Edited sentence: Brands affected are Hygrade, Shopsy's and Maple Leaf at its plant in Hamilton, Ontario, due to the possibility that they may contain traces of Listeria monocytogenes.No cases of listeriosis related to this recall have been confirmed.On August 4th 2009, roughly one year after the 2008 recall of Maple Leaf Foods products due to listeriosis contamination, another recall was ordered on 9 wiener products