摘要
      抗生素耐药性基因（ARGs）可以从环境微生物转移到人类病原体，从而导致细菌感染治疗失败。过度使用抗生素污染的水产养殖被认为是臭名昭著的ARGs库。然而，ARGs在水产养殖系统中抗生素暴露下的起源、历时变化和流动性仍然难以捉摸。我们的研究结果表明，恩诺沙星的应用还增加了除喹诺酮类耐药基因外的各种ARG的相对丰度，并诱导ARG在小龙虾肠道和沉积物细菌中传播。进一步的研究表明，转座酶介导的重组是抗生素胁迫下ARGs水平基因转移（HGT）的主要驱动因素。值得注意的是，恩诺沙星的应用还诱导了一些携带多个ARG的宏基因组组装基因组（MAG）的产生，这些基因组被鉴定为新物种。此外，肠杆菌科在水产养殖中构成了一个可移动的ARG池。因此，水产养殖为抗生素耐药性的产生和传播提供了潜在的广泛环境途径。我们对人工使用抗生素的水产养殖中ARG的时间变化和传播模式的研究结果对抗生素耐药性的管理至关重要，这对生态系统和健康具有重大影响。
Abstract
Antibiotic resistance genes (ARGs) can be transferred from environmental microbes to human pathogens, thus leading to bacterial infection treatment failures. The aquaculture polluted by over-used antibiotics is considered as a notorious reservoir of ARGs. However, the origin, diachronic changes, and mobility of ARGs under antibiotic exposure in aquaculture systems remain elusive. Our findings showed that enrofloxacin application also increased the relative abundance of various ARGs in addition to quinolone-resistance genes and induced ARG dissemination in crayfish gut and sediment bacteria. Further investigation indicated that the transposase-mediated recombination was the major driver of horizontal gene transfer (HGT) of ARGs under antibiotic stress. Notably, enrofloxacin application also induced the generation of some metagenome-assembled genomes (MAGs) carrying multiple ARGs, which were identified as novel species. Additionally, Enterobacteriaceae constituted a mobile ARG pool in aquaculture. Therefore, aquaculture provides potential wide environmental pathways for generation and spread of antibiotic resistance. Our findings of ARG temporal variations and dissemination pattern in aquaculture with artificial use of antibiotics are critical to the management of antibiotic resistance, which is of great ecosystem and health implications.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422020556