摘要

      目前，有关烟雾中抗生素耐药基因（ARGs）的分布及其与空气中细菌的相关性的信息有限。本研究以公开的宏基因组数据为基础，分析了严重烟雾颗粒物（PMs）中ARGs的多样性和丰度，揭示了205种空气中ARG亚型的存在，其中31种为优势亚型，编码对11种抗生素的耐药性。在可检测到的ARGs中，四环素、β-内酰胺和氨基糖苷类耐药基因的丰度最高，烟雾和土壤中ARGs的组成特征相似。烟雾事件期间，PM2.5样品中空气中arg的总丰度为4.90～38.07ppm，PM10样品中arg的总丰度为7.61～38.49ppm，分别是非烟雾日的1.6～7.7倍和2.1～5.1倍。空气中ARGs呈复杂的共生模式，受细菌群落、理化因子和气象因子共同作用的影响较大。以乳酸杆菌和抗磺胺基因sul1为重点，研究了微生物类群与空气中ARGs共现网络。研究结果有助于了解烟雾中ARGs的分布规律，为潜在的健康风险评价提供依据。

      Information is currently limited regarding the distribution of antibiotic resistance genes (ARGs) in smog and their correlations with airborne bacteria. This study characterized the diversity and abundance of ARGs in the particulate matters (PMs) of severe smog based on publicly available metagenomic data, and revealed the occurrence of 205 airborne ARG subtypes, including 31 dominant ones encoding resistance to 11 antibiotic types. Among the detectable ARGs, tetracycline, β-lactam and aminoglycoside resistance genes had the highest abundance, and smog and soil had similar composition characteristics of ARGs. During the smog event, the total abundance of airborne ARGs ranged from 4.90 to 38.07ppm in PM_2.5 samples, and from 7.61 to 38.49ppm in PM₁₀ samples, which were 1.6-7.7 times and 2.1-5.1 times of those in the non-smog day, respectively. The airborne ARGs showed complicated co-occurrence patterns, which were heavily influenced by the interaction of bacterial community, and physicochemical and meteorological factors. Lactobacillus and sulfonamide resistance gene sul1 were determined as keystones in the co-occurrence network of microbial taxa and airborne ARGs. The results may help to understand the distribution patterns of ARGs in smog for the potential health risk evaluation.

       https://www.sciencedirect.com/science/article/pii/S0048969717325731?via%3Dihub