Abstract：
In this study, the occurrence and distribution of 49 antibiotic resistance genes (ARGs) and two integrase genes (intl1, intl2) in three major rivers of Hainan Island, China, were investigated in July 2021, and to explore the spatial distribution of the target genes in the three rivers with the potential influencing factors such as regional characteristics and environmental factors. The results showed that a total of 46 ARGs and two integrase genes were detected in water and sediment, and the absolute abundance of ARGs ranged from 1.16 × 103 to 2.97 × 107 copies/L and 3.34 × 103-1.55 × 107 copies/g. ARGs of macrolides, aminoglycosides, and sulfonamides were this study\'s main types of ARGs. The aadA2, tetE, ermF, tetX, aac(6\')-Ib, tetW, and qnrS genes are predominant ARGs in the water and sediment of the three rivers. The relative abundance of ARGs shows higher abundance in the midstream and downstream and lower abundance in the upstream and estuarine. After conducting a correlation analysis, it was found that there was a significant positive correlation between the ARGs detected in the water of the three main rivers. However, in sediment, tetC was negatively correlated with tetQ, macB was negatively correlated with ermF and ereA (p < 0.05), while the remaining ARGs showed positive correlations. Specifically, there was no significant positive correlation between tetQ and tetC, macB and ereA, and ermF in the sediments. Among the nine environmental factors studied, pH was found to be the main factor associated with the occurrence of ARGs in the aquatic environment, but it was also significantly associated with only nine ARGs. Among the detected heavy metals, only Cd and Zn showed significant correlations with the two ARGs in the water bodies of the three main rivers. It indicated that the pollution of ARGs in the three major rivers was in the initial stage, the detection abundance was low, the influence of environmental factors was small, and the interaction between ARGs seemed to be the main driving force. This study provides a scientific basis for further understanding the occurrence of ARGs and their influencing factors in a tropical island environment, and lays a foundation for subsequent management.
摘要：
在这项研究中,海南岛三大河流49个抗生素抗性基因(ARGs)和两个整合酶基因(intl1、intl2)的发生与分布,中国,于2021年7月进行了调查，并探讨了目标基因在三条河流中的空间分布以及区域特征和环境因子等潜在影响因素。结果表明,在水体和沉积物中共检测到46个ARGs和2个整合酶基因,ARGs的绝对丰度范围为1.16×103至2.97×107拷贝/L和3.34×103-1.55×107拷贝/g。大环内酯类的ARGs，氨基糖苷类,磺胺类药物是本研究的主要ARGs类型。aadA2，tete，ermF,tetX,aac(6\')-Ib,tetW,qnrS基因是三条河流水体和沉积物中的主要ARGs。ARGs的相对丰度在中游和下游显示较高的丰度，在上游和河口显示较低的丰度。在进行相关分析后，发现在三个主要河流的水中检测到的ARGs之间存在显着正相关。然而,在沉积物中，tetC与tetQ呈负相关，macB与ermF和ereA呈负相关(p<0.05),其余ARGs呈正相关。具体来说,tetQ与tetC之间无显著正相关,macB和ereA,和沉积物中的ermF。在研究的九个环境因素中，发现pH是与水生环境中ARGs发生相关的主要因素，但它也仅与9种ARGs显著相关。在检测到的重金属中，在三条主要河流的水体中，只有Cd和Zn与两种ARGs表现出显著的相关性。结果表明，三大河流的ARGs污染处于起步阶段，检测丰度低，环境因素的影响很小，ARG之间的相互作用似乎是主要的驱动力。本研究为进一步了解热带海岛环境中ARGs的发生及其影响因素提供了科学依据。为后续管理奠定基础。
