Seasonal variation of macrolide resistance gene abundances in the South Fork Iowa River Watershed.

摘要: The Midwestern United States is dominated by agricultural production with high concentrations of swine, leading to application swine manure onto lands artificial subsurface drainage. Previous reports have indicated elevated levels antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations which administer antimicrobials. While previous studies examined the occurrence ARGs operations, little information known how their transport from tile-drained fields receiving impacts downstream environments. To further our knowledge this area, samples were collected five locations agriculturally South Fork Iowa River Watershed approximately 840,000 present 76,000ha basin. Samples monthly three stream sites two main drainage outlets. analyzed for macrolide ermB, ermF 16S rRNAgene abundance using qPCR. Abundance erm ranged below limits quantification >107 copies 100mL-1 water. Eighty-nine percent contained one these ARGs. Results indicate significantly more ermB outlets than when normalized rRNA (p<0.0001). Both revealed temporal trends abundance. higher gene identified occurring mid-Spring late-Fall are likely due application.