Abstract
Abstract The generation and dissemination of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment has become a critical risk to human health. This study is based on a pilot-scale simulated water distribution system to understand the effects of chlorine disinfection treatment (without free chlorine) on ARB and ARGs in biofilms. The hydraulic parameters and pipe materials of the system were simulated based on a drinking water system. The results of the colony counts showed that bacterial multi-antibiotic resistance could be enhanced 13-fold in the biofilms of the pipeline. The use of high-throughput qPCR (HT-qPCR) indicated that the total relative abundance of ARGs in biofilm samples increased significantly (p < 0.05), while the diversity of bacteria was shown to be reduced via taxonomic analysis of the V3–V4 region of 16S rRNA. The prominent types of ARGs were conferred resistance by aminoglycoside and β-lactam after the chlorine disinfection treatment, and antibiotic deactivation was the main mechanism. Phyla Proteobacteria had the highest abundance in both treatment and control groups but decreased from 70.81% (initial biofilm sample) to 26.09% (the sixth-month biofilm sample) in the treatment groups. The results show that the chlorine disinfection plays a role in the risk of development of bacterial antibiotic resistance in pipe networks owing to bacteria in biofilms. This study was the first to investigate the contribution of chlorination without free chlorine to the bacterial community shift and resistome alteration in biofilms at a pilot-test level.
Highlights
IntroductionThe generation and dissemination of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) represent a global risk to public health (Pruden et al 2006)
The use of antibiotics has induced a number of environmental issues
This study investigated the effects of the chlorine disinfection process on bacterial antibiotic resistance in a water distribution system at a pilot-test level
Summary
The generation and dissemination of ARB and ARGs represent a global risk to public health (Pruden et al 2006). Antibiotic resistance is encoded by ARGs (Allen et al 2010), which are genes that can be readily shared among bacteria, and even spread from bacteria, human and animal sources to drinking water systems (Armstrong et al 1981; Faria et al 2009; Zhong et al 2010). A wide number of ARB and ARGs in drinking water systems have been detected during the last several decades (Pavlov et al 2004; Zhang et al 2009; Jia et al 2015). Studies have shown that the quantities of both ARB and ARGs were larger compared with the drinking water achieved after treatment (Xi et al 2009; Lv et al 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
