摘要
      作为一种广泛使用的消毒技术，氯化对抗生素耐药性和细菌群落的影响受到了极大的科学关注，而与病原体相关的健康风险在很大程度上是未知的。考虑到这一点，本研究使用宏基因组分析和培养方法相结合，通过模拟氯化剂量和人类健康问题（饮用水和游泳池），揭示了氯化对抗生素抗性基因及其细菌宿主（总微生物和大肠杆菌）的影响。抗性分析表明，氯化过程可以显著降低总ARGs的丰度和多样性，而对机会致病菌大肠杆菌分离株的去除率有限，为6.0-8.7%。在所有观察到的515种ARG亚型中，105种核心亚型被鉴定出来，并且在氯化过程中对总微生物和大肠杆菌都是持久的。抗生素敏感性试验表明，氯化处理能有效去除耐多药大肠杆菌分离株，但对四环素耐药菌株有选择性。通过使用宏基因组装箱策略，检索到氯化后富集18.1-102%的五个携带ARG的基因组（分为拟杆菌门、厚壁菌门和放线菌门）。Bray-Curtis差异性、网络和原菌分析均表明，残留的抗生素耐药性和细菌群落主要由氯化驱动。此外，还提出了一种监测氯化相关抗微生物耐药性风险的系统管道。这些共同提高了我们对氯化处理相关公众关注的知识，作为监测和控制抗生素耐药性的重要参考和指导。
Abstract
As a widely used disinfection technology, the effects of chlorination on antibiotic resistome and bacterial community received great scientific concerns, while the pathogens associated health risks kept largely unknown. With this concern, the present study used metagenomic analysis combined with culture method to reveal chlorination effects on antibiotic resistance genes (ARGs) and their bacterial hosts (total microbes and Escherichia coli) through simulating the chlorination dosage with human health concerns (drinking water and swimming pool). The resistome profiling showed that chlorination process could significantly decrease both abundance and diversity of total ARGs, while with limited removal rates of 6.0–8.7% for opportunistic pathogens E. coli isolates. Of all the observed 515 ARG subtypes, 105 core subtypes were identified and persistent during chlorination for both total microbes and E. coli. Antibiotic susceptibility test showed that chlorination treatment could efficiently remove multi-resistant E. coli isolates but select for tetracycline resistant isolates. Five ARG-carrying genomes (assigned to Bacteroidetes, Firmicutes, Actinobacteria) enriched by 18.1–102% after chlorination were retrieved by using metagenomic binning strategies. Bray-Curtis dissimilarity, network and procrustes analyses all indicated the remained antibiotic resistome and bacterial community were mainly chlorination-driven. Furthermore, a systematic pipeline for monitoring chlorination-associated antimicrobial resistance risks was proposed. These together enhance our knowledge of chlorination treatment associated public concerns, as important reference and guidance for surveillance and control of antibiotic resistance.

https://www.sciencedirect.com/science/article/pii/S0160412021006036