By: Dr. Scott Dee
The topic of antimicrobial resistance (AMR) is both confusing and controversial. It seems that a day doesn’t go by without the opportunity to read a new article, blog and/or a social media posting. Unfortunately, most of these publications attempt to scare us rather than educate us. In addition, many of these communications focus on the topic of overuse of antimicrobials in livestock populations and how this is promoting AMR. However, based on what I have read, the discussions I have had with experts in the field, as well as the results of internal studies we have conducted in Pipestone, I don’t think it’s quite that simple and here are a few examples:
- AMR occurs in the absence of antimicrobial use.
Fact: Peer-reviewed publications have reported the identification of resistance genes from a 4-million year old cave (Nature Communications) and the colon and feces of an 11th-century human mummy (PlosOne), long before antibiotics had been discovered.
- The level of antibiotic usage does not influence the level of antibiotic resistance.
Fact: The percentage of resistant bacteria recovered from livestock populations treated with high levels of antibiotics is no different than what is found in those treated with low levels. In other words, it appears that level of use (high dose versus low dose) doesn’t matter.
- The key to AMR is gene acquisition.
Fact: The development of AMR is due to the transfer of resistance genes between bacteria via mobile genetic elements such as plasmids. These DNA fragments can carry resistance genes to multiple antibiotics. Since many of the antibiotics that are used in humans and animals are derived from a small number of bacteria and molds, there is a lot of conserved genes that can be passed around and resistance to a human antibiotic can be observed, even if it’s never been used in an animal.
- The source of resistant genes is not the animal, it’s the environment.
Fact: Evidence of AMR to certain types of antibiotics can be found in livestock environments, despite never using these medicines on the farm and in the animals.
So what do we do? Quit using antibiotics and let sick animals suffer? I strongly disagree with this approach and in particular disagree with the “No Antibiotics Ever” approach to raising livestock. This is simply a marketing ploy that cares more about return on investment than animal well-being. While antibiotic use always needs to be practiced responsibly, for the sake of reducing animal suffering, we need to treat those individuals afflicted with bacterial diseases. In addition, we need to:
- Become educated: Rather than rely on the Internet and social media for your information, talk to reliable sources, such as Dr. Mike Apley of Kansas State University, or Drs. Peter Davies and Randy Singer from the University of Minnesota. These people are highly qualified and are great sources of non-biased information.
- Record antibiotic use: Keep accurate records of how much medicine you use to treat sick animals. Use VFD and prescription information to measure actual usage.
- Track AMR: Use food safety-based protocols employing NARMS standards to measure the level of resistance in your herds. Remember that sampling the environment and/or healthy animals is more representative than tissue samples from a couple of dead pigs. Your veterinarian and the state diagnostic laboratory faculty are great resources for setting this up.
- Manage the environment: Utilize proven health technologies and effective sanitation programs to reduce pathogen load and subsequent challenge in the animal environment. A clean, well-ventilated facility, i.e., the proverbial “an ounce of prevention”, goes a long way to reducing the need for antibiotics, aka, “the pound of cure”.
Clearly AMR is a very challenging topic; however, my confidence is rising that we can not only understand it but also do our part to manage it properly and meet the needs of our consumer groups. We know what to do, we just have to get to work!