摘要

        Mcr-1和blaNDM-1抗生素耐药基因（ARGs）可产生对大肠杆菌素和碳青霉烯类抗生素的耐药性，这两种抗生素通常是三级护理医院最后使用的抗生素。这两种arg在饮用水供应系统中的传播及其对健康肠道细菌的影响研究甚少。本研究探讨mcr-1和blaNDM-1在饮用水系统中的传播及其对小鼠肠道细菌耐药性的影响。亚基因组分析表明，太浦河和晋泽水库水源水受到了ARGs的污染。Mcr-1和blaNDM-1可以通过配水系统传播。即使是先进的水处理（臭氧和生物活性炭）也不能有效地去除mcr-1和blaNDM-1。配水系统中低浓度氯胺消毒剂对限制精氨酸丰度无效。研究还发现，通过水平基因转移（HGT），流动基因在ARGs在整个供水系统中的传播中起着重要作用。统计分析表明，温度对整个供水系统中mcr-1和blaNDM-1的丰度没有影响。最后一个办法是ARG，mcr-1可以从饮用水传播到健康的小鼠肠道。与饮用水中蜡样芽孢杆菌不同，hirae肠球菌中mcr-1的存在强烈地支持了肠道内HGT的存在。这项研究对饮用水在将精氨酸传播到肠道中的作用提供了新的见解，并有力地表明，饮用水除了与肠道中最后使用精氨酸的流行有关的其他因素外，也可能发挥主要作用。

        Mcr-1 and bla_NDM-1 antibiotic resistance genes (ARGs) confer resistance to colistins and carbapenems, which are often antibiotics used as a last resort in tertiary care hospitals. Dissemination of these two ARGs in drinking water supply systems and their effect on healthy gut bacteria are poorly studied. In this study, the dissemination of mcr-1 and bla_NDM-1 in a drinking water supply system, and their effect on the antibiotic resistance of mouse gut bacteria are explored. Metagenome analysis revealed that source water (Taipu river and Jinze reservoir) was polluted with ARGs. Mcr-1 and bla_NDM-1 can be disseminated through the water distribution system. Even advanced water treatments (ozone and biological activated carbon (BAC)) could not effectively remove mcr-1 and bla_NDM-1. Low concentrations of chloramine disinfectants in the water distribution system were not effective at limiting ARG abundance. Mobile genetic elements were also found to play a major role in the dissemination of ARGs via horizontal gene transfer (HGT) throughout the water supply system. Statistical analysis revealed that there was no effect of temperature on the abundance of mcr-1 and bla_NDM-1 throughout the water supply system. A last resort ARG, mcr-1 can disseminate from drinking water to the healthy mouse gut. The presence of mcr-1 in a strain belonging to Enterococcus hirae, which is different from the strain belonging to the Bacillus cereus group isolated from drinking water, strongly supports the phenomena of HGT inside the gut. This research provides novel insights into the role of drinking water in disseminating ARGs to the gut and strongly suggests that drinking water may also play a major role apart from other factors known to be involved in the prevalence of last resort ARGs in the gut.

        https://linkinghub.elsevier.com/retrieve/pii/S0269-7491(19)35702-1