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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #403253
Research Project: Soil, Crop, and Manure Biochemistry and Molecular Ecology: Bridging Knowledge Gaps in Microbiome Response to Management

Location: Sustainable Agricultural Systems Laboratory

Title: Antibiotic resistance partitioning during on-farm manure separation and high temperature rotary drum composting

Author
item POINDEXTER, CARLTON - Non ARS Employee
item YARBERRY, ANDREA - Non ARS Employee
item GEORGAKAKOS, CHRISTINE - University Of Connecticut
item Rice, Clifford
item LANSING, STEPHANIE - University Of Maryland

Submitted to: American Journal of Environmental Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2024
Publication Date: 9/30/2024
Citation: Poindexter, C., Yarberry, A., Georgakakos, C., Rice, C., Lansing, S. 2024. Antibiotic resistance partitioning during on-farm manure separation and high temperature rotary drum composting. American Journal of Environmental Sciences. 152:701-713. https://doi.org/10.1016/j.jes.2024.06.043.
DOI: https://doi.org/10.1016/j.jes.2024.06.043

Interpretive Summary: Buildup of antibiotics and antibiotic resistance genes in cow manure is a major area of concern since this can lead to antibiotic effectiveness declines for human and animal pathogens and the antibiotics themselves may occur at harmful levels. Directly tracking the antibiotics and the resistance genes in a manure bedding recovery unit processing system was done by analytical chemical analyses, using resistance marker genes, and bacterial plate monitoring. We found that the manure bedding recovery unit processing system performed poorly as almost all antibiotics and antibiotic resistance genes were not affected. This bedding recovery method was poorly designed for antibiotic and antibiotic resistance gene removal; however, knowledge of its shortcomings may help scientists and engineers improve designs in the future.

Technical Abstract: Manure application as fertilizer can increase environmental exposure risk, as antibiotics, antibiotic resistance bacteria (ARB), and antibiotic resistant genes (ARGs) can be transmitted to agricultural fields, and adjacent natural systems. Understanding how specific antibiotics and ARGs respond within different manure fractions during on-farm management is limited. The study objective was to conduct a mass flow analysis determining the fate of antibiotic resistance factors (antibiotics, ARGs, and ARB) through solid-liquid separation, with the solid fraction continuing through a bedding recovery unit (BRU) via high temperature rotary composting for use of the manure solids as dairy cow bedding. The results show that most of the manure mass containing the antibiotic resistance factors went untreated following solid-liquid separation, with 95% of the mass leaving the separator as a liquid and pumped to a storage lagoon for field application and 5% proceeding to BRU processing. The tetracyclines and tulathromycin sorbed to the manure solids, while the beta lactams, ampicillin, and benzylpenicilloic acid were only found in the liquid fraction. The removal of antibiotic residuals during the BRU composting was insignificant, yet 40%-73% of the antibiotics were in the liquid fraction. The BRU composting was 100% effective in removing the ARB examined. Five of the eight ARGs (intl1, sul1, tetQ, tetX, and tetM) had significant reduction (>95%) following the BRU composting treatment. While the three other ARGs (tetW, ermB, and bla2) remained constant despite treatment. This study highlighted the importance of examining manure management from a mass balance perspective and understanding antibiotic resistance risk factors.