Chinese Farms Breed Antibiotic-Resistant Bacteria

In 2011, human consumption of antibiotics in China was ten times the global average. Because overuse of the drugs can give rise to resistance in the bacteria they target, the Health Ministry has repeatedly promised to cut down on unnecessary use.

Overconsumption among humans is not the only problem, however. Among the various side effects of China’s surging meat consumption is the large-scale adoption of American-style intensive farming techniques, including routine preventative dosing of animals. A paper published last week by researchers at the Chinese Academy of Science and Michigan State University documents the consequent proliferation of drug-resistant bacteria at three large pig farms around China. From Maryn McKenna at Wired:

If you’ve followed news about food in China (at this blog or elsewhere), you’ll have seen that regulation of food safety is failing under the twin pressures of needing to produce a lot of protein and wanting to make a lot of money. (I think of food in China as being where the United States was before Upton Sinclair came along.) This lack of regulation is as true for agricultural antibiotic use as it is for other aspects of food production. China is both the largest producer and the largest consumer of antibiotics in the world, and it is putting almost half of its annual production into agriculture: about 96 million kilograms, which by my math (using the newest ADUFA numbers in my last post) works out to about 7 times what the US is using each year.

[…] To quote from the paper: “The diverse set of resistance genes detected potentially confer resistance to all major classes of antibiotics, including antibiotics critically important for human medicine.”

[…] Their summation:

The diversity and abundance of (antibiotic resistance genes) reported in this study is alarming and clearly indicates that unmonitored use of antibiotics and metals on swine farms has expanded the diversity and abundance of the antibiotic resistance reservoir in the farm environment. The coenrichment of ARGs and transposases further exacerbates the risks of transfer of ARGs from livestock animals to human-associated bacteria, and then spread among human populations.

Overuse of antibiotics in agriculture is still a major problem in the United States, where 80% of all antibiotics sold are consumed by farm animals and the industry has fought beak and trotter to resist regulation. In a New York Times report last September, Sabrina Tavernise summed up the stakes:

Antibiotics are considered the crown jewels of modern medicine. They have transformed health by stopping infections since they went into broad use after World War II. But many scientists say that their effectiveness is being eroded by indiscriminate use, both to treat infections in people and to encourage growth in chickens, turkeys, cows and pigs.

Whatever the cause, resistant bacteria pose significant public health risks. Routine infections once treated with penicillin pills now require hospitalizations and intravenous drip antibiotics, said Cecilia Di Pentima, director of clinical services at the Infectious Diseases Division at Vanderbilt University’s Department of Pediatrics. Infections from such strains of bacteria are believed to cause thousands of deaths a year.

“The single biggest problem we face in infectious disease today is the rapid growth of resistance to antibiotics,” said Glenn Morris, director of the Emerging Pathogens Institute at the University of Florida. “Human use contributes to that, but use in animals clearly has a part too.”

See further discussion of “the doomsday scenario of a world without antibiotics” at the Bulletin of the World Health Organization in 2010, and a Telegraph report on antibiotic overuse in China and its dangers from the same year.

Last month, Shanghai-based researchers shed new light on one process by which bacteria develop resistance. From Alice Yan at South China Morning Post:

Now researchers at Fudan University’s Shanghai Medical College say they have uncovered an important mechanism leading to resistance. The team, led by Professor Alastair Murchie, a British molecular biologist, said in a paper in the peer-reviewed journal Cell last week, that they had found a special section of ribonucleic acid (RNA) in some infectious bacteria that could make antibiotics useless.

[…] Murchie said that while aminoglycoside antibiotics accounted for only about 20 per cent of all antibiotics, the research was important because drug resistance remained a significant threat due to the way it evolved and emerged.

“It’s important that we understand the underlying mechanism [of] why resistance happens, how are the bacteria so flexible and why do they respond so well to treatment by antibiotics?” Murchie said.