Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
Sci Total Environ. 2019 Jun 10;668:193-203. doi: 10.1016/j.scitotenv.2019.02.454. Epub 2019 Mar 1.
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.
越来越多的证据表明，环境因素在影响抗生素耐药基因（ARGs）的传播和耐药人类病原体的传播方面起着关键作用。然而，我们对有助于抗生素耐药性发展和传播的生态和进化环境因素的了解还很缺乏。在这里，我们使用高通量定量 PCR 分析方法对从海洋和河流海滩采集的 61 个土壤样本中的广泛的 ARGs 进行了分析，这些海滩是人类活动的热点，也是环境 ARGs 向人类病原体潜在传播的平台。我们确定了影响这些生态系统中 ARGs 的多样性、丰度和组成的主要非生物和生物因素。总共检测到 110 个赋予 8 大类抗生素耐药性的 ARGs。核心耐药组主要与β-内酰胺类和多药耐药性相关，占 ARGs 总丰度的 66.9%。在所有样本中，具有多药耐药性的 oprJ 基因是检测到的最广泛的 ARG 亚型。总 ARGs 和核心耐药组的相对丰度与电导率以及钠和氯浓度等与盐度相关的特性显著相关。随机森林分析和结构方程模型表明，在考虑多个驱动因素后，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 ARGs 的丰富储存库，盐度是塑造土壤耐药组分布模式的主要因素。
