With the festive season underway, we thought we’d put the spotlight on current research helping to keep our favourite festive foods free from disease-causing microbes.

Foodborne illness is a big problem. There are 2.4 million cases of foodborne illness reported in the UK each year, with many more unreported and a total estimated cost of £9 billion to the UK economy.

Here at the Quadram Institute, we use our expertise in microbiology and genomics to understand current and emerging threats to food safety. Our research and projects funded through the UK Food Safety Research Network, study the safety of several foods popular over the festive period including smoked salmon, pork and cheese.

Plus, we take a look at the science exploring the safety of newer additions to the festive food scene, like plant-based alternatives.

Science to help keep smoked salmon safe to eat

Smoked salmon is packed full of nutrients such as omega 3. It’s a popular food to start the festive feasting but it can contain the bacteria Listeria monocytogenes.

Listeria monocytogenes can cause an illness called listeriosis. Cases of listeriosis are rare, and in healthy adults and children Listeria usually causes few or no symptoms. However, some people including those that are pregnant, older or have a weakened immune system have a higher risk of becoming ill and developing severe illness, called invasive listeriosis.

Here at the Quadram Institute, Dr Matthew Gilmour leads a group of researchers studying Listeria. The team are working to understand microbial traits of Listeria that contribute to its significant risk as a foodborne contaminant and how it causes disease.

Dr Matthew Gilmour is one of the Co-directors of the UK Food Safety Research Network (FRSN) which connects the food industry, health policymakers and academia to collaboratively pursue shared research priorities that will protect the UK from foodborne hazards. The network funds collaborative projects between scientists, policymakers and the food industry.

One project funded by the FSRN is exploring how bacteriophages (viruses that infect bacteria) could be used as a biocontrol agent in aquaculture to help reduce the risk of Listeria in seafood like salmon.

Along with the science studying the safety of eating salmon, there’s also advice we can each follow to stay safe from Listeria. As pregnant people or those who have a weakened immune system are more likely to suffer severe symptoms from Listeria infection, they are advised to cook before eating cold-smoked or cured fish products, such as smoked salmon or gravlax. The Food Standards Agency have detailed advice on what you can do to reduce the risk of becoming ill due to Listeria.

Keeping watch of bacteria in Pigs in blankets

A food often found at the festive table is pigs in blankets, made of pork with bacon wrapped around sausages.

Over 18 months our researchers collected a range of foods, including pork products, from different retail outlets in Norfolk and characterised any Salmonella bacteria present. Salmonella bacteria are a common cause of food poisoning, with 30,000 cases reported each year in the UK.

Along with sampling pork products, they also looked at chicken and prawns. The survey led by Dr Samuel Bloomfield found that overall Salmonella prevalence on foods on sale was low: 9.6% of raw chicken, 3.7% of raw prawn and 1.3% of raw pork samples were contaminated with Salmonella.

The team used whole-genome sequencing which allowed them to identify genes that give the bacteria specific properties, such as an enhanced ability to cause infections or resist antimicrobials.

Like with all meat, cooking pork at the right temperature and for the correct length of time will kill any harmful bacteria that may be present.

Advancing our understanding of microbial risks of alternative plant-based foods

More and more people are switching from meat to new plant-based alternatives.

Though we know lots about the nutrition and environmental benefits of alternative proteins and plant-based foods we know less about their food safety.

A project funded by the UK Food Safety Research Network is focused on understanding what are the safety risks and vulnerabilities associated with these new plant-based products and processes of production.

Speeding up safety tests on cheese

Cheese is often a food eaten during the festive seasons. Good microbes are key to cheese production and we can see fungi in blue cheese too.

Though cheese is often home to friendly microbes, bad disease-causing microbes can sometimes be found in them too. Currently, many detection methods for monitoring the safety of cheese take days or even weeks. We need approaches that flag problems in hours or even minutes.

A project funded by the FSRN involving researchers and those in the cheese industry is working on using a rapid, antibody-based biosensor that’s been validated in the laboratory for sensitivity against key pathogens as part of an environmental monitoring programme. This will give cheese producers a new tool for a more proactive approach to underpin food safety.

Through ongoing research into the microbes living in our food, the wider food chain and environment we’re learning more about how we can improve the safety of some of our festive favourites. The Food Standards Agency has a Christmas food hygiene guide for what you can do to help keep your Christmas safe from food poisoning too.