摘要

      淡水环境容易受到通过不同来源释放的残留抗生素的污染，例如农业径流、污水排放和附近农场的淋洗。因此，淡水环境可以成为抗生素影响微生物的水库，是一个重要的公共卫生问题。降解和稀释过程是预测淡水水库抗生素耐药性传播实际风险的基础。本文综述了淡水中抗药性细菌（ARBs）和基因（ARGs）的主要检测方法及其在这些环境中的流行情况。最后，本文还对ARB/ARG在这些环境中的稀释、降解、传播以及持久性和归宿进行了综述。以培养为基础的单菌株方法和分子技术，包括聚合酶链反应（PCR）、定量聚合酶链反应（qPCR）和宏基因组学，是淡水环境中ARB和ARGs定量的技术。与水坝、池塘和泉水相比，大多数河流系统中的ARBs含量都非常高（高达总检出细菌的98%），其次是湖泊（高达总检出细菌的77%）。最令人关注的是产超广谱β-内酰胺酶的肠杆菌科、耐甲氧西林金黄色葡萄球菌（MRSA）和耐万古霉素肠球菌（VRE）的发生，它们引起高度流行性感染。稀释和自然降解并不能完全消除淡水环境中的ARB和ARG。即使淡水中的ARB被阳光有效地灭活了，它们含有ARGs的DNA仍然可以保持完整，并且能够将抗性转移到非抗性菌株。抗生素耐药性持续存在，并保存在被高浓度抗生素污染的淡水体内。本地淡水ARB可以直接传播给人类，也可以在微生物群中短暂插入。这些发现令人不安，特别是对于那些依赖淡水资源来饮用、灌溉作物和以鱼的形式提供食物的人来说。

       Freshwater environments are susceptible to possible contamination by residual antibiotics that are released through different sources, such as agricultural runoffs, sewage discharges and leaching from nearby farms. Freshwater environment can thus become reservoirs where an antibiotic impact microorganisms, and is an important public health concern. Degradation and dilution processes are fundamental for predicting the actual risk of antibiotic resistance dissemination from freshwater reservoirs. This study reviews major approaches for detecting and quantifying antibiotic resistance bacteria (ARBs) and genes (ARGs) in freshwater and their prevalence in these environments. Finally, the role of dilution, degradation, transmission and the persistence and fate of ARB/ARG in these environments are also reviewed. Culture-based single strain approaches and molecular techniques that include polymerase chain reaction (PCR), quantitative polymerase chain reaction (qPCR) and metagenomics are techniques for quantifying ARB and ARGs in freshwater environments. The level of ARBs is extremely high in most of the river systems (up to 98% of the total detected bacteria), followed by lakes (up to 77% of the total detected bacteria), compared to dam, pond, and spring (<1%). Of most concern is the occurrence of extended-spectrum β-lactamase producing Enterobacteriaceae, methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus (VRE), which cause highly epidemic infections. Dilution and natural degradation do not completely eradicate ARBs and ARGs in the freshwater environment. Even if the ARBs in freshwater are effectively inactivated by sunlight, their ARG-containing DNA can still be intact and capable of transferring resistance to non-resistant strains. Antibiotic resistance persists and is preserved in freshwater bodies polluted with high concentrations of antibiotics. Direct transmission of indigenous freshwater ARBs to humans as well as their transitory insertion in the microbiota can occur. These findings are disturbing especially for people that rely on freshwater resources for drinking, crop irrigation, and food in form of fish.

       https://www.sciencedirect.com/science/article/pii/S0269749119314435?via%3Dihub