Institute for Water Quality and Resource Management, University of Technology Vienna, Austria; Austrian Agency for Health and Food Safety AGES, Division of Data, Statistics and Risk Assessment, Department for Integrative Risk Assessment, Vienna, Austria; Institute of Virology Stefan S. Nicolau, Romanian Academy of Science, Bucharest, Romania.
Austrian Agency for Health and Food Safety AGES, Division of Data, Statistics and Risk Assessment, Department for Integrative Risk Assessment, Vienna, Austria.
Sci Total Environ. 2021 Feb 20;756:143699. doi: 10.1016/j.scitotenv.2020.143699. Epub 2020 Dec 1.
Antimicrobial resistance (AR) represents a global threat in human and veterinary medicine. In that regard, AR proliferation and dissemination in agricultural soils after manure application raises concerns on the enrichment of endogenous soil bacterial population with allochthonous antibiotic resistance genes (ARGs). Natural resilience of agricultural soils and background concentrations of ARGs play key roles in the mitigation of AR propagation in natural environments. In the present study, we carried out a longitudinal sampling campaign for two crop vegetation periods to monitor spatial and temporal changes in the abundance of seven clinically relevant ARGs (sul1, ermB, vanA, aph(3')-IIa, aph(3')-IIIa, bla and tet(W)) and ribosomal 16S RNA. The absolute and relative abundances of the selected ARGs were quantified in total community DNA extracted from agricultural (manured and non-manured) and forest soils, fresh pig faeces and manure slurry. We observed that ARG concentrations return to background levels after manure-induced exposure within a crop growing season, highlighting the resilience capacity of soil. Naturally occurring high background concentrations of ARGs can be found in forest soil in due distance under low anthropogenic influences. It was observed that pesticide application increases the concentrations of three out of seven ARGs tested (ermB, aph(3')-IIIa and tet(W)). Moreover, we noticed that the absolute abundances of sul1, vanA, ermB and bla resistance genes show an increase by 100- to 10,000- fold, from maturation of fresh pig faeces to manure. Outcomes of our study suggest that agricultural soil environments show a strong capacity to alleviate externally induced disturbances in endogenous ARG concentrations. Naturally occurring high concentrations of ARGs are present also in low human impacted environments represented by the indigenous resistome.
抗微生物药物耐药性（AMR）在人类和兽医医学中是一个全球性的威胁。在这方面，在粪便施用于农业土壤后，抗生素耐药基因（ARGs）在土壤中自然发生的扩散和传播引起了人们的关注。农业土壤的自然恢复力和背景 ARG 浓度在减缓自然环境中的 AR 传播方面起着关键作用。在本研究中，我们进行了两次作物植被期的纵向采样活动，以监测七种临床相关 ARG（sul1、ermB、vanA、aph(3')-IIa、aph(3')-IIIa、bla 和 tet(W))和核糖体 16S RNA 的丰度的时空变化。从农业（施肥和未施肥）和森林土壤、新鲜猪粪便和粪浆中提取的总群落 DNA 中定量了选定的 ARG 的绝对和相对丰度。我们观察到，在一个作物生长季节内，粪便诱导暴露后，ARG 浓度恢复到背景水平，突出了土壤的恢复能力。在受人为影响较小的情况下，在森林土壤中可以发现自然存在的高背景 ARG 浓度。我们观察到，在七种测试的 ARG 中，有三种（ermB、aph(3')-IIIa 和 tet(W)）的浓度因农药的应用而增加。此外，我们注意到，从新鲜猪粪便到粪肥的成熟过程中，sul1、vanA、ermB 和 bla 耐药基因的绝对丰度增加了 100 到 10000 倍。我们的研究结果表明，农业土壤环境具有很强的能力来缓解内源 ARG 浓度的外部诱导干扰。在自然发生的低人为影响环境中，也存在着高浓度的 ARG，这些 ARG 代表了本土的耐药组。
