Poultry farms that use organic methods that don’t involve antibiotics have significantly lower levels of drug-resistant bacteria that can potentially spread to human, according to a new study lead by the University of Maryland’s School of Public Health.

Antibiotic-resistant bacteria have become a problem for health care providers whose choices become limited in treating infection in humans, but there hasn’t been enough data on the sources. So, researchers say the findings, published Wednesday online in Environmental Health Perspectives, are important.