Exploring a cradle of multi-resistant bacteria -- antibiotic resistance in soil and its link to different land use types and intensities

对多种抗生素耐药的人类病原菌对公众健康构成威胁，被认为是21世纪世纪的主要全球挑战之一。这些细菌携带的一些抗生素抗性基因已被追溯到土壤来源，并可能通过例如，地下水或野生动物在这个项目中，土壤的抗生素耐药性池的动态将被分析沿着广泛的土地利用类型和强度在三个生物多样性探索。为了提供土地利用对抗生素耐药基因丰度水平影响的可靠评估，将对所有草原EP和森林VIP地块的土壤DNA进行实时定量PCR分析。土地利用引起的变化，在社区配置文件中的抗除草剂的土壤细菌被破译的微观实验，包括评估和定量的细菌群落动态。另一个重点是确定伴随不同土地利用类型和强度的质粒发生的变化，因为这些移动的遗传元件是抗生素耐药性的主要来源，并有助于其传播。在这种情况下，我们将确定IncP-1质粒的丰度，它可以携带多种抗生素耐药决定簇，并允许基因在远亲细菌之间转移。将通过应用长读段测序方法估计携带抗生素耐药基因的环状质粒的总体多样性。此外，基于功能的筛选先前构建的土壤宏基因组文库将进行，以发现抗生素抗性基因的丰富性和机制与土地利用强度的差异。为了预测人类活动对多重耐药菌传播的可能后果，迫切需要对不同土地利用类型和强度影响的土壤抗生素耐药性进行全面了解。该项目将提供有关土地利用对土壤抗生素耐药性库和转移潜力影响的详细信息。此外，生物多样性探索研究平台内的密切合作将阐明土壤中抗生素耐药性与非生物和生物因素（如重金属浓度或真菌类群丰度）之间的联系。

Human pathogenic bacteria resistant to multiple classes of antibiotics pose risks to public health and are considered as one of the major global challenges within the 21st century. Some of the antibiotic resistance genes carried by these bacteria have been traced to soil origins and can potentially spread via e.g., groundwater or wildlife. In this project, the dynamics of soil`s antibiotic resistance pool will be analyzed along a wide array of land use types and intensities within the three Biodiversity Exploratories. To provide robust assessment of land use impacts on antibiotic resistance gene abundance levels, real-time quantitative PCR-based analysis of soil DNA derived from all grassland EP and forest VIP plots will be carried out. Land use-induced changes in community profiles of antibiotic-resistant soil bacteria are deciphered within a microcosm experiment, including assessment and quantification of bacterial community dynamics. Another focus is the identification of shifts in plasmid occurrence accompanying different land use types and intensities, as these mobile genetic elements are a major source for antibiotic resistance and contribute to its dissemination. In this context, we will determine the abundance of IncP-1 plasmids, which can carry multiple antibiotic resistance determinants and allow gene transfer between distantly related bacteria. Overall diversity of antibiotic resistance gene-harboring circular plasmids will be estimated by applying a long-read sequencing approach. Moreover, function-based screening of previously constructed soil metagenomic libraries will be performed, to discover differences in richness of antibiotic resistance genes and mechanisms associated with land use intensity. To predict possible consequences of anthropogenic activities on spread of multi-resistant bacteria, comprehensive knowledge on antibiotic resistance in soil affected by different land use types and intensities is urgently required. This project will provide detailed information about land use impacts on soil`s antibiotic resistance reservoir and transfer potential. Furthermore, close collaborations within the Biodiversity Exploratories research platform will elucidate linkages between antibiotic resistance in soil and abiotic as well as biotic factors such as heavy metal concentrations or abundance of fungal taxa.