地下水中磺胺类抗性基因的迁移性能及基因组学分析  

Migration characteristics and genomic analysis of sulfonamide-resistant genes in groundwater

作　　者：张卓然 李佳澄 刘翔[1] 张宁[3] ZHANG Zhuoran;LI Jiacheng;LIU Xiang;ZHANG Ning(School of Environment,Tsinghua University,Beijing 100084;School of Environment,Beijing Normal University,Beijing 100875;Transport Planning and Research Institute,Ministry of Transport,Beijing 100028)

机构地区：[1]清华大学,环境学院,北京100084 [2]北京师范大学,环境学院,北京100875 [3]交通运输部规划研究院,北京100028

出　　处：《环境科学学报》2024年第12期60-67,共8页Acta Scientiae Circumstantiae

基　　金：北京市科技计划(No.Z181100005318002)。

摘　　要：地下水中磺胺类抗性基因sul1是抗性基因的主要组成成分,这类抗性基因由抗性菌携带,以胞内形式为主,它的迁移主要取决于抗性菌的性质.目前,对sul1在多孔介质中迁移行为的研究主要采用抗性质粒或模式菌株,未考虑实际背景地下水中土著菌迁移性能和水平基因转移(HGT)的影响.本文从地下水中筛选获得具有磺胺抗性细菌,选择其中一株稳定携带sul1的优势菌(Stutzerimonas stuzeri),测试了其生长曲线、sul1和int I1数量变化,并进行了迁移性能及全基因组学测序.结果表明,该抗性菌在实际地下水背景溶液中具有生物胶体性质不稳定、迁移性强、自聚能力低和生物膜形成困难的特点.经全基因组分析表明,sul1和int I1基因稳定存在于一个194 kbp长的接合质粒上,由细菌携带的磺胺类胞内抗性基因存在HGT可能,且容易随细菌在地下水中迁移.本研究为深入理解地下水中抗性基因的迁移机制和防控策略提供了重要依据.The sulfonamide resistance gene sul1,mainly in intracellular form,is a major component of antibiotic resistance genes(ARGs)in groundwater.The migration of sul1 depends primarily on the properties of the resistant bacteria.Currently,studies on the migration process of sul1 in porous media have mainly used resistant plasmids or model strains without considering the effects of indigenous bacterial migration properties and horizontal gene transfer(HGT)in groundwater.In this work,sulfonamide-resistant bacteria were screened from groundwater and a dominant strain(Stutzerimonas stuzeri)stably carrying sul1 was selected.A series of tests were performed,including the analysis of growth curves,changes in sul1and int I1 gene quantities,migration capabilities,and whole genome sequencing(WGS).These results demonstrate that the resistant bacteria exhibited unstable biological coagulation properties,a strong migratory tendency,and a diminished ability for self-aggregation.Furthermore,the bacteria exhibit a notable difficulty in forming biofilms in actual groundwater solutions.WGS identified the presence of sul1 and int I1 on a 194 kbp long plasmid,indicating the possibility of HGT among bacteria and the migration of sul1 in groundwater.These findings provide a crucial foundation on deepening our understanding of the migration mechanism of resistance genes and developing effective strategies for preventing and controlling their spread in groundwater.

关 键 词：地下水 磺胺类抗性基因 水平基因转移 全基因组测序 

分 类 号：X523[环境科学与工程—环境工程]