Before I get into the meat of the post (SEE WHAT I DID THERE?), let me state for the record that I think the U.S. needs to do much more in terms of limiting antibiotic use in agriculture, especially since the economic costs are pretty small. We’re not choosing between affordable food and preserving the power of antibiotics.
That said, the recent Consumer Reports, erm, report about antibiotic resistant bacteria is nothing new. In fact, the results (pdf) are nearly identical to their 2007 report. The frequencies of resistance are pretty similar–for many drugs in many organisms, there are slight increases, but most aren’t statistically significant. In terms of current clinical practice, there’s little to worry about (e.g., ciprofloxacin resistance is very low in E. coli). The only disconcerting thing is the very low frequency of ertapenem resistance in Klebsiella pneumoniae. Ertapenem resistance can be associated with broad carbapenem resistance, though, in these strains, it’s not.
The real problem is that this is a shoddy study. It’s basically getting a bunch of scary sounding data and releasing it to make a policy point (one that I happen to agree with). But Consumer Reports didn’t do the heavy lifting–the genetics (or genomics)–that we need to really make sense of these data. Are these strains similar to clinical isolates, including those particular good at causing disease? Is the ertapenem resistance associated with carbapenemases*?
Between it being a rerum of their 2007 report (and is completely expected from the NARMS data which has documented very slow increases in resistance) and the absence of genetic information, this report is sound and fury signifying not much.
*Some carbapenem-resistant strains require two mechanisms for resistance: a carbapenemase that chews up the antibiotic, and a mutated porin that decreases the amount of antibiotic that enters the cell.