The American division of Israel’s Sabra salad company, the biggest seller of hummus in the United States, on Thursday issued a recall for some 30,000 cases of its classic hummus salad.

The company said it suspected that some of the packages had been contaminated with Listeria, a sometimes-toxic bacteria that usually causes stomach aches, but has been known to cause far more serious diseases, including meningitis.

The U.S. Food and Drug Administration (FDA) said Wednesday that several samples of hummus collected last month from markets tested positive for the Listeria monocytogenes, the bacterium that causes listeriosis.

The FDA said that there was no evidence that anyone had gotten sick from eating Sabra hummus. Nevertheless, the company decided on a voluntary recall.

In a notice, Sabra said that “consumers who have purchased any of these products are urged to dispose of or return it to the place of purchase for a full refund. Consumers with any questions may call toll free 1-888-957-2272, Monday – Friday 9:00 a.m. to 4:30 p.m. Central Time.”

The company listed the identification information for the products at a special web link.

Listeria is sometimes found in agricultural products that have been contaminated by manure. It is more often found in animal products, but is sometimes the result of soil where manure was used as fertilizer.