Listeria Monocytogenes

Illustration depicting a sign with a Listeria concept.

Why is Listeria Monocytogenes Such a Big Deal?

Listeria is a bacterium found in soil, plants, and water, and causes a serious infection known as Listeriosis – a disease that has severe complications that often requires hospitalization. The bacteria can be found in animals like cattle, sheep and goats, and contact with an infected animal, or consumption of contaminated meat, can cause a serious infection in humans.

The Listeria bacteria is common in foods such as smoked fish, meats and cheeses and can also be found in in raw vegetables. Whilst the bacteria can be destroyed by cooking raw meat at temperatures higher than 65 °C., unlike some other types of bacteria, Listeria tend to multiply in cooler temperatures, with the potential for contamination of cooked food that has been packaged – which is why safe food handling should be taken very seriously.

Once the Listeria Monocytogenes bacteria enter the human body it can cause symptoms such as mild flu, fever and gastroenteritis. Most reported cases have been due to consumption of contaminated foods.

Food Handlers need to understand that there is a risk of infection when foods, especially meats, are not cooked properly. High risk food sectors must fully adhere to Food Standards Agency guidelines when processing food that is prone to Listeria contamination and ensure that workers receive rigorous food safety training with constant qualified supervision.

By ensuring very high standards of food hygiene the potential hazard posed by Listeria can be significantly reduced, and this means ensuring there is a properly documented HACCP policy in place with trained and supervised staff.

Prevention is always better than cure so high risk foods should always be avoided by pregnant women, young children, the sick and elderly, and especially those with weakened immune systems as Listeria spreads from cell to cell, attacking the host’s immune system. It has been treated successfully with antibiotics such as penicillin.