摘要

       抗微生物剂通常用于传统的畜牧生产，而粪肥则广泛应用于农田作为肥料。这种做法引发了有关施肥对 (i) 土壤微生物群组成和 (ii) 抗菌素和抗菌素耐药性 (AMR) 在环境中传播的影响的问题。本研究在意大利北部的一个高密度农业区进行，旨在评估（奶牛、鸡和猪）粪肥施用对土壤微生物组、抗菌剂浓度和抗菌素抗性基因 (ARG) 丰度的影响。我们发现粪便中的微生物群落组成与土壤中的微生物群落组成不同且多样性较少，粪便施用仅略微改变土壤微生物组。例外的是厚壁菌门、Tenericutes 和 Cloacimonetes，它们在施肥土壤中显着富集。在所研究的抗菌剂中，只有氟甲喹浓度在施肥后增加，尽管不显着。粪便中的 ARGs 更丰富，ermA、ermB、blaOXA-1 和 oqxA 在施肥土壤中显着富集。观察到 oqxA 和 qnrS 丰度与氟甲喹浓度之间呈正相关，同时还观察到一些 ARG 和微生物分类群（例如，oqxA 与酸杆菌和 Gemmatimonadetes 相关）。这项研究表明，施肥对土壤微生物组几乎没有影响，但可能有助于将特定的 ARG 传播到环境中。此外，氟甲喹残留似乎会促进 oqxA 和 qnrS 在土壤中的出现。

       Antimicrobials are commonly used in conventional livestock production and manure is widely applied to agricultural lands as fertilizer. This practice raises questions regarding the effects of fertilization on (i) soil microbiota composition and (ii) spread of antimicrobials and antimicrobial resistance (AMR) in the environment. This study was conducted in a high-density farming area of Northern Italy and aimed at assessing the impact of (dairy cattle, chickens and swine) manure application on soil microbiome, antimicrobial concentrations and antimicrobial resistance gene (ARG) abundance. We found the microbial community composition in manure to be different and less diverse than in soil, with manure application altering only marginally the soil microbiome. Exceptions were the phyla Firmicutes, Tenericutes and Cloacimonetes, which significantly enriched in fertilized soil. Of the antimicrobials investigated, only flumequine concentrations increased after manure application, albeit non-significantly. ARGs were more abundant in manure, with ermA, ermB, blaOXA-1 and oqxA being significantly enriched in fertilized soil. Positive correlations between oqxA and qnrS abundances and flumequine concentrations were observed, together with the co-occurrence of some ARGs and microbial taxa (e.g. oqxA correlated with Acidobacteria and Gemmatimonadetes). This study showed that manure application has little effect on soil microbiome but may contribute to the dissemination of specific ARGs into the environment. Moreover, flumequine residues seem to enhance the emergence of oqxA and qnrS in soil.

https://www.sciencedirect.com/science/article/abs/pii/S0048969720369357