摘要

      饮用水中抗生素耐药基因（ARGs）的增殖及其向病原微生物的水平转移可能导致抗生素失效。然而，饮用水中的抗微生物监测目前还不是常规的。ARGs的细菌宿主，特别是饮用水中的小型微生物，可能无法通过膜过滤消毒有效去除，从而对人体健康构成威胁。本研究采用基于宏基因组学的方法，对中国大陆、香港、新加坡12个城市20户家庭饮用水样品中的微量微生物（0.2-0.45μm）的耐药性进行了研究。共检测到265个ARG亚型，隶属于17个ARG亚型，其丰度在4.0 × 10-2到1.0 × 100个拷贝/细胞之间。多药耐药基因、杆菌肽耐药基因和氨基糖苷类耐药基因占优势，43个ARGs亚型由小型微生物特异携带。宏基因组组装策略显示三种条件致病菌，即产碱假单胞菌、铜绿假单胞菌和gordonae分枝杆菌，分别携带mexW、aph（3’）-i和aac（2’）-i。根据ARG、病原菌和携带ARG的病原菌的存在，将饮用水样分为三组。这些对饮用水中小型微生物的抗生素抗性的新见解表明，需要对饮用水供应进行更全面的ARGs监测和监测。这些发现，加上本研究提出的观点和策略，可以支持改善饮用水安全的倡议。

       The proliferation of antibiotic resistance genes (ARGs) in drinking water and their potential horizontal transfer to pathogenic microbes may cause failure of antibiotics. However, antimicrobial resistome monitoring in drinking water is not currently routine. The bacterial hosts of ARGs, especially small-sized microbes in drinking water, may not be effectively removed by membrane filtration disinfection and thus pose threats to human health. In the present study, using metagenomic based approach, we investigated antibiotic resistome of small-sized microbes (0.2-0.45 μm) in 20 household drinking water samples from 12 cities in Mainland China, Hong Kong and Singapore. A total of 265 ARG subtypes belonging to 17 ARG types were detected at abundances ranging from 4.0 × 10^-2 to 1.0 × 10⁰ copies/cell. Multidrug, bacitracin and aminoglycoside resistance genes are dominant, and 43 ARG subtypes were specifically carried by small-size microbes. Metagenomic assembly strategy revealed fragments of three opportunistic pathogen, i.e. Pseudomonas alcaligenes, Pseudomonas aeruginosa and Mycobacterium gordonae, carried mexW, aph(3')-I and aac(2')-I, respectively. Drinking water samples were classified into three groups based on the presence of ARG, pathogen and ARG-carrying pathogen. These new insights into the antibiotic resistome of small microbes in drinking water over a broad scale indicate the need for more comprehensive ARGs monitoring and surveillance of drinking water supplies. These findings, together with the perspectives and strategies proposed in this study, could support initiatives to improve drinking water safety.

       https://www.sciencedirect.com/science/article/abs/pii/S0043135419300302?via%3Dihub