McEachran Andrew D, Blackwell Brett R, Hanson J Delton, Wooten Kimberly J, Mayer Gregory D, Cox Stephen B, Smith Philip N
Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA.
Environ Health Perspect. 2015 Apr;123(4):337-43. doi: 10.1289/ehp.1408555. Epub 2015 Jan 22.
Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized.
The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards.
PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing.
Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind.
Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs.
抗生素耐药性的出现和传播已成为全球健康威胁，且常常与临床和兽用化疗药物的过度使用和滥用相关。现代工业规模的动物饲养作业广泛依赖包括抗生素在内的兽用药物来促进动物生长。排泄后，抗生素通过径流、淋溶以及粪便土地施用在环境中传输；然而，来自饲养场的空气传播尚未得到描述。
本研究的目的是确定抗生素、抗生素耐药基因（ARG）和反刍动物相关微生物通过大规模肉牛饲养场产生的颗粒物（PM）进行空气传播的程度。
在10个肉牛饲养场的下风处和上风处收集PM。从PM中提取后，通过高效液相色谱-串联质谱法定量五种兽用抗生素，通过靶向定量聚合酶链反应定量ARG，并通过16S rRNA扩增和测序分析微生物群落多样性。
来自饲养场的空气传播PM促进了几种兽用抗生素以及含有ARG的微生物群落的扩散。饲养场下风处空气中PM中几种抗生素的浓度范围为0.5至4.6μg/g PM。在饲养场下风处收集的PM的微生物群落富含反刍动物相关分类群，与上风处的PM组合相比有所不同。此外，与上风处相比，在饲养场下风处收集的PM中编码对四环素类抗生素耐药的基因明显更为丰富。
来自饲养场的风传播PM含有抗生素、细菌和ARG。
