Antibiotic-resistant MRSA bacteria have been found in piglets in England for the first time.

The discovery of livestock associated (LA) MRSA in piglets was reported last week in the Veterinary Record, after the disease was isolated from piglets suffering from a skin disease at a breeding-finishing farm in the East of the country.
 
In a joint statement on the discovery, leaders from the veterinary profession said the case was “not surprising,” but downplayed the role of antibiotics use.

The British Veterinary Association (BVA) and Pig Veterinary Society (PVS) said in a joint statement on Tuesday that the industry in the UK is promoting testing of live pig imports for MRSA, though this is not officially required. Even so, they said, “With the movement of different livestock species and humans between the UK and countries with high prevalence of LA-MRSA it is disappointing but perhaps not surprising to have detected LA-MRSA in pigs in England.”
 
Livestock-associated MRSA was first reported in pigs in the Netherlands in 2005, and rapidly spread throughout the European pig population through the trade of live animals. The UK imports few live pigs from Europe, but last year MRSA was found in pigs in Northern Ireland, though this is the first known case in mainland Britain.

The two veterinary societies added, “It is also worth noting that whilst antimicrobial use has played a role in the emergence of MRSA, its subsequent spread relates mainly to it being a successful bacterial species, not to antimicrobial use. LA-MRSA has been found in animals in which no antimicrobials have been used.”

However, they went on, “BVA and PVS are actively concerned with antimicrobial resistance across the majority of species including humans. We have welcomed the UK 5 Year Antimicrobial Resistance Strategy (2013-2018) and we are firmly of the opinion that the ‘One Health’ approach of medical and veterinary professionals working together will be crucial to the success of the Strategy.”

The vets’ groups said that Public Health England has declared the LA-MRSA is not a significant threat to public health, though organic farming groups said the discovery comes just weeks after scientists on the European mainland reported that the same strain of MRSA is evolving to become a serious hazard for humans.

The UK’s chief medical officer professor dame Sally Davies has warned that growing antibiotic resistance poses a threat to life as we know it, equal to that posed by climate change, and that drug resistant bacteria “Could cast [medicine] back into the dark ages” unless action is taken to preserve effective antibiotics.

Antibiotics campaigners urge testing and reduced use

Cóilín Nunan, Principal Scientific Adviser to the Alliance to Save Our Antibiotics, claimed on Friday that Defra had refused to take action and test all imported pigs from MRSA-positive countries, though recommendations were made almost ten years ago.

Nunan continued, “It’s scandalous that Defra still isn’t doing any proper MRSA surveillance of British pigs. Defra’s inactivity on this issue for years has allowed this situation to develop. These cases are likely to only be the tip of the iceberg.”

Though farmers and farm workers are most at risk from LA-MRSA, which has been known to infect humans, the Alliance said that last year alone scientists in Germany, Spain, the Netherlands and Denmark all reported increasing number of cases in people with no direct livestock contact, suggesting the strain is evolving to spread more easily from human to human. In December, French, Swiss and Dutch scientists published genetic evidence that this is now happening. The scientists called for “active surveillance” of a subpopulation of MRSA which can spread more easily between species (a process known as zoonosis).

However, though many European countries have acknowledged the threat, the UK has refused to carry out any active MRSA surveillance of its pig and poultry, other than an EU-mandated survey of pigs in 2008. The current cases only came to light after an outbreak of skin disease affecting 60 piglets on a farm in eastern England. Two piglets were tested by Defra scientists at the Animal and Plant Health Agency (APHA) and both were MRSA positive.

Cóilín Nunan added, “The latest European research shows that livestock-associated MRSA could become a much bigger public-health threat unless decisive action is taken. In the Netherlands they implemented large reductions in farm antibiotic use and the number of human cases of livestock-associated MRSA is now falling. This shows that restricting farm antibiotic use can have real benefits for human health. The British government should urgently take similar action here.”