摘要

抗生素/重金属的共存和蚯蚓粪中抗性基因的过度表达已成为一个新兴的环境问题。关于化学污染物与生物大分子化合物之间的相互作用和相互关系知之甚少。本研究从中国长江三角洲地区选取三种典型的蚯蚓粪样品，研究抗生素，重金属及相应的抗生素抗性基因（ARGs）和重金属抗性基因（HRGs）。结果表明四环素（TC），铜（Cu），锌（Zn），镉（Cd），相应的TC抗性基因（tetA，tetC，tetW，tetM，tetO和tetS）和HRGs（copA，三种蚯蚓粪样品中的pcoA，cusA，czcA，czcB和czcR）。此外，ARG水平与蚯蚓粪中的水溶性TC分数呈正相关，HRG丰度与可交换重金属含量相同（p <0.05）。此外，在蚯蚓粪样品中ARG和HRG丰度之间存在正相关，表明涉及两种基因表达的密切调节机制。这里得到的结果可以为蚯蚓粪中重金属，TC和相关抗性基因混合污染的控制风险提供新的见解。

Coexistence of antibiotics/heavy metals and the overexpression of resistance genes in the vermicompost has become an emerging environmental issue. Little is known about the interaction and correlation between chemical pollutants and biological macromolecular compounds. In this study, three typical vermicompost samples were selected from the Yangtze River Delta region in China to investigate the antibiotic, heavy metal and corresponding antibiotic resistance genes (ARGs) and heavy metal resistance genes (HRGs). The results indicated the prevalence of tetracycline (TC), copper (Cu), zinc (Zn), cadmium (Cd), corresponding TC-resistance genes (tetA, tetC, tetW, tetM, tetO, and tetS) and HRGs (copA, pcoA, cusA, czcA, czcB, and czcR) in the three vermicompost samples. In addition, the ARG level was positively associated with the water-soluble TC fraction in the vermicompost, and it was same between the HRG abundance and exchangeable heavy metal content (p < 0.05). Moreover, a positive correlation was found between ARG and HRG abundance in the vermicompost samples, suggesting a close regulation mechanism involving the expression of both genes. The result obtained here could provide new insight into the controlling risk of heavy metals, TC, and relevant resistance genes mixed contamination in the vermicompost.

https://www.ncbi.nlm.nih.gov/pubmed/30321709