摘要

       1 类整合酶 intI1 被认为是人为污染的良好代表，因为它与赋予抗生素抗性的基因有关。 1 类整合子的基因盒可以携带多种抗生素抗性基因（ARGs）并在微生物之间进行水平基因转移。本研究应用高通量测序技术结合 intI1 数据库和基因组组装来量化来自 8 个生态系统的 64 个环境样本中 intI1 的丰度，并研究第 1 类携带的携带 ARG 的基因盒 (ACGC) 的不同排列。整合子。检测到的 intI1 的丰度范围从 3.83 × 10–4 到 4.26 × 10° intI1/细胞。 intI1 和 ARG 丰度之间的高相关性（Pearson's r = 0.852）表明 intI1 可以被视为环境中 ARG 的重要指标。氨基糖苷类抗性基因最常在基因盒中观察到，由 57% 组装的 ACGC 携带，其次是甲氧苄氨嘧啶和 β-内酰胺抗性基因。本研究建立了广泛监测各种环境样本中的 intI1 和扫描整合子携带的 ARG 的管道。这些发现补充了我们对携带移动遗传元件的 1 类整合子和 ARGs 分布的认识，有利于未来对 ARGs 水平基因转移的研究。

       Class 1 integrase intI1 has been considered as a good proxy for anthropogenic pollution because of being linked to genes conferring resistance to antibiotics. The gene cassettes of class 1 integrons could carry diverse antibiotic resistance genes (ARGs) and conduct horizontal gene transfer among microorganisms. The present study applied high-throughput sequencing technique combined with an intI1 database and genome assembly to quantify the abundance of intI1 in 64 environmental samples from 8 ecosystems, and to investigate the diverse arrangements of ARG-carrying gene cassettes (ACGCs) carried by class 1 integrons. The abundance of detected intI1 ranged from 3.83 × 10–4 to 4.26 × 10° intI1/cell. High correlation (Pearson’s r = 0.852) between intI1 and ARG abundance indicated that intI1 could be considered as an important indicator of ARGs in environments. Aminoglycoside resistance genes were most frequently observed on gene cassettes, carried by 57% assembled ACGCs, followed by trimethoprim and beta-lactam resistance genes. This study established the pipeline for broad monitoring of intI1 in various environmental samples and scanning the ARGs carried by integrons. These findings supplemented our knowledge on the distribution of class 1 integrons and ARGs carried on mobile genetic elements, benefiting future studies on horizontal gene transfer of ARGs.

https://pubs.acs.org/doi/abs/10.1021/acs.est.6b05887