Location: Agroecosystems Management ResearchTitle: Antibiotic resistance and community analysis of surface and subsurface drainage waters in the South Fork Iowa River watershed Author
|Moorman, Thomas - Tom|
Submitted to: Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/27/2017
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: The Midwest is a center for swine production leading to application of swine manure onto lands that have artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations which administer antimicrobials. While previous studies have examined the occurrence of ARGs around confined swine feeding operations, little information is known how their transport from tile-drained fields receiving swine manure application impacts surrounding environments. In order to further our knowledge in this area, water samples were collected from five locations in the agriculturally dominated South Fork Iowa River Watershed with approximately 840,000 swine present in the 78,000 ha basin. Samples were collected monthly from three stream sites and two main artificial subsurface drainage outlets. Samples were analyzed for macrolide resistance genes ermB, ermF and 16S abundance using qPCR. Additionally, 16S rRNA gene community analysis will be performed. Abundance of erm genes ranged below limits of quantification to >10+7 copies 100 mL-1. Eighty-nine percent of stream water samples contained one of these two ARGs. Results indicate significantly more ermB and ermF in main drainage outlets than stream samples when normalized by 16S abundance (p<0.0001). Both artificial drainage locations revealed temporal trends for ermB and ermF abundance when normalized to 16S abundance. The higher resistance gene concentrations identified in artificial drainage samples occurring mid-Spring and late-Fall are likely due to manure application. The presence of these ARGs in these streams suggests there is opportunity for horizontal transfer to pathogenic species.