摘要
      水产养殖病原体和抗生素抗性基因（ARGs）共同存在于水生环境中。积累的证据表明，水产养殖病原体可以促进质粒介导的ARGs的水平转移。然而，爱德华氏菌（E.piscicida）在ARG传播中的作用仍不完全清楚。此外，三氯生（TCS）对鱼形大肠杆菌介导的ARGs传播的潜在影响尚不清楚，因此建立了交配模型系统来研究ARGs的转移过程。结果表明，豌豆E.piscicida通过水平基因转移（HGT）在RP4上传播ARGs。此外，TCS暴露促进了这一过程。与对照相比，浓度为2至20μg/L的TCS使偶联转移频率提高了约1.2–1.4倍。TCS通过刺激活性氧（ROS）的产生、增加细胞膜通透性和改变偶联转移相关基因的表达来促进ARGs的HGT。总之，研究结果表明，水产养殖病原体传播ARGs，而新出现的污染物TCS增强了ARGs在细菌之间的转移。
Abstract
Aquaculture pathogen and antibiotic resistance genes (ARGs) co-occur in the aquatic environment. Accumulated evidence suggests that aquaculture pathogens can facilitate the horizontal transfer of plasmid-mediated ARGs. However, the role of Edwardsiella piscicida (E. piscicida) in ARG dissemination is still not fully understood. In addition, the potential impact of triclosan (TCS) on the spread of ARGs mediated by E. piscicida is still unknown, so a mating model system was established to investigate the transfer process of ARGs. The results showed that E. piscicida disseminated ARGs on RP4 by horizontal gene transfer (HGT). Furthermore, TCS exposure promoted this process. The conjugative transfer frequencies were enhanced approximately 1.2–1.4-fold by TCS at concentrations from 2 to 20 μg/L, when compared with the control. TCS promoted the HGT of ARGs by stimulating reactive oxygen species (ROS) production, increasing cell membrane permeability, and altering expressions of conjugative transfer–associated genes. Together, the results suggested that aquaculture pathogens spread ARGs and that the emerging contaminant TCS enhanced the transfer of ARGs between bacteria.

https://link.springer.com/article/10.1007/s11356-022-20082-8