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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Egg Safety & Quality Research » Research » Publications at this Location » Publication #325891

Research Project: Genetic Analysis of Poultry-Associated Salmonella enterica to Identify and Characterize Properties and Markers Associated with Egg-Borne Transmission of Illness

Location: Egg Safety & Quality Research

Title: Background antibiotic resistance patterns in antibiotic-free pastured poultry production

Author
item Rothrock, Michael
item Hiett, Kelli
item Guard, Jean
item Jackson, Charlene

Submitted to: CSA News
Publication Type: Popular Publication
Publication Acceptance Date: 2/1/2016
Publication Date: 3/2/2016
Citation: Rothrock Jr, M.J., Hiett, K.L., Guard, J.Y., Jackson, C.R. 2016. Background antibiotic resistance patterns in antibiotic-free pastured poultry production. CSA News. 61(2):13.

Interpretive Summary: Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in these systems are needed to understand the impact of agricultural practices on AR. In the Antiobiotics in Agroecosystems: Stae of the Science special issue of the Journal of Environmental Quality, USDA-ARS researchers looked at the AR profiles of major foodborne pathogens (Salmonella, Campylobacter, Listeria, Escherichia coli) from antibiotic-free, pasture-raised broiler production. The AR profiles were compared across target microbes, farms, and along the farm-to-fork continuum for each flock to determine the background AR in antibiotic-free broiler production. All target pathogens exhibited some level of AR, with the highest prevalences in Listeria and Salmonella (both also exhibited the highest levels of multidrug resistance). Although closely related, Salmonella and E. coli demonstrated distinct AR profiles even when isolated from the same sample, and Salmonella isolates demonstrated clear farm-specific AR patterns. Agriculture’s role in AR-related issues cannot be effectively determined until background AR is appropriately understood. This study showed that in the absence of antibiotics, AR profiles of major foodborne pathogens can be highly variable between farms, flocks, and within the same sample between similar microbes. Therefore, future AR studies need to account for this background AR to truly assess not only agriculture’s role, but how to reduce agriculture’s true impact, in environmental AR issues.

Technical Abstract: Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in these systems are needed to understand the impact of agricultural practices on AR. In the Antiobiotics in Agroecosystems: Stae of the Science special issue of the Journal of Environmental Quality, USDA-ARS researchers looked at the AR profiles of major foodborne pathogens (Salmonella, Campylobacter, Listeria, Escherichia coli) from antibiotic-free, pasture-raised broiler production. The AR profiles were compared across target microbes, farms, and along the farm-to-fork continuum for each flock to determine the background AR in antibiotic-free broiler production. All target pathogens exhibited some level of AR, with the highest prevalences in Listeria and Salmonella (both also exhibited the highest levels of multidrug resistance). Although closely related, Salmonella and E. coli demonstrated distinct AR profiles even when isolated from the same sample, and Salmonella isolates demonstrated clear farm-specific AR patterns. Agriculture’s role in AR-related issues cannot be effectively determined until background AR is appropriately understood. This study showed that in the absence of antibiotics, AR profiles of major foodborne pathogens can be highly variable between farms, flocks, and within the same sample between similar microbes. Therefore, future AR studies need to account for this background AR to truly assess not only agriculture’s role, but how to reduce agriculture’s true impact, in environmental AR issues.