摘要

   Mcr-1 和 blaNDM-1 抗生素抗性基因 (ARG) 赋予对粘菌素和碳青霉烯类抗生素的抗性，这通常是三级医疗医院最后使用的抗生素。对这两种 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的研究很少。在这项研究中，探讨了 mcr-1 和 blaNDM-1 在饮用水供应系统中的传播，以及它们对小鼠肠道细菌抗生素耐药性的影响。宏基因组分析显示源水（太浦河和金泽水库）被 ARGs 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 (BAC)）也无法有效去除 mcr-1 和 blaNDM-1。配水系统中低浓度的氯胺消毒剂不能有效限制 ARG 丰度。还发现移动遗传元件在通过整个供水系统的水平基因转移 (HGT) 传播 ARGs 中发挥重要作用。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。作为最后的手段 ARG，mcr-1 可以从饮用水传播到健康的小鼠肠道。在属于平肠球菌的菌株中存在 mcr-1，该菌株不同于从饮用水中分离出的蜡样芽孢杆菌菌株，强烈支持肠道内 HGT 的现象。这项研究提供了关于饮用水在将 ARGs 传播到肠道中的作用的新见解，并强烈表明，除了已知的其他与最终手段 ARGs 在肠道中的流行有关的因素之外，饮用水也可能发挥重要作

  Mcr-1 and blaNDM-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 blaNDM-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 blaNDM-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 blaNDM-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 blaNDM-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://www.sciencedirect.com/science/article/abs/pii/S0269749119357021