Abstract：
Booster disinfection was often applied to control the microorganism\'s growth in long-distance water supply systems. The effect of booster disinfection on the changing patterns of antibiotic resistance and bacterial community was investigated by a simulated water distribution system (SWDS). The results showed that the antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) were initially removed after dosing disinfectants (chlorine and chloramine), but then increased with the increasing water age. However, the relative abundance of ARGs significantly increased after booster disinfection both in buck water and biofilm, then decreased along the pipeline. The pipe materials and disinfectant type also affected the antibiotic resistance. Chlorine was more efficient in controlling microbes and ARGs than chloramine. Compared with UPVC and PE pipes, SS pipes had the lowest total bacteria, ARB concentration, and ARB percentage, mainly due to higher disinfectant residuals and a smoother surface. The significant correlation (rs = 0.77, p < 0.001) of the 16S rRNA genes was observed between buck water and biofilm, while the correlations of targeted ARGs were found to be weak. Bray-Curtis similarity index indicated that booster disinfection significantly changed the biofilm bacterial community and the disinfectant type also had a marked impact on the bacterial community. At the genus level, the relative abundance of Pseudomonas, Sphingomonas, and Methylobacterium significantly increased after booster disinfection. Mycobacterium increased after chloramination while decreased after chlorination, indicating Mycobacterium might resist chloramine. Pseudomonas, Methylobacterium, and Phreatobacter were found to correlate well with the relative abundance of ARGs. These results highlighted antibiotic resistance shift and bacterial community alteration after booster disinfection, which may be helpful in controlling potential microbial risk in drinking water.
摘要：
在远程供水系统中，增压消毒通常用于控制微生物的生长。通过模拟配水系统（SWDS）研究了加强消毒对抗生素耐药性和细菌群落变化规律的影响。结果表明，在添加消毒剂（氯和氯胺）后，抗生素抗性细菌（ARB）和抗生素抗性基因（ARGs）最初被去除，但随着水龄的增加而增加。然而,在降压水和生物膜中加强消毒后，ARGs的相对丰度显着增加，然后沿着管道减少。管道材料和消毒剂类型也影响抗生素抗性。氯在控制微生物和ARGs方面比氯胺更有效。与UPVC和PE管相比，SS管道的细菌总数最低，ARB浓度,和ARB百分比，主要是由于较高的消毒剂残留物和更光滑的表面。在降压水和生物膜之间观察到16SrRNA基因的显着相关性（rs=0.77，p<0.001），而靶向ARGs的相关性较弱。Bray-Curtis相似指数表明，加强消毒显著改变了生物膜细菌群落，消毒剂类型对细菌群落也有显著影响。在属一级，假单胞菌的相对丰度，鞘氨醇单胞菌,加强消毒后，甲基杆菌明显增加。分枝杆菌在氯胺化后增加，而在氯化后减少，表明分枝杆菌可能抵抗氯胺。假单胞菌,甲基杆菌,和不动杆菌被发现与ARGs的相对丰度相关。这些结果强调了加强消毒后抗生素耐药性的转变和细菌群落的改变，这可能有助于控制饮用水中潜在的微生物风险。
