Can Listeria survive in the cold?
Listeria: Thriving in the ColdBy Chris Wiant, MPH, PhD May 15, 2015 The equivalent of 15 semi-truckloads of Jenis Splendid Ice Cream was recalled earlier this year due to possible contamination with Listeria bacteria. The recall cost the company $2.5 million, but it was the right response. Another ice cream producer, Blue Bell Creameries, recalled all of its products made at all of its facilities after Listeria was found in its Chocolate Chip Cookie Dough Ice Cream. According to a CDC update, as of May 7, 2015, ten patients from four states had been infected with Listeria from Blue Bell Creameries ice cream. Three patients from Kansas have died. CDC estimates that each year one in six Americansabout 48 million of usexperience food poisoning. 128,000 are hospitalized and 3,000 die. Although only about 1600 people get sick from Listeria each year, it is the third leading cause of death from food poisoning after Salmonella and Toxoplasma gondii. 1In 2011, a Listeria outbreak associated with cantaloupe killed 33 people, caused one miscarriage, and sickened over 147 people in 28 states, according to CDC. The outbreak was traced to unsanitary post-harvest processing on a Colorado farm, including discontinuing washing cantaloupe with a chlorine-based disinfectant solution. Cantaloupe can harbor soil and bacteria in the grooves of its irregular exterior, which can be transferred into the fruit upon slicing it with a knife. Listeria Loves the Cold Listeria thrives in cold environments. An article in Infection Control Today notes that Listeria may infect ready-to-eat deli meats and hot dogs, refrigerated meat spreads, unpasteurized milk and dairy products, soft cheese made with unpasteurized milk, refrigerated smoked seafood, and raw sprouts. Kansas State University food safety specialist Fadi Aramouni explains that although the pasteurization process destroys Listeria in ice cream, the bacteria can survive elsewhere in an environment, aided by poor sanitation procedures. In such environments, Listeria may persist in cool, moist areas of condensation, such as drains and light fixtures. He also points out that in the ice-cream making process, inclusions such as cookie dough and pecans are added post-pasteurization, presenting a potential opportunity to introduce pathogens that would not be subject to pasteurization. On Guard for Listeria Listeria becomes a greater risk to health as people age into their senior years. Other at-risk populations include pregnant women and their newborns, young children and people with weakened immune systems. CDC reports that Listeria can cause miscarriage and meningitis. There is no way to know by inspecting it that Listeria has contaminated your food. Here are some tips based on FDA advice for avoiding Listeria in foods:
Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council. Click here to download this article 1*Gram-positive bacteria are bacteria that contain a thick cell wall that absorb a violet dye when the Gram Stain Test is administered and the cells are viewed through a microscope. In contrast, gram-negative bacteria, characterized by thinner cell walls but inner and outer cell membranes, do not retain the dye, and appear red or pink in the Gram Stain Test. Gram-negative bacteria cause a wide range of infections. |