Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou, 510275, China.
School of Environmental and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China.
Ecotoxicol Environ Saf. 2019 Jul 30;176:300-308. doi: 10.1016/j.ecoenv.2019.03.099. Epub 2019 Apr 1.
Antibiotic resistance genes (ARGs) are considered environmental pollutants. Comprehensive characterization of the ARGs in pristine environments is essential towards understanding the evolution of antibiotic resistance. Here, we analyzed ARGs in soil samples collected from relatively pristine Antarctica using metagenomic approaches. We identified 79 subtypes related to 12 antibiotic classes in Antarctic soils, in which ARGs related to multidrug and polypeptide were dominant. The characteristics of ARGs in Antarctic soils were significantly different from those in active sludge, chicken feces and swine feces, in terms of composition, abundance and potential transferability. ARG subtypes (e.g., bacA, ceoB, dfrE, mdtB, amrB, and acrB) were more abundant than others in Antarctic soils. Approximately 60% of the ARGs conferred antibiotic resistance via an efflux mechanism, and a low fraction of ARGs (∼16%) might be present on plasmids. Culturable bacterial consortiums isolated from Antarctic soils were consistently susceptible to most of the tested antibiotics frequently used in clinical therapies. The amrB and ceoB carried by culturable species did not express the resistance to aminoglycoside and fluoroquinolone at the levels of clinical concern. Our results suggest that the wide use of antibiotics may have contributed to developing higher antibiotic resistance and mobility.
抗生素耐药基因 (ARGs) 被认为是环境污染物。全面描述原始环境中的 ARGs 对于理解抗生素耐药性的进化至关重要。在这里，我们使用宏基因组学方法分析了来自相对原始的南极洲的土壤样本中的 ARGs。我们在南极土壤中鉴定出了与 12 种抗生素类相关的 79 种亚型，其中与多药和多肽相关的 ARGs 占主导地位。南极土壤中 ARGs 的特征在组成、丰度和潜在可转移性方面与活性污泥、鸡粪和猪粪中的 ARGs 明显不同。ARG 亚型（如 bacA、ceoB、dfrE、mdtB、amrB 和 acrB）在南极土壤中比其他亚型更为丰富。大约 60%的 ARGs 通过外排机制赋予抗生素耐药性，而一小部分 ARGs（约 16%）可能存在于质粒上。从南极土壤中分离出的可培养细菌联合体对大多数临床治疗中常用的测试抗生素均表现出敏感性。可培养物种携带的 amrB 和 ceoB 对氨基糖苷类和氟喹诺酮类药物的耐药性并未达到临床关注的水平。我们的研究结果表明，抗生素的广泛使用可能导致了更高的抗生素耐药性和可移动性的发展。
