摘要
      最近的进展提供了压倒性的证据，证明大气颗粒物携带大量抗生素耐药性基因（ARGs）。也有文献表明，受污染的空气会促进细菌发病机制和抗微生物耐药性（AMR）的传播。这些研究通常使用独立于培养的方法，揭示颗粒物中复杂的微生物组和耐药组组成，而直接证明存在活的功能性细菌的培养依赖性方法尚未完全应用。近年来，世界各地努力减少空气颗粒物污染，使包括中国在内的世界许多地区的空气更加清洁。大气颗粒物在改善空气条件方面是否仍然可以作为致病菌和AMR的载体，这已成为一个需要解决的有趣问题。为了回答这个问题，在这项工作中，使用了一种依赖于培养的方法来找出大气颗粒物在相对“清洁”的空气中传播致病菌和AMR的假定作用。通过在未工业化、污染较轻的大学校园中采集颗粒物，培养和鉴定颗粒物中的细菌，并表征这些细菌的发病机制和AMR特性，得出了有趣的发现，即即使在相对“清洁”的空气中，耐抗生素的致病菌也很普遍；并且包括整合子在内的可移动遗传元件是广泛存在的。特别是，在收集的空气样本中，可以识别出可能对健康构成重大威胁的耐多药溶血性芽孢杆菌菌株。在空气传播的细菌中也首次发现了复杂的1类整合子，其中两种携带新的抗生素抗性基因盒阵列，这表明AMR在空气中水平转移的危险。总之，使用依赖于培养的方法，这项工作表明，大气颗粒物是传播细菌发病机制和AMR的可行媒介，即使在相对“清洁”的空气中，空气中抗生素耐药性病原体的威胁也是显著的。
Abstract
Recent advances provided overwhelming evidence that atmospheric particulate matters carry a substantial amount of antibiotic resistance genes (ARGs). It has also been documented that polluted air facilitates transmission of bacterial pathogenesis and antimicrobial resistance (AMR). These investigations generally used culture-independent approaches which reveal sophisticated microbiomic and resistomic compositions in particulate matters, while culture-dependent methods directly demonstrating presence of live, functional bacteria has not been fully applied. In recent years, efforts undertaken worldwide managed to reduce air particulate matter pollution, leading to cleaner air in many parts of world, including China. Whether atmospheric particulate matters may still function as vehicles for pathogenic bacteria and AMR in improving air conditions is turning into an interesting question to address. In attempt to answer this question, a culture-dependent approach is used to find out the putative role of atmospheric particulate matters in relatively ‘clean’ air to transmit pathogenic bacteria and AMR in this work. By harvesting particulate matters in an unindustrialized and less-polluted university campus, culturing and identifying bacteria in particulate matters, and characterizing pathogenesis and AMR properties of these bacteria, interesting findings were made that even in relatively ‘clean’ air, antibiotic-resistant pathogenic bacteria are prevalent; and that mobile genetic elements including integrons are widespread. In particular, in air samples collected, multidrug-resistant hemolytic Bacillus strains that may pose significant health threat could be identified. Complex class 1 integrons, two of which carry novel antibiotic resistant gene cassette arrays, were also found for the first time in airborne bacteria, suggesting the danger of horizontal transfer of AMR in air. In conclusion, using culture-dependent methods, this work shows that atmospheric particulate matters are viable vehicles for the transmission of bacterial pathogenesis and AMR, and that even in relatively ‘clean’ air, the threat of airborne antibiotic-resistant pathogens is significant.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722060752