Friday, December 14, 2007

What we eat

Yesterday, I serendipitously walked by poster H41C-0661 at American Geophysical Union (AGU): Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes

* You, Y (you.yaqi@jhu.edu), Department of Geography and Environmental Engineering, Johns Hopkins University and a whole bunch of other people, including her PhD advisor.
Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (ECa) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of ECa and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (TcR), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of TcR bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated TcR genes and to explore a link between the presence of TcR and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent TcR gene. This gene will be monitored in future experiments, in which we will study the transmission of TcR to naive E. coli under selective pressure of TcR. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.
Why did this poster catch my eye? The words tetracycline and poultry, together. Then it hit me.

My doctors and I have been trying to figure out if I am sensitive to chicken in some way. I tested not allergic to chicken proteins. There is a theory that chicken is high in arachadonic acid, a chemical in the inflammation pathway. Perhaps the arachadonic acid found in chicken and beef are exacerbating inflammation of my joints and skin?

If so, then why don't fruits like bananas, also high in arachadonic acid, cause inflammation? Why is it sporadic? Why don't I have the inflammation every time I eat meat?

I am allergic to tetracycline. They feed it to animals. When I eat the dead animals, I am taking tetracycline. Only it is not labeled anywhere. That is apparently legal.

Ya Qi helpfully told me that tetracycline is fed to chickens to help shorten the time to market (40 days from hatchling to roast chicken!). It is fed to pretty much all 'conventionally raised' animals. tetracyline is so prevalent in our food system that the TcR gene has been found in organic beef (and even flies). The presence of the TcR gene in an animal doesn't mean it has been fed tetracycline. It only means that tetracycline resistance is now a common characteristic in our environment, due to heavy and indiscriminate use in the past and present.

How did dumping drugs and other chemicals into our food chain become 'conventional' farming and not doing so become 'alternative' farming?

Her poster showed the apparatus that she used to get a core of the soil floor of a poultry shed. It is like the ones used to get ice cores from glaciers. So cool. The stuff she told me about factory farming in the US and China, not so cool. It kind of turns the stomach, actually. We eat organic dairy and eggs. But we don't always buy organic meats. Now I know better.

See the full abstracts for that poster session. It is hair-rising. Don't read it right after eating.

2 comments:

  1. Depressing isn't it? The fish is full of mercury and the meat is full of antibiotics and hormones. Baby toys have phthalates in them and bottles bottles leach bisphenol-A. And then there are flame-retardants, which you would think would be a good thing, but early exposure could lead to brain development problems and dusruption of sex and thyroid hormones. (See the Dec. issue of the "Southern Sierran.") There's more, but I won't get into all of it.

    If the human race thinks it can avoid the extinction that faces the rest of the living species on this polluted Earth, we are sadly mistaken.

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  2. Hmmm, food for thought indeed. It is really disturbing that we don't know what we're eating! I'd love to eat exclusively from farms and growers I know and trust, but in this day and age, is that possible?

    It's so amazing to me how bad the conditions are in agriculture and animal husbandry. If I didn't know any better, I would've thought it was all a plot out of some dystopian science fiction novel.

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