摘要

传播抗生素耐药性的环境途径最近受到越来越多的关注。水生环境可作为抗微生物抗性细菌，抗微生物残留物和抗菌素抗性基因（ARG）的储库或来源。因此，必须确定污染水在传播抗菌素耐药性中的作用。这项研究的目的是评估湄公河三角洲淡水系统中的抗菌残留物，ARGs和微生物群。我们从越南芹aqu的水产养殖和河流中选择了12个淡水点，并分别用LC / MS / MS和实时PCR分析了45个抗菌残留物和8个ARGs。进行基于16S rDNA的宏基因组分析以表征水微生物群。磺胺甲恶唑（10/12）和磺胺二甲嘧啶（7/12）的残留物与磺胺抗性基因sul1（11/12）和sul2（9/12）一起被广泛检测到。此外，在8个淡水系统（8/12）中检测到磺胺甲恶唑残留物和β-内酰胺酶抗性基因blaCTX-M-1，表明这些淡水系统可能已被人类活动污染。宏基因组分析表明，所有测试的淡水系统都含有变形门菌，放线菌和拟杆菌，占总微生物群的64％。此外，位于后院水产养殖废水汇合点的Cai Rang河养殖场（Ri-E）含有多核菌，Variovorax和Limnohabitans，占总微生物的78.4％以上。细菌多样性分析表明，与其他地区相比，Ri-E表现出最低的多样性。主坐标分析显示，后院养殖水体微生物的差异可以用农民的水产养殖技术来解释。

The environmental pathways for the dissemination of antibiotic resistance have recently received increased attention. Aquatic environments act as reservoirs or sources of antimicrobial-resistant bacteria, antimicrobial residues, and antimicrobial resistance genes (ARGs). Therefore, it is imperative to identify the role of polluted water in the dissemination of antimicrobial resistance. The aim of this study was to evaluate the antimicrobial residues, ARGs, and microbiota in the freshwater systems of the Mekong Delta. We selected 12 freshwater sites from aquacultures and rivers in Can Tho, Vietnam and analyzed them for 45 antimicrobial residues and 8 ARGs by LC/MS/MS and real-time PCR, respectively. A 16S rDNA-based metagenomic analysis was conducted to characterize the water microbiota. Residues of sulfamethoxazole (10/12) and sulfadimidine (7/12) were widely detected, together with the sulfa-resistance genes sul1 (11/12) and sul2 (9/12). Additionally, sulfamethoxazole residues and the β-lactamase-resistance gene blaCTX-M-1 were detected in eight freshwater systems (8/12), suggesting that these freshwater systems may have been polluted by human activity. The metagenomic analysis showed that all the tested freshwater systems contained the phyla Proteobacteria, Actinobacteria, and Bacteroidetes, representing 64% of the total microbiota. Moreover, the Cai Rang River site (Ri-E), which is located at the merge point of wastewaters from backyard-based aquacultures, contained the genera Polynucleobacter, Variovorax, and Limnohabitans, representing more than 78.4% of the total microbiota. Bacterial diversity analysis showed that the Ri-E exhibited the lowest diversity compared with other regions. Principal coordinate analysis showed that the differences among water microbiotas in backyard-based aquacultures could be explained by the farmers' aquaculture techniques.

https://www.sciencedirect.com/science/article/pii/S0269749116307345