The subsidiary, Cappola Food Inc, makes dry cured meat for the North America market.
The processing giant said it is working cooperatively with the CFIA, who have confirmed that no illnesses have been reported, and, in addition, that there is no food safety risk as a result of the find.
The finding of listeria in a food plant can occur on a daily basis, said Maple Leaf Foods in a statement, and it added that the detection of listeria at the Cappola facility was evidence of a properly functioning protocol.
It claims that the goal of a well designed listeria detection programme in ready-to-eat plants is to discover and eradicate the bacterium, and it said that the practices Maple Leaf has put in place in this regard are performing as designed.
"The greatest risk to the Canadian food safety system is the multitude of Canadian plants which do not find positive test results simply because they don't test adequately,” argues the company’s chief executive, Michael McCain. “If you test, you will find and you can eradicate with the proper protocols. If you don't test, you won't find, but there will be no eradication which is the real food safety risk in this country."
Over the past three months, the company said that it has collected over 42,300 test results across its 24 packaged meat plants: “This represents an average of 1,760 results per plant - an unprecedented level of testing to provide an early warning system.”
And, the processor maintains its rate of listeria positive tests across its plants is consistently less than 1 per cent, which it said is 50 to 80 per cent better than industry data available from the US.
Last month, the company settled consumer lawsuits to the tune of CAN$27m (US$22.5m); the lawsuits were filed in the wake of the listeriosis contamination of produce from Maple Leaf's Toronto processing plant in August, which was linked to widespread illness and the deaths of about 20 people.