摘要
      动物养殖场被认为是抗生素抗性基因（ARGs）和抗生素抗性细菌（ARB）的关键库。抗生素耐药性通过气溶胶从动物养殖场传播到周围环境已成为一个日益令人担忧的问题。在这里，我们调查了空气中ARGs（尤其是人畜共患病原体）在养鸡场和奶牛场环境中的传播模式和暴露风险。从畜舍和周围环境（逆风和顺风区域）收集气溶胶、灰尘和动物粪便样本，以评估ARG剖面。对空气中葡萄球菌的抗生素耐药性表型和基因型进行了特别分析，以揭示空气中ARGs的暴露风险。结果表明，在逆风（50米/100米）和顺风（50米-100米/150米）的空气环境中检测到空气中的ARG，其中至少30%的细菌类群分散在动物舍中。此外，大气扩散模型显示，空气中的ARG可以沿着风向从动物舍扩散到10公里的距离。在空气中可培养的细菌中发现了临床上重要的病原体。葡萄球菌属、鞘氨醇单胞菌属和不动杆菌属是空气中ARGs的潜在细菌宿主。从养鸡场（n=148）和奶牛场（n=87）的环境中分离到空气中的葡萄球菌。值得注意的是，所有来自鸡相关环境的分离株都具有多药耐药性（>3种临床相关抗生素），其中80%以上携带甲氧西林耐药性基因（mecA）和相关的ARGs和MGEs。动物舍和顺风居民区的灰尘中存在大量ARGs和多种病原体，表明动物粪便来源的ARGs在生物气溶胶中积累。养鸡环境中的员工和当地居民通过吸入接触鸡源ARGs和多药耐药葡萄球菌。这项研究强调了空气中ARGs和抗生素耐药性病原体对人类健康的潜在暴露风险。
Abstract
Animal farms have been considered as the critical reservoir of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB). Spread of antibiotic resistance from animal farms to the surrounding environments via aerosols has become a growing concern. Here we investigated the dispersal pattern and exposure risk of airborne ARGs (especially in zoonotic pathogens) in the environment of chicken and dairy farms. Aerosol, dust and animal feces samples were collected from the livestock houses and surrounding environments (upwind and downwind areas) for assessing ARG profiles. Antibiotic resistance phenotype and genotype of airborne Staphylococcus spp. was especially analyzed to reveal the exposure risk of airborne ARGs. Results showed that airborne ARGs were detected from upwind (50 m/100 m) and downwind (50 m/100 m/150 m) air environment, wherein at least 30% of bacterial taxa dispersed from the animal houses. Moreover, atmospheric dispersion modeling showed that airborne ARGs can disperse from the animal houses to a distance of 10 km along the wind direction. Clinically important pathogens were identified in airborne culturable bacteria. Genus of Staphylococcus, Sphingomonas and Acinetobacter were potential bacterial host of airborne ARGs. Airborne Staphylococcus spp. were isolated from the environment of chicken farm (n = 148) and dairy farm (n = 87). It is notable that all isolates from chicken-related environment were multidrug-resistance (>3 clinical-relevant antibiotics), with more than 80% of them carrying methicillin resistance gene (mecA) and associated ARGs and MGEs. Presence of numerous ARGs and diverse pathogens in dust from animal houses and the downwind residential areas indicated the accumulation of animal feces origin ARGs in bioaerosols. Employees and local residents in the chick farming environment are exposed to chicken originated ARGs and multidrug resistant Staphylococcus spp. via inhalation. This study highlights the potential exposure risks of airborne ARGs and antibiotic resistant pathogens to human health.

https://www.sciencedirect.com/science/article/pii/S0160412021005523