Canada's food watchdog and Ivanhoe Cheese Inc. on Wednesday issued a recall of certain cheese products distributed in Ontario because they may be contaminated with Listeria monocytogenes.

The recall affects the following Ivanhoe, Great Canadian and Igbal products with best before dates ranging from Feb. 20 to March 1, 2009:

• Cheddar.
  
• Marble (Brick and Cheddar).
  
• Asiago.
  
• Gouda.
  
• Swiss.
  
• Parmesan.
  
• Mozzarella.
  
• Havarti.
  
• Colby.
  
• Brick.
  
• Feta.
  

The cheese products were sold in grocery stores and at deli counters.

No associated illnesses have been reported.

People who eat foods contaminated with listeria may carry the bacteria and not develop listeriosis. Those most vulnerable to developing the disease include the elderly, infants and patients with a compromised immune system.

Pregnant women who develop listeriosis in their first trimester are at risk of miscarriage, while women in the later stages of pregnancy are at risk of delivering a stillborn or acutely ill infant.