Fresh Express has recalled an expired produce product because a test on one package came back positive for Listeria monocytogenes.

The recalled 9 0z. Leafy Green Romaine Salad carry the expired use-by date of September 16. Consequently, the recalled product is no longer available in stores. Fresh Express issued the recall to cover the unlikely event consumers might have the expired romaine in their home refrigerators.

The produce company said there were no consumer complaints and no known illnesses involving the romaine.

“The recall notification is being issued out of an abundance of caution in keeping with the company’s commitment to protect the public health, Fresh Express said.

“In an unlikely event consumers may still have this particular salad – now well beyond its Use-by Date and expected usability – in their refrigerators, they should not eat it and throw it out,” the recall statement said.

Consumers with questions may call the Fresh Express Consumer Response Center at (800) 242-5472 during the hours of 8 a.m. to 7 p.m. Eastern Daylight Time.

Recalled salad details are:

Product: Fresh Express Leafy Green Romaine Salad in a 9 oz. package

Use-by Date: September 16 (located in upper right hand corner of package)

Product Code: I246A5BMG (located in upper right hand corner of package)

Distribution: Primarily Midwest and Eastern states of the U.S.

According to Fresh Express instructions and retail store procedures, expired salads are removed from store shelves. Fresh Express says it is coordinating closely with regulatory officials.

Listeria monocytogenes is an organism that can cause foodborne illness in a person who eats a food item contaminated with it. Symptoms of infection may include fever, muscle aches, and gastrointestinal symptoms such as nausea or diarrhea.

If it spreads to the nervous system symptoms may include headache, stiff neck or confusion. The illness primarily affects pregnant women and adults with weakened immune systems. Most healthy adults and children rarely become seriously ill.

USDA’s Microbiological Data Program (MDP) tests fresh produce, but given the nature of the product it is sometimes consumed before some test results are available.