OTTAWA - The company at the centre of Canada's latest E. coli scare took responsibility for the problem Thursday as Agriculture Minister Gerry Ritz stared down a firestorm of opposition criticism of one of the largest food recalls in Canadian history.

"We take full responsibility for our plant operations and the food it produces, which is consumed by Canadians from coast to coast," XL Foods Inc., said in a news release.

"We are doing everything we can to take the lead in an enhanced comprehensive food safety program for our plant," said the company, which operates the meat plant in Brooks, Alta., where the contamination first occurred.

Ritz, meanwhile, called a news conference on short notice — his second in as many days — to address what he called "misinformation" about the E. coli scare.

The XL plant has had its licence suspended, and it won't be restored until the minister gets written notice from the Canadian Food Inspection Agency that the plant is safe, Ritz said.

"There's a tremendous amount of misinformation out there and extrapolation that there are cuts to our food safety system," said Ritz.

"I'm here to tell you that is absolutely not true, not factual at all."

Ritz later attended question period in the House of Commons for the first time all week, where he faced calls for his resignation from NDP Leader Tom Mulcair.

Mulcair accused Ritz of withholding information from the Canadian public for several days following the time E. coli was first detected in early September.

"The minister of agriculture knew what was going on. He withheld what he knew from Canadians and he's refusing to be accountable," Mulcair said.

"He's the one who put this self-regulating system in place, he is responsible. Why is this minister of agriculture still in his position? He must resign."

Ritz countered by saying there's "no such thing" as a self-regulating system in Canada, noting that 46 inspection-agency staff were working at the plant while it was operating — an increase over previous levels.

"We take this very seriously, Mr. Speaker," Ritz said. "We're working to ensure the CFIA has the regulations they require and the monetary capacity to get the job done."

George Da Pont, the agency's president, said he won't sign off on reopening the plant until the CFIA is thoroughly satisfied that all problems have been resolved. Inspectors are testing every carcass still inside the plant, Da Pont said.

During his news conference, Ritz said a lot of "misinformation" has come out of question period, although he didn't point to any specifics. The Commons held an emergency debate on the situation Wednesday evening.

"We continue to enhance the ability of CFIA to address these types of situations, we rely on Public Health Canada to do the expert job that they do, working with provincial colleagues, to identify illnesses out there that would lead us to issue warnings and so forth," he said.

Ritz said Thursday there are four cases of E. coli poisoning in Canada that have been linked back to tainted meat that came from the plant.

"To this point ... we've only had four confirmed cases linking back to XL," Ritz said. "We're scientifically looking at others, but this is a science project, not a political process."

Alberta public health officials say they have found a fifth case linked to XL.

Canadian consumers can expect to see even more recall announcements as inspectors continue to check meat and documents, officials say.

Meanwhile, the Senate agriculture committee amended a forthcoming bill on food safety to include a mandatory review every five years of the resources and inspectors available to enforce the system.

"I do believe that this bill will enhance and speed up recalls should they be necessary and I do believe this will add to food safety in general," said Conservative Sen. Don Plett, sponsor of the bill.

Interim Liberal Leader Bob Rae, meanwhile, has asked the auditor general for a full review of the food-safety system.

Rae said the beef recall underlines the weaknesses of the system and the urgent need for review.

"We request that the auditor general of Canada conduct a full and immediate audit of all government of Canada resources and procedures that support food safety in Canada, as well as issue recommendations for changes and improvements," Rae wrote.

Note to readers: This is a corrected story. A previous version wrongly said Thursday's comment was the first statement issued by XL.

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  • While most strains of E. coli are harmless, the Public Health Agency Of Canada warns that some strains including E. coli O157: H7, can make people sick, and in serious complications can include kidney failure.

  • Symptoms include severe stomach cramps, diarrhea, vomiting and fever that is generally less than 38.5˚C/101˚F and tend to last for five to seven days.

  • High risk individuals include the very young, elderly, pregnant women and those with weakened immune systems.

  • Hemolytic uremic syndrome (HUS), which can be fatal, can develop in around 5 to 10 per cent of those who get sick from E. coli O157:H7 overall and about 15 per cent of young children and the elderly. Symptoms of HUS vary. Some people have seizures or strokes and some need blood transfusions and kidney dialysis. Others live with side effects such as permanent kidney damage.

  • Proper hygiene including hand washing and safe food handling and preparation practices are recommended to prevent the illness.

  • While E. coli is generally associated with ground meat, Alberta Health Services warns that the bacteria can also be found in foods including poultry, pork, cheese, sprouts, lettuce, yogurt, and unpasteurized milk and fruit juices and advises Albertans to take precaution.