Federal officials are working with Conagra Brands to investigate Salmonella infections associated with Duncan Hines cake mix. The multinational food giant today recalled some of the mixes because one flavor tested positive for the outbreak strain of the bacteria.

“The FDA is investigating the manufacturing facility that made recalled Duncan Hines cake mixes,” according to an investigation announcement posted Monday by the Food and Drug Administration. “FDA and the CDC informed Conagra Brands that a sample of Duncan Hines Classic White Cake Mix that contained Salmonella Agbeni matched the Salmonella collected from ill persons reported to the CDC. This was determined through Whole Genome Sequencing, a type of DNA analysis.”

Conagra owns the manufacturing facility that produced the Duncan Hines cake mixes. Investigators from the FDA are collecting test samples of products and environmental samples from the equipment and surfaces in the manufacturing plant.

Both FDA and Conagra officials say consumers should not bake with or eat the recalled cake mixes. They also are renewing advice against eating uncooked batter, flour, cake mix powder, or anything containing uncooked flour or eggs.

The Conagra recall notice says it distributed the implicated cake mixes to retailers nationwide in the United States and to “limited” international export markets.

“While it has not been definitively concluded that this product is linked to the outbreak and the investigation is still ongoing, Conagra has decided to voluntarily recall the specific Duncan Hines variety identified, Classic White, and three other varieties — Classic Butter Golden, Signature Confetti and Classic Yellow — made during the same time period out of an abundance of caution,” the recall notice states.

The FDA investigation notice says the Centers for Disease Control and Prevention has received reports of five illnesses. It is likely that additional illnesses will be added to the case count because of the time lag between when a person becomes sick and when the CDC receives confirmed laboratory test results.

Investigators from the CDC are continuing to interview the sick people to determine whether they were exposed to Duncan Hines cake mixes before becoming ill.

Conagra’s recall notice says “several of the individuals reported consuming a cake mix at some point prior to becoming ill, and some may have also consumed these products raw and not baked.”

“Consumers are reminded to wash their hands, work surfaces, and utensils thoroughly after contact with raw batter products, to follow baking instructions, and to never eat raw batter,” Conagra’s notice says. “Consumers who have purchased these items are advised not to consume them and to return them to the store where originally purchased.”

Consumers with questions can call Conagra at 888-299-7646 or visit www.duncanhines.com.