A paper released recently, by the University of Iowa team that is the lone US research group tracking “pig MRSA” ST398, caused a ripple. (It came out while I was at ScienceOnline and it’s taken me a while to catch up.) The paper compares the occurrence of MRSA, drug-resistant staph, on various cuts of retail pork from pigs that were raised either conventionally in confinement, with routine use of antibiotics, or in an alternative rearing scheme with no antibiotics. (NB: Not “organic,” despite what some headlines said; that’s a separate issue of USDA licensure.) The team found that both conventionally raised and antibiotic-free meat carried MRSA, both the human-associated kind and the pig-adapted kind.
The TL;DR over the past week has been: 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?
My interpretation is a little more nuanced. But 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.