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Johne R, Scholz J, Falkenhagen A. Heat stability of foodborne viruses - Findings, methodological challenges and current developments. Int J Food Microbiol 2024; 413:110582. [PMID: 38290272 DOI: 10.1016/j.ijfoodmicro.2024.110582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/12/2024] [Accepted: 01/14/2024] [Indexed: 02/01/2024]
Abstract
Heat treatment of food represents an important measure to prevent pathogen transmission. Thus far, evaluation of heat treatment processes is mainly based on data from bacteria. However, foodborne viruses have gained increasing attention during the last decades. Here, the published literature on heat stability and inactivation of human norovirus (NoV), hepatitis A virus (HAV) and hepatitis E virus (HEV) was reviewed. Data for surrogate viruses were not included. As stability assessment for foodborne viruses is often hampered by missing infectivity assays, an overview of applied methods is also presented. For NoV, molecular capsid integrity assays were mainly applied, but data from initial studies utilizing novel intestinal enteroid or zebrafish larvae assays are available now. However, these methods are still limited in applicability and sensitivity. For HAV, sufficient cell culture-based inactivation data are available, but almost exclusively for one single strain, thus limiting interpretation of the data for the wide range of field strains. For HEV, data are now available from studies using pig inoculation or cell culture. The results of the reviewed studies generally indicate that NoV, HAV and HEV possess a high heat stability. Heating at 70-72 °C for 2 min significantly reduces infectious titers, but often does not result in a >4 log10 decrease. However, heat stability greatly varied dependent on virus strain, matrix and heating regime. In addition, the applied method largely influenced the result, e.g. capsid integrity assays tend to result in higher measured stabilities than cell culture approaches. It can be concluded that the investigated foodborne viruses show a high heat stability, but can be inactivated by application of appropriate heating protocols. For HAV, suggestions for safe time/temperature combinations for specific foods can be derived from the published studies, with the limitation that they are mostly based on one strain only. Although significant improvement of infectivity assays for NoV and HEV have been made during the last years, further method development regarding sensitivity, robustness and broader applicability is important to generate more reliable heat inactivation data for these foodborne viruses in future.
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Affiliation(s)
- Reimar Johne
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Johannes Scholz
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Alexander Falkenhagen
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
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2
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Ritter AC, Ricart Arbona RJ, Mourino AJ, Palillo MB, Aydin M, Fahey JR, Lipman NS. Mechanical Washing Prevents Transmission of Bacterial, Viral, and Protozoal Murine Pathogens from Cages. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2023; 62:131-138. [PMID: 36746440 PMCID: PMC10078927 DOI: 10.30802/aalas-jaalas-22-000105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/01/2022] [Accepted: 12/20/2022] [Indexed: 02/08/2023]
Abstract
Infectious agents have varying susceptibilities to thermal inactivation and/or mechanical removal from cages by the use of heated, pressurized water. In this study, we tested whether 5 specific infectious organisms (Candidatus savagella [segmented filamentous bacterium (SFB)], Helicobacter sp., mouse norovirus (MNV), Tritrichomonas sp., and Entamoeba muris) could survive the cage wash process and still infect naïve mice. These 5 organisms were chosen due to their prevalence in rodent colonies, environmental stability, and/or potential to influence experimental outcomes. Cages that had housed mice shedding all 5 organisms were assigned to 1 of 3 treatment groups: 1) sanitization in a tunnel washer followed by autoclaving (121 °C [250 °F] for 20 min; n = 40 cages); 2) sanitization in a tunnel washer (82 °C [180 °F] for an average of 30 s; n = 40 cages); or 3) control (bedding change only; n = 40 cages). The presence of these agents in the cage was assessed by performing PCR on swabs of the empty soiled cage interior before and after the treatment. In addition, to determine if any residual nucleic acid was infectious, 2 Swiss outbred (J:ARC(S)) female mice were housed for 7 d in cages from each treatment group. The above procedures were then repeated so that every week each pair of J:ARC(S) mice ( n = 10 pairs of mice/treatment group) were housed in another cage that underwent the same treatment; this was done for a total of 4 consecutive, 1-wk-long periods. Swabs collected from soiled cages were PCR-positive for SFB, Helicobacter, MNV, Tritrichomonas, and Entamoeba in 99%, 97%, 39%, 63%, and 73% of the cages tested, respectively. Cages in the tunnel wash group that were PCR-positive for SFB, Helicobacter, Tritrichomonas, and Entamoeba before treatment remained PCR-positive in 8%, 15%, 43%, and 10% of positive cages, respectively. None of the cages from the autoclave group were PCR-positive for any of the agents after treatment. None of the mice housed in cages in either the autoclave or tunnel wash groups became infected with any of the agents. However, 80%, 60%, and 100% of the pairs of mice housed in untreated cages were PCR-positive for SFB, MNV, and Entamoeba, respectively. None of the mice housed in untreated cages were positive for Helicobacter or Tritrichomonas. Our results suggest that nucleic acids from these bacterial and protozoal organisms may remain in cages after mechanical cage washing, but these nucleic acids are not infectious, and autoclaving is not necessary to prevent transmission.
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Affiliation(s)
- Amanda C Ritter
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, The Rockefeller University, New York, New York; Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center and Weill Cornell Medicine, New York, New York;,
| | - Rodolfo J Ricart Arbona
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, The Rockefeller University, New York, New York; Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center and Weill Cornell Medicine, New York, New York
| | | | - Michael B Palillo
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, The Rockefeller University, New York, New York
| | - Mert Aydin
- The Jackson Laboratory, Bar Harbor, Maine
| | | | - Neil S Lipman
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, The Rockefeller University, New York, New York; Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center and Weill Cornell Medicine, New York, New York;,
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Estimation of Bacteriophage MS2 Inactivation Parameters During Microwave Heating of Frozen Strawberries. J Food Prot 2023; 86:100032. [PMID: 36916576 DOI: 10.1016/j.jfp.2022.100032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/25/2022]
Abstract
Frozen berries have been repeatedly linked to acute gastroenteritis caused by norovirus, the most common cause of foodborne illness in the United States. Many guidelines recommend that frozen berries be microwaved for at least 2 min, but it is unclear if this thermal treatment is effective at inactivating norovirus. The objective of this study was to model the effect of microwave heating at varying power levels on the survival of bacteriophage MS2, a norovirus surrogate, when inoculated onto frozen strawberries. Bacteriophage MS2 was inoculated onto the surface of frozen strawberries with a starting concentration of approximately 10 log PFU/g. Samples (either 3 or 5 whole strawberries) were heated in a 1300-Watt domestic research microwave oven (frequency of 2450 MHz) at power levels of 30, 50, 70, and 100% (full power), for times ranging from 15 to 300 s to determine inactivation. Temperatures at berry surfaces were monitored during heating using fiberoptic thermometry. All experiments were conducted in triplicate. The primary model for thermal inactivation was a log-linear model of logN vs. time. The secondary model was for a D-value decreasing linearly with temperature and an added term that was path-dependent on the thermal history. Parameters in the model were estimated using dynamic temperature history at the surface of the berry, via nonlinear regression using all data simultaneously. The root mean square error was ∼0.5 PFU/g out of a total 6-log reduction. Log reductions of 1.1 ± 0.4, 1.5 ± 0.5, 3.1 ± 0.1, and 3.8 ± 0.2 log PFU/g were observed for 30, 50, 70, and 100% microwave power levels when three berries were heated for 60 s. D-values were 21.4 ± 1.95 s and 10.6 ± 1.1 s at 10 and 60°C, respectively. This work demonstrates an approach to estimate inactivation parameters for viruses from dynamic temperature data during microwave heating. These findings will be useful in predicting the safety effect of microwave heating of berries in the home or food service.
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Velebit B, Milojević L, Baltić T, Grković N, Gummalla S, Velebit M, Škoko I, Mojsova S, Putnik P. Efficacy of cold atmospheric plasma for inactivation of viruses on raspberries. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2022.103121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Norovirus Genogroup II Epidemics and the Potential Effect of Climate Change on Norovirus Transmission in Taiwan. Viruses 2022; 14:v14030641. [PMID: 35337048 PMCID: PMC8948982 DOI: 10.3390/v14030641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/27/2022] [Accepted: 03/18/2022] [Indexed: 12/10/2022] Open
Abstract
The activity of norovirus varies from season to season, and the effect of climate change on the incidence of norovirus outbreaks is a widely recognized yet poorly understood phenomenon. Investigation of the possible association between climatic factors and the incidence of norovirus is key to a better understanding of the epidemiology of norovirus and early prediction of norovirus outbreaks. In this study, clinical stool samples from acute gastroenteritis outbreaks were collected from January 2015 to June 2019 in Taiwan. Data analysis from our study indicated that more than half of the cases were reported in the winter and spring seasons, including those caused by norovirus of genotypes GII (genogroup II).2, GII.3, GII.6, and GII.17, and 45.1% of the patients who tested positive for norovirus were infected by the GII.4 norovirus in autumn. However, GII.6 norovirus accounted for a higher proportion of the cases reported in summer than any other strain. Temperature is a crucial factor influencing patterns of epidemic outbreaks caused by distinct genotypes of norovirus. The results of this study may help experts predict and issue early public warnings of norovirus transmission and understand the effect of climate change on norovirus outbreaks caused by different genotypes and occurring in different locations.
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Ezzatpanah H, Gómez‐López VM, Koutchma T, Lavafpour F, Moerman F, Mohammadi M, Raheem D. New food safety challenges of viral contamination from a global perspective: Conventional, emerging, and novel methods of viral control. Compr Rev Food Sci Food Saf 2022; 21:904-941. [DOI: 10.1111/1541-4337.12909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 12/11/2022]
Affiliation(s)
- Hamid Ezzatpanah
- Department of Food Science and Technology, Science and Research Branch Islamic Azad University Tehran Iran
| | | | - Tatiana Koutchma
- Guelph Research and Development Center Agriculture and Agri‐Food Canada Guelph Ontario Canada
| | | | - Frank Moerman
- Department of Chemistry Catholic University of Leuven ‐ KU Leuven Leuven Belgium
| | | | - Dele Raheem
- Arctic Centre (NIEM) University of Lapland Rovaniemi Finland
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Abstract
Respiratory syncytial virus (RSV) is a leading viral cause of pediatric respiratory infections and early infant mortality. Despite extensive development efforts currently underway, there remain no vaccines available for the prevention of RSV. RSV is an enveloped, negative-strand RNA virus that utilizes two different proteins (G and F) to mediate attachment and entry into host cells. These G and F proteins are the primary determinants of viral strain-specific differences and elicit protective neutralizing antibodies during natural infection in humans. Earlier studies have demonstrated that these proteins play an additional role in regulating the stability of RSV particles in response to temperature and pH. However, it remains unclear how much variability exists in the stability of RSV strains and what contribution changes in temperature and pH make to the clearance of virus during an active infection. In this study, we evaluated the impacts of changes in temperature and pH on the inactivation of four different chimeric recombinant RSV strains that differ exclusively in G and F protein expression. Using these data, we developed predictive mathematical models to examine the specific contributions and variations in susceptibility that exist between viral strains. Our data provide strain-specific clearance rates and temperature–pH landscapes that shed light on the optimal contributions of temperature and pH to viral clearance. These provide new insight into how much variation exists in the clearance of a major respiratory pathogen and may offer new guidance on optimization of viral strains for development of live-attenuated vaccine preparations.
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8
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Ailavadi S, Morgan MT, D'Souza DH. Aichi virus inactivation by heat in 2-ml glass vials. J Food Sci 2021; 86:4110-4118. [PMID: 33929042 DOI: 10.1111/1750-3841.15747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/28/2022]
Abstract
Aichi virus (AiV) that results in gastroenteritis worldwide, is spread through contaminated shellfish and water. The resistance/tolerance of AiV to common inactivation processes along with the absence of commercially available vaccines makes it necessary to study its thermal inactivation kinetics. This research evaluated the heat inactivation of AiV in cell-culture media using 2-ml sterile glass vials by the linear and Weibull models. Heat treatments of AiV titers of 7 log plaque forming units (PFU)/ml were conducted thrice in a water-bath at 50, 54, and 58 °C for up to 90 min. Plaque assays for each dilution in duplicate were used to determine infectious virus titers. Linear model D-values for AiV at 50 ± 1 °C (± = standard error) (come-up time = 68 s), 54 ± 0.7 °C (130 s), and 58 ± 0.6°C (251 s) were 43.3 ± 4.23 (R2 = 0.40, RMSE = 0.56), 5.69 ± 0.28 (R2 = 0.80, RMSE = 0.43), and 1.20 ± 0.63 min (R2 = 0.69, RMSE = 0.39), respectively, and the linear model z-value was 5.14 ± 0.39°C (R2 = 0.99, RMSE = 0.08). For the same temperatures, the Weibull model td = 1 values were 20.98 ± 8.8 (R2 = 0.62, RMSE = 0.46, α (scale parameter) = 2.30, β (shape parameter) = 0.38), 3.84 ± 0.69 (R2 = 0.85, RMSE = 0.38, α = 1.08, β = 0.66), and 0.87 ± 0.10 min (R2 = 0.80, RMSE = 0.32, α = 0.22, β = 0.61), respectively and the z-value (using Td = 1 ) was 5.79 ± 0.22 °C (R2 = 1.0, RMSE = 0.03). A better fit was obtained with the Weibull model for log reductions versus time with higher R2 and lower RMSE values. Application of AiV inactivation parameters can help reduce the risk of AiV outbreaks.
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Affiliation(s)
- Sukriti Ailavadi
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
| | - Mark T Morgan
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
| | - Doris H D'Souza
- Department of Food Science, University of Tennessee, Knoxville, TN, USA
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9
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Guillier L, Martin-Latil S, Chaix E, Thébault A, Pavio N, Le Poder S, Batéjat C, Biot F, Koch L, Schaffner DW, Sanaa M. Modeling the Inactivation of Viruses from the Coronaviridae Family in Response to Temperature and Relative Humidity in Suspensions or on Surfaces. Appl Environ Microbiol 2020. [PMID: 32680860 DOI: 10.1128/2020.05.26.20114025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
Temperature and relative humidity are major factors determining virus inactivation in the environment. This article reviews inactivation data regarding coronaviruses on surfaces and in liquids from published studies and develops secondary models to predict coronaviruses inactivation as a function of temperature and relative humidity. A total of 102 D values (i.e., the time to obtain a log10 reduction of virus infectivity), including values for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were collected from 26 published studies. The values obtained from the different coronaviruses and studies were found to be generally consistent. Five different models were fitted to the global data set of D values. The most appropriate model considered temperature and relative humidity. A spreadsheet predicting the inactivation of coronaviruses and the associated uncertainty is presented and can be used to predict virus inactivation for untested temperatures, time points, or any coronavirus strains belonging to Alphacoronavirus and Betacoronavirus genera.IMPORTANCE The prediction of the persistence of SARS-CoV-2 on fomites is essential in investigating the importance of contact transmission. This study collects available information on inactivation kinetics of coronaviruses in both solid and liquid fomites and creates a mathematical model for the impact of temperature and relative humidity on virus persistence. The predictions of the model can support more robust decision-making and could be useful in various public health contexts. A calculator for the natural clearance of SARS-CoV-2 depending on temperature and relative humidity could be a valuable operational tool for public authorities.
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Affiliation(s)
- Laurent Guillier
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Sandra Martin-Latil
- Laboratory for Food Safety, French Agency for Food, Environmental, and Occupational Health and Safety, University of Paris-EST, Maisons-Alfort, France
| | - Estelle Chaix
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Anne Thébault
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Nicole Pavio
- UMR Virologie 1161, ENVA, INRAE, Anses, Maisons-Alfort, France
| | | | - Christophe Batéjat
- Environment and Infectious Risks Unit, Laboratory for Urgent Response to Biological Threats (CIBU), Institut Pasteur, Paris, France
| | - Fabrice Biot
- Bacteriology Unit, French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Lionel Koch
- Bacteriology Unit, French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Donald W Schaffner
- Department of Food Science, Rutgers University, New Brunswick, New Jersey, USA
| | - Moez Sanaa
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
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Guillier L, Martin-Latil S, Chaix E, Thébault A, Pavio N, Le Poder S, Batéjat C, Biot F, Koch L, Schaffner DW, Sanaa M. Modeling the Inactivation of Viruses from the Coronaviridae Family in Response to Temperature and Relative Humidity in Suspensions or on Surfaces. Appl Environ Microbiol 2020; 86:e01244-20. [PMID: 32680860 PMCID: PMC7480392 DOI: 10.1128/aem.01244-20] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/15/2020] [Indexed: 02/08/2023] Open
Abstract
Temperature and relative humidity are major factors determining virus inactivation in the environment. This article reviews inactivation data regarding coronaviruses on surfaces and in liquids from published studies and develops secondary models to predict coronaviruses inactivation as a function of temperature and relative humidity. A total of 102 D values (i.e., the time to obtain a log10 reduction of virus infectivity), including values for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were collected from 26 published studies. The values obtained from the different coronaviruses and studies were found to be generally consistent. Five different models were fitted to the global data set of D values. The most appropriate model considered temperature and relative humidity. A spreadsheet predicting the inactivation of coronaviruses and the associated uncertainty is presented and can be used to predict virus inactivation for untested temperatures, time points, or any coronavirus strains belonging to Alphacoronavirus and Betacoronavirus genera.IMPORTANCE The prediction of the persistence of SARS-CoV-2 on fomites is essential in investigating the importance of contact transmission. This study collects available information on inactivation kinetics of coronaviruses in both solid and liquid fomites and creates a mathematical model for the impact of temperature and relative humidity on virus persistence. The predictions of the model can support more robust decision-making and could be useful in various public health contexts. A calculator for the natural clearance of SARS-CoV-2 depending on temperature and relative humidity could be a valuable operational tool for public authorities.
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Affiliation(s)
- Laurent Guillier
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Sandra Martin-Latil
- Laboratory for Food Safety, French Agency for Food, Environmental, and Occupational Health and Safety, University of Paris-EST, Maisons-Alfort, France
| | - Estelle Chaix
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Anne Thébault
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
| | - Nicole Pavio
- UMR Virologie 1161, ENVA, INRAE, Anses, Maisons-Alfort, France
| | | | - Christophe Batéjat
- Environment and Infectious Risks Unit, Laboratory for Urgent Response to Biological Threats (CIBU), Institut Pasteur, Paris, France
| | - Fabrice Biot
- Bacteriology Unit, French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Lionel Koch
- Bacteriology Unit, French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France
| | - Donald W Schaffner
- Department of Food Science, Rutgers University, New Brunswick, New Jersey, USA
| | - Moez Sanaa
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France
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Abstract
The same term “dose-response curve” describes the relationship between the number of ingested microbes or their logarithm, and the probability of acute illness or death (type I), and between a disinfectant’s dose and the targeted microbe’s survival ratio (type II), akin to survival curves in thermal and non-thermal inactivation kinetics. The most common model of type I curves is the cumulative form of the beta-Poisson distribution which is sometimes indistinguishable from the lognormal or Weibull distribution. The most notable survival kinetics models in static disinfection are of the Chick-Watson-Hom’s kind. Their published dynamic versions, however, should be viewed with caution. A microbe population’s type II dose-response curve, static and dynamic, can be viewed as expressing an underlying spectrum of individual vulnerabilities (or resistances) to the particular disinfectant. Therefore, such a curve can be described mathematically by the flexible Weibull distribution, whose scale parameter is a function of the disinfectant’s intensity, temperature, and other factors. But where the survival ratio’s drop is so steep that the static dose-response curve resembles a step function, the Fermi distribution function becomes a suitable substitute. The utility of the CT (or Ct) concept primarily used in water disinfection is challenged on theoretical grounds and its limitations highlighted. It is suggested that stochastic models of microbial inactivation could be used to link the fates of individual viruses or bacteria to their manifestation in the survival curve’s shape. Although the emphasis is on viruses and bacteria, most of the discussion is relevant to fungi, protozoa, and perhaps worms too.
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Pitino MA, O'Connor DL, McGeer AJ, Unger S. The impact of thermal pasteurization on viral load and detectable live viruses in human milk and other matrices: a rapid review. Appl Physiol Nutr Metab 2020; 46:10-26. [PMID: 32650645 DOI: 10.1139/apnm-2020-0388] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Holder pasteurization (62.5 °C, 30 min) of human milk is thought to reduce the risk of transmitting viruses to an infant. Some viruses may be secreted into milk - others may be contaminants. The effect of thermal pasteurization on viruses in human milk has yet to be rigorously reviewed. The objective of this study is to characterize the effect of common pasteurization techniques on viruses in human milk and non-human milk matrices. Databases (MEDLINE, Embase, Web of Science) were searched from inception to April 20th, 2020, for primary research articles assessing the impact of pasteurization on viral load or detection of live virus. Reviews were excluded, as were studies lacking quantitative measurements or those assessing pasteurization as a component of a larger process. Overall, of 65 131 reports identified, 109 studies were included. Pasteurization of human milk at a minimum temperature of 56-60 °C is effective at reducing detectable live virus. In cell culture media or plasma, coronaviruses (e.g., SARS-CoV, SARS-CoV-2, MERS-CoV) are highly susceptible to heating at ≥56 °C. Although pasteurization parameters and matrices reported vary, all viruses studied, except parvoviruses, were susceptible to thermal killing. Future research important for the study of novel viruses should standardize pasteurization protocols and should test inactivation in human milk. Novelty In all matrices, including human milk, pasteurization at 62.5 °C was generally sufficient to reduce surviving viral load by several logs or to below the limit of detection. Holder pasteurization (62.5 °C, 30 min) of human milk should be sufficient to inactivate nonheat resistant viruses, including coronaviruses, if present.
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Affiliation(s)
- Michael A Pitino
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada.,Translational Medicine Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Deborah L O'Connor
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada.,Translational Medicine Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Allison J McGeer
- Department of Microbiology, Sinai Health, Toronto, ON M5G 1X5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A1, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada
| | - Sharon Unger
- Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada.,Division of Neonatology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Pediatrics, Sinai Health, Toronto, ON M5G 1X5, Canada.,Department of Pediatrics, University of Toronto, Toronto, ON M5G 1X8, Canada
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13
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Patwardhan M, Morgan MT, Dia V, D'Souza DH. Heat sensitization of hepatitis A virus and Tulane virus using grape seed extract, gingerol and curcumin. Food Microbiol 2020; 90:103461. [PMID: 32336357 DOI: 10.1016/j.fm.2020.103461] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 09/23/2019] [Accepted: 02/10/2020] [Indexed: 11/30/2022]
Abstract
Human noroviruses (HNoV) and hepatitis A virus (HAV) are predominantly linked to foodborne outbreaks worldwide. As cell-culture systems to propagate HNoV in laboratories are not easily available, Tulane virus (TV) is used as a cultivable HNoV surrogate to determine inactivation. Heat-sensitization of HAV and TV by "generally recognized as safe'' (GRAS) substances can potentially reduce their time-temperature inactivation parameters during processing to ensure food safety. Curcumin, gingerol (from ginger), and grape seed extract (GSE) reportedly have anti-inflammatory, immune-modulating and antiviral properties. The objective of this study was to determine and compare the D-values and z-values of HAV and TV at 52-68 °C with or without curcumin (0.015 mg/ml), gingerol (0.1 mg/ml), or GSE (1 mg/ml) in 2-ml glass vials. HAV at ~7 log PFU/ml and TV at ~6 log PFU/ml were diluted in phosphate buffered saline (PBS) and added to two sets of six 2-mL sterile glass vials. One set served as the control and the second set had the three extracts individually added for thermal treatments in a circulating water bath for 0-10 min. The D-values for TV in PBS ranged from 4.55 ± 0.28 to 1.08 ± 0.16 min, and for HAV in PBS ranged from to 9.21 ± 0.24 to 0.67 ± 0.19 min at 52-68 °C. Decreased D-values (52-58 °C) for TV with curcumin ranging from 4.32 ± 0.25 to 0.62 ± 0.17 min, gingerol from 4.09 ± 0.18 to 0.72 ± 0.09 min and GSE from 3.82 ± 0.18 to 0.80 ± 0.07 min, with similar trends for HAV were observed. The linear model showed significant differences (p < 0.05) between the D-values of HAV and TV with and without plant extracts for most tested temperatures. This suggests that GRAS substances can potentially lower temperature and time regimens needed to inactivate HAV and TV.
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Affiliation(s)
- Mayuri Patwardhan
- Department of Food Science, 2600 River Drive, University of Tennessee, Knoxville, TN, 37996, USA
| | - Mark T Morgan
- Department of Food Science, 2600 River Drive, University of Tennessee, Knoxville, TN, 37996, USA
| | - Vermont Dia
- Department of Food Science, 2600 River Drive, University of Tennessee, Knoxville, TN, 37996, USA
| | - Doris H D'Souza
- Department of Food Science, 2600 River Drive, University of Tennessee, Knoxville, TN, 37996, USA.
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Predictive models for thermal inactivation of human norovirus and surrogates in strawberry puree. Food Control 2019. [DOI: 10.1016/j.foodcont.2018.08.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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15
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16
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Abstract
Risk is an inherent component of human existence, as is our creation of ways to avoid or minimize such risks. The formal process of assessing the likelihood and magnitude of risk, using that information to manage risk, and then communicating the process to others, forms the basis for risk analysis. This chapter provides an overview of the steps of risk analysis with a focus on risk assessment for foodborne viruses, particularly quantitative efforts that model and estimate the risks these viruses pose to human health. Most risk assessments in food and environmental virology performed in the last decade have focused on water, fresh produce, molluscan shellfish, and prepared foods. Recent examples of enteric virus risk modeling efforts are discussed in detail, as are several of the difficulties and intricacies of performing risk assessments for foodborne viruses compared to bacteria and other agents. This is a relatively new area of study, but one that will continue to grow as national and international agencies continue to adopt and require the methodology for food safety and the protection of human health.
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Peng J, Tang J, Barrett DM, Sablani SS, Anderson N, Powers JR. Thermal pasteurization of ready-to-eat foods and vegetables: Critical factors for process design and effects on quality. Crit Rev Food Sci Nutr 2015; 57:2970-2995. [DOI: 10.1080/10408398.2015.1082126] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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