Understanding how different surfaces and environmental biofilms found in food processing plants affect the spread of COVID-19.

Meat processing plants have been at the center of the SARS-CoV-2 pandemic, with a recent report citing 90% of US facilities having multiple outbreaks during 2020 and 2021. We explored the potential for biofilms to act as a reservoir in protecting, harboring, and dispersing SARS-CoV-2 throughout the meat processing facility environment. To do this, we used Murine Hepatitis Virus (MHV), as a surrogate for SARS-CoV-2, and meat processing facility drain samples to develop mixed-species biofilms on materials found in meat processing facilities (stainless steel (SS), PVC, and ceramic tiles). After exposure to the biofilm organisms for five days post-inoculation at 7°C we conducted quantitative PCR (qPCR) and plaque assays to determine whether MHV could remain both detectable and viable. Our data provides evidence that coronaviruses can remain viable on all the surfaces tested and are also able to integrate within an environmental biofilm. Although a portion of MHV was able to remain infectious after incubation with the environmental biofilm, a large reduction in plaque numbers was identified when compared with the viral inoculum incubated without biofilm on all test surfaces, which ranged from 6.45-9.27-fold higher. Interestingly, we observed a 2-fold increase in the virus-environmental biofilm biovolume when compared to biofilm without virus, indicating that the biofilm bacteria both detected and reacted to the virus. These results indicate a complex virus-environmental biofilm interaction. Although we observed better survival of MHV on a variety of surfaces commonly found in meat processing plants alone than with the biofilm, there is the potential for biofilms to protect virions from disinfecting agents, which has implications for the potential of SARS-CoV-2 prevalence within the meat processing plant environment. Also given the highly infectious nature of SARS-CoV-2, particularly for some of the variant strains such as omicron, having even a residual level of virus present represents a serious health hazard. The increase in biofilm biovolume in response to virus is also a concern for food safety due to the potential of the same being seen with organisms associated with food poisoning and food spoilage.

Microbiological Quality of Ready-to-Eat Salad Products Collected from Retail and Catering Settings in England during 2020 to 2021.

ABSTRACT: Salad and other fresh produce were collected in England from retail and catering businesses during 2020 to 2021 and were tested for Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria, Bacillus cereus, and E. coli. Of the 604 samples collected, 57% were from retail settings and 43% were from catering settings; 61% were either salad leaves or salad leaves mixed with other products. Equal numbers of samples were prepacked or loose, and 50% were refrigerated at the time of sampling. Combining results for all microbiological parameters, 84% were interpreted as satisfactory, 12% were interpreted as borderline, and 4% were interpreted as unsatisfactory. One sample (prepacked leaves, cucumber, and tomato from a caterer) was categorized as unacceptable and potentially injurious because of detection of STEC O76; no STEC from human infections in the United Kingdom matched this isolate. No Salmonella enterica was detected, but Listeria monocytogenes was recovered from 11 samples: 1 at 20 CFU/g and the remainder at <20 CFU/g. B. cereus was detected at borderline levels (103 to ≤105 CFU/g) in 9% of samples and at an unsatisfactory level (>105 CFU/g) in one sample. E. coli was detected in 3% of samples at borderline levels (20 to ≤102 CFU/g) and in 4% at unsatisfactory levels (>102 CFU/g). There was a significant association between detection of L. monocytogenes and borderline or unsatisfactory levels of E. coli. There were no specific risk profiles associated with products with the higher levels of B. cereus, STEC, or Listeria, but elevated levels of E. coli were predominantly confined to loose products from the United Kingdom collected from caterers in summer or autumn 2021 and may have resulted from relaxation of COVID-19 restrictions. Among the L. monocytogenes isolates, only one matched those from human cases and was recovered from a prepacked mixed salad from a catering business in 2021. This isolate was the same strain as that responsible for a multicountry outbreak (2015 to 2018) associated with Hungarian-produced frozen sweet corn; no link to the outbreak food chain was established.

Current Status and Future Trends in Removal, Control, and Mitigation of Algae Food Safety Risks for Human Consumption.

With the rapid development of the economy and productivity, an increasing number of citizens are not only concerned about the nutritional value of algae as a potential new food resource but are also, in particular, paying more attention to the safety of its consumption. Many studies and reports pointed out that analyzing and solving seaweed food safety issues requires holistic and systematic consideration. The three main factors that have been found to affect the food safety of algal are physical, chemical, and microbiological hazards. At the same time, although food safety awareness among food producers and consumers has increased, foodborne diseases caused by algal food safety incidents occur frequently. It threatens the health and lives of consumers and may cause irreversible harm if treatment is not done promptly. A series of studies have also proved the idea that microbial contamination of algae is the main cause of this problem. Therefore, the rapid and efficient detection of toxic and pathogenic microbial contamination in algal products is an urgent issue that needs to be addressed. At the same time, two other factors, such as physical and chemical hazards, cannot be ignored. Nowadays, the detection techniques are mainly focused on three major hazards in traditional methods. However, especially for food microorganisms, the use of traditional microbiological control techniques is time-consuming and has limitations in terms of accuracy. In recent years, these two evaluations of microbial foodborne pathogens monitoring in the farm-to-table chain have shown more importance, especially during the COVID-19 pandemic. Meanwhile, there are also many new developments in the monitoring of heavy metals, algal toxins, and other pollutants. In the future, algal food safety risk assessment will not only focus on convenient, rapid, low-cost and high-accuracy detection but also be connected with some novel technologies, such as the Internet of Things (artificial intelligence, machine learning), biosensor, and molecular biology, to reach the purpose of simultaneous detection.

Evaluation of the Thermo ScientificTM SureTectTMListeria monocytogenes PCR Assay in a Broad Range of Foods and Selected Environmental Surfaces: Pre-Collaborative and Collaborative Study, First Action 2021.05.

BACKGROUND: The Thermo Scientific™ SureTect™ Listeria monocytogenes PCR Assay uses Solaris reagents for performing PCR for the rapid and specific detection of Listeria monocytogenes in a broad range of foods and selected environmental surfaces. OBJECTIVE: To demonstrate reproducibility of the SureTect Listeria monocytogenes PCR Assay in a collaborative study using a challenging matrix, full-fat cottage cheese (25 g). To extend the scope of the method. METHOD: In the collaborative study, the candidate method was compared to the United States Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 10 Listeria reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems™ QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). Eighteen participants from 10 laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Three levels of contamination were evaluated for each matrix. Statistical analysis was conducted according to the probability of detection (POD) statistical model. In addition, to extend the scope, six matrix studies were performed comparing the candidate method to the FDA/BAM reference method. One of these matrixes was also compared to the ISO 11290-1:2017 Microbiology of the Food Chain-Horizontal Method for the Detection and Enumeration of Listeria monocytogenes and of Listeria spp.-Part 1: Detection Method Reference Method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated, and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. The two PCR instruments used in the study performed equivalently. All presumptive positives were confirmed via the alternative confirmation procedure. In the pre-collaborative studies, the results showed comparable performances between the candidate method and the reference method for all matrixes tested. CONCLUSIONS: Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 25 g full-fat cottage cheese is known to be a challenging matrix to test. No unusual cross-contamination or false positive/negative data were reported, highlighting the ease of use, reproducibility, and robustness of the method.

Efficacy of washing produce in removing human coronavirus OC43 and murine norovirus.

AIMS: Fresh produce is often a vehicle for the transmission of foodborne pathogens such as human norovirus. Thus, it is recommended to wash the surface of produce before consumption, and one of the most common ways to wash produce is by rinsing under running tap water. This study determined the effectiveness of removal of human coronavirus-OC43 (HCoV-OC43), as a surrogate for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and murine norovirus-1 (MNV-1), as a surrogate for human norovirus, from contaminated lettuce, apples and cucumbers. METHODS AND RESULTS: The produce surfaces were artificially inoculated in conjunction with faecal material to represent natural contamination. Rinsing under tap water for 10 s at 40 ml/s removed 1.94 ± 0.44, 1.42 ± 0.00 and 1.42 ± 0.42 log of HCoV-OC43 from apple, cucumber and lettuce respectively. The same washing technique removed 1.77 ± 0.17, 1.42 ± 0.07 and 1.79 ± 0.14 log of MNV-1 from apple, cucumber and lettuce respectively. This washing technique was effective at reducing a significant amount of viral contamination, however, it was not enough to eliminate the entire contamination. There was no significant difference in the reduction of viral load between the two viruses, nor between the three surfaces tested in this study. CONCLUSIONS: Our data suggest that washing under tap water would be an efficient way of reducing the risk of foodborne viral transmission only if the level of contamination is less than 2 log PFU. SIGNIFICANCE AND IMPACT OF STUDY: This study demonstrates that running tap water was effective at reducing the amount of infectious HCoV-OC43 and MNV on produce surfaces, and washing produce continues to be an important task to perform prior to consumption to avoid infection by foodborne viruses, particularly for foods which are eaten raw.

Cross-Contamination on Atypical Surfaces and Venues in Food Service Environments.

ABSTRACT: Cross-contamination of raw food to other surfaces, hands, and foods is a serious issue in food service. With individuals eating more meals away from home, contracting a foodborne illness from a food service establishment is an increasing concern. However, most studies have concentrated on hands or food contact surfaces and neglected atypical and unusual surfaces (surfaces that are not typically identified as a source of cross-contamination) and venues. This review was conducted to identify atypically cross-contaminated surfaces and atypical venues where cross-contamination could occur that have not been examined thoroughly in the literature. Most surfaces that could be at risk for cross-contamination are frequently touched, are rarely cleaned and sanitized, and can support the persistence and/or growth of foodborne pathogens. These surfaces include menus, spice and condiment containers, aprons and coveralls, mobile devices and tablets, and money. Venues that are explored, such as temporary events, mobile vendors, and markets, are usually limited in space or infrastructure, have low compliance with proper hand washing, and provide the opportunity for raw and ready-to-eat foods to come into contact with one another. These factors create an environment in which cross-contamination can occur and potentially impact food safety. A more comprehensive cleaning and sanitizing regime encompassing these surfaces and venues could help mitigate cross-contamination. This review highlights key surfaces and venues that have the potential to be cross-contaminated and have been underestimated or not fully investigated. These knowledge gaps indicate where further work is needed to fully understand the role of these surfaces and venues in cross-contamination and how it can be prevented.

Evaluation of the Thermo Scientific SureTectTM Listeria Species PCR Assay in a Broad Range of Foods and Selected Environmental Surfaces: Pre-Collaborative and Collaborative Study, First Action 2021.06.

BACKGROUND: The Thermo Scientific SureTect™ Listeria species PCR assay utilizes SolarisTM reagents for performing PCR for the rapid and specific detection of Listeria species in a broad range of foods and selected environmental surfaces. OBJECTIVE: To demonstrate reproducibility of the Thermo Scientific SureTect Listeria species PCR assay in a collaborative study using a challenging matrix, full-fat cottage cheese (25 g), to extend the scope of the method. METHODS: In the collaborative study, the candidate method was compared to the US Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Ch. 10 Listeria reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). The candidate method included its own confirmation procedure. Eighteen participants from 10 laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Statistical analysis was conducted according to the probability of detection (POD) statistical model. In addition, in order to extend the scope of the method, seven matrix studies were performed comparing the candidate method to the FDA/BAM reference method. One of these matrixes was also compared to the ISO 11290-1:2017 Microbiology of the food chain-Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp.-Part 1: Detection method reference method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. The two PCR instruments used in the study performed equivalently. All presumptive positives were confirmed via the alternative confirmation procedure. In the pre-collaborative studies, the results showed comparable performances between the candidate method and the reference method for all matrixes tested. CONCLUSION: Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 25 g full-fat cottage cheese is known to be a challenging matrix to test. No unusual cross-contamination, or false-positive/negative data was reported, highlighting the ease of use, reproducibility, and robustness of the candidate method.

Investigating the Campylobacter enteritis winter peak in Germany, 2018/2019.

Surveillance of notified Campylobacter enteritis in Germany revealed a recurrent annual increase of cases with disease onset several days after the Christmas and New Year holidays ("winter peak"). We suspected that handling and consumption of chicken meat during fondue and raclette grill meals on the holidays were associated with winter peak Campylobacter infections. The hypothesis was investigated in a case-control study with a case-case design where notified Campylobacter enteritis cases served as case-patients as well as control-patients, depending on their date of disease onset (case-patients: 25/12/2018 to 08/01/2019; control-patients: any other date between 30/11/2018 and 28/02/2019). The study was conducted as an online survey from 21/01/2019 to 18/03/2019. Adjusted odds ratios (aOR) were determined in single-variable logistic regression analyses adjusted for age group and sex. We analysed 182 data sets from case-patients and 260 from control-patients and found associations of Campylobacter infections after the holidays with meat fondue (aOR 2.2; 95% confidence interval (CI) 1.2-3.8) and raclette grill meals with meat (aOR 1.5; 95% CI 1.0-2.4) consumed on the holidays. The associations were stronger when chicken meat was served at these meals (fondue with chicken meat: aOR 2.7; 95% CI 1.4-5.5; raclette grill meal with chicken meat: aOR 2.3; 95% CI 1.3-4.1). The results confirmed our initial hypothesis. To prevent Campylobacter winter peak cases in the future, consumers should be made more aware of the risks of a Campylobacter infection when handling raw meat, in particular chicken, during fondue or raclette grill meals on the holidays.

The diversity and function of sourdough starter microbiomes.

Humans have relied on sourdough starter microbial communities to make leavened bread for thousands of years, but only a small fraction of global sourdough biodiversity has been characterized. Working with a community-scientist network of bread bakers, we determined the microbial diversity of 500 sourdough starters from four continents. In sharp contrast with widespread assumptions, we found little evidence for biogeographic patterns in starter communities. Strong co-occurrence patterns observed in situ and recreated in vitro demonstrate that microbial interactions shape sourdough community structure. Variation in dough rise rates and aromas were largely explained by acetic acid bacteria, a mostly overlooked group of sourdough microbes. Our study reveals the extent of microbial diversity in an ancient fermented food across diverse cultural and geographic backgrounds.

Sourdough bread is an ancient fermented food that has sustained humans around the world for thousands of years. It is made from a sourdough 'starter culture' which is maintained, portioned, and shared among bread bakers around the world. The starter culture contains a community of microbes made up of yeasts and bacteria, which ferment the carbohydrates in flour and produce the carbon dioxide gas that makes the bread dough rise before baking. The different acids and enzymes produced by the microbial culture affect the bread's flavor, texture and shelf life. However, for such a dependable staple, sourdough bread cultures and the mixture of microbes they contain have scarcely been characterized. Previous studies have looked at the composition of starter cultures from regions within Europe. But there has never been a comprehensive study of how the microbial diversity of sourdough starters varies across and between continents. To investigate this, Landis, Oliverio et al. used genetic sequencing to characterize the microbial communities of sourdough starters from the homes of 500 bread bakers in North America, Europe and Australasia. Bread makers often think their bread's unique qualities are due to the local environment of where the sourdough starter was made. However, Landis, Oliverio et al. found that geographical location did not correlate with the diversity of the starter cultures studied. The data revealed that a group of microbes called acetic acid bacteria, which had been overlooked in past research, were relatively common in starter cultures. Moreover, starters with a greater abundance of this group of bacteria produced bread with a strong vinegar aroma and caused dough to rise at a slower rate. This research demonstrates which species of bacteria and yeast are most commonly found in sourdough starters, and suggests geographical location has little influence on the microbial diversity of these cultures. Instead, the diversity of microbes likely depends more on how the starter culture was made and how it is maintained over time.

Prevalence of Listeria monocytogenes and Salmonella spp. in Different Ready to Eat Foods from Large Retailers and Canteens over a 2-Year Period in Northern Italy.

This study aims to give an overview of the prevalence of Listeria monocytogenes and Salmonella spp. in 9727 samples (2996 for L. monocytogenes and 6731 for Salmonella spp.) from different categories of ready-to-eat (RTE) foods, collected over 2 years from 28 large retailers and 148 canteens in the regions of northern Italy. The RTE samples were classified into two groups according to the preparation methods: (i) multi-ingredient preparations consisting of fully cooked food ready for immediate consumption, or with minimal further handling before consumption (Group A), and (ii) multi-ingredient preparations consisting of cooked and uncooked food, or preparations consisting of only raw ingredients (Group B). L. monocytogenes and Salmonella spp. were investigated in both of these categories. The overall prevalence of L. monocytogenes and Salmonella spp. was 0.13% and 0.07%, respectively. More specifically, L. monocytogenes was found in 0.04% of 2442 analysed RTE food samples belonging to group A and in 0.54% of 554 samples belonging to group B. Furthermore, 0.03% of 5367 RTE food samples from group A and 0.21% of 1364 samples from group B tested positive for Salmonella spp. In conclusion, the results obtained in this study can provide a significant contribution to L. monocytogenes and Salmonella spp. risk analysis in RTE foods.

Decreased Incidence of Infections Caused by Pathogens Transmitted Commonly Through Food During the COVID-19 Pandemic - Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2017-2020.

Foodborne illnesses are a substantial and largely preventable public health problem; before 2020 the incidence of most infections transmitted commonly through food had not declined for many years. To evaluate progress toward prevention of foodborne illnesses in the United States, the Foodborne Diseases Active Surveillance Network (FoodNet) of CDC's Emerging Infections Program monitors the incidence of laboratory-diagnosed infections caused by eight pathogens transmitted commonly through food reported by 10 U.S. sites.* FoodNet is a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture's Food Safety and Inspection Service (USDA-FSIS), and the Food and Drug Administration. This report summarizes preliminary 2020 data and describes changes in incidence with those during 2017-2019. During 2020, observed incidences of infections caused by enteric pathogens decreased 26% compared with 2017-2019; infections associated with international travel decreased markedly. The extent to which these reductions reflect actual decreases in illness or decreases in case detection is unknown. On March 13, 2020, the United States declared a national emergency in response to the COVID-19 pandemic. After the declaration, state and local officials implemented stay-at-home orders, restaurant closures, school and child care center closures, and other public health interventions to slow the spread of SARS-CoV-2, the virus that causes COVID-19 (1). Federal travel restrictions were declared (1). These widespread interventions as well as other changes to daily life and hygiene behaviors, including increased handwashing, have likely changed exposures to foodborne pathogens. Other factors, such as changes in health care delivery, health care-seeking behaviors, and laboratory testing practices, might have decreased the detection of enteric infections. As the pandemic continues, surveillance of illness combined with data from other sources might help to elucidate the factors that led to the large changes in 2020; this understanding could lead to improved strategies to prevent illness. To reduce the incidence of these infections concerted efforts are needed, from farm to processing plant to restaurants and homes. Consumers can reduce their risk of foodborne illness by following safe food-handling and preparation recommendations.

Evaluation of the Thermo Scientific SureTect Salmonella Species PCR Assay in a Broad Range of Foods and Select Environmental Surfaces: Pre-Collaborative and Collaborative Study: First Action 2021.02.

BACKGROUND: The Thermo Scientific™ SureTect™ Salmonella species PCR Assay utilizes Solaris™ reagents for performing PCR for the rapid and specific detection of Salmonella species in a broad range of foods and select environmental surfaces. OBJECTIVE: The aims were to demonstrate the reproducibility of the Thermo Scientific SureTect Salmonella species PCR Assay in a collaborative study using a challenging matrix, cocoa powder, and to extend the scope of the method. METHOD: In the collaborative study, the candidate method was compared to the US Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 Salmonella reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems™ QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). Fourteen participants from nine laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Three levels of contamination were evaluated for each matrix. Statistical analysis was conducted according to the probability of detection statistical model. In addition, 11 matrix studies were performed comparing the candidate method to the FDA/BAM Chapter 5 or US Department of Agriculture, Food Safety and Inspection Service, Microbiology Laboratory Guidebook 4.10 Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Siluriformes (Fish) Products and Carcass and Environmental Sponges reference method. Nine of these matrices were also compared to the EN ISO 6579-1:2017/Amd.1:2020(E) Microbiology of the food chain-Horizontal method for the detection, enumeration and serotyping of Salmonella-Part 1: Detection of Salmonella spp.-AMENDMENT 1: Broader range of incubation temperatures, amendment to the status of Annex D, and correction of the composition of MSRV and SC reference method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated, and the method demonstrated acceptable interlaboratory reproducibility as determined in the collaborative evaluation. False-positive and false-negative rates were determined for the matrix and produced values of <2%. The two PCR thermocyclers (QS5, 7500 Fast) performed equivalently. There were no result differences between candidate method confirmations and reference method confirmations. In the pre-collaborative matrix extension, the results from the matrix studies showed a comparable performance between the candidate method and the tested reference methods. CONCLUSIONS: Based on the data generated, the method demonstrated acceptable interlaboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 375 g cocoa powder is known to be a challenging matrix for PCR methods. No unusual cross-contamination or false-positive/negative was reported, highlighting the ease of use, reproducibility, and robustness of the method.

Human Coronaviruses Do Not Transfer Efficiently between Surfaces in the Absence of Organic Materials.

Human coronaviruses, including SARS-CoV-2, are known to spread mainly via close contact and respiratory droplets. However, other potential means of transmission may be present. Fomite-mediated transmission occurs when viruses are deposited onto a surface and then transfer to a subsequent individual. Surfaces can become contaminated directly from respiratory droplets or from a contaminated hand. Due to mask mandates in many countries around the world, the former is less likely. Hands can become contaminated if respiratory droplets are deposited on them (i.e., coughing or sneezing) or through contact with fecal material where human coronaviruses (HCoVs) can be shed. The focus of this paper is on whether human coronaviruses can transfer efficiently from contaminated hands to food or food contact surfaces. The surfaces chosen were: stainless steel, plastic, cucumber and apple. Transfer was first tested with cellular maintenance media and three viruses: two human coronaviruses, 229E and OC43, and murine norovirus-1, as a surrogate for human norovirus. There was no transfer for either of the human coronaviruses to any of the surfaces. Murine norovirus-1 did transfer to stainless steel, cucumber and apple, with transfer efficiencies of 9.19%, 5.95% and 0.329%, respectively. Human coronavirus OC43 transfer was then tested in the presence of fecal material, and transfer was observed for stainless steel (0.52%), cucumber (19.82%) and apple (15.51%) but not plastic. This study indicates that human coronaviruses do not transfer effectively from contaminated hands to contact surfaces without the presence of fecal material.

Viruses in fermented foods: are they good or bad? Two sides of the same coin.

The emergence of Coronavirus disease 2019 as a global pandemic has increased popular concerns about diseases caused by viruses. Fermented foods containing high loads of viable fungi and bacteria are potential sources for virus contamination. The most common include viruses that infect bacteria (bacteriophage) and yeasts reported in fermented milks, sausages, vegetables, wine, sourdough, and cocoa beans. Recent molecular studies have also associated fermented foods as vehicles for pathogenic human viruses. Human noroviruses, rotavirus, and hepatitis virus have been identified in different fermented foods through multiple routes. No severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) virus or close members were found in fermented foods to date. However, the occurrence/persistence of other pathogenic viruses reveals a potential vulnerability of fermented foods to SARS-CoV-2 contamination. On the other side of the coin, some bacteriophages are being suggested for improving the fermentation process and food safety, as well as owing potential probiotic properties in modern fermented foods. This review will address the diversity and characteristics of viruses associated with fermented foods and what has been changed after a short introduction to the most common next-generation sequencing platforms. Also, the risk of SARS-CoV-2 transmission via fermented foods and preventive measures will be discussed.

Carrying out pseudo dual nucleic acid detection from sample to visual result in a polypropylene bag with CRISPR/Cas12a.

Amplification-based nucleic acid detection is widely employed in food safety, medical diagnosis and environment monitoring. However, conventional nucleic acid analysis has to be carried out in laboratories because of requiring expensive instruments and trained personnel. If people could do nucleic acid detection at home by themselves, the application of nucleic acid detection would be greatly accelerated. We herein reported a polypropylene (PP) bag-based method for convenient detection of nucleic acids in the oil-sealed space. The PP bag has three chambers which are responsible for lysis, washing and amplification/detection, respectively. After adding sample, nucleic acids are adsorbed on magnetic particles (MPs) and moved into these three chambers successively through immiscible oil channel by an external magnet. Combined with isothermal amplification, the PP bag can be incubated in a water bath or milk warmer and acted as a reaction tube. With highly specific CRISPR technology, Salmonella typhimurium (St) and SARS-CoV-2 can be visually detected in these PP bags within 1 h, indicating its potential household application. To further improve the reliability of nucleic acid testing at home, a logic decision method is introduced by detecting both target and endogenous reference gene. Positive/negative/invalid detection result can be obtained by chronologically adding the CRISPR reagents of target and endogenous reference gene. We anticipate that this PP bag can provide a novel toolkit for nucleic acid detection in people's daily life.

Animal-based food systems are unsafe: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fosters the debate on meat consumption.

OBJECTIVE: The current pandemic restarts a debate on permanently banning wildlife consumption in an effort to prevent further public health threats. In this commentary, we offer two ideas to enhance the discussion on foodborne zoonotic diseases in food systems. DESIGN: First, we focus on the probable consequences that the loss of access to wildlife could cause to the status of food and nutrition security of many people in developing countries that rely on bushmeat to subsist. Second, we argue that all animal-based food systems, especially the ones based on intensive husbandry, present food safety threats. CONCLUSION: To ban the access to bushmeat without a rational analysis of all human meat production and consumption in the global animal-based food system will not help us to prevent future outbreaks.