New form of MRSA Found in Cows' Milk...

 

A new strain of MRSA has been found in cows’ milk.

The same strain of the superbug has also been discovered in patients being treated for wound infections.

It is the first time any form of MRSA has been traced to dairy cattle in the UK.

However, experts insist there is no overall threat to the safety of milk sold in shops.


This is because any kind of MRSA in dairy products is destroyed by the heat used in the process of pasteurisation.

Scientists warned that further research would be required to find out if humans were spreading the bug to cows or vice versa.

The discovery raises concern that intensive farming methods may be encouraging the emergence of new MRSA strains which are resistant to an ever-wider range of antibiotics.

Organic farming lobby The Soil Association last night called for a complete ban on routine use of antibiotics in livestock because of fears they may promote drug-resistant bacteria.

Helen Browning of the Soil Association, said: ‘Under acute price pressure, dairy systems are becoming ever more antibiotic dependent.

We need to get farmers off this treadmill, even if that means that milk has to cost a few pennies more.

‘That would be a very small price to pay for maintaining the efficacy of these life-saving drugs.’

The MRSA strain was discovered by researchers at Cambridge University investigating mastitis, a serious disease in dairy cows.

Dr Mark Holmes, a veterinary scientist who led the research, said they found a drug resistant form of MRSA which did not match existing strains.

MRSA, or methicillin-resistant Staphylococcus aureus, is a usually harmless and common bacterium carried on the skin which can be deadly if it infects wounds.

Checks found the mutated MRSA in 13 of 940 samples from 450 English dairy herds.

Further research confirmed the strain was also in humans, says a report published today in the journal The Lancet Infectious Diseases.

Samples from screening tests and patients treated for MRSA wound infections revealed 12 instances of the strain from Scotland, 15 from England and 24 from Denmark. It was also identified in Ireland and Germany.

The scientists also spotted a ‘clustering’ of human and cow samples that suggested transmission between them.

 

‘Although there is circumstantial evidence that dairy cows are providing a reservoir of infection, it is still not known for certain if cows are infecting people, or people are infecting cows.’

Dr Holmes said: ‘Although there is circumstantial evidence that dairy cows are providing a reservoir of infection, it is still not known for certain if cows are infecting people, or people are infecting cows.’

MRSA infection is often found in hospital patients, but a drive to improve hygiene has dramatically cut the number of fatal cases.

There were 1,290 in 2008 and 781 in 2009.

Researchers have no information about the virulence of the new strain, which has so far not been linked to any deaths.

It is treated with the same antibiotics used against ‘normal’ MRSA.

They said workers on dairy farms might be at higher risk of becoming carriers, but the food chain was unlikely to be affected.

Unpasteurised milk can only be sold directly from farms in England, and bugs in unpasteurised cheeses struggle to survive the human digestive system. The Department of Health said it would review the issue.

A spokesman from the Food Standards Agency said: ‘The risk of contracting this strain of MRSA through milk is extremely low because the vast majority of cows’ milk is pasteurised.’

 

 

Jenny Hope - MailOnline