This is sorta cool – unless you contract a subset of listeria and have heart problems.

Listeria is everywhere, as Michael McCain of Maple Leaf Foods likes to remind everyone, but Nancy Freitag, from the University of Illinois, Chicago, reports in the Journal of Medical Microbiology that some listeria strains had modified surface proteins that helped target the heart.

"A significant number - about 10% - of L. monocytogenes infections involve the heart. In these cases, death rate from cardiac illness is estimated to be up to 35%, yet very little is known about how these bacteria infect heart tissues."

Scientists in the United States discovered that mice infected with the strains had up to 15 times more bacteria in their hearts than those exposed to other forms of listeria.

The bug has an unusual ability to grow in low temperatures and can be found in a wide range of foods including soft cheeses, cold meat products, raw vegetables, fish, salads and unpasteurized milk.

Pregnant women are especially susceptible to listeria, which can cause them to miscarry.