The strain of MRSA known as ST398 is resistant to antibiotics, so doctors find it difficult to treat infected people effectively.
And farmers, vets and abattoir workers who come into contact with the cows and their calves can become infected, allowing the bug to spread into the wider community. That has happened in the Netherlands where the same strain of MRSA has caused illness among nursing home residents.
MRSA ST398 was first seen in pigs in Holland in 2003. It has since become epidemic in European and North American pig populations and has spread to poultry and cattle.
It is one of a number of superbugs that have emerged in recent years, apparently as a result of the overuse of antibiotics by farmers treating sick animals. Over time the farm animal bugs develop a resistance. READ MORE