Rebecca Goldburg, pHD and Terri L. Stiffler, MS. Environmental Health, Environmental Defense, 257 Park Avenue South, New York, NY 10010, 212-616-1236, bgoldburg@environmentaldefense.org

Antimicrobials are used extensively in U.S. animal agriculture. By one estimate more than 70 percent of antimicrobials used in the U.S. are fed to livestock and poultry for growth promotion or routine prophylaxis. This use contributes to the emerging crisis of antimicrobial resistant pathogens. To date, analyses of the impact of agricultural antimicrobials on the incidence of resistant pathogens affecting people have focused on the "food pathway." Antimicrobials fed to animals cause bacteria living in the animals' GI tracts, including Salmonella and other pathogens, to become resistant to these drugs. The slaughter process can spread these resistant foodborne pathogens to meat products. These bacteria may then infect consumers who eat undercooked meat or other foods that become cross-contaminated.

We describe evidence that antimicrobial resistant bacteria arising from agriculture affect people through more pathways than food, including a) via agricultural workers and b) via the spread of resistant bacteria and genes in manure-polluted water. We present estimates of the quantities of antimicrobials and antimicrobial-resistant bacteria in waste generated by the eight billion swine, poultry, and beef cattle produced in the U.S. annually, suggesting that manure may be a significant conduit for antimicrobial resistance. Consideration of nonfood pathways has important policy consequences: while ongoing efforts to reduce the incidence of foodborne pathogens may help reduce health impacts of agriculturally generated resistant bacteria, these efforts alone are not sufficient to address agriculture's contribution to the resistance problem, particularly in light of the documented ability of bacteria to transfer resistance genes to unrelated species.

Learning Objectives:

• Understand uses of antimicrobials in animal agriculture.
• Recognize importance of nonfood pathways in consideration of use of antimicrobials in animal agriculture.
• Ability to articulate policy actions that should be considered for nonfood pathways and assess current food pathway focus.

Keywords: Antibiotic Resistance, Environment

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.