A few weeks back, we reported on a study out of the University of Iowa that tested supermarket pork for antibiotic-resistant Staph bacteria (aka MRSA). The researchers found MRSA at the same rate for conventionally raised meat and for meat raised without antibiotics. In her well-respected WIRED blog on the topic, Superbug, Maryn Mckenna summed up the media response to the news like this:
There’s just as much resistant bacteria on drug-free meat as there is on conventional meat, so why spend the money — or raise the alarm over farm antibiotic use?
But she disputed that conclusion:
My takeaway is that, in its underlying data, the study proves what campaigners against ag antibiotic use keep saying: that once you use antibiotics indiscriminately and drive the emergence of resistant organisms, you have no way of predicting where that resistance DNA will end up.
For most of us, any sign of MRSA in our food is pretty creepy. (Although the bacteria doesn’t make it through the cooking process, meat can still be what scientists call a “vector,” or a mode of transmission, when we handle it). So we tracked down McKenna, who is also a columnist and contributing editor for Scientific American and the author of Superbug: The Fatal Menace of MRSA. Her take on the research may surprise you.