MRSA found in our milk: Superbug strain can cause serious infections in humans and is resistant to antibiotics
Scientists tested 1,500 samples of bulk milk and found seven cases of MRSA ST398 from five farms in England, Scotland and Wales
The superbug can cause serious and occasionally deadly infections in humans
07:46 GMT, 21 December 2012
A potentially deadly MRSA superbug has been found in British milk for the first time.
The superbug – already a problem in farm animals on the Continent – can cause serious and occasionally deadly infections in humans and is becoming a cause of udder infections in dairy cows.
The strain of MRSA known as ST398 is resistant to antibiotics, so doctors find it difficult to treat infected people effectively.
Superbug: A strain of MRSA has been found in British milk for the first time
In theory the bug should be killed off when milk is heat-treated in the pasteurisation process before it reaches the high street or doorstep. However, some people prefer unpasteurised milk and cheese in the belief it is better for them or tastes nicer.
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.
Strain: Farmers, vets and abbatoir workers who come into contact with cows and their calves can become infected
The Soil Association, which campaigns for organic farming, is calling for a government investigation to establish the spread of the MRSA and a crackdown on the use of antibiotics on UK farms.
Scientists from the department of veterinary medicine at the University of Cambridge tested 1,500 samples of bulk milk and found seven cases of MRSA ST398 from five farms in England, Scotland and Wales.
They said the high level of antibiotic resistance in the bug means the findings are ‘of significance to both veterinary and human health’. Dr Mark Holmes, a senior lecturer in preventive veterinary medicine, said the discovery was made while looking for a different strain of MRSA found in cows and people.
He said: ‘Until this discovery it was always assumed that this form of livestock MRSA was a problem on the Continent, but it has now jumped the Channel. It now seems that it is established in this country – perhaps one in every 200 farms.
‘If it ends up becoming more commonplace it will, sooner or later, cause disease in people here.’
Dr Holmes said the major question is why MRSA is appearing in farm animals and whether this is linked to intensive farming and the associated heavy use of antibiotics.
He asked: ‘Should we be thinking again about the type and range of antibiotics we use in farm animals Is it wise to have a lot of preventive use of antibiotics, particularly in dairy cows
‘They get a lot of mastitis – udder infection – because they are driven hard to produce a lot of milk, which is the only way farmers can make money.
‘I think you have to look at the pressures the supermarkets create by screwing the farmers down so tightly on costs.’