The rise in illnesses due to antibiotic resistant bacteria has always been both easier and harder to understand than scientists have led us to believe.
Easier because on the one hand, the problem all boils down to one maxim: "The more we use them, the faster we lose them (antibiotics, that is)." In articulating his theory of natural selection, Charles Darwin fleshed out the concept. We live within a huge ecosystem of bacteria in which we humans are just one small cog. When we introduce a stressor into that system—antibiotics—we create the conditions where the bugs that most naturally resistant those antibiotics will be the ones that thrive and come to dominate our mutual environments.
Harder to understand, perhaps, because this bacterial ecosystem is a much more complex, nuanced world than most of us ever think about. It turns out that bacteria can swap their genes with ease with even unrelated families of bacteria. This includes the genes that render them resistant to antibiotics. Moreover, because these drug resistant genes are often physically connected to one another, bacteria that before was killable with several antibiotics, could, in one fell swoop, become much less killable.
What prompted this blog is the latest study (Graham J et al. Sci Total Environ. April 2009) showing that these bugs and the genes that make them resistant could be carried by flies—yes, flies—from farms to elsewhere. Now foolishly, about 70 percent of all antibiotic supplies in the U.S. are used as additives to animal feed for chickens, pigs and beef cattle to make them grow faster under more stressful, confined conditions prevalent in factory farms. Researchers at Johns Hopkins University looked at poultry manure from these factory farms and compared the drug resistance of the bacteria in the litter with the bacteria on the flies collected nearby. And guess what, the drug resistance was pretty much the same.
We don't know where else those flies were headed to, but wherever it is, the implications aren't good.
So, next time you do find a fly in your soup, just say, "Waiter, no superbugs, please."
