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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #381633
Research Project: The Use of Treated Municipal Waste Water as a Source of New Water for Irrigation

Location: Water Management and Conservation Research

Title: Occurrence and distribution of antibiotics and corresponding antibiotic resistance genes in different soil types irrigated with treated wastewater

Author
item SEYOUM, MITIKU - Ben Gurion University Of Negev
item OBAYOMI, OLABIYI - Ben Gurion University Of Negev
item BERNSTEIN, NIRIT - Volcani Center (ARO)
item Williams, Clinton
item GILLOR, OSNAT - Ben Gurion University Of Negev

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2021
Publication Date: 8/15/2021
Citation: Seyoum, M.M., Obayomi, O., Bernstein, N., Williams, C.F., Gillor, O. 2021. Occurrence and distribution of antibiotics and corresponding antibiotic resistance genes in different soil types irrigated with treated wastewater. Science of the Total Environment. 72. Article 146835. https://doi.org/10.1016/j.scitotenv.2021.146835.
DOI: https://doi.org/10.1016/j.scitotenv.2021.146835

Interpretive Summary: Up to 90% of antibiotics used for therapeutic treatment can be eliminated and caried through the sewar treatment system. In addition, a significant portion of the antibiotics that enter a wastewater treatment plant leave the plant unchanged. When wastewater is used for irrigation the presence of antibiotics have been hypothesized to lead to an increase in the development of antibiotic resistance. A study was conducted to quantify the development of antibiotic resistance due to antibiotic challenges. Results indicate that there is no direct link between the concentration of antibiotics and the development of antibiotic resistance.

Technical Abstract: Diminishing freshwater (FW) supplies necessitate the reuse of treated wastewater (TWW) for various purposes, like irrigation of agricultural lands. However, there is a growing concern that irrigation with TWW may transfer antibiotic resistance genes (ARGs) to the soil and crops. We hypothesized that TWW irrigation would increase the prevalence of antibiotic residues together with the corresponding ARGs in the irrigated soil. We further predicted that soil texture, especially pH, clay content, and organic matter, would increase the antibiotic residues concentrations and thus ARGs dissemination. To test our predictions, three soils types (loamy-sand, loam, and clay) were irrigated with two water types (FW and TWW), over two consecutive seasons. 54 water and soil samples were collected during the field experiments and monitored for their physico-chemical parameters, the abundance of seven antibiotic residues, and their corresponding ARGs together with class 1 integrase (intI1). The results revealed no direct link between the antibiotics or physico-chemical properties and ARGs or intl1 in neither water nor the irrigated soils. Moreover, the relative abundances of the ARGs were independent of the irrigation water quality, but dependent on the soil type, especially the clay content. Our results showed that despite the accumulation of antibiotics in TWW irrigated soils, the ARGs’ profiles did not significantly differ from FW irrigated soils. Yet, the accumulated antibiotics might have long-term effects on the agricultural soil resistome, warranting further investigation.