Spatial behavior and source tracking of extracellular antibiotic resistance genes in a chlorinated drinking water distribution system

• Published in: Journal of hazardous materials Vol. 425; p. 127942
• Main Authors: Liang, Yong-bing, Li, Hai-bei, Chen, Zheng-shan, Yang, Yi-di, Shi, Dan-yang, Chen, Tian-jiao, Yang, Dong, Yin, Jing, Zhou, Shu-qing, Cheng, Chun-yan, Shao, Yi-fan, Li, Jun-wen, Jin, Min
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.03.2022
• Subjects: Anti-Bacterial Agents - pharmacology; Drinking Water; Drinking water distribution system; Drug Resistance, Microbial - genetics; EDNA-releasing community; Extracellular antibiotic resistance genes; Genes, Bacterial; Source tracking; Spatial Behavior; Waste Water; Water Purification; EDNA-releasing community; Spatial behavior; Drinking water distribution system; Source tracking; Extracellular antibiotic resistance genes
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127942

Antibiotic resistance genes (ARGs) are receiving increasing concerns due to the antibiotic resistance crisis. Nevertheless, little is known about the spatial behavior and sources of extracellular ARGs (eARGs) in the chlorinated drinking water distribution systems (DWDSs). Here, tap water was continuously collected to reveal the occurrence of both eARGs and intracellular ARGs (iARGs) along a chlorinated DWDS. Afterward, the correlation between eARGs, eDNA-releasing communities, and communities of planktonic bacteria was further analyzed. The eARG concentration decreased significantly, whereas the proportion of vanA and blaNDM-1 increased. Further, the diversity of the eDNA-releasing community increased markedly with increasing distance from the drinking water treatment plant (DWTP). Moreover, the dominant eDNA-releasing bacteria shifted from Acinetobacter, Pseudomonas, and Methylobacterium-Methylorubrum in finished water from the DWTP to Bacteroides, Faecalibacterium, Staphylococcus, and Parabacteroides in the DWDS. In terms of eARG source, thirty genera were significantly correlated with seven types of eARGs that resulted from the lysis of dead planktonic bacteria and detached biofilms. Conversely, the iARGs concentration increased, whereas the biodiversity of the planktonic bacteria community decreased in the sampling points along the DWDSs. Our findings provide critical insights into the spatial behavior and sources of eARGs, highlighting the health risks associated with ARGs in DWDSs. [Display omitted] •eARG concentration decreased, and vanA and blaNDM-1 proportion increased along the DWDS•The diversity of the eDNA-releasing community increased along the DWDS•iARG concentrations increased along the DWDS, whereas planktonic bacteria decreased•eARGs originated from the planktonic community of the DWTP and biofilm in the pipe