Submitted to: Current Opinion in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2014
Publication Date: 7/2/2014
Citation: Durso, L.M., Cook, K.L. 2014. Impacts of antibiotic use in agriculture: what are the benefits and risks? Current Opinion in Microbiology. 19:37-44. DOI: 10.1016/J.MIB.2014.05.019.
Interpretive Summary: There are both benefits and risks to the use of antibiotics in food animals. The main benefit that most people agree upon is the use of antibiotics to treat sick animals and prevent their suffering. The main risk that most people agree upon is the transfer of resistance from animals to humans via food, water, and the environment. While there is a solid theoretical underpinning to these concerns, the applied details of how antibiotic resistant bacteria and antibiotic resistance genes physically move from the farm to the hospital are unclear. Because we don’t know these details, it is difficult to decide which specific antibiotic drugs, resistant bacteria, or resistance genes (the DNA instructions that code for resistance) should be measured on farms and in the environment. Complicating matters is the fact that antibiotic resistance is naturally occurring, especially in the soil. Antibiotics originally came from soil bacteria, and the soil is a large reservoir of resistance, including resistance that has caused problems with treating sick people. If we want to be able to measure how well a specific intervention has reduced resistance on the farm, then we need to know how much and what type of resistance was there to start with – and subtract out that baseline information. In the context of reducing the impact of agricultural antibiotic resistance on human health, the focus needs to be on determining which types of resistance from farms and feedlots is relevant for human health and can be impacted by agricultural best management practices.
Technical Abstract: Antibiotic drugs provide clear benefits for food animal health and welfare, while simultaneously providing clear risks due to enrichment of resistant microorganisms. There is no consensus, however, on how to evaluate benefits and risks of antibiotic use in agriculture, or the impact on public health. Recent soil resistome work emphasizes the importance of environmental reservoirs of antibiotic resistance (AR), and provides a starting point for distinguishing AR that can be impacted by agricultural practices from AR naturally present in a system. Manure is the primary vehicle introducing antibiotic drugs, AR bacteria and AR genes from animals into the environment. Manure management, therefore, impacts the transfer of AR from agricultural to human clinical settings via soil, water, and food. Ongoing research on the ecology of naturally occurring and anthropogenically derived AR in agroecosystems is necessary to adequately quantify the benefits and risks associated with use of antibiotics in food animals.