Antibiotic resistance genes (ARGs) are frequently detected in drinking water. Transformation of extracellular antibiotic resistance genes (eARGs) is an important pathway for horizontal gene transfer, which facilitates the spread of ARGs among different species. Although most studies have pointed out that the presence of some common carbon-containing disinfection by-products, such as trihalomethanes, can increase the frequency of transformation by increasing the content of reactive oxygen species (ROS), nitrogen-containing disinfection by-products (N-DBPs), such as bromoacetamide (BAcAm), can also induce bacterial resistance to antibiotics by stimulating ROS. However, it is unclear whether such N-DBPs can similarly promote the transformation of ARGs in bacteria. In this study, the effect of BAcAm on the transformation of eDNA carrying ARGs was investigated, and found that DNA integration and repair (ruv, rec), efflux pumps (emr), and genes related to membrane proteins (bam, opm) were up-regulated in E. coli after addition of BAcAm. Furthermore, in addition to analyzing common functional genes, in terms of metabolic gene expression, which is usually overlooked, the genes related to amino acid biosynthesis (pot, arg, lys) were up-regulated while genes related to sulfur metabolism, which has a higher metabolic cost (thi, sssu) were down-regulated, which suggests that E. coli is able to effectively defend itself against the threat posed by BAcAm to its survival. In conclusion, the factors affecting the conversion of eDNA carrying ARGs into E. coli cells by BAcAm were suggested and elaborated that E. coli carrying ARGs can adapt to various unfavorable environments by regulating relevant metabolic mechanisms and survive in drinking water environment for a long period of time.

中文翻译：

---

利用转录组分析揭示饮用水环境浓度下的溴乙酰胺对携带 ARG 的 eDNA 转化的影响


饮用水中经常检测到抗生素抗性基因 (ARG)。细胞外抗生素抗性基因（eARG）的转化是水平基因转移的重要途径，有助于ARG在不同物种之间的传播。尽管大多数研究指出，一些常见的含碳消毒副产物，如三卤甲烷的存在，可以通过增加活性氧（ROS）的含量来增加转化频率，但含氮消毒副产物（ N-DBPs），例如溴乙酰胺（BAcAm），也可以通过刺激活性氧诱导细菌对抗生素产生耐药性。然而，目前尚不清楚此类 N-DBP 是否能够同样促进细菌中 ARG 的转化。本研究研究了BAcAm对携带ARGs的eDNA转化的影响，发现DNA整合和修复（ruv、rec）、外排泵（emr）以及膜蛋白相关基因（bam、opm）上调-添加 BAcAm 后在大肠杆菌中受到调节。此外，除了分析常见的功能基因外，在通常被忽视的代谢基因表达方面，与氨基酸生物合成相关的基因（pot、arg、lys）上调，而与硫代谢相关的基因表达上调，硫代谢相关的基因表达量较高。较高的代谢成本（thi、sssu）被下调，这表明大肠杆菌能够有效地防御 BAcAm 对其生存构成的威胁。总之，提出并阐述了影响BAcAm将携带ARGs的eDNA转化为大肠杆菌细胞的因素，携带ARGs的大肠杆菌可以通过调节相关的代谢机制来适应各种不利的环境，并在饮用水环境中长期生存。的时间。