI TECHNOL INT 2015; 22:173-80. [PMID: 25888680 DOI: 10.1177/1082013215582107] [Citation(s) in RCA: 15] [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: 01/12/2015] [Accepted: 03/20/2015] [Indexed: 11/16/2022]
Abstract
The aim of this study was to evaluate the effect of high hydrostatic pressure treatment combined with moderate processing temperatures (25 ℃-50 ℃) on the inactivation of Escherichia coli O157: H7 (ATCC 700728), E. coli K12 (ATCC 23716), and pectin methyl esterase in orange juice, using pressures of 250 to 500 MPa with times ranging between 1 and 30 min. Loss of viability of E. coli O157:H7 increased significantly as pressure and treatment time increased, achieving a 6.5 log cycle reduction at 400 MPa for 3 min at 25 ℃ of treatment. With regard to the inactivation of pectin methyl esterase, the greatest reduction obtained was 90.05 ± 0.01% at 50 ℃ and 500 MPa of pressure for 15 min; therefore, the pectin methyl esterase enzyme was highly resistant to the treatments by high hydrostatic pressure. The results obtained in this study showed a synergistic effect between the high pressure and moderate temperatures in inactivating E. coli cells.
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Affiliation(s)
- E F Torres
- Instituto de Agroquímica y Tecnología de Alimentos, Avenida Agustín Escardino, Valencia, Spain
| | - G González-M
- Alpina Research Institute (IAI), Alpina Productos Alimenticios S.A, Cundinamarca, Colombia
| | - B Klotz
- Alpina Research Institute (IAI), Alpina Productos Alimenticios S.A, Cundinamarca, Colombia
| | - D Rodrigo
- Instituto de Agroquímica y Tecnología de Alimentos, Avenida Agustín Escardino, Valencia, Spain
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Gómez-Jódar I, Ros-Chumillas M, Palop A. Effect of heating rate on highly heat-resistant spore-forming microorganisms. FOOD SCI TECHNOL INT 2015; 22:164-72. [PMID: 25852134 DOI: 10.1177/1082013215580494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 11/21/2014] [Accepted: 03/05/2015] [Indexed: 11/16/2022]
Abstract
Highly heat-resistant spore-forming Bacillus cause nonsterility problems in canned food and reduce the shelf life of many processed foods. The aim of this research was to evaluate the thermal inactivation of Bacillus sporothermodurans IIC65, Bacillus subtilis IC9, and Geobacillus stearothermophilus T26 under isothermal and nonisothermal conditions. The data obtained showed that B. sporothermodurans and B. subtilis were more heat resistant than G. stearothermophilus. The survival curves of B. sporothermodurans and B. subtilis showed shoulders, while the survival curves of G. stearothermophilus showed tails. Under nonisothermal treatment, at heating rates of 1 and 20 ℃/min, time needed to completely inactivate G. stearothermophilus was shorter than that required for B. sporothermodurans and B. subtilis. In complex heat treatments (heating-holding-cooling), the survival curves of B. sporothermodurans and B. subtilis showed the same activation shoulders than those obtained under isothermal treatments and the activation shoulders were again absent in the case of G. stearothermophilus. Predictions fitted quite well the data obtained for B. sporothermodurans. In contrast, the data for B. subtilis showed half a log cycle more survival than expected and in the case of G. stearothermophilus, the survival curve obtained showed much higher inactivation than expected.
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Affiliation(s)
- Isabel Gómez-Jódar
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
| | - María Ros-Chumillas
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
| | - Alfredo Palop
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
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Abstract
Kv4 channels represent the main class of brain A-type K+ channels that operate in the subthreshold range of membrane potentials (Serodio, P., E. Vega-Saenz de Miera, and B. Rudy. 1996. J. Neurophysiol. 75:2174- 2179), and their function depends critically on inactivation gating. A previous study suggested that the cytoplasmic NH2- and COOH-terminal domains of Kv4.1 channels act in concert to determine the fast phase of the complex time course of macroscopic inactivation (Jerng, H.H., and M. Covarrubias. 1997. Biophys. J. 72:163-174). To investigate the structural basis of slow inactivation gating of these channels, we examined internal residues that may affect the mutually exclusive relationship between inactivation and closed-state blockade by 4-aminopyridine (4-AP) (Campbell, D.L., Y. Qu, R.L. Rasmussen, and H.C. Strauss. 1993. J. Gen. Physiol. 101:603-626; Shieh, C.-C., and G.E. Kirsch. 1994. Biophys. J. 67:2316-2325). A double mutation V[404,406]I in the distal section of the S6 region of the protein drastically slowed channel inactivation and deactivation, and significantly reduced the blockade by 4-AP. In addition, recovery from inactivation was slightly faster, but the pore properties were not significantly affected. Consistent with a more stable open state and disrupted closed state inactivation, V[404,406]I also caused hyperpolarizing and depolarizing shifts of the peak conductance-voltage curve ( approximately 5 mV) and the prepulse inactivation curve (>10 mV), respectively. By contrast, the analogous mutations (V[556,558]I) in a K+ channel that undergoes N- and C-type inactivation (Kv1.4) did not affect macroscopic inactivation but dramatically slowed deactivation and recovery from inactivation, and eliminated open-channel blockade by 4-AP. Mutation of a Kv4-specific residue in the S4-S5 loop (C322S) of Kv4.1 also altered gating and 4-AP sensitivity in a manner that closely resembles the effects of V[404, 406]I. However, this mutant did not exhibit disrupted closed state inactivation. A kinetic model that assumes coupling between channel closing and inactivation at depolarized membrane potentials accounts for the results. We propose that components of the pore's internal vestibule control both closing and inactivation in Kv4 K+ channels.
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Affiliation(s)
- H H Jerng
- Department of Pathology, Anatomy and Cell Biology, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
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