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The Other Side of Antimicrobial Resistance

Opinion

An editorial was recently published by Food Safety News entitled “Letter from the Editor: Antibiotic Resistance” (1). For the most part, I agree with this article. However, there are a few points that I think need clarification. I will use a “point-counterpoint” approach, although not all of these counterpoints are arguments.

Point: “Antibiotics are integral in the treatment of many foodborne diseases, making this an important issue for the food safety community.”

Counterpoint: Yes, antimicrobial resistance (AMR) is a big deal. Antimicrobials are used in treating infections. However, they are not the first line of defense for treating foodborne illness, even in cases requiring hospitalization. Instead, the primary course of treatment is fluid therapy (2). Therefore, even if we could erase AMR in foodborne pathogens, it is unlikely that there will be a significant improvement in the outcome of foodborne illness cases.

Point: Drug-resistant infections take a staggering toll in the United States and across the globe. Just one organism, methicillin-resistant Staphylococcus aureus (MRSA), kills more Americans every year than emphysema, HIV/AIDS, Parkinson’s disease and homicide combined. Nearly 2 million Americans per year develop hospital-acquired infections (HAIs), resulting in 99,000 deaths – the vast majority of which are due to antibacterial-resistant pathogens. Two common HAIs alone (sepsis and pneumonia) killed nearly 50,000 Americans and cost the U.S. health care system more than $8 billion in 2006.

Counterpoint: The impact of AMR is staggering. Resistant infections have been a problem since the discovery of penicillin, which is the reason for the invention of multiple types of antibiotics (3). It is also important to realize that very few of the bacteria listed in the above paragraph are related to livestock and food. In addition, several other medically important bacteria, such as Pseudomonas aeruginosa, Streptococcus pneumoniae, and Mycobacterium tuberculosis, have resistance patterns that cannot be explained from livestock antimicrobial usage (4).

Point: “Antibiotics are becoming less and less effective, in part due to over-prescription and inappropriate use.”

Counterpoint: I don’t really disagree with this point, but I would like to “fine tune” it a bit. As soon as an antibiotic is first used, resistance begins to develop. Bacteria evolve under the selection pressure of antibiotic exposure. It is how they survive. Inappropriate or unnecessary use means extra pressure on the bacterial population, thus increasing the speed of evolution.

To the extent that agriculture is guilty for antimicrobial resistance, we repent. It is important to note that many producer groups are making major efforts to become more prudent in antimicrobial use, just like what is being done in human medicine.

Point: “If I am reading scientists correctly, there are multiple theories for antibiotic resistance and agreement that some occurs naturally in the environment. Some of these theories involve antibiotic uses by both humans and animals.”

Counterpoint: Both points are correct. The ability to resist antibiotics has been around since the first microbe. Many types of antimicrobial resistance were recently discovered in four million-year-old dirt that had never been touched by man or beast (5). Subsequently, any antimicrobial usage, even if appropriate, allows the resistant strains to become more prominent.

Point: “Yet, is it just me, or is antibiotics used in animal agriculture the only thing we hear about when antibiotic resistance comes up? Am I wrong to look at antibiotic resistance as a big circle with animal issues maybe involving a 25 percent slice with lots of other unknowns out there?”

Counterpoint: No counter argument here. You are correct! Agriculture is taking way too much of the heat for its contribution to antibiotic resistance, and all published risk assessments show this contribution to be negligible. I would venture to say the percentage is much less that 25 percent. One paper I published shows the average American is more likely to die from a bee sting (one in six million) than to get a few extra days of diarrhea due to macrolide (a common animal antibiotic) use in livestock (6,7).

Point: “I just have this feeling that allowing animal diseases to go untreated would not contribute to food safety.”

Counterpoint: Again, I agree. Failure to treat or prevent illness leads to needless animal suffering. Additionally, some new research is showing that healthy animals that have recovered from a respiratory or infectious illness are more likely to be contaminated with foodborne pathogens such a Salmonella or Campylobacter (8,9).

Point: “Antibiotic resistance is complex issue. Help direct our coverage by suggesting people we should talk to and places we should go. Where’s the cutting edge research being done? This is not just some problem on the farm we haven’t solved. It’s bigger, broader and more complex. Now, please submit your answers.”

Counterpoint: Amen brother. There many questions that have not been addressed. If society was not so busy pushing draconian and meaningless solutions such as the PAMTA (Preservation of Antibiotics for Medical Treatment Act) or collecting usage data without good data on resistance, then resources would be available to answer many of your thoughtful questions.

References

(1) Flynn, D. 2012. Letter from the Editor: Antibiotic Resistance.
http://www.foodsafetynews.com/2012/08/letter-from-the-editor-antibiotic-resistance/#.UFeIPbKPU-I

(2) Food Poisoning Center, Sanford, FL. 2011. What is the treatment for food poisoning?
http://www.medicinenet.com/food_poisoning/page6.htm#what_is_the_treatment_for_food_poisoning

(3) D’Costa, V. et al. 2011. Antibiotic Resistance is ancient. Nature 477:457-461
http://www.nature.com/nature/journal/v477/n7365/full/nature10388.html

(4) Bywater, R.J., Casewell, M.W. 2000. An Assessment of the impact of antibiotic resistance in different bacterial species and of the contribution of animal sources to resistance in human infections. Journal of Antimicrobial Chemotherapy 46(4):643-645. http://jac.oxfordjournals.org/content/46/4/643.full.pdf+html

(5) Bhullar, K. et al. 2012. Antibiotic Resistance is Prevalent in an Isolated Cave Microbiome. PLoS One
7(4): 1-11.

(6) Ropeik D. et al. (2002). RISK! A Practical Guide for Deciding What’s Really Safe and What’s Really Dangerous in the World Around You. Houghton Mifflin Company, Boston, 2002.

(7) Hurd, H. S., et al. (2003). The Public Health Consequences of Macrolide Use in Food Animals: A Deterministic Risk Assessment. Journal of Food Protection, 67:5, 980-992.

(8) Hurd, HS, Yaegar MJ, Brudvig, JM, Taylor, DT, Wang, B. 2012. Lesion severity at processing as a predictor of Salmonella contamination of swine carcasses. American Journal of Veterinary Research 73(1):91-97.

(9) Hurd, HS, Brudvig, J, Dickson, J, Mirceta, J, Polovinski, M, Matthews, N, Griffith, R. 2008. Swine Health Impact on Carcass Contamination and Human Foodborne Risk. Public Health Reports. 123:343-351.

© Food Safety News
  • pawpaw

    Scott and Dan,
    Thanks for this discussion. Could either of you (or FSN readers) point to additional statements on or discussions of this issue? Either for general public or for veterinary/human health/microbiology professionals?
    I teach General Biology, and am on the lookout for topics my students can read and write about, especially those with reasoned discussion.
    Thanks!

  • Michael Bulger

    Dr. Hurd seems to make the argument that because AMR develops in more ways than one, we shouldn’t make concerted efforts to address overuse in livestock. Casually dismissing a “few extra days of diarrhea” might be easy for a healthy adult with healthcare. On the other hand, to an elderly person or the small child of a farmworker, an infection usually treated with macrolides can cause lasting health problems or even be fatal. Dr. Hurd might deem a small number of such cases statistically insignificant when compared to other causes of death and illness (like car accidents and bee allergies), but that is not a moral case for failing to act and prevent incidences of sickness and death.
    Certainly, AMR is a problem that extends beyond livestock production. That does not change the fact that livestock production contributes to the problem and needs to be a part of the solution. Here is what some major health and science organizations have to say:
    “Clearly, a decrease in the inappropriate use of antimicrobials in human medicine alone is not enough. Substantial efforts must be made to decrease inappropriate use of antimicrobials in animals and agriculture as well.” – National Academy of Science’s Institutes of Medicine
    “There is clear evidence of the human health consequences [from agricultural antimicrobials, including] infections that would not have otherwise occurred, increased frequency of treatment failures (in some cases death) and increased severity of infections.” – World Health Organization
    http://books.nap.edu/openbook.php?isbn=030908864X&page=R1
    http://www.who.int/foodsafety/micro/meetings/en/report.pdf

  • Veggie Sue

    OK so you make well reasoned and scientifically accurate counterpoints. You don’t seem to understand our agenda, however. See, we merely use a conflated argument about scary antibiotic resistance as a wedge to smear and hopefully damage agriculture. We will not be satisfied until all agriculture is but a void in the hallucinatory memories of future hunter-gatherer vegans. Please stop fact checking our arguments. We won’t listen to reason anyway so you are wasting your time. Stop antibiotics in livestock NOW! Stop animal agriculture NOW! Stop all agriculture NOW! Live off the fat of the land NOW! Get away from my nuts an berries NOW! Oh, the outrage.

  • The author of this piece has danced around the issue of antibiotic use with livestock by focusing primarily on antibiotic use with humans. No one is disputing the fact that most antibiotic resistance has roots in human usage, but that isn’t a reason to more closely examine the abuse of antibiotics on farms.
    The author states that withholding antibiotics would cause needless suffering in animals, but using antibiotics to cure sick animals has rarely been the issue–it’s the use of antibiotics in animal feed that is the issue. That, and using antibiotics as a way of compensating for atrocious livestock practices.
    To repeat from my comment to the original story:
    Part of this overall strategy is improving antibiotic use in agriculture. Most antibiotics in use today are being used on farms. We can’t ask people to change their daily lives without also demanding that farms change their daily procedures.
    Using antibiotics for growth purposes needs to be ended, now.
    Using antibiotics as a way of compensating for poor or insufficient agricultural practices also needs to end now.
    To use an analogy, antibiotic use on farms today would be equivalent to having children eat out of garbage pans and play in infectious disease wards–all without once washing their hands. Instead, they’d be given daily doses of antibiotics.
    Does this sound like an effective strategy for children? Then why is it an effective strategy for our food animals?
    Shoving too many animals into too tight spaces without a healthy environment and enough people to adequately care for them, and then using antibiotics to head off the inevitable diseases that result is atrocious animal husbandry.
    Study demonstrating a link between antibiotic resistance and using antibiotics in animal feed:
    http://www.npr.org/blogs/thesalt/2012/02/21/147190101/how-using-antibiotics-in-animal-feed-creates-superbugs
    And before you bring up the North Carolina study that implies it is the environment leading to resistance, not antibiotic use:
    http://nationalhogfarmer.com/health/debunking-myths-about-antibiotic-resistance-pigs
    Another article that effectively addresses the issue states that indiscriminate use of antibiotics is what led to the environmental contamination in the first place–effectively proving the inherent dangers of indiscriminate use of antibiotics in livestock:
    http://www.wired.com/wiredscience/2012/01/drug-resistant-pork/
    The author stated:
    “To the extent that agriculture is guilty for antimicrobial resistance, we repent. It is important to note that many producer groups are making major efforts to become more prudent in antimicrobial use, just like what is being done in human medicine.”
    In what ways are producers making major efforts to become more prudent? I’ve not seen anything from major producers except efforts to undermine the concern.
    An example:
    http://www.meatmythcrushers.com/myths/myth-antibiotic-use-in-livestock-production-is-a-human-health-risk.html

  • Thanks for all the thoughtful comments. I will try to reply to a few, except Veggie Sue 😉
    1. I do not, nor does the veterinary profession promote overuse or injudicious use of antibiotics. Currently, I travel the world telling vets and farmers, “get your antibiotic use house in order”
    2. Nor am I saying there is NO RISK from on-farm antibiotic use. All quantitative peer-reviewed risk assessment published to date, show a low but not zero risk.
    The issue is one of quantity, if we ban on-farm antibiotic use will there really be much change is some public health measure such as human illness days?
    3. To Mr Bugler’s point about elderly and children. Those people are included in my risk calculations. Unfortunately, national policy debates usually focus around the mean or most likely events, not these subpopulations.
    4. Antibiotics for growth promotion was effectively ended by FDA Guidance 209

  • Farmer with a Dell

    Shelley paints an imaginatively disparaging picture of modern American agriculture.
    She obviously has no real clue what she’s ranting about. She does, however, regurgitate HSUS talking points with practiced skill. To suggest our livestock is sick all the time is insane. She does it to imply we are incompetent or we are cruel and inhumane. It is just the usual HSUS smear propaganda.
    Our livestock is healthy, growthy, efficient and we farmers, of all people, have the highest regard for animals and our farm environments. It is HSUS shills who wallow in pools of toxic mental vomit and who inhumanely pollute our minds with their hateful amateur science anarchy. Just so many empty heads blathering on and on and on with their misinformed opinions about how other people should live. No one is benefiting from that except the paid hogs feeding at the HSUS donation trough.

  • Dr. Hurd, thank you for the courteous response.
    I don’t think anyone has ever suggested banning all uses of antibiotics with livestock. In Denmark, the ban against antibiotic use is for uses other than therapeutic. The country did later ban the use of certain antibiotics for therapeutic use, but not all antibiotics.
    So what do you consider to be an ‘appropriate’ use of antibiotics?
    As you mention, FDA #209 is a guidance document. Though producers do seem to be taking the guidance seriously, everything is voluntary.
    http://nationalhogfarmer.com/health/nppc-growth-promotion-antibiotics-will-disappear-3-5-years
    The problem with this voluntary effort is that it isn’t enforceable–a reverse Dickinsonian, “Please, sir, we want less”. And the FDA is silent on the preventative use of antibiotics.
    http://online.wsj.com/article/SB10001424052702304444604577338063592731138.html

  • Michael Bulger

    Thank you for the response, Dr. Hurd. I think it is important to point out that PAMTA does not ban antibiotics. It restricts the use of medically important antibiotics so that they would not be used at subtherapetuic levels (i.e., at low levels in feed and water) on otherwise healthy animals. This type of use continues irregardless of FDA guidance. Is that not correct?

  • Randi

    Question for M. Bugler. You admit livestock can be part of the solution. What is the remainder of the solution? Why are you obsessed with the 25% role of agriculture to the exclusion of other threats 3 times as potent? A holistic approach will be the only sustainable approach if you are genuinely interested in preserving antibiotic efficacy, as you would have us believe. I’m just not getting that warm trusting sensation with you Mr. Bugler. Let’s just say I don’t trust the purity of your intentions. You don’t pass the smell test, and I’ve raised three fine daughters whose various suitors honed my intuition to near perfection.

  • Joel

    Nice try Fw/a Dell — There’s plenty of problems with Modern Meat — ever since tried and true livestock raising practices became so heavily industrialized to maximize — not quality — but quantity. That’s “efficiency” for you — another word for chap profits.
    CAFOs ARE cruel — and animals living in those squalid close confinement conditions Require medicated feed to keep them” alive” and putting on market weight.

  • Ted

    Ahhh…the usual confusing muddle of fictitious nonsense gushing forth from our professional anti-agriculture wonks. With one breath they scream modern agriculture is cruel and all the livestock is sick and dying. With a second breath they whine antibiotics don’t work anymore and we are all going to be killed by mutant bacteria in our food. With a final belch they claim antibiotics are required to keep livestock alive. Except if livestock is produced in an appropriately inefficient and backward timewarp.
    How does that arithmetic tally? You geniuses seem to be claiming antibiotics work except when they don’t but only after they already have right up until they won’t work any longer the way they always used to work in some imaginary bygone era…or something along those conceptual lines….roughly speaking….well, close enough to cast some bludgeoning laws and other cool punitive police state stuff.
    What you jokers really are telling us is paid professional complainers don’t have the first good clue of what you’re railing about. Anyone who listens to you and takes you seriously — about anything, not just veterinary pharmacology — deserves the bitter embarrassing disappointment they will invariably experience when your disingenuous recommendations blow back all over them. Fools for a living. Nice work if you can find it.

  • husna aijaz

    The author’s counterpoints are a legitimate perspective on this noteworthy debate in the Agricultural industry. The discussion is very intriguing from all perspectives and the debate will never end. From my personal opinion, if alternate measures can be adopted to prevent animal cruelty and reduce foodborne illnessess, then remediation measures should atleast be put in place. However, ultimately, the Farmers and the Veterinarians know best as to what the challenges are in the given scenario.
    For those interested in finding more on why things are done the way they are, here is the link to the Journal of Animal Science:
    http://www.journalofanimalscience.org/

  • Rex

    Shelly,
    Enforcement means fear justifies the police power of the state and in our modern courts, any agenda driven tort case by any group with a nothion of how the world should be.
    In agriculture, education has done incredible things. Twenty years ago a beef quality audit indicated two serious problems. Needle absesses in rump roasts and antibiotic residue. The Beef Checkoff funded the Beef Quality Assurance program which managed to educate and enroll as certified 10% of the hundreds of thousands of beef producers. They managed to talk about the issues with other producers. Today, absesses in muscle meat are none existent in beef cattle and the antibiotic residues are on the order of about 6 cases in the 30 million or so beef cattle harvested annually.
    Can you imagine theFBI or Homeland Security accomplishing doing same with the murder rate?