摘要
      抗生素在全球范围内的广泛使用加速了环境中的抗微生物耐药性。作为最大的抗生素消费者之一，畜牧场是AMR流行的热点，尤其是那些在大气中的畜牧场可以远距离传播，并对公众造成吸入风险。在这里，我们收集了养猪场的总悬浮颗粒物和集约化养猪区的环境空气。使用扩增子和宏基因组测序方法分析细菌群落和抗生素耐药性。随后，与报告的医院样本进行比较，估计AMR风险和吸入暴露于潜在的人类致病性抗生素耐药性细菌（HPARB）。结果表明，养猪场通过增加丰度、减少多样性和改变成分来塑造空气传播的细菌群落。猪粪便对养猪场空气中的细菌贡献了77%，对环境空气贡献了约35%。养猪场的空气传播抗生素耐药性主要是对四环素类、氨基糖苷类和林可沙酰胺类产生耐药性，超过48%的耐药性来自猪粪便。与医院空气不同，厚壁菌门是养猪环境中的优势细菌，包括梭菌、链球菌和气球菌在内的条件病原体是抗生素耐药性基因（ARGs）的主要宿主。其中，从所有猪粪和养猪场空气样本的宏基因组中检索到携带（转座酶/重组酶相关）ARGs和毒力因子基因的半乳糖裂解链球菌的基因组，但在任何医院空气样本中都没有检测到它们。这表明乳酸链球菌在养猪环境中对人类健康有潜在危害。养猪场的空气比医院的空气和猪粪面临更高的AMR风险。养猪场工人吸入HPARB的量比在医院工作的人高出约三个数量级。因此，这项研究描述了细菌和抗生素耐药性体从猪粪便向环境的大气传播。
Abstract
Globally extensive use of antibiotics has accelerated antimicrobial resistance (AMR) in the environment. As one of the biggest antibiotic consumers, livestock farms are hotspots in AMR prevalence, especially those in the atmosphere can transmit over long distances and pose inhalation risks to the public. Here, we collected total suspended particulates in swine farms and ambient air of an intensive swine farming area. Bacterial communities and antibiotic resistomes were analyzed using amplicon and metagenomic sequencing approaches. AMR risks and inhalation exposure to potential human-pathogenic antibiotic-resistant bacteria (HPARB) were subsequently estimated with comparison to the reported hospital samples. The results show that swine farms shaped the airborne bacterial community by increasing abundances, reducing diversities and shifting compositions. Swine feces contributed 77% of bacteria to swine farm air, and about 35% to ambient air. Airborne antibiotic resistomes in swine farms mainly conferred resistance to tetracyclines, aminoglycosides and lincosamides, and over 48% were originated from swine feces. Distinct to the hospital air, Firmicutes were dominant bacteria in swine farming environments with conditional pathogens including Clostridium, Streptococcus and Aerococcus being major hosts of antibiotic resistance genes (ARGs). Therein, genomes of S. alactolyticus carrying (transposase/recombinase-associated) ARGs and virulence factor genes were retrieved from the metagenomes of all swine feces and swine farm air samples, but they were not detected in any hospital air samples. This suggests the indication of S. alactolyticus in swine farming environments with potential hazards to human health. Swine farm air faced higher AMR risks than hospital air and swine feces. The inhalation intake of HPARB by a swine farm worker was about three orders of magnitude higher than a person who works in the hospital. Consequently, this study depicted atmospheric transmission of bacteria and antibiotic resistomes from swine feces to the environment.

https://www.sciencedirect.com/science/article/pii/S0160412023000247