School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
Environ Int. 2020 Jan;134:105318. doi: 10.1016/j.envint.2019.105318. Epub 2019 Nov 11.
The biotoxicity and public health effects of airborne bacteria and antibiotic resistance genes (ARGs) in fine particulate matter (PM) are being increasingly recognized. The characteristics of bacterial community composition and ARGs in PM under different rainfall conditions were studied based on the on-site synchronous measurements in downtown Beijing. Marked differences were evident in the bacterial community characteristics of PM before, during, and after rain events (p < 0.05). The rain intensities affected the bacterial community abundance in PM and heavy rain had greater washing effects. The Proteobacteria (phylum level), α-Proteobacteria (class level), Pseudomonadales (order level), Pseudomonadaceae (family level), and Cyanobacteria (genus level) were the dominant bacterial taxa associated with PM in Beijing during rain events. However, the bacteria at each level that displayed the biggest percentage variance was not the dominant type under different rain intensities. The ermB, tetW, and mphE genes were the primary ARGs, with abundances of 18 to 30 copies/m, which was a relatively smaller value than other observations. Real-time monitoring of the meteorological condition of rain events and physicochemical properties of PM were used to identify the main factors during rainfall. The bacterial community was sensitive to the ionic and metal element components of PM during rainfall. The abundance of ARGs was closely correlated with some groups of the bacterial community, which were also close to the initial value before the rain. Statistical analysis demonstrated that temperature, relative humidity, and duration of rain were the primary meteorological factors for the biological characteristics. The ionic species, rather than metal elements, in PM were the sensitive factors for the bacteria community and ARGs, which varied at the phylum, class, order, family, and genus levels. The observations provide insights for the biological risk assessment in an urban rainfall water and the potential health impact on citizens.
空气中细菌和抗生素耐药基因（ARGs）的生物毒性和对公众健康的影响正日益受到关注。本研究基于北京市中心的现场同步测量，研究了不同降雨条件下细颗粒物（PM）中细菌群落组成和 ARGs 的特征。在降雨前后，PM 中细菌群落特征存在显著差异（p < 0.05）。降雨强度影响 PM 中细菌群落的丰度，大雨具有更大的冲刷作用。在降雨期间，北京 PM 中与细菌相关的主要细菌类群是变形菌门（门水平）、α-变形菌纲（纲水平）、假单胞菌目（目水平）、假单胞菌科（科水平）和蓝细菌属（属水平）。然而，在不同降雨强度下，显示出最大百分比变化的细菌并非是优势类型。 ermB、tetW 和 mphE 基因是主要的 ARGs，丰度为 18 到 30 拷贝/m，这是一个相对较小的值，与其他观察结果相比。实时监测降雨事件的气象条件和 PM 的物理化学性质，以识别降雨期间的主要因素。细菌群落对降雨期间 PM 的离子和金属元素成分敏感。ARGs 的丰度与细菌群落的一些群组密切相关，与降雨前的初始值也相近。统计分析表明，温度、相对湿度和降雨持续时间是影响生物特性的主要气象因素。PM 中的离子种类而不是金属元素，是细菌群落和 ARGs 的敏感因素，在门、纲、目、科和属水平上发生变化。这些观察结果为城市降雨水中的生物风险评估提供了依据，并可能对市民的健康产生潜在影响。
