UNIVERSITY PARK, Pa. — Dairy cows, exposed for a few years to drinking water contaminated with heavy metals, carry more pathogens loaded with antimicrobial-resistance genes able to tolerate and survive various antibiotics.
That’s the finding of a team of researchers that conducted a study of two dairy herds in Brazil four years after a dam holding mining waste ruptured, and it spotlights a threat to human health, the researchers contend.
The study is the first to show that long-term persistence of heavy metals in the environment may trigger genetic changes and interfere with the microorganism communities that colonize dairy cows, according to researcher Erika Ganda, assistant professor of food animal microbiomes, Penn State.
“Our findings are important because if bacterial antimicrobial resistance is transferred via the food chain by milk or meat consumption, it would have substantial implications for human health,” she said. “What we saw is, when heavy metal contamination is in the environment, there is potential for an increase of so-called ‘superbugs.’”