Resistome and mobilome in surface runoff from manured soil as affected by setback distance

Authors: MWARE, NOELLE - University Of Nebraska; HALL, MARLA - University Of Nebraska; REJENDRAN, SELVAKUMAR - University Of Nebraska; Gilley, John; BARTELT-HUNT, SHANNON - University Of Nebraska; ZHANG, YLFAN - Wayne State University; LI, XU - University Of Nebraska

Submitted to: Journal of Hazardous Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2022
Publication Date: 1/14/2022
Citation: Mware, N.A., Hall, M.C., Rejendran, S., Gilley, J.E., Bartelt-Hunt, S.L., Zhang, Y., Li, X. 2022. Resistome and mobilome in surface runoff from manured soil as affected by setback distance. Journal of Hazardous Materials. 429. Article 128278. https://doi.org/10.1016/j.jhazmat.2022.128278.
DOI: https://doi.org/10.1016/j.jhazmat.2022.128278

Interpretive Summary: Land application of livestock manure introduces antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) into the environment. The objective of this study was to 1) examine the changes in ARGs and MGEs in runoff and soil as a function of setback distance, i.e., the distance between manured soil and an outlet to surface water, and 2) quantify the contributions of manure and background soil to the ARGs and MGEs in runoff and soil. It was determined in a field study that the abundance of ARGs and MGEs decreased in runoff with increases in setback distance. It was estimated that a setback distance of ~40 m is required to reduce the total abundance of ARGs and MGEs in runoff to that of the experimental control. In contrast to runoff, the abundance of ARGs and MGEs within the soil of the setback region was not affected by manure-borne constituents. It was found that background soil gradually became the predominant source of the ARGs and MGEs in runoff as setback distance increased. The quantitative information from this study demonstrates how manure borne ARGs and MGEs dissipated in agricultural runoff with increasing setback distance and had limited impacts on soil within the setback region.

Technical Abstract: Land application of livestock manure introduces antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) into the environment. The objective of this study was to 1) examine the changes of resistome and mobilome in runoff and soil as a function of setback distance, i.e., the distance between manured soil and an outlet to surface water, and 2) quantify the contributions of manure and background soil to the ARGs and MGEs in runoff and soil. The resistome and mobilome in runoff and soil from a field-scale plot study were characterized using a high throughput quantitative polymerase chain reaction (HT-qPCR) array consisting of 144 primer sets. The abundance of ARGs and MGEs decreased in runoff with increases in setback distance. It was estimated that a setback distance of ~40 m is required to reduce the total abundance of ARGs and MGEs in runoff to that of the experimental control. In contrast to runoff, the abundance of ARGs and MGEs within the soil of the setback region was not affected by manure-borne resistome and mobilome. SourceTracker analysis on HT-qPCR data revealed that background soil gradually became the predominant source of the ARGs and MGEs in runoff as setback distance increased. The quantitative information from this work demonstrates how manure borne ARGs and MGEs dissipated in agricultural runoff with increasing setback distance and had limited impacts on the resistome and mobilome of soil within the setback region.