Tag Archives: MRSA

Antibiotics in Big Agribusiness

A recent comment reminded me about my major issue with farming animals. This is a system-wide problem and applies to meat, dairy, eggs as well as animals grown for fur or leather. The vast majority of animal products come from large factory farms where antibiotics (among other things) are routinely mixed into feed.

Naturally these drugs end up in meat, milk and eggs but more importantly they end up in manure. Not a lot reaches your body (though some research suggests otherwise) and our sanitary sewer systems have the potential to sterilize it in the case that it does. The manure that the animals depicted below are ankle deep in (or like the lagoon in the photo below, common at pork and poultry operations, is loaded with both microbes and everything that animals have excreted via their manure.

Microbes are great at adapting. They don’t have a lot of genetic baggage to lug around and can make a baby (for them it’s called fission) in as little as 30 minutes given lots of nutrients. What little genetic material they have can mutate rapidly. For creatures with as much genetic material and specific molecular processes and expansive tissue differentiation as humans, we think of mutation as being a bad thing but for bacteria it means being able to adapt quickly to harsh conditions. In this case, harsh conditions is the presence of huge quantities of several kinds of antibiotics.

Because bacteria can reproduce rapidly and mutate rapidly in the presence of copious nutrients (manure), the chance of making a mutant able to withstand all of those antibiotics is very high. The most famous resistant bacteria is methicillin resistant Staphylococcus aureus or MRSA which has caused mayhem in hundreds of hospitals, schools, nursing homes and prisons around the world. This particular microbe is resistant to all antibiotics that are related to penicillin (called beta-lactam antibiotics) and those related to Keflex (called cephalospirins). Big agribusiness was quick to point the finger at hospitals where the resistant strains first appeared as the source of the resistant bacteria. Doctors who prescribed antibiotics were blamed for not being judicious about dispensing the life-saving drugs but the reality is that these deadly bacteria came from the hands of farm workers and evolved in the presence of agricultural antibiotics.

What makes this particular strain so dangerous is something called “horizontal gene transfer”. You and I pass our genes vertically, from parent to child. This is one of the drawbacks of having so many cells. Bacteria only have one cell and can actually exchange genes between members of their own species but also between other species, like if I lent you a book that teaches us both how to avoid bear traps. Now you know how to avoid bear traps too! Now imagine that this book can also be read by bears, cats, dogs and elephants. Bear traps would be useless on all these animals too. This is why antibiotic resistance is a big deal; microbes can share these genes so that antibiotics become universally useless.

So whether or not you’re vegan or vegetarian, the next time you think about buying leather or meat or anything that came from an animal, consider whether or not you’ll be able to enjoy it knowing you or someone you care about could die or be seriously injured by a drug resistant infection. Have no illusions about it, new threats arise every day from these practices.

The farm bill is up for discussion this year. It dictates whether or not these practices are acceptable. Big agribusiness lobbyists say animal products can’t be grown ‘efficiently’ without antibiotics, so let your representatives know how you feel about using antibiotics instead of practicing proper animal husbandry.

This is Christie, signing off!

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