Don’t let listeria make itself at home in the kitchen - MSU Extension

Mary Donaldson<[email protected]>, Michigan State University Extension - October 28, 2024

Updated from an original article written by Lisa Treiber, Michigan State University Extension.

Listeria in the refrigerator or freezer can cause serious health issues.

Listeria is the third leading cause of death from foodborne illness in the U.S. Michigan State University Extension recommends people know how to prevent illnesses potentially caused by eating food contaminated with listeria.

This pathogenic bacterium causes the foodborne illness, listeriosis. The Centers for Disease Control and Prevention has identified symptoms common to listeriosis. Flu-like symptoms such as fever, headache, muscle aches, stiff neck, tiredness, loss of balance and seizures may be noticeable within two days and up to three months.

To decrease the risk of foodborne illnesses, handwashing is the single most important activity.

The Centers for Disease Control and Prevention (CDC) recommends washing hands before, during and after preparing food, as well as before and after eating. MSU Extension recommends washing hands after handling or feeding pets, as listeria has also contaminated pet food. Proper handwashing removes visible soil as well as pathogenic microorganisms that cannot be seen.

Cleaning and sanitizing kitchen work surfaces and equipment minimizes the risk of cross-contaminating other food, work surfaces or equipment. For cutting boards, clean and sanitize before preparing a different food. The Food and Drug Administration (FDA) recommends that all fruits and vegetables are rinsed under running water just before eating, cutting or cooking. Produce with a firm skin or hard rind can be cleaned with a produce brush. This includes fruits and vegetables with rinds that will be removed before preparing or eating, like avocados, bananas, cantaloupe, onions and oranges. Cutting through unrinsed fruits and vegetables can transfer bacteria from the skin to the flesh.

Can listeria grow in the refrigerator? Unlike most bacteria, refrigeration will not keep listeria from growing, and freezing will not kill the pathogen. Listeria can grow at refrigeration temperatures. To slow the growth, the air temperature in the refrigerator should be at 40 degrees Fahrenheit (4 degrees Celsius) or below and the freezer air temperature should be at 0 degrees Fahrenheit (-18 degrees Celsius), per the U.S. Department of Agriculture. Appliance thermometers are relatively inexpensive and are convenient to monitor the air temperature of the refrigerator and freezer.

To keep bacteria like listeria controlled, wipe up spills immediately and regularly clean, including the inside walls, shelves, and drawers of the refrigerator. Also, know how long food can be stored in the refrigerator by using the Foodkeeper app. Leftovers should be refrigerated within two hours and used within three to four days. The longer food is stored in the refrigerator, the more listeria has a chance to grow and potentially contaminate other food.

Is listeria destroyed by cooking? Listeria and other bacteria linked to foodborne illnesses can be reduced to safe levels by cooking food to the correct internal temperatures. Use a food thermometer to verify the temperature of food using the temperature guidelines from the U.S. Department of Agriculture. Food must reach minimum internal temperatures to lower the risk of foodborne illness.

Product

Minimum Internal Temperature and Rest Time

Beef, pork, veal and lamb steaks, chops, roasts

145 degrees Fahrenheit (62.8 degrees Celsius) and allow to rest for at least three minutes

Ground meats

160 degrees Fahrenheit (71.1 degrees Celsius)

Ground poultry

165 degrees Fahrenheit (73.9 degrees Celsius)

Ham, fresh or smoked (uncooked)

145 degrees Fahrenheit (62.8 degrees Celsius) and allow to rest for at least three minutes

Fully cooked ham (to reheat) from USDA-inspected plants

140 degrees Fahrenheit (60 degrees Celsius) and 165 degrees Fahrenheit (73.9 degrees Celsius) if not from a USDA-inspected plant

Poultry

165 degrees Fahrenheit (73.9 degrees Celsius)

Eggs

160 degrees Fahrenheit (71.1 degrees Celsius)

Fish and shellfish

145 degrees Fahrenheit (62.8 degrees Celsius)

Leftovers

165 degrees Fahrenheit (73.9 degrees Celsius)

Casseroles

165 degrees Fahrenheit (73.9 degrees Celsius)

The Food and Drug Administration recommends people with weakened immune systems and Individuals who are pregnant should avoid food considered high risk for causing listeriosis. The risk can be lowered by heating deli meats, hot dogs and cold cuts until steaming hot or 165 degrees Fahrenheit (73.9 degrees Celsius) before serving.

Following these recommendations will decrease the risk of becoming ill from listeriosis and other foodborne illness. Additionally, be aware of food recall announcements. Lastly, stay healthy by understanding which people may be at a greater risk for foodborne illness.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

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