当家禽饲养场停止使用抗生素

Conventional poultry farms use antibiotics extensively, which contributes to the rise of antibiotic-resistant pathogens. But farms that turn to organic practices, including a ban on antibiotics, can greatly reduce antibiotic-resistant bacteria within only the first year of the change. That’s according to a new study in the journal Environmental Health Perspectives. [Amy Sapkota et al., "Lower Prevalance of Antibiotic-resistant Enterococci on U.S. Conventional Poultry Farms that Transitioned to Organic Practices"]

The scientists studied 10 conventional poultry farms and 10 large-scale newly organic poultry farms. They tested for the presence of enterecocci, microorganisms commonly found in both conventional and organic poultry farms. And they compared the bacteria’s resistance to 17 antimicrobials. The researchers say they were surprised at how quick and precipitous was the fall in resistance.

Take Enterococcus faecalis: on the conventional farms, 67 percent were resistant to the antibiotic erythromycin, while only 18 percent were on the newly organic farms. And 42 percent of the same pathogen had a multidrug resistance on conventional farms, but that number dropped to 10 percent on the organic ones. The researchers expect drug-resistant bacteria levels to drop even further the longer a farm remains organic. Because if you’re going to count chickens, it’s a good idea to count bacteria too.

—Cynthia Graber