垃圾填埋场中不同填埋年限固体废弃物的抗生素抗性基因污染特征

Pollution characteristics of the antibiotic resistance genes in solid waste of different ages in landfills

为探究垃圾填埋场中不同填埋年限固体废弃物中抗生素抗性基因(ARGs)的多样性及变化规律,采集了内蒙古巴彦淖尔市某垃圾填埋场中不同填埋年限(2、5、8年)的固体废弃物样本,基于宏基因组测序技术(mNGS),并通过生物信息学分析,考察固体废弃物中ARGs的污染特征。结果表明,3种固体废弃中共检测出21类ARGs,填埋2、5、8年的固体废弃物中ARGs的总相对丰度分别为3.783×10^(-1)、4.267×10^(-1)、6.741×10^(-1),其中大环内酯-林可胺-链霉杀阳菌素类、磺胺类、多药类、氯霉素类、氨基糖苷类、四环素类、万古霉素类和杆菌肽类是主要的ARGs种类,相对丰度占比合计均在90%以上。固体废弃物中共检测出259种ARGs亚型,相对丰度最高的ARGs亚型属于大环内酯-林可胺-链霉杀阳菌素类ARGs。随着填埋年限的增加,固体废弃物中ARGs的丰度以及多样性也会随之增加,因此其潜在环境风险也相应增加。

In order to investigated the diversity and transformation law of antibiotics resistance genes(ARGs)in solid waste of different ages in landfill,different solid waste samples(landfill ages were 2,5 and 8 years respectively)were collected from a waste landfill in Bayannur City,Inner Mongolia.Metagenomics next generation sequencing(mNGS)and bioinformatics analysis were used to examine the contamination characteristics of ARGs.The results showed that 21 types of ARGs were detected in the three types of solid waste,and the total relative abundance of ARGs in solid waste that had been landfilled for 2,5 and 8 years was 3.783×10^(-1),4.267×10^(-1) and 6.741×10^(-1),respectively.Macrolide-lincosamide-streptogramin,sulfonamide,multidrug,chloramphenicol,aminoglycoside,tetracycline,vancomycin and bacitracin were the main types of ARGs,their total relative abundance in solid waste samples with different landfill ages were all above 90%.There were 259 ARGs subtypes were detected in the solid waste samples,and the ARGs subtypes with the highest relative abundance belonged to the macrolide-lincosamide-streptogramin.The relative abundance and diversity of ARGs in solid waste would increase with the increase of the landfill ages,thus the potential environmental risk of solid waste was also increasing.