College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, China.
Ecotoxicol Environ Saf. 2022 Sep 1;242:113919. doi: 10.1016/j.ecoenv.2022.113919. Epub 2022 Jul 25.
The vertical distribution of sulfonamides (SAs), tetracyclines (TCs), macrolides (MLs), and their related antibiotic resistance genes (ARGs) were comprehensively investigated and characterized in a representative municipal solid waste (MSW) landfill in China. The total concentrations of target antibiotics in the MSW landfill were SAs > TCs > MLs. The abundances of mexF (10.78 ± 0.65 logcopies/g) and sul genes (9.15 ± 0.54 logcopies/g) were relatively high, while the tet genes (7.19 ± 0.77 logcopies/g) were the lowest. Both the abundance of antibiotics and genes fluctuated with landfill depth, and the ARGs of the same antibiotics were consistent with depth change. Intl1 and sul genes (sul1, sul2) were tightly connected, and a close relationship also existed between tet genes (tetM, tetQ) and MLs resistance genes (ermB, mefA). High-throughput sequencing showed the dominant genera were Sporosarcina (38%) and Thiobacillus (17%) at sampling points A and C, while the microbial community varied with depth increase at point B were Brevundimonas (20%), Sporosarcina (20%), Pseudomonas (24%), Lysobacter (28%), and Thioalkalimicrobium (14%), respectively. Network analysis further visualized the relationship among antibiotics, genes, and microbial communities and the results indicated the non-random connection among them and the possible host of the target gene. Even at 12.0 m below the landfill surface, the pollution of antibiotics resistance was still serious, which posed difficulties for subsequent landfill remediation and pollution control.
本研究全面调查和分析了中国某典型城市生活垃圾填埋场中磺胺类（SAs）、四环素类（TCs）、大环内酯类（MLs）及其相关抗生素耐药基因（ARGs）的垂直分布特征。该填埋场中，目标抗生素的总浓度表现为 SAs＞TCs＞MLs。mexF（10.78±0.65logcopies/g）和 sul 基因（9.15±0.54logcopies/g）的丰度相对较高，而 tet 基因（7.19±0.77logcopies/g）的丰度最低。抗生素和基因的丰度均随填埋深度而波动，且相同抗生素的 ARGs 与深度变化一致。Intl1 和 sul 基因（sul1、sul2）紧密相关，tet 基因（tetM、tetQ）和 MLs 耐药基因（ermB、mefA）之间也存在密切关系。高通量测序结果显示，在采样点 A 和 C，优势菌属分别为 Sporosarcina（38%）和 Thiobacillus（17%），而在采样点 B，微生物群落随深度增加而变化，优势菌属分别为 Brevundimonas（20%）、Sporosarcina（20%）、Pseudomonas（24%）、Lysobacter（28%）和 Thioalkalimicrobium（14%）。网络分析进一步可视化了抗生素、基因和微生物群落之间的关系，结果表明它们之间存在非随机联系，以及目标基因的可能宿主。即使在距离填埋场表面 12.0 米的深度，抗生素耐药性的污染仍然很严重，这给后续的填埋场修复和污染控制带来了困难。
