Routes of Resistance
Our focus on using antibiotics to kill bacteria has blinded us to their diverse functions in the organisms that make these chemicals
Last year, some 50 million pounds of antibiotics were used in the United States, an amount that would correspond to roughly 5 tablespoons—or 75 doses—of antibiotics per person. In fact, much of this antibiotic—as much as 70 percent by some estimates—is being used not to treat infections, but instead to promote food production, as antibiotics have become a key ingredient in the American food chain. We are, in short, marinating the living world in antibiotics.
Against this backdrop, the emergence of antibiotic-resistant pathogenic bacteria can hardly come as a surprise. Antibiotics, after all, are used to suppress and kill bacteria, and bacteria, like every other living thing, have no greater evolutionary imperative than to stay alive. Our overuse of antibiotics methodically rewards any bacterium fortunate enough to carry a mutation that confers even slight resistance to the substance in its environment. The less-fortunate bacteria die, leaving behind empty ecological space for resistant strains to fill. Slowly and inexorably, we thus enrich the world with bacteria that now scoff at our attempts to control them.