Shares in Irish company Greencore have dropped after the company voluntarily initiated a recall of products in the US. The sandwich maker, which is listed in London, recalled batches of sandwiches issued towards the end of last month over fears that they could contain listeria, it emerged late last week.

The US Food and Drug Association (FDA) conducted environmental sampling at the companys Rhode Island plant, which found traces of the bacteria, which can cause infections in children and elderly people as well as miscarriages in pregnant women.

But the regulatory body said no traces of listeria had been found in finished products and Greencore said it had not received any reports of confirmed illnesses as a result of the sandwiches. Currently, Greencore makes sandwiches, salads and desserts in the US for customers, including Starbucks.

Greencore said its actions were purely precautionary. It recalled egg salad sandwiches, ham salad sandwiches, and seafood stuffing issued last month to certain US retailers.

Although the FDA said that no other Greencore products were affected by the possible contamination, the reputation of the company took a battering and its shares closed down 7.24 percent in London.