摘要
      带有抗微生物细菌的牲畜粪便通过径流和雾化到达农场地面、粪坑、农田和更广泛的环境。关于灰尘在农场抗微生物耐药性（AMR）传播中的作用，几乎没有研究。目前尚不清楚农场灰尘中抗微生物耐药性基因（ARGs）的浓度和潜在决定因素。因此，在这项研究中，使用qPCR对空气中农场灰尘中的绝对ARG水平（代表人和动物可能接触的水平）和相对ARG丰度（代表细菌种群中的水平）进行了量化。在9个欧洲国家的174只家禽（肉鸡）和159个养猪场的947个新沉降的农场灰尘样本中，用静电降尘器（EDC）捕获了4个ARG。通过线性混合建模，确定了与粪便ARG水平、抗菌药物使用（AMU）以及农场和动物相关参数的相关性。结果显示，农场灰尘和粪便中的相对丰度相似，两个库之间存在显著的正相关（范围在0.21到0.82之间）。猪的AMU与同一马厩灰尘中ARG的丰度呈正相关。较高的生物安全标准与家禽中ARG的相对丰度较低和猪中ARG相对丰度较高有关。灰尘中ARG绝对水平较低的原因包括夏季和家禽的某些床上用品，以及动物密度和猪的夏季较低。这项研究表明，不同的途径有助于形成畜牧场的防尘性，与灰尘的产生有关，或影响细菌微生物组。农场灰尘是ARGs的一个大库，可能会传播给其他库中的细菌。已确定的农业灰尘中ARG丰度的决定因素可以指导未来的研究和潜在的农业管理政策。
Abstract
Livestock feces with antimicrobial resistant bacteria reaches the farm floor, manure pit, farm land and wider environment by run off and aerosolization. Little research has been done on the role of dust in the spread of antimicrobial resistance (AMR) in farms. Concentrations and potential determinants of antimicrobial resistance genes (ARGs) in farm dust are at present not known. Therefore in this study absolute ARG levels, representing the levels people and animals might be exposed to, and relative abundances of ARGs, representing the levels in the bacterial population, were quantified in airborne farm dust using qPCR. Four ARGs were determined in 947 freshly settled farm dust samples, captured with electrostatic dustfall collectors (EDCs), from 174 poultry (broiler) and 159 pig farms across nine European countries. By using linear mixed modeling, associations with fecal ARG levels, antimicrobial use (AMU) and farm and animal related parameters were determined. Results show similar relative abundances in farm dust as in feces and a significant positive association (ranging between 0.21 and 0.82) between the two reservoirs. AMU in pigs was positively associated with ARG abundances in dust from the same stable. Higher biosecurity standards were associated with lower relative ARG abundances in poultry and higher relative ARG abundances in pigs. Lower absolute ARG levels in dust were driven by, among others, summer season and certain bedding materials for poultry, and lower animal density and summer season for pigs. This study indicates different pathways that contribute to shaping the dust resistome in livestock farms, related to dust generation, or affecting the bacterial microbiome. Farm dust is a large reservoir of ARGs from which transmission to bacteria in other reservoirs can possibly occur. The identified determinants of ARG abundances in farm dust can guide future research and potentially farm management policy.

https://www.sciencedirect.com/science/article/pii/S0013935122000421