摘要
      在资源有限的环境中，粪便指示细菌分析是唯一进行的微生物水质测试，而抗生素耐药性基因（ARGs）等新出现的污染物往往被忽视。为了解决这一知识差距，从尼泊尔加德满都谷地的浅井（n=24）、深井（n=16）、石喷口（n=14）、泉水（n=8）、油罐车加油站（TFS；n=12）、水罐车（n=12）和饮用水处理厂（DWTP；原水和处理水各n=6）采集了水样，在2015年12月至2016年8月期间，研究五种ARG（blaNDM-1、blaCTX−M、tetB、qnrS和sul1）和一类整合酶基因（intI1）的存在。在浅井和石喷口的水样中检测到所有ARG，而在深井和泉水中未检测到blaNDM-1和blaCTX−M。在比TFS更多的水罐车样本中检测到tetB和intI1，这表明水罐车没有定期消毒。在DWTP的处理水中仅检测到sul1和intI1。intI1在整个水处理过程中的持续性以及与我们研究中包括的大多数ARG的显著强相关性（ρ>0.5，p<0.05）表明，intI1适用于评估山谷饮用水中ARG的污染和命运。在管道分配之前，处理过的水中游离氯含量较低，这促使水质管理人员对自来水中的病原体和ARGs进行评估。建议对饮用水源中新出现的污染物（如抗生素）进行进一步研究，这些污染物未经常规评估，但可以为抗生素耐药性在环境中的传播提供选择性压力。
Abstract
In resource-limited settings, fecal indicator bacterial analysis is the only microbiological water quality test performed, and emerging contaminants, such as antibiotic resistance genes (ARGs), are often neglected. To address this knowledge gap, water samples were collected from shallow wells (n = 24), deep wells (n = 16), stone spouts (n = 14), springs (n = 8), tanker filling stations (TFS; n = 12), water tankers (n = 12), and drinking water treatment plants (DWTPs; n = 6 each of raw and treated water) of the Kathmandu Valley, Nepal, between December 2015 and August 2016 to investigate the presence of five ARGs (blaNDM-1, blaCTX−M, tetB, qnrS, and sul1) and class one integrase gene (intI1). All ARGs were detected in water samples from shallow wells and stone spouts, whereas blaNDM-1 and blaCTX−M were not detected in deep wells and springs. tetB and intI1 were detected at a greater number of water tanker samples than TFS, indicating that water tankers were not disinfected regularly. Only sul1 and intI1 were detected in treated water of DWTPs. Persistence of intI1 throughout the water treatment process and significantly strong correlation (ρ > 0.5, p < 0.05) with the majority of ARGs included in our study suggested the suitability of intI1 to assess the contamination and fate of ARGs in drinking water of the valley. Low free chlorine levels in treated water before pipeline distribution urge water quality managers to evaluate tap water for pathogens and ARGs. Further studies are recommended on emerging contaminants, such as antibiotics, in drinking water sources that are not routinely assessed but can provide selective pressure for the spread of antibiotic resistance in the environment.

https://www.sciencedirect.com/science/article/pii/S2667010022000865