Chen Haiyang, Li Yuezhao, Sun Wenchao, Song Liuting, Zuo Rui, Teng Yanguo
Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, College of Water Sciences, Beijing Normal University, No 19, Xinjiekouwai Street, Beijing 100875, China.
Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, College of Water Sciences, Beijing Normal University, No 19, Xinjiekouwai Street, Beijing 100875, China.
Environ Int. 2020 Apr;137:105538. doi: 10.1016/j.envint.2020.105538. Epub 2020 Feb 3.
Antimicrobial resistance has been a global public health concern. The river-lake systems are one of the tightly connected terrestrial ecosystems and, appear to be reservoirs of antibiotic resistant genes (ARGs) and dispersal routes of resistant pathogens because they are easily impacted by human activities. Currently, systematic knowledge on the prevalence, transfer risk and source of ARGs in river-lake systems is largely lacking. In this study, we focused on the high-throughput profiling and source-sink relationship disentangling of ARGs in the sediments of an interconnected river-lake system (Fuhe River and its receiving Lake Baiyang in northern China). To this end, 40 surface sediments were collected for metagenomic shotgun sequencing. The profile and co-occurrence of ARGs in the sediments of the river-lake system were comprehensively characterized, as well as the mobile genetic elements (MGEs) carrying ARGs and their potential resistome dissemination risk. CrAssphage, a recently-discovered bacteriophage, was used to track human fecal pollution on the prevalence of ARGs. Meanwhile, a novel fast expectation-maximization microbial source tracking (FEAST) method was combined with linear discriminant analysis effect size method (LEfSe) for quantitatively apportioning the contribution of river sediment to the presence of ARGs in the receiving lake. Results showed abundant and diverse ARGs (24 types consisting of 510 subtypes) were detected in the sediments of the river-lake system, including some emerging ARGs such as mcr-1, tetX and carbapenemases types. Network analysis suggested non-random co-occurrence patterns of ARGs within the same type and among different types. Importantly, a number of MGE-carrying contigs were identified with jointly containing one or more ARGs, resulting in higher resistome risk potential in Lake Baiyang than many worldwide lakes. Source tracking indicated the prevalence of ARGs in the sediments of the river-lake system might be largely explained by the extent of human fecal contamination, and apportionment estimates the load transport from Fuhe River contributed more than 80% of ARGs to the receiving Lake Baiyang.
抗菌药物耐药性一直是全球公共卫生关注的问题。河湖系统是紧密相连的陆地生态系统之一，由于易受人类活动影响，似乎是抗生素抗性基因（ARGs）的储存库和抗性病原体的传播途径。目前，关于河湖系统中ARGs的流行情况、转移风险和来源的系统知识在很大程度上仍然缺乏。在本研究中，我们聚焦于一个相互连通的河湖系统（中国北方的府河及其接纳的白洋淀）沉积物中ARGs的高通量分析及源汇关系解析。为此，采集了40份表层沉积物进行宏基因组鸟枪法测序。全面表征了河湖系统沉积物中ARGs的分布特征和共现情况，以及携带ARGs的可移动遗传元件（MGEs）及其潜在的抗性组传播风险。利用最近发现的噬菌体CrAssphage来追踪人类粪便污染对ARGs流行情况的影响。同时，将一种新型的快速期望最大化微生物源追踪（FEAST）方法与线性判别分析效应大小方法（LEfSe）相结合，以定量评估河流沉积物对接纳湖泊中ARGs存在的贡献。结果表明，在河湖系统的沉积物中检测到了丰富多样的ARGs（24种类型，包含510个亚型），包括一些新兴的ARGs，如mcr - 1、tetX和碳青霉烯酶类型。网络分析表明，同类型和不同类型的ARGs之间存在非随机的共现模式。重要的是，鉴定出了一些携带MGEs的重叠群，它们共同包含一个或多个ARGs，导致白洋淀的抗性组风险潜力高于世界上许多湖泊。源追踪表明，河湖系统沉积物中ARGs的流行情况可能在很大程度上由人类粪便污染程度来解释，并且分摊估计府河的负荷传输对白洋淀接纳的ARGs贡献超过80%。
