It turns out that antibiotic resistance genes may be increasing thanks to their use in farming. Scientists have found that using antibiotics in agriculture could be increasing resistance globally, which is troubling news for the health system.
In this latest study, the researchers looked at large-scale swine farms in China and one population of pigs in the U.S. After looking at these locations, they found the presence of many partner genes, which are resistance genes and mobile genetic elements found together. More specifically, when one gene increased or decreased in abundance, the partner gene did the exact same thing.
The Chinese farms, in particular, are close to large cities. This means that controlling antibiotic resistance in pigs is crucial to minimizing human risk. If antibiotic resistance is transferred over, people could become very sick and need far more extensive treatments to be cured.
That's not all that the researchers found. It turns out that some of the partner genes can make bacteria resistant to antibiotics that weren't even fed to the animals. It's likely that partner genes were present in the same bacteria that were resistant to one of the antibiotics that were fed to the pigs.
"In the fight against the rise of antibiotic resistance, we need to understand that the use of one antibiotic or, in some cases, antibacterial disinfectants may increase the abundance of multidrug resistant bacteria," said James Tiedje of MSU, one of the researchers involved in the new study. "Tracking the source of antibiotic resistance is quite complicated because antibiotic use, which increases the occurrence of resistance, is widespread, and antibiotic resistance can spread between bacteria."
This isn't just a local problem, either. This is a global problem. As the researchers point out, "multidrug resistance is just a plane ride away."
"Our results clearly show the diversity of resistance genes on swine farms and that many genes likely originated from the same source," Tiedje said. "We also showed the linkage of resistance genes to each other as well as genes that enable them to be clustered in one bacteria or shared among bacteria. These findings will help guide practice and policies for prudent agricultural antibiotic use and to minimize antibiotic resistance genes spread to pathogens."
The findings were published in the April 12 issue of the journal mBio.
