摘要
      红树林接收水产养殖废水和城市污水，因此是抗生素抗性基因（ARGs）的潜在库。然而，红树林生态系统中ARGs缺乏全面的概况。我们使用宏基因组技术揭示了ARGs在中国东南部六个红树林生态系统中的发生、宿主范围和潜在的流动性。根据深度测序数据，共鉴定出348种ARG亚型。大量的ARGs与阿哌拉嗪、杆菌肽、β-内酰胺、氟喹诺酮、大环内酯林可酰胺链脲菌素和多粘菌素有关。提出了抗性基因tetR、aac（6′）-Iae、aac（3）-IXa、vanRA、vanRG和aac（3′）-Ig作为红树林生态系统中ARG的指标，可用于定量评估100种其他共发生ARG的丰度。值得注意的是，在348种已鉴定的ARG亚型中，有250种被注释为与ARG相关的移动遗传元件，这表明ARG在红树林生态系统中传播的潜在风险很高。通过调查ARGs在6281个基因组草案中的分布，超过42个细菌门被确定为ARGs的假定宿主。其中21.97%是潜在的耐多药宿主，包括人类和动物机会性病原体。这项研究增加了我们对红树林生态系统中抗生素耐药性分布和传播的了解，有助于改善全球ARG风险评估和管理。
Abstract
Mangrove receives aquaculture wastewater and urban sewage, and thus is a potential reservoir for antibiotic resistance genes (ARGs). However, there is a dearth of a comprehensive profile of ARGs in mangrove ecosystems. We used metagenomic techniques to uncover the occurrence, host range, and potential mobility of ARGs in six mangrove ecosystems in southeastern China. Based on deep sequencing data, a total of 348 ARG subtypes were identified. The abundant ARGs were associated with acriflavine, bacitracin, beta-lactam, fluoroquinolone, macrolide-lincosamide-streptogramin, and polymyxin. Resistance genes tetR, aac(6′)-Iae, aac(3)-IXa, vanRA, vanRG, and aac(3)-Ig were proposed as ARG indicators in mangrove ecosystems that can be used to evaluate the abundance of 100 other co-occurring ARGs quantitatively. Remarkably, 250 of 348 identified ARG subtypes were annotated as mobile genetic elements-associated ARGs, indicating a high potential risk of propagation of ARGs in mangrove ecosystems. By surveying the distribution of ARGs in 6281 draft genomes, more than 42 bacterial phyla were identified as the putative hosts of the ARGs. Among them, 21.97% were potentially multidrug-resistant hosts, including human and animal opportunistic pathogens. This research adds to our understanding of the distribution and spread of antibiotic resistomes in mangrove ecosystems, helping improve ARG risk assessment and management worldwide.

https://www.sciencedirect.com/science/article/abs/pii/S0301479723003687