摘要

    在各种大气环境中已经检测到抗生素抗性基因（ARG）。机载ARG的传播对公共健康构成威胁。但是，由于可收集的机载颗粒物的可用性有限以及样品的生物含量低，因此很难量化机载ARG。在这项研究中，提出了一种用于收集和检测机载ARG的优化方案。实验结果表明，随着时间的推移，恢复效率往往会先上升然后下降，建议捕获范围为550-780拷贝/ mm2，以确保恢复效率大于75％。由于细胞壁被机械破坏并且核酸被释放，缓冲液洗涤保护了ARGs的溶解。比较了缓冲液洗涤中缓冲液体积与膜面积的三个比率。用1.4 µL / mm2缓冲液洗涤可检测到最高浓度的机载ARG。此外，大多数细胞被超声预处理（5分钟）破坏，从而可以有效地检测空中样本的ARGs。同时，扩展超声处理可以破坏细胞结构，基因序列被分解成碎片。因此，本研究可为不同环境下机载ARGs的高效过滤器收集提供理论依据。提出了一种优化的采样方法，即缓冲液洗涤量为1.4 µL / mm2，超声处理时间为5分钟。在两个实验室中根据改进的协议对室内机载ARG进行了检查。结果表明，室内实验室大气中的机载ARGs可能对居民构成相当大的健康风险，我们应该注意一些复杂的室内空气环境。

    Antibiotic resistance genes (ARGs) have been detected in various atmospheric environments. Airborne ARGs transmission presents the public health threat. However, it is very difficult to quantify airborne ARGs because of the limited availability of collectable airborne particulate matter and the low biological content of samples. In this study, an optimized protocol for collecting and detecting airborne ARGs was presented. Experimental results showed that recovery efficiency tended to increase initially and then declined over time, and a range of 550–780 copies/mm2 of capture loading was recommended to ensure that the recovery efficiency is greater than 75%. As the cell walls were mechanically disrupted and nucleic acids were released, the buffer wash protects ARGs dissolution. Three ratios of buffer volume to membrane area in buffer wash were compared. The highest concentrations of airborne ARGs were detected with 1.4 µL/mm2 buffer wash. Furthermore, the majority of the cells were disrupted by an ultrasonication pretreatment (5 min), allowing the efficiency ARGs detection of airborne samples. While, extending the ultrasonication can disrupt cell structures and gene sequence was broken down into fragments. Therefore, this study could provide a theoretical basis for the efficient filter collection of airborne ARGs in different environments. An optimized sampling method was proposed that the buffer wash was 1.4 µL/mm2 and the ultrasonication duration was 5 min. The indoor airborne ARGs were examined in accordance with the improved protocol in two laboratories. The result demonstrated that airborne ARGs in an indoor laboratory atmosphere could pose the considerable health risk to inhabitants and we should pay attention to some complicated indoor air environment.

    https://link.springer.com/article/10.1007/s11783-020-1274-5