MRSA found in pork on sale in UK

MRSA found in pork on sale in UK

The use of antibiotics in the rearing of animals has been a much discussed issue in recent weeks, with regulatory and corporate moves across a number of countries. Ben Cooper examines recent events in the context of the widespread concern over antimicrobial resistance.

When an issue is in the news at the same time in opposite corners of the world, it is reasonable to assume it is of global magnitude and worldwide concern. This is currently the case with antimicrobial resistance (AMR) and the description is entirely warranted.

Only a day before the US Food and Drug Administration (FDA) unveiled its Veterinary Feed Directive (VFD) on 2 June, the Australian government launched a five-year National Antimicrobial Resistance Strategy.

The previous week had seen the World Health Organization (WHO) adopt a revised resolution on AMR, endorsing a global action plan on the issue.

Recent weeks have also witnessed moves on antibiotic use from food companies including Tyson Foods, 2 Sisters, Foster Farms and Wal-Mart, following earlier moves by McDonald's and Pilgrim's Pride.

The news last week that the MRSA 'superbug' had been found in pork in a number of UK supermarkets brought the topic chillingly back to the headlines.

The moves by food companies reflect and are a response to growing public concern over antibiotic use in farming. However, ironically, public misunderstanding of antibiotics is playing a significant - and probably larger - part in growing antimicrobial resistance.

A survey in Australia revealed that 65% of Australians believe, quite mistakenly, antibiotics will help them recover from a cold or flu more quickly. One in five people expect antibiotics as a treatment for colds and flu and, far more worrying, nearly 60% of general practitioners surveyed would prescribe antibiotics in response to a patient request.

Antibiotics revolutionised medicine and have themselves made countless treatments possible. On average, antibiotics are estimated to add 20 years to each person's life in the UK. However, drug-resistant strains of bacteria are estimated now to account for some 5,000 deaths a year in the UK, and as many as 25,000 deaths a year in Europe. The Alliance to Save Our Antibiotics, a coalition of health professionals, animal welfare groups and other NGOs, predicts that antimicrobial resistance will account for as many as 1m deaths across Europe by 2025.

While public concern focuses on the impact antimicrobial resistance has on human health, it is the impact on animal health that is of immediate concern to farmers and meat producers. As this affects the safety and cost of the mass production of food, it is also of great relevance to food companies and to consumers.

The WHO resolution underlines the point, stating: "For farmers, animal husbandry and the food industry, the loss of effective antimicrobial agents to treat sick animals damages food production and family livelihoods." It goes on to say that food is "one of the possible vehicles for transmission of resistant bacteria from animals to human beings".

As part of a 'One Health' approach, animal and human health are increasingly considered holistically. This approach is informing the WHO's work, and policy directions in the UK, the EU, Australia and the US.

Thankfully, the particularly serious issue of using antibiotics to boost growth promotion has been and is being addressed through regulation. It has, for example, been banned in the EU since 2006.

Nevertheless, while the VFD and regulations like it elsewhere may protect the public from overuse or the abuse of antibiotics in meat and poultry production, it represents continued governmental support for the use of antibiotics for medical reasons. Many would maintain this too is unsustainable, but while there is no medical alternative the mass production of meat for now depends on their continued use.

"I think growth-promoting antibiotics is gone. I think everyone accepts that," Mark Cook, professor of animal sciences at the University of Wisconsin-Madison, tells just-food. "We still need to treat disease. We can't let animals become sick. That would be inhumane. With regards to sustainability, we must find new ways to fight disease."

Prof. Cook's ground-breaking research in this area itself potentially offers a new way of tackling the AMR issue.

Rather than targeting the bacteria, his approach focuses on what the pathogen does to the host animal's immune system, introducing an antibody which effectively "turns the immune system back on". The animal's own immune system then "does the rest of the work", Prof. Cook continues. "Targeting bacteria is very difficult; they keep developing resistance. Why not target the host and get the same result. Our targeting just lets the host do what it is trained to do and outwits the microbes' outwitting."

In the largest test of his 'host targeting' approach to date, some 300,000 chickens were fed the antibody which gave them full protection against coccidiosis, a bacterial infection common in farm animals. Other smaller-scale tests on larger livestock have also been positive.

Prof. Cook adds that the process is "natural" as it is not a drug that is introduced but an antibody from a hen. "Our approach is simple. We use antibodies in the egg of laying hens, and you can't get more natural than that," he says. Somewhat surprisingly, however, organic farmers have not as yet shown interest. "They don't like to feed animal products to animals even though all animals naturally consume animal products in early life. I hope they will consider this if needed and accept it."

The need for research both into the contributory human factors exacerbating antimicrobial resistance and into eventual alternatives to antibiotics could not be more pressing.

Late last year, UK prime minister David Cameron convened an expert, multi-disciplinary panel to conduct a review into why so few antimicrobial drugs had been launched in recent years. While antibiotics support - and make viable - so many new treatments and surgical procedures which in turn can save lives, medical progress in the field itself has slowed dramatically. Interestingly, the panel will be led by an economist, Jim O'Neill, with David Cameron describing the dearth of new drugs as a "market failure".

Meanwhile, the Longitudinal Prize was also launched late last year, offering the winner a GBP10m prize to develop a point-of-care diagnostic test to allow more targeted use of antibiotics and help reduce misdiagnosis and over-prescribing.

The moves by food companies to respond to consumer concerns by offering more meat products produced without antibiotics or use their buying power to reduce antibiotic use in animal rearing are admirable but these efforts represent little more than a small first step - albeit a positive one - in tackling a truly frightening global health issue.

What perhaps the recent flurry of activity from policymakers, industry and others may at least signify is that any complacency over AMR now appears to be well and truly a thing of the past. However, all that means is that the world has finally and fully woken up to a terrifying problem. The battle itself has only just begun.