长江武汉段水源地典型抗生素及抗性基因污染特征与生态风险评价

Pollution Characteristics and Risk Assessment of Antibiotics and Resistance Genes in Different Water Sources in the Wuhan Section of the Yangtze River

为了探究长江武汉段水源地抗生素和抗性基因(ARGs)的分布特征和相关性以及潜在生态风险,采用固相萃取-超高效液相色谱串联质谱法(SPE-UPLC-MS/MS)和实时荧光定量PCR技术分别分析了全武汉市饮用水水源地中13种抗生素和10种ARGs的赋存水平.结果表明,在16处水源地样品中共检出9种抗生素,浓度范围为ND(未检出)~177.36 ng·L^(-1),红霉素、磺胺嘧啶和磺胺对甲氧嘧啶的检出率均为100%,抗生素浓度分布呈现(以汉江汇入口划分长江干流上下游):支流举水<长江干流下游<长江干流上游<支流汉江<支流滠水.长江干流下游ARGs总绝对丰度明显高于长江干流上游和汉江,磺胺类ARGs显著高于其他三类ARGs耐药基因的平均丰度(P<0.05),ARGs中sul1与sul2、ermB、qnrS、tetW和intI1等5种ARGs存在显著正相关关系(P<0.01),相关系数分别为0.768、 0.648、 0.824、 0.678和0.790,磺胺类ARGs组内相关性弱于组间ARGs的相关性.磺胺甲噁唑、金霉素、罗红霉素和恩诺沙星等4种抗生素对水生敏感生物具有中风险,生态风险熵热图中各风险区占比情况依次为:9.0%(中风险)、 30.6%(低风险)和60.4%(无风险).16处水源地的联合毒性生态风险评估(RQ_(sum))均为中风险,所涉及河流的RQ_(sum)(平均值)依次为:0.222(支流汉江)<0.267(长江干流)<0.299(其他支流).

The distribution characteristics,correlations,and potential ecological risks of 13 antibiotics and 10 antibiotic resistance genes(ARGs)in 16 water sources in Wuhan were analyzed using solid-phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)and real-time quantitative PCR technology.The distribution characteristics and correlations and potential ecological risks of antibiotics and resistance genes in this region were analyzed.The results showed that a total of nine antibiotics were detected in the 16 water source samples,and the concentration range was ND-177.36 ng·L^(-1).The concentration distribution presented as follows:Tributary Jushui River<lower reaches of the main stream of the Yangtze River<upstream of the main stream of the Yangtze River<Tributary Hanjiang River<Tributary Sheshui River.The total absolute abundance of ARGs after the Yangtze River and Hanjiang River confluence was significantly higher than that before the confluence,and the average abundance of sulfa ARGs was significantly higher than that of the other three ARGs resistance genes(P<0.05).There was a significant positive correlation between sul1 and sul2,ermB,qnrS,tetW,and intI1 in ARGs(P<0.01),and the correlation coefficients were 0.768,0.648,0.824,0.678,and 0.790,respectively.The correlation within the sulfonamide ARGs group was weak.Correlation of ARGs between groups.Four antibiotics,sulfamethoxazole,aureomycin,roxithromycin,and enrofloxacin,had a medium risk to aquatic sensitive organisms,and the proportion of each risk area in the ecological risk map was 9.0%(medium risk),30.6%(low risk),and 60.4%(no risk).The combined ecological risk assessment(RQ_(sum))of the 16 water sources indicated medium risk,and the RQ_(sum)(mean)of the rivers involved was 0.222(Tributary Hanjiang River)<0.267(main stream of the Yangtze River)<0.299(other tributaries).