摘要

       越来越多的证据表明环境因素在影响抗生素抗性基因 (ARG) 的传播和抗性人类病原体的传播中起着关键作用。然而，我们对导致抗生素耐药性发展和传播的生态和进化环境因素缺乏了解。在这里，我们使用从海洋和河滩收集的 61 个土壤样本中的高通量定量 PCR 分析对各种 ARG 进行了分析，这些土壤样本是人类活动的热点和环境 ARG 可能向人类病原体传播的平台。我们确定了影响这些生态系统中 ARG 的多样性、丰度和组成的主要非生物和生物因素。共检测到 110 个 ARG，它们对八类主要抗生素产生耐药性。核心抗性组主要属于β-内酰胺类和多药抗性，占ARGs总丰度的66.9%。赋予多药耐药性的 oprJ 基因是在所有样品中检测到的最广泛的 ARG 亚型。总 ARG 和核心电阻组的相对丰度与盐度相关特性显着相关，包括电导率和钠和氯的浓度。随机森林分析和结构方程模型表明，在考虑了多个驱动因素后，盐度是调节海滩土壤 ARGs 分布模式的最重要因素。这些发现表明，海滩土壤是 ARG 的丰富库，盐度是塑造土壤抗性组分布模式的主要因素。

       Growing evidence points to the pivotal role of the environmental factors in influencing the transmission of antibiotic resistance genes (ARGs) and the propagation of resistant human pathogens. However, our understanding of the ecological and evolutionary environmental factors that contribute to development and dissemination of antibiotic resistance is lacking. Here, we profiled a wide variety of ARGs using the high-throughput quantitative PCR analysis in 61 soil samples collected from ocean and river beaches, which are hotspots for human activities and platforms for potential transmission of environmental ARGs to human pathogens. We identified the dominant abiotic and biotic factors influencing the diversity, abundance and composition of ARGs in these ecosystems. A total of 110 ARGs conferring resistance to eight major categories of antibiotics were detected. The core resistome was mainly affiliated into β-lactam and multidrug resistance, accounting for 66.9% of the total abundance of ARGs. The oprJ gene conferring resistance to multidrug was the most widespread ARG subtype detected in all the samples. The relative abundances of total ARGs and core resistome were significantly correlated with salinity-related properties including electrical conductivity and concentrations of sodium and chloride. Random forest analysis and structural equation modelling revealed that salinity was the most important factor modulating the distribution patterns of beach soil ARGs after accounting for multiple drivers. These findings suggest that beach soil is a rich reservoir of ARGs and that salinity is a predominant factor shaping the distribution patterns of soil resistome.

https://www.sciencedirect.com/science/article/abs/pii/S0048969719309660