Bug adapts to attack heart

POTENTIALLY deadly varieties of a common food bug found in cheese and ready meals are "uniquely adapted" to infect the heart, a study has found.

The listeria strains are most likely to target people with pre-existing heart problems, or who have had heart valve replacements, say researchers.

Scientists in the US 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. They hope to develop ways of identifying the strains, to protect those most at risk.

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 and salads.

Listeria infections may cause flu-like symptoms and a upset stomach, or lead to serious illness involving the blood and nervous system.