Antibiotic resistance: a human and animal issue

Antibiotic resistance: a human and animal issue

Antibiotics and their use in food animals will be the illuminating consumer issue this year, explains National Pork Producers Council President Ron Prestage, a veterinarian and South Carolina hog producer. Rightfully so; consumers depend on antibiotics as a critical tool to help keep them healthy when they get ill, just as hog farmers depend on antimicrobials to help sick pigs.

Tom Burkgren, executive director of the American Association of Swine Veterinarians, explains that hog producers and veterinarians have worked with the issue of antibiotic resistance from an animal pathogen standpoint for decades.

“On the farm level, they understand the aspect if you use antibiotics, you do run the risk of those bacteria developing resistance to what you use,” Burkgren says. “On a very practical level, it has been part of the daily life of how we use antibiotics on-farm judiciously to preserve the effectiveness for our animals.”

Both consumers and hog producers want the long-term effectiveness of antibiotics to remain and share the concern over antibiotic-resistant bacteria.

“When they [consumers] hear and read about the use of antibiotics in food animals and the possibility that they can cause antibiotic resistance, it gets people’s antennae up,” Prestage says.

This year the federal government and the White House have prioritized a reduction in antibiotic-resistant bacteria to slow its emergence. Building on the Executive Order issued in September 2014 by President Barack Obama, the administration announced in March a “National Action Plan for Combating Antibiotic Resistant Bacteria.”

While government and the pork industry agree that slowing the growth of antibiotic resistance is a worthy objective, clearly communicating how it relates to antibiotic use in food animals is an ongoing challenge.

First, Prestage clarifies that it is an ordinary phenomenon in nature that if there is a threat to survivability, the challenged will evolve to live. So, when antibiotics were first developed and being administered, the antimicrobial drugs started killing bad bacteria. The bacteria evolved to survive. Moreover, at the same time the antibiotics were developed, scientists had predicted that resistance would occur — a tidbit that pork producers need to internalize and educate Congress and regulators about, Prestage notes.

Another confusing issue is antibiotic growth-promoters (AGPs) — a low level of antibiotics fed to meat-producing animals for the purpose of growth. This was a label claim made by pharmaceutical companies that stated if the product was used in low doses, it would improve the animals’ feed efficiency.

Honestly, Prestage says, if you feed an antibiotic to perfectly healthy animals, it will not change anything. The reason AGPs have worked over the years is that those animals that receive them have a subclinical disease that is not at the threshold for showing visible signs like going off feed, fever or sluggish energy. Those low levels of antimicrobials clear that subclinical disease up; therefore, the animal is healthier and converting feeding more efficiently.

The federal government’s ban on using antibiotics purely for growth promotion will be implemented nationwide in December 2016 under the Food and Drug Administration’s guidances 209 and 213.

These are guidances that Prestage has no objection to, but he says some education for both legislators and livestock producers is necessary.

“The secret is that you use only use the antibiotics necessary. It is easier, cheaper, more ethical and more effective to use lower levels, appropriately timed, to try to prevent and control a disease than it is to wait until they get sick and use higher levels of antibiotics  — usually later in the growth cycle and closer to the time the animals go to market,” Prestage says. “It is just common sense.”

He adds that producers who administer antibiotics earlier, at lower levels and in the right way, for preventing and controlling sickness will use fewer antibiotics than any other way.

Still, Prestage recognizes there is a percentage of the public that feels no antibiotics should be used. That creates a big conflict.

“As a responsible pork producer, we have a moral and ethical obligation to take care of the animal in our care. Antibiotics are tools that we need to use to be able to do that,” Prestage says passionately. “Safe food comes from healthy animals, and it is not in the best interest of consumers for antibiotics not to be used in food animals.”

In the antibiotic debate, there are two extreme views: those who do not want any antibiotics used, and those who believe no restrictions should be placed on using antimicrobials in animal agriculture at all.

Prestage further explains there is a sweet spot for using antibiotics, and it falls in the middle of the two extreme viewpoints. The FDA’s guidances 209 and 213 fall into the middle ground, which eliminates the use of AGPs and requires licensed veterinarian consultations for the use of antibiotics in feed or water for prevention or treatment of disease.

Antimicrobial evolution

Dating back to the late 1990s, the AASV and the pork industry were the first species group to approve the judicious use of antibiotics guidelines.

“We were the first group to put judicious use in a written form,” Burkgren says. “Producers today versus 20 years ago are much more aware of how to use antibiotics, and the consequence of that use not only for animals but its potential impact on human health.”

Burkgren credits that link to such education programs as Pork Quality Assurance Plus and the involvement of veterinarians on the farm.

Paul Sundberg, National Pork Board senior vice president of science and technology, says the veterinarian and hog-producer relationship has been the foundation of PQA Plus since the program was created in 1989.

“From the early version of the PQA through the recent PQA Plus program, one of the cornerstone practices is the reliance of the producer to work with their veterinarian,” Sundberg says.

The pork industry was the first among the animal agriculture community to embrace the practice that a veterinarian, with a strong patient-client relationship, should be consulted before any medicine is administered, Prestage says.

The standard practice for the oversight of a veterinarian is important to ensure responsible use of antimicrobials, along with other medicine. It also provides the producer with the reassurance that the right medicine is given at the right time for that particular situation.

The PQA Plus program assists the producer to make sure the appropriate health protocol is taken, the proper records are kept and correct withdrawal time is observed. All established standards were developed by the U.S. pork industry long before the current antibiotic-resistant debate.

“Pork producers are going to be the leaders in trying to get to a new level of understanding and responsibility in use of antibiotics in the animals under our care,” Prestage says. “We will be the example for all animal agriculture industries.”

The development of the PQA Plus program and the routine revisions are based on sound science and consultation of experts, including the involvement of the AASV.

The next step for PQA Plus is to update the program to assist producers to meet the Veterinary Feed Directive, requiring a veterinarian’s prescription for administering antimicrobials through feed or water given to animals, so producers are ready when the requirement goes into effect in 2016.

“We are always trying to look over the hill and predict what will come next,” Sundberg says. “So the producers are prepared.”

Still, the new antibiotic-use regulations will change the use on the farm. For certain aspects of the new rules, pork producers who follow PQA Plus guidelines may not notice the modifications in their daily operations.

Burkgren stresses the removal of products from the marketplace adds a degree of complexity on the farm. Hog producers are very aware of AGP claims about use of those products for feed efficiency. For the most part, producers are more discerning over the use of those products because they are more fine-tuned with feed budgets and the return on investment.

Even though the AGPs are used for the production claim, those antibiotics do have some therapeutic effect on the pigs, particularly in the gut.

“Taking growth-promotion antibiotics away, certainly there could be some impact health-wise, especially the weaning-aged pigs and growing pig,” Burkgren says.

Measuring success

One challenge is accurately measuring antibiotic use on the farm and antibiotic resistance in humans. There are no good metrics for measuring success. Right now, there are no good data to serve as benchmarks to document the use of antibiotics and antibiotic resistance before certain products are taken off the market under Guidance 213, Burkgren points out.

He adds, “It is a little concerning from the standpoint of the FDA — and how do you declare victory when you do not have a baseline measured?”

Sundberg agrees that currently there is no true measurement of the evolution of antibiotic resistance and the use in animal agriculture.

However, there are three entities that have looked into the antibiotic use. The USDA has conducted National Animal Health Monitoring System studies of hog producers for more than 20 years that have included questions on antibiotic use. The AASV also examined the use of antibiotics in pork production. The FDA tracks the sales data of antibiotics. Still, there is limitation to the present data being collected. Sundberg says the NPB is advocating for a proper measurement of antibiotic stewardship across all species.

“A quantity of antibiotics does not necessarily give you a picture of correct use of antibiotics,” Sundberg says.

Moreover, he explains further that just because the use of antibiotics goes up in a given year, it does not guarantee proper use. For the short term, the removal of AGPs from the market will probably translate to less antibiotics use in general. However, Burkgren notes, therapeutic use may increase. It normally takes a higher dose of antibiotics for therapeutic use than for growth promotion.

Government funding

The White House plan brings the concern over antibiotic-resistant bacteria that affects humans, but also includes animals, to the forefront. The federal government attention to the issue will be encouraging for hog farmers.

“Hopefully, it does evaluate it to a funding issue. I think that funding is going to be the key to how it really affects — in a positive way — what we do on the farm,” Burkgren says.

While a certain part of the national plan is to change regulations and remove certain products from the market, the real need is to fund research and product development that will aid veterinarians and producers on the farm level.

“A best way to fight antibiotic resistance is to approve more products. So you can use a wider array of antibiotics and not have to use the same product all the time,” Burkgren explains. “In food animal medicine we are limited on the number of products that we can use.”

Although Obama’s plan still needs final congressional approval, the administration proposed an appropriation of $1.2 billion in its fiscal-year 2016 budget.

The NPB welcomes the possibility of new research funds to curb antibiotic resistance and the chance to sit down with the agencies to establish research priorities. For more than a decade, the pork checkoff has been funding and conducting antibiotic resistance research.

“Anything that we can work with the government on to help set priorities is very good; and secondly, to coordinate research efforts is welcomed,” Sundberg says. “It is important not to duplicate efforts.”

There are still questions remaining on the White House national plan. One large concern is how the appropriated funds, once approved, will be allocated across the goals. Additionally, the source of the new money has yet to be disclosed. Lastly, the 2020 timeline set by the White House is aggressive, especially in regard to product research and development.

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