More research may be needed in antibiotic resistance from farm to fork

In a study published in Critical Reviews in Food Science and Nutrition, a team of interdisciplinary scientists examined published literature for evidence of a relationship between antibiotic use in agricultural animals and drug-resistant foodborne Salmonella infections in humans. According to the 2013 U.S. Centers for Disease Control and Prevention (CDC) Antibiotic Resistance Threats Report, two of the 18 pathogens that are of concern in the United States may have a direct link to agriculture—one of them being Salmonella.

The researchers reviewed 104 articles in the United States, Canada, Denmark, Scotland, and Ireland over the past five years. Animals included in the reviewed studies were chicken, turkeys, pigs, beef cattle, and dairy cows.

The overall prevalence of Salmonella and drug-resistance found in the systematic review aligns with recent National Antimicrobial Resistance Monitoring System (NARMS) reports. The 2013 NARMS report showed that 81% of the Salmonella from human infections carried no resistance to any antibiotic, while Salmonella resistance rates in animals vary by the antibiotic tested.

The results of the review brought to light important concerns about Salmonella and demonstrated that more research in this area is needed. For example, six articles showed increased antibiotic resistance in organisms derived from animals, not retail meats, used in conventional farming, versus those from antibiotic-free operations. No studies were found that followed animal-associated antibiotic resistant isolates from farm to retail products.

“While there were some studies worth noting in our review, it is most apparent that there is a greater need for a more robust data collection system and heightened publication expectations in the United States for transparency in antibiotic usage in both animals and humans,” said Kristi Helke, lead scientist from the University of South Carolina. “There is still much more research to be done. The agriculture and healthcare industries must work hand-in-hand with the scientific community, government regulatory agencies, and human health community in order to ensure safe, humane, and affordable food sources to the public.”

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