1. To what extent do water reuse treatments reduce antibiotic resistance indicators? A comparison of two full-scale systems.
- Author
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Keenum I, Calarco J, Majeed H, Hager-Soto EE, Bott C, Garner E, Harwood VJ, and Pruden A
- Subjects
- Humans, Escherichia coli, Angiotensin Receptor Antagonists pharmacology, Angiotensin-Converting Enzyme Inhibitors pharmacology, Drug Resistance, Microbial genetics, Anti-Bacterial Agents pharmacology, Genes, Bacterial, Wastewater, Water Purification
- Abstract
Water reuse is an essential strategy for reducing water demand from conventional sources, alleviating water stress, and promoting sustainability, but understanding the effectiveness of associated treatment processes as barriers to the spread of antibiotic resistance is an important consideration to protecting human health. We comprehensively evaluated the reduction of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in two field-operational water reuse systems with distinct treatment trains, one producing water for indirect potable reuse (ozone/biologically-active carbon/granular activated carbon) and the other for non-potable reuse (denitrification-filtration/chlorination) using metagenomic sequencing and culture. Relative abundances of total ARGs/clinically-relevant ARGs and cultured ARB were reduced by several logs during primary and secondary stages of wastewater treatment, but to a lesser extent during the tertiary water reuse treatments. In particular, ozonation tended to enrich multi-drug ARGs. The effect of chlorination was facility-dependent, increasing the relative abundance of ARGs when following biologically-active carbon filters, but generally providing a benefit in reduced bacterial numbers and ecological and human health resistome risk scores. Relative abundances of total ARGs and resistome risk scores were lowest in aquifer samples, although resistant Escherichia coli and Klebsiella pneumoniae were occasionally detected in the monitoring well 3-days downgradient from injection, but not 6-months downgradient. Resistant E. coli and Pseudomonas aeruginosa were occasionally detected in the nonpotable reuse distribution system, along with increased levels of multidrug, sulfonamide, phenicol, and aminoglycoside ARGs. This study illuminates specific vulnerabilities of water reuse systems to persistence, selection, and growth of ARGs and ARB and emphasizes the role of multiple treatment barriers, including aquifers and distribution systems., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Amy Pruden reports financial support was provided by National Science Foundation. Amy Pruden reports financial support was provided by Centers for Disease Control and Prevention. Amy Pruden reports financial support was provided by US Bureau of Reclamation. Amy Pruden reports financial support was provided by Hampton Roads Sanitation District. Charles Bott is an an employee of Hampton Roads Sanitation District. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
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