摘要

      抗药性病原体每年夺去数千人的生命，目前被认为是对公众健康最严重的威胁之一。除了临床环境外，土壤生态系统也是抗生素耐药性决定因素的主要来源，它们可能在不同的微生物生境中传播，并通过水平基因转移被人类病原体获得。因此，在这些生态系统中检索环境因子的综合信息，有助于抗生素抗性基因和可移动基因元素的积累，具有重要的全球意义。本文采用实时定量PCR技术，对温带草原和森林土壤中与医学相关的抗生素抗性基因、1类整合子和IncP-1质粒进行了定量分析。生成的数据集可以进行分析，与区域影响脱钩，并能够识别土地利用方式和土壤特性，从而提高抗生素抗性基因和流动基因元素的丰度。在草地土壤中，大环内酯类抗药性基因mefA和磺胺类抗药性基因sul2的丰度与有机施肥呈正相关，aac（6′）-lb的丰度随刈割次数的增加而增加，表现出对不同氨基糖苷类抗药性。就森林土壤而言，β-内酰胺抗性基因blaIMP-12与真菌多样性显著相关，这可能是由于不同的真菌种类可以产生β-内酰胺。此外，除了blaIMP-5和blaIMP-12外，森林土壤中分析的抗生素抗性基因以及IncP-1质粒和1类整合子的检测频率低于通常与人类活动接近的草地土壤。

      Antibiotic-resistant pathogens claim the lives of thousands of people each year and are currently considered as one of the most serious threats to public health. Apart from clinical environments, soil ecosystems also represent a major source of antibiotic resistance determinants, which can potentially disseminate across distinct microbial habitats and be acquired by human pathogens via horizontal gene transfer. Therefore, it is of global importance to retrieve comprehensive information on environmental factors, contributing to an accumulation of antibiotic resistance genes and mobile genetic elements in these ecosystems. Here, medically relevant antibiotic resistance genes, class 1 integrons and IncP-1 plasmids were quantified via real time quantitative PCR in soils derived from temperate grasslands and forests, varying in land use over a large spatial scale. The generated dataset allowed an analysis, decoupled from regional influences, and enabled the identification of land use practices and soil characteristics elevating the abundance of antibiotic resistance genes and mobile genetic elements. In grassland soils, the abundance of the macrolide resistance gene mefA as well as the sulfonamide resistance gene sul2 was positively correlated with organic fertilization and the abundance of aac(6′)-lb, conferring resistance to different aminoglycosides, increased with mowing frequency. With respect to forest soils, the beta-lactam resistance gene bla_IMP-12 was significantly correlated with fungal diversity which might be due to the fact that different fungal species can produce beta-lactams. Furthermore, except bla_IMP-5 and bla_IMP-12, the analyzed antibiotic resistance genes as well as IncP-1 plasmids and class-1 integrons were detected less frequently in forest soils than in soils derived from grassland that are commonly in closer proximity to human activities.

      https://www.mdpi.com/2073-4425/11/2/150