By Andi Anderson
Michigan State University researchers, with global partners, conducted a 14-year study mapping the spread of antibiotic resistance genes (ARGs) in livestock waste across 26 countries.
Their findings show that animal manure is a major source of ARGs, which can transfer to bacteria that infect humans, making common infections harder to treat.
The team analyzed more than 4,000 manure samples from pigs, chickens, and cattle. Using this data, they built a global map to identify where dangerous ARGs are most common and ranked those most likely to transfer into harmful human pathogens.
“Genes from manure can make their way into the water we drink, the food we eat and the bacteria that make us sick,” said MSU’s Dr. James Tiedje. He stressed the urgency of managing this threat, as antimicrobial resistance caused over 1.27 million deaths globally in 2019.
Co-author Dr. Xun Qian emphasized that manure can serve as an early warning system for resistance spread. In high-production countries like the U.S. and China, manure showed higher gene diversity and abundance, pointing to the need for improved monitoring.
The study also found that countries with strict policies, such as Denmark, have successfully reduced farm-related antibiotic resistance.
The U.S. took a step in 2017 with its Veterinary Feed Directive, and China followed with similar measures. These changes show promise, but experts warn that resistance continues to pose a serious global threat.
Tiedje concluded, “Antibiotic resistance isn’t just a medical issue, it’s an environmental one too. If we want antibiotics to keep working, we must reduce risky use on farms and strengthen global cooperation.”
Photo Credit: michigan-state-university-msu
Categories: Michigan, Livestock