Battling Antibiotic Resistance

Problem

How is the food supply threatened by antimicrobial resistance?

• Resistance to antimicrobials is one of the top 10 global public health threats facing humanity, decreasing the effectiveness of medicines and making infections harder to treat.

Findings

Researchers examined dairy cows within an area contaminated by an environmental disaster involving 11 billion gallons of mining waste, which affected drinking water supplies.

• The scientists compared the relative abundance and prevalence of bacterial antimicrobial-resistance genes in the contaminated cattle with those on an unaffected farm, and they found that exposure to heavy metal contamination results in the selection of bacteria that have resistance genes to heavy metals, biocides, and several drugs.

Impact

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. If antibiotic resistance is transferred via milk or meat consumption, it could have substantial implications for human health

Research Credit

Team

• Natalia Carrillo Gaeta, Emily Van Syoc (Bean), Asha Marie Miles, Daniel Ubriaco Oliveira Gonçalves de Carvalho, Mario Augusto Reyes Alemán, Jeferson Silva Carvalho, Erika Ganda

Participating Department

• Animal Science

Competitive Funding

• São Paulo Research Foundation
• Brazilian Agency CAPES
• National Institutes of Health (Ruth L. Kirschstein National Research Service Award (NRSA) Institutional Research Training Grant)

Federal and State Appropriations

• USDA NIFA Hatch Project PEN04752, Accession #1023328
• Hatch Multistate Project PEN04731, Accession #1022444

Emerging Discoveries

Dairy cows exposed to heavy metals worsen antibiotic-resistant pathogen crisis

November 16, 2020

Dairy cows, exposed to drinking water contaminated with heavy metals for a few years, 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.

Published Research

A Cross-Sectional Study of Dairy Cattle Metagenomes Reveals Increased Antimicrobial Resistance in Animals Farmed in a Heavy Metal Contaminated Environment

• Gaeta, N. C., Bean, E., Miles, A. M., Carvalho, D. U. O. G. D., Alemán, M. A. R., Carvalho, J. S., Gregory, L., & Ganda, E. (2020). A Cross-Sectional Study of Dairy Cattle Metagenomes Reveals Increased Antimicrobial Resistance in Animals Farmed in a Heavy Metal Contaminated Environment. Frontiers in Microbiology, 11, [590325]. https://doi.org/10.3389/fmicb.2020.590325