Maple Leaf Foods, one of Canada’s biggest food processors, is struggling to contain damage from a listeria outbreak at a Toronto meat-packing plant linked to the deaths of at least six and possibly up to 12 people.

The company, which also operates in the US, UK and Asia, has withdrawn 220 items from sale, ranging from sausages to sandwiches, and has temporarily closed the contaminated plant. Its shares, listed in Toronto, have lost more than a quarter of their value in the past 10 days.