摘要

    抗生素抗性基因（ARG）是新兴污染物，对全球人类健康构成潜在风险。在这项研究中，进行了宏基因组分析，以研究ARGs在稻田生态系统，小龙虾单养池塘生态系统和水稻小龙虾养殖场生态系统中的分布。结果表明，在小龙虾单一养殖和水稻-小龙虾养殖生态系统中，MacB和BcrA是两个主要的ARG，大环内酯类不仅在水中，而且在小龙虾的沉积物和肠道中都是主要的抗生素。同时，小龙虾养殖生态系统水和沉积物中一些较低丰度的ARGs与稻田的丰度差异显着，小龙虾养殖系统和稻田的ARGs的多样性差异更大。利用冗余分析（RDA）进行的综合分析和优势ARG的分布表明，差异与总氮（TN），总磷（TP），叶绿素a（Chla），高锰酸盐指数（CODMn）和高浓度有关。稻田水中的硝酸盐含量与稻田沉积物中氮，磷，钾和有机质（OM）的含量较高有关。小龙虾养殖池和水稻小龙虾养殖场中ARGs的源跟踪器显示，小龙虾养殖池中的沉积物主要起着ARGs的“汇”的作用，小龙虾的水和肠相互促成高发生率。 ARGs。在小龙虾养殖场和小龙虾单一养殖池中，小龙虾肠和沉积物的ARG贡献率分别降低和增加，这可能与小龙虾养殖场中小龙虾的生物量较低和水深较低有关。

    Antibiotic resistance genes (ARGs) are emerging contaminants that pose a potential risk to human health worldwide. In this study, a metagenomic analysis was performed to investigate the distribution of ARGs in paddy field ecosystems, crayfish monoculture pond ecosystems, and rice-crayfish cultivation field ecosystems. The results showed that MacB and BcrA are two dominant ARGs, and macrolide is the dominant antibiotic not only in the water, but also in the sediment and gut of crayfish, in both the crayfish monoculture and the rice-crayfish cultivation ecosystems. Meanwhile, some lower-abundance ARGs in the water and sediment of crayfish cultivation ecosystems were significantly different in their abundance than those in rice paddy fields, and the ARGs in crayfish culture system and rice paddy fields showed even higher dissimilarities of diversity. Comprehensive analysis with redundancy analysis（RDA）and the distribution of dominant ARGs showed that the dissimilarity was related to the higher concentrations of total nitrogen (TN), total phosphorus (TP), chlorophyll a (Chla), permanganate index (CODMn), and nitrate in the water of rice paddy fields, and was related to the higher contents of N, P, K, and organic matter (OM) in the sediment of rice paddy fields. The source trackers of ARGs within the crayfish cultivation ponds and the rice-crayfish cultivation fields showed that the sediment in crayfish cultivation ponds mainly played the role of the ‘sink’ for ARGs, and the water and gut of crayfish mutually contributed to the high rates of ARGs. The ARG contribution rates of crayfish gut and sediment decreased and increased, respectively, in rice-crayfish cultivation fields and in crayfish monoculture ponds, which might be related to the lower crayfish biomass and the lower water depth in rice-crayfish cultivation fields.

    https://www.sciencedirect.com/science/article/abs/pii/S0269749121007260