Norovirus and Hepatitis A risk in Australian greens and berries

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The apparent international rise in foodborne virus outbreaks attributed to fresh produce and the increasing importance of fresh produce in the Australian diet has led to the requirement to gather information to inform the development of risk management strategies.

A prevalence survey for norovirus (NoV) and hepatitis A virus (HAV) in fresh Australian produce (leafy greens, strawberries and blueberries) at retail was undertaken during 2013–2014 and data used to develop a risk profile. The prevalence of HAV in berries and leafy greens was estimated to be <2%, with no virus detected in produce during the yearlong survey. The prevalence of NoV in fresh strawberries and blueberries was also estimated to be <2% with no virus detected in berries, whilst for leafy greens the NoV prevalence was 2.2%.

Prevalence of a bacterial hygiene indicator, Escherichia coli, was also investigated and found to range from <1% in berries to 10.7% in leafy greens. None of the NoV positive leafy green samples tested positive for E. coli, indicating it is a poor indicator for viral risk.

The risk was evaluated using standard codex procedures and the Risk Ranger tool. Taking all data into account, including the hazard dose and severity, probability of exposure, probability of infective dose and available epidemiological data, the risk of HAV and NoV foodborne illness associated with fresh Australian berries (strawberries and blueberries) sold as packaged product was deemed to be low. The risk of foodborne illness from HAV associated with leafy greens was also deemed to be low, but higher than that for fresh berries, due mainly to the potential for recontamination post-processing if sold loose. The risk of foodborne illness from NoV associated with leafy greens was deemed to be low/moderate. Despite the prevalence of NoV in leafy greens being low and the inability to discriminate between infective and non-infective virus using PCR based methodologies, the fact that NoV was detected resulted in a higher risk associated with this pathogen-product pairing; compounded by the higher prevalence of NoV within the community compared to HAV, and the potential for leafy greens to become contaminated following processing if sold loose.

Estimating risk associated with human norovirus and hepatitis A virus in fresh Australian leafy greens and berries at retail 26 August 2019

International Journal of Food Microbiology

Valeria A.Torok, Kate R.Hodgson, Jessica Jolley, Alison Turnbull, Catherine McLeod

https://doi.org/10.1016/j.ijfoodmicro.2019.108327

https://www.sciencedirect.com/science/article/pii/S0168160518306974

Food Safety Talk 191: Make KABOBs with Gordon

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Don and Ben are joined by friend Gordon Hayburn, dog judge and VP food safety and quality at Trophy Foods. The guys talk dogs, monorchids and online food discussions. They go on to talk about plant-based meat alternatives, is chicken really chicken and the fallout and management of food fraud. The episode ended on how food safety culture gets implemented and a discussion of kebab, er, KABOB, making.

Download the episode here, or on iTunes

Show notes so you can follow along at home:

2 dead, 184 sick linked to Spanish listeriosis outbreak

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Last Tuesday a 90-year-old woman passed away, becoming the second death in Spain’s burgeoning listeria outbreak linked to La Mecha branded ‘carne mechada.’

The outbreak has been traced to utensils (slicers? Something lost in translation) used in the preparation of the food products.

Now experts say the bacteria may be present in other products from the Magrudis factory in Sevilla. All its production has been recalled with experts saying at least two other products are at high risk of having been infected.

Medical authorities say this strain of the bacterium is particularly virulent, taking three days to incubate. Normally the incubation period is up to 70 days.

E. coli O111:H8: Chaource Lincet and Gaugry raw milk cheeses recalled in France

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A few hundred Chaource raw milk cheese brands Lincet and Gaugry, sold throughout France, are subject to a recall procedure after the demonstration of the presence of Escherichia coli. A check has highlighted in these products, manufactured by the Lincet cheese factory in Vaudes in the Aube, the presence of Escherichia coli O111: H8, indicates the cheese Friday in a statement.

This bacterium is likely to cause serious problems in anyone consuming the product, she adds. Nearly 700 Chaource AOP cheeses of 500 grams raw milk, bearing the lot number 227.210 and with a deadline of consumption to 27 September 2019, are concerned, according to the press release.

Lincet brand cheeses have been sold in a variety of supermarket chains, both traditional and fresh, while Gaugry branded cheeses have been distributed in the dairy and market channels.

Connecticut Coast Guard academy medical staff bring bacterial outbreak under control

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With hundreds of new Coast Guard Academy cadets, or swabs (how perfect is that – dp), starting their military training, staff at the medical clinic on campus have had their hands full during the summer months.

Julia Bergman of Military writes that the outbreak was magnified two weeks ago, when a bacterial infection began spreading among swabs.

What started as a few swabs reporting similar symptoms — fever, nausea, vomiting — ultimately grew to about 40 people — both swabs and second-class cadets overseeing their training, who were suspected of having the same infection. Swabs are separated by companies and it became clear that the symptoms were being reporting primarily by swabs assigned to two of the companies.

“When you start putting together your epidemiological hat, really quickly you’re like, ‘Oh, we need to contain this,'” said Capt. Esan O. Simon, medical director at the clinic, who’s only been on the job about two months.

Clinic staff contacted the microbiology team at Lawrence + Memorial Hospital in New London, who were able to quickly analyze the labs and determine that it was a bacterial infection.

At the clinic, which employs about 60 people, it was an all-hands-on-deck effort with staff working around the clock to manage the situation. Within a three-hour period, they screened more than 400 people, including cadets and officer candidates.

Infections can spread quickly on college campuses. Swabs live and train alongside one another. Add to that the stress of their seven-week summer training.

Initially the sick swabs were told to stay in the barracks and wear face masks, and they were instructed on how to clean bacteria from their rooms.

When the number of cases started creeping up, clinic staff separated the sickest of the swabs from their peers and placed them in a separate wing in the barracks to prevent the infection from spreading.

“You didn’t want the folks in the same food line as the whole entire campus and that kind of thing,” Simon said.

A system was devised to deliver meals and administer medication to the isolated swabs, to minimize their exposure to the rest of the campus.

Staff were able to quickly contain the situation, which could have been a lot worse, said Cmdr. Dave Milne, a spokesman for the academy. Only a few cadets are still sick.

Celebrity chef to advise UK government on hospital food following Listeria deaths

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Health chiefs are to set national standards for hospital food after the deaths of six people in a listeria outbreak.

Great British Bake Off judge Prue Leith (right) will advise the Government review into bedside meals, amid growing criticism of patients’ food.

The “root-and-branch” probe, launched by the Department of Health today, will examine whether the number of hospitals doing catering in-house can be increased.

Prue said: “Millions of pounds are wasted in hospitals with food ending up in the bin – unpalatable food being the main complaint.

A hospital meal should be a pleasure and comfort, and it should help, not hinder, the patient’s recovery.”

Health Secretary Matt Hancock called for the review in June when the six people died after getting listeria from prepackaged sandwiches and salads.

Hopefully there will be some Listeria scientists on the advisory panel.

Norwegian Authority warns pregnant women to avoid ginger supplements

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The Norwegian Food Safety Authority warns pregnant women and women planning to become pregnant to avoid ginger supplements and ginger-containing shots.

Will Chu of Nutra reports the warning comes after the Danish Technical University (DTU) and the Danish Veterinary and Food Administration carried out a new risk assessment that found a higher abortion risk in animal studies.

In the report, the DTU said the results did not exclude the possibility that large ginger quantities could also increase this risk in humans.

“The DTU Food Institute concludes that in many cases ginger root ingestion from a single ginger shot will be larger (up to 20-23 grams (g) per day) than the fresh or dried amount typically eaten in the diet. ​

“Experiments in rats indicate that ginger can affect the normal foetal development,”​ says the report​​, dated 21 December 2018.

 “The studies conducted so far in humans did not investigate whether ginger can have a harmful effect early in pregnancy. Animal studies suggest that it may be a particularly sensitive period. ​

“There is a small safety margin between the daily dose linked to harmful effects during pregnancy in rats and the amount of ginger that can be consumed with one ginger shot,”​ the report continues.

Along with the Norwegian Food Safety Authority, the Norwegian Institute of Public Health assessed the Danish report, supporting its conclusions and issuing the warning against taking ginger shots and supplements with ginger.

Foodborne pathogen sheltered by harmless bacteria that support biofilm formation

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Pathogenic bacteria that stubbornly lurk in some apple-packing facilities may be sheltered and protected by harmless bacteria that are known for their ability to form biofilms, according to Penn State researchers, who suggest the discovery could lead to development of alternative foodborne-pathogen-control strategies. 

That was the key finding that emerged from a study of three tree-fruit-packing facilities in the Northeast where contamination with Listeria monocytogenes was a concern. The research, done in collaboration with the apple industry, was an effort to better understand the microbial ecology of food-processing facilities. The ultimate goal is to identify ways to improve pathogen control in the apple supply chain to avoid foodborne disease outbreaks and recalls of apples and apple products.

“This work is part of Penn State’s efforts to help producers comply with standards set forth in the federal Food Safety Modernization Act, often referred to as FSMA,” said researcher Jasna Kovac, assistant professor of food science, College of Agricultural Sciences. “The Department of Food Science at Penn State, through research and extension activities, has an ongoing collaboration with the apple industry, led by Luke LaBorde, professor of food science.”

The research was done in collaboration with the apple industry, in an effort to better understand the microbial ecology of food-processing facilities. The ultimate goal is to identify ways to improve pathogen control in the apple supply chain to avoid foodborne disease outbreaks and recalls of apples and apple products. 

In the study, researchers sought to understand the composition of microbiota in apple-packing environments and its association with the occurrence of the foodborne pathogen Listeria monocytogenes. Their testing revealed that a packing plant with a significantly higher Listeria monocytogenes occurrence was uniquely dominated by the bacterial family Pseudomonadaceae and the fungal family Dipodascaceae.

“As we investigated the properties of these microorganisms, we learned that they are known to be very good biofilm formers,” said lead researcher Xiaoqing Tan (upper left), a recently graduated master’s degree student in food science and a member of the Penn State Microbiome Center, housed in the Huck Institutes of the Life Sciences. “Based on our findings, we hypothesize that these harmless microorganisms are supporting the persistence of Listeria monocytogenes because they protect the harmful bacteria by enclosing them in biofilms. We are testing this hypothesis in a follow-up study.”

The findings of the research, published today (Aug. 21) in Microbiome, provide insight into the Listeria contamination problem and may lead to researchers and the apple industry getting closer to solving it, Kovac believes. Equipment in fruit-processing plants — such as brush conveyors — have a poor sanitary design that makes them difficult to clean and sanitize, she pointed out. She and LaBorde plan to work with the apple industry to devise more effective cleaning and sanitizing strategies.

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Researchers collected samples in apple-packing facilities in which Listeria monocytogenes has been persistent. They discovered that harmless bacteria may be sheltering the pathogens.

 “Following up on these findings, we are experimenting with some of the nonpathogenic strains of bacteria that are not harmful to humans to see whether they can be used as biocontrols,” she said. “Once applied on the surfaces of the equipment in these environments, they may be able to outcompete and suppress Listeria, thus reducing food-safety risks and potential regulatory action. We are still exploring that approach in a controlled laboratory environment. If it proves to be feasible, we would like to test it in apple-packing and processing facilities.”

The challenge presented by microbiota possibly sheltering Listeria monocytogenes is not limited to fruit-processing facilities or produce, Penn State researchers suspect. They will soon begin analyzing microbial communities in dairy-processing facilities to determine the microbial composition and ecology of these environments.

Adaptation to life inside cattle may be driving E. coli to develop harmful features

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A large-scale study of the genetic differences and similarities among E. coli bacteria from cattle and humans indicates that features causing food poisoning in humans may continuously be emerging in bacteria from cattle as a means to better adapt to their environment.

While E. coli bacteria are one of the most well-known causes of food poisoning, a wide variety of E. coli strains exists, many of which are harmless, permanent residents of our intestines. However, the ingestion of harmful strains of E. coli on contaminated food can lead to severe illness, vomiting, and diarrhea.

“To develop the most effective preventive measures, we need a deep understanding of the source and living conditions of the bacteria,” says Yoshitoshi Ogura, associate professor at Kyushu University’s Department of Bacteriology, who led the research.

“Although cattle have long been thought to be a main source of E. coli that cause food poisoning, why dangerous forms would keep appearing in cattle has been unclear.”

Ogura’s group, in collaboration with researchers across Japan and in France, Belgium, and the United States, set out to help answer this question by investigating the genetics of E. coli bacteria collected from cattle and humans in 21 countries spanning six continents.

“To date, there have been only a limited number of reports of the genome sequences of E. coli from cattle, so we needed to fill that gap,” comments Yoko Arimizu, first author on the paper in Genome Research announcing the new results.

While the largest number of samples was from Japan, strains from other regions exhibited characteristics that were well distributed among those from Japan, indicating a good diversity of the set of samples.

Based on the genetic features of the bacteria, the researchers could generally separate the different strains of E. coli into two groups, with one primarily consisting of bacteria collected from humans and the other of those from cattle.

Applying the same analysis to clinically obtained E. coli that are known to cause illness, the researchers found that most of the strains causing intestinal problems belonged to the group associated with cattle.

Furthermore, many of the samples from cattle exhibited features similar to those causing food poisoning, such as the production of Shiga toxin. While these features generally appear not to cause illness in cattle, their prevalence in the investigated samples suggests that such characteristics are beneficial for life in a cattle’s intestine.

“As long as there is pressure to maintain or strengthen these illness-producing characteristics to better adapt to living in a cattle’s intestine, new variants of E. coli that cause food poisoning are likely to continue appearing,” states Ogura.

The researchers speculate that these characteristics may help E. coli protect itself from bacteria-eating organisms present in cattle intestines, but more work is needed to identify the exact reason.