通过宏基因组分箱方法揭示南极联合冰川土壤中ARG宿主

Deciphering hosts of antibiotic resistance genes by metagenomic binning approaches in Union Glacier,Antarctica

抗生素抗性基因(ARGs)引起的抗菌素耐药性(AMR)对人类健康构成日益严重的威胁。准确鉴定ARG宿主对于评估AMR从环境向人类病原菌传播的风险至关重要,但目前对原始环境中ARG宿主的研究鲜有报道。本研究基于从NCBI下载的南极土壤宏基因组测序数据,利用宏基因组学组装和分箱技术对联合冰川地区中ARG宿主的分布、抗性机制与迁移潜力进行探究。结果表明:在构建的80个MAGs中,有18个MAGs可携带86个ARGs(13种ARG类型),并以多抗耐药类、氨基香豆素、利福平、糖肽类和β-内酰胺类抗性基因为主,且不同的ARG类型呈现不同的宿主分布模式。在ARGs宿主中,共发现21个ACCs(ARG-carrying contigs)携带可移动遗传元件(MGEs),其中最常见MGEs的是移位酶,其次是转座酶、整合酶、接合转移蛋白和重组酶。这些MGEs可与ARGs形成特定的ARGMGE共存模式,以多种方式促进抗生素耐药性的产生和传播。此外,埃希氏杆菌(Escherichia)、伯克氏菌(Burkholderiaceae)及类诺卡氏菌(Nocardioides)可携带多种ARGs,是联合冰川土壤中重要的ARGs储存库。研究结果为环境中抗生素耐药性的风险评估和控制提供依据。

Antimicrobial resistance(AMR),caused by antibiotic resistance genes(ARGs),is a growing threat to human health.Deciphering of ARG hosts is crucial for assessing the risk of AMR transmission from environment to human pathogens.Currently,ARG hosts in remote and pristine areas are poorly understood.Here,based on metagenomic data from Antarctic Union Glacier areas,the distribution pattern,resistance mechanism,and migration potential of ARG hosts were investigated by using metagenomic assembly and binning methods.A total of 80 MAGs(metagenome-assembled genomes)were constructed in the Antarctic Union Glacial soils,of which 18 MAGs could carry 86 ARGs(13 ARG types).The most commonly detected ARG types were related to multidrug,aminocoumarin,rifampicin,glycopeptide,and bata-lactams.Different ARGs present different host-association resistance patterns.In the ARG hosts,21 ACCs(ARGcarrying contigs)were found to carry MGEs(mobile genetic elements).Among those MDEs,translocase is the most common one,followed by transposase,integrase,conjugated transfer protein and recombinase.The MGEs and ARGs formed certain ARG-MGE co-existence patterns to promote the spread of AMR.In addition,due to carrying multiple ARGs,Escherichia,Burkholderiaceae,and Nocardioides members were important ARG repositories in Union Glacier soils.Together,these results provided basis for the risk assessment and control of environmental antibiotic resistance.