The salmonella bacteria found in a tub of King Nut peanut butter at a Minnesota nursing home are genetically identical to the bug that sickened 30 people across the state and nearly 400 around the country, Minnesota authorities said Monday.
The Minnesota Departments of Agriculture and Health announced that laboratory tests confirmed a genetic match between the bacteria.
The testing confirmed what state officials suspected on Friday when they announced that salmonella in an opened tub of peanut butter was the same strain as the bug the sickened 30 Minnesotans, including one elderly woman with a complicating health problems who died. The latest testing confirmed that it has the same genetic fingerprint as the bug that has sickened people nationwide since September.
On Sunday the King Nut Co. of Solon, Ohio, said it voluntarily asked customers to stop selling King Nut and another brand, Parnell's Pride, both of which are marketed nationally to institutions such as nursing homes, hospitals and schools. In Minnesota, distributors are pulling the peanut butter tubs from cafeterias, said Heidi Kassenborg, director of the state agriculture department's dairy and food division.
"This is not something you get in a grocery store," she said. "This product could be in institutions with some pretty vulnerable populations, people who are ill and children."
Federal health officials are now looking for the original source of the contamination, said Carlota Medus, an epidemiologist with the Minnesota Department of Health. The original contamination could have occurred in the manufacturing process or have come from ingredients, she said. Although salmonella is commonly associated with raw meat and produce, it can also grow in uncooked processed foods.
The Centers for Disease Control and Prevention and the Food and Drug Administration are testing to see whether King Nut peanut butter elsewhere is contaminated with salmonella that has the same genetic fingerprint, Medus said.
In Minnesota, the investigation is continuing as well. The Health Department is looking for the bug in unopened tubs of peanut butter to make sure that contamination did not occur after they were opened. Medus said the state is also investigating some cases of people who became ill without having eaten the peanut butter.
Minnesota disease investigators were the first to make the link between the disease outbreak and peanut butter. Early on, state investigators noted that a number of people who became ill were "peanut butter eaters," Medus said. But "what really helped us solve this was having several cases in institutional settings."
Investigators from the Agriculture Department were able to compare food purchase invoices from the institutions where people had become ill. What they all had in common was King Nut Peanut Butter, she said.
Then, late last week, they tested an opened tub from a nursing home where at least one person had become ill. Not only did it have salmonella, but it also was the same strain as the one identified in the Minnesota cases. Over the weekend, further tests confirmed that the salmonella that had infected the people was a genetic match for the one in the peanut butter.
Medus said she expects a few more cases to pop up in Minnesota. The Health Department is awaiting test results on a handful of pending cases. More cases may be reported now that the peanut butter link has become widely known.
Eating food contaminated with salmonella can result in abdominal cramping, diarrhea and fever. Anyone who believes that they may have become ill as a result of eating this product or foods made with this product should contact their health care provider, health officials said.
Josephine Marcotty • 612 673 7394