Xu Like, Ouyang Weiying, Qian Yanyun, Su Chao, Su Jianqiang, Chen Hong
Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Environ Pollut. 2016 Jun;213:119-126. doi: 10.1016/j.envpol.2016.02.013. Epub 2016 Feb 15.
Antibiotic resistance genes (ARGs) are present in surface water and often cannot be completely eliminated by drinking water treatment plants (DWTPs). Improper elimination of the ARG-harboring microorganisms contaminates the water supply and would lead to animal and human disease. Therefore, it is of utmost importance to determine the most effective ways by which DWTPs can eliminate ARGs. Here, we tested water samples from two DWTPs and distribution systems and detected the presence of 285 ARGs, 8 transposases, and intI-1 by utilizing high-throughput qPCR. The prevalence of ARGs differed in the two DWTPs, one of which employed conventional water treatments while the other had advanced treatment processes. The relative abundance of ARGs increased significantly after the treatment with biological activated carbon (BAC), raising the number of detected ARGs from 76 to 150. Furthermore, the final chlorination step enhanced the relative abundance of ARGs in the finished water generated from both DWTPs. The total enrichment of ARGs varied from 6.4-to 109.2-fold in tap water compared to finished water, among which beta-lactam resistance genes displayed the highest enrichment. Six transposase genes were detected in tap water samples, with the transposase gene TnpA-04 showing the greatest enrichment (up to 124.9-fold). We observed significant positive correlations between ARGs and mobile genetic elements (MGEs) during the distribution systems, indicating that transposases and intI-1 may contribute to antibiotic resistance in drinking water. To our knowledge, this is the first study to investigate the diversity and abundance of ARGs in drinking water treatment systems utilizing high-throughput qPCR techniques in China.
抗生素抗性基因（ARGs）存在于地表水中，通常无法被饮用水处理厂（DWTPs）完全去除。对携带ARGs的微生物消除不当会污染供水，并导致动物和人类疾病。因此，确定DWTPs消除ARGs的最有效方法至关重要。在此，我们检测了来自两个DWTPs及其配水系统的水样，并利用高通量定量PCR检测了285种ARGs、8种转座酶和intI-1的存在情况。两个DWTPs中ARGs的流行情况有所不同，其中一个采用传统水处理，另一个采用深度处理工艺。用生物活性炭（BAC）处理后，ARGs的相对丰度显著增加，检测到的ARGs数量从76种增加到150种。此外，最终的氯化步骤提高了两个DWTPs产生的成品水中ARGs的相对丰度。与成品水相比，自来水中ARGs的总富集倍数在6.4至109.2倍之间，其中β-内酰胺抗性基因的富集倍数最高。在自来水样本中检测到6种转座酶基因，转座酶基因TnpA-04的富集倍数最大（高达124.9倍）。我们观察到在配水系统中ARGs与移动遗传元件（MGEs）之间存在显著的正相关，这表明转座酶和intI-1可能在饮用水抗生素抗性中起作用。据我们所知，这是中国首次利用高通量定量PCR技术研究饮用水处理系统中ARGs的多样性和丰度的研究。
