鳗鲡养殖废弃物抗性基因赋存特征及其与抗生素和微生物群落的相关性

The occurrence of antibiotic resistance genes in eel culture waste and its correlation with antibiotics and the microbial community

为揭示鳗鲡养殖废弃物中抗生素抗性基因(antibiotic resistance genes,ARGs)的赋存特征以及探讨抗生素残留和微生物群落对ARGs的影响,采集鳗鲡养殖场排污口底泥和养殖废水样品,应用实时荧光定量PCR(quantitive real-time PCR,qPCR)对ARGs赋存特征进行分析,利用高效液相色谱-串联质谱(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)对样品中的抗生素残留进行定量检测,同时采用Illumina NovaSeq高通量测序技术分析底泥和废水中的微生物群落结构特征,进一步对ARGs与抗生素、ARGs与微生物群落结构的相关性进行研究.结果显示,鳗鲡养殖废弃物中的优势ARGs为sul2、tetA和tetG,其相对丰度> 1.0×10-2copies/16S rRNA,处于较高水平;在鳗鲡养殖废弃物中共检测到4种喹诺酮类抗生素和1种四环素类抗生素,未检测到磺胺类抗生素残留,且残留抗生素与ARGs之间的相关性不显著(P≥0.05);底泥与废水中的菌群结构存在一定的差异,Proteobacteria为鳗鲡养殖废弃物中丰度最高的门类,其中菌属Cetobacterium、Plesiomonas、Polynucleobacter与特定ARGs之间存在显著性正相关(P <0.05).因此,鳗鲡养殖废弃物中ARGs的污染情况较为严重,微生物群落的变化对环境抗生素抗性有显著影响;研究结果可为后续控制ARGs的传播提供基础理论数据.(图5表4参38)

To understand the occurrence and effects of antibiotics and the microbial community on antibiotic resistance genes(ARGs) in eel culture waste, this study assessed the pollution status of ARGs in sediment and wastewater from eel farms. ARG profiles were explored using qPCR, concentrations of the antibiotics were examined by HPLC-MS/MS, and microbial community structures of sediment and wastewater were analyzed using Illumina NovaSeq high-throughput sequencing technologies. Moreover, the relationships between ARGs and antibiotics, as well as the microbial community, were investigated. The results demonstrated that the relative abundance of sul2, tetA, and tetG(above 1.0 × 10-2 copies/16 S rRNA) were the predominant ARGs in all samples. A total of four chloramphenicols and one tetracycline were detected in the samples, sulfonamides were not detected, and the correlation between antibiotics and ARGs in the samples were not significant(P ≥ 0.05). Overall, differences in the diversity of microbial communities were found, with Proteobacteria being the most abundant phylum in all samples. The genera Cetobacterium, Plesiomonas, and Polynucleobacter were significantly(P < 0.05) and positively correlated with specific ARGs. In conclusion, a relatively high abundance of ARGs were found in eel culture waste samples, and the microbiome significantly influenced the antibiotic resistome. These results provide basic theoretical data for controlling the transmission of ARGs.