摘要

      揭示近岸人类活动对海洋和大陆生物气溶胶的选择压力、过渡带珠江口（113.52 oE，22.69 oN）空气传播病原体和抗生素抗性基因（ARGs）的污染概况和潜在暴露风险海洋和大陆环境之间，进行了充分探索。结果表明，生物气溶胶中细菌总数差异较大，春季和夏季平均污染水平分别为1.86×105和4.35×104 cfu m-3，高于空气传播真菌。生物气溶胶的主要空气动力学直径在可呼吸大小范围内（<4.7μm），微生物群落的多样性和丰度差异很大。此外，许多机会致病菌（伯克霍尔德菌-帕拉伯克霍尔德菌、葡萄球菌和不动杆菌）和真菌（链格孢菌、青霉菌和枝孢菌）在生物气溶胶样品中占优势。在检测到的 21 个 ARGs 亚型中，四环素抗性基因 tetA 最丰富，其次是氨基糖苷类抗性基因和移动遗传元件。相关性分析表明，病原体群落的变化对生物气溶胶中ARGs的流行有显着影响。基于微生物的平均日剂量率和人类直接摄入的 ARGs，还评估了珠江口生物气溶胶的健康风险。总之，机会病原体的存在和 ARG 的多样性加强了在未来空气质量监测和风险评估中考虑生物气溶胶的呼吁。

      To reveal the selective pressures of near-shore human activities on marine and continental bioaerosols, the pollution profile and potential exposure risk of airborne pathogens and antibiotic-resistance genes (ARGs) in Pearl River Estuaries (113.52 oE, 22.69 oN), a transitional zone between marine and continental environments, were fully explored. The results showed that the total bacteria among bioaerosols varied largely with average pollution levels of 1.86 × 105 and 4.35 × 104 cfu m−3 in spring and summer, respectively, and were high than those of airborne fungi. The predominant aerodynamic diameters of bioaerosols were in respirable size range (<4.7 µm), and the microbes communities’ diversity and abundance varied significantly. Besides, many opportunistic pathogenic bacteria (Burkholderia-Paraburkholderia, Staphylococcus and Acinetobacter) and fungi (Alternaria, Penicillium and Cladosporium) were dominant in bioaerosol samples. Of 21 ARGs subtypes detected, the tetracycline resistance gene tetA was the most abundant, followed by aminoglycoside resistance gene and mobile genetic elements. Correlation analysis revealed that the changes of pathogens community contributed significantly to the prevalence of ARGs in bioaerosol. Based on the average daily dose rates of microorganisms and human direct intake of ARGs, health risk of bioaerosols from the Pearl River Estuaries were also evaluated. In summary, the presence of opportunistic pathogens and diversity of ARGs strengthens the call to consider the bioaerosol in air quality monitoring and risk assessment in the future.

      https://www.sciencedirect.com/science/article/pii/S0160412020318894