QUEBEC - Quebec's Agriculture Department defended itself vigorously for a decision to throw out all cheese that may have come into contact with products contaminated with Listeria, saying the measures were necessary to save lives.

Criticized and under attack by cheese producers and retailers for allegedly over-estimating health concerns and using draconian measures that hit them in the pocketbook, the department answered its critics on Wednesday saying it had no choice but to order all products discarded.

Department spokesman Guy Auclair said that inspectors visited 300 retailers over the weekend armed with a list of recalled cheeses after two more cheese manufacturers and 11 products were added to the list on the weekend.

Inspectors ensured all potentially contaminated products were thrown out and oversaw the disinfection of all work surfaces. All products that may have been cross-contaminated by one of the recalled cheeses also had to be discarded.

There has been criticism from store owners who say they've lost large sums of money because of the government's decision, but Auclair said the virulence of the Listeria strain and the severity of the illnesses caused by the bacterium justified the decision.

"We can say with certainty that the operations that we conducted allowed us to prevent further illness and even save lives," Auclair told a news conference in Quebec City on Wednesday, flanked by representatives of the cheese industry.

There have been 22 cases of listeriosis in Quebec stemming from an outbreak of Listeria in various cheeses, with one confirmed death.

Four more cases remain under study, Auclair said.

Seven pregnant women have also been infected and six babies have been born prematurely in the province as a result, with three of the newborns still battling listeriosis in hospital.

In another recent case, a woman who was five-months pregnant lost her child on Tuesday after contracting listeriosis, health officials confirmed. Dr. Horacio Arruda of Quebec public health said it wasn't clear if the woman contracted the bacteria through the contaminated cheeses.

Arruda said he wouldn't be surprised if other cases cropped up in the coming days, but added that the discovery of two sources of contamination could help to stop the spread.

Inspectors have visited 43 factories in Quebec and 32 have been cleared, Auclair said. Nine others are still awaiting test results.

Gilles Lafontaine, president of the Societe des fromages du Quebec, which represents about 150 cheese makers across the province, said he understands the frustrations of the association's members but called on their good faith to help resolve the crisis.

"We all want this to end, but we must absolutely collaborate with authorities if we want to see this end as soon as possible," Lafontaine said.

Other associations sought to reassure the public that cheeses still in stores were fine to consume.

It's unclear just how much the operation has cost producers.

Auclair said the government and the province's cheese producers plan to implement a new detection program in the coming weeks, but could not provide any details.

The annual average of listeriosis cases in Quebec is about 50. The public health department reported 63 cases in 2007 and 49 in 2006. Those at risk of becoming ill from listeriosis are the elderly, the very young, pregnant women and those with weakened immune systems.

A separate salmonella outbreak, also linked to Quebec cheese, has claimed one life.