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Wednesday, July 17, 2013

Antibiotics in Agriculture

Trio of sliders, FlipBurger, Atlanta, GA

One of the selling points of Pecking Order is that their chicken is sourced from FreeBird, a company dedicated to "antibiotic-free chicken". In fact, you'll see this increasingly strident and righteous decrying of the use of antibiotics in animal husbandry (to a much lesser extent among plants). This, however, is accompanied by an awful lot misconceptions mixed in with factually correct but incomplete statements. The issue is incredibly complex, but exasperated calls to simply ban the use of antibiotics in livestock is shortsighted and ultimately costly (if only in enforcement issues).

So, perhaps we need to walk though this in small steps. I won't complete everything in one post, but I'll try to address some of the poorly understood matters involved.

Why is there even a concern about antibiotic use in livestock? 

Sadly, the public outcry about antibiotic uses seems to be tied to chemophobes, who project the idea that meat is contaminated with antibiotics, and this is somehow toxic to humans - thereby parlaying the manipulation of disgust to accomplish public misconception. The scientific concern, however, is far more subtle that that - after all, antibiotics enter commercial use because they are relatively safe for humans while being harmful to bacteria. It stems from promoting antibiotic resistance.

What are antibiotics anyway?

In general, antibiotics are weapons microbes use against each other, which we humans have coopted for our purposes. Think of it this way - in the competitive arena of microbiology, each type of microbe is scrabbling for survival against all other species for limited resources, just like the rest of the larger life forms. One way to compete is to produce chemicals that impede other species from growing - but, of course, the producer will need an antidote to keep it alive. This arms race is constantly going on all over the biosphere. What we call antibiotics are, to an extent, the subset of these chemicals that we humans have purified, tested, characterized, and then used against bacteria.

Of course, no livestock is ever raised in a sterile environment - all of them are teeming with myriad microbes that are using these chemical weapons against each other. Strictly speaking - there is no such thing as antibiotic-free meat. While we may not have characterized, patented, bottled and leveraged these compounds, in all likelihood, antibiotics are being produced by the different microbes already living in and among all animals (including humans).

Fortunately, humans are genetically distant enough from bacteria that the same compounds have minimal, if any, effects on us, while killing the targeted bacteria. Or does it? Remember that antidote? For every antibiotic produced by a microbe, in all likelihood, a resistance mechanism already exists. In fact, antibiotic resistance was documented with the earliest uses of antibiotics - and predates even our discovery of DNA as the hereditary molecule.

The key is how prevalent this resistance mechanism spreads. The genius of evolution as a concept is that we can predict that the more often an antibiotic is used by humans, the less effective it is the next time around. The microbial world is like a defective Borg population - they don't resist after one try, but they eventually get there. So, we want to curb antibiotic use to extend the useful life of particular classes of antibiotics.

In future postings, I'll tackle why antibiotic resistance can be such a scary phenomenon, why it's being used in animal husbandry - and why banning may not be as simple as people make it sound.

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