 What to know about the risk of listeria. Hello, I'm Megan Grebner with Healthy Living on Brownfield. The most recent recalls for popular foods contaminated with listeria include ice cream and smoked salmon. Dr. Haley Oliver, a professor of food science at Purdue University, talks about how the foods we love can become contaminated with a bacteria. Listeria is actually a bacteria that we can find really easily out in nature.