摘要

      抗生素抗性基因 (ARG) 的环境选择被认为是由抗生素或金属残留引起的，经常用于牲畜。在这项研究中，我们检查了三个商业家禽养殖场，将抗生素和金属残留物的共存模式与 ARG 的存在相关联。我们量化了 283 个 ARG、12 个移动遗传元件 (MGE)、49 种靶向抗生素、7 种重金属并测序了 16S rRNA 基因。 ARG 的丰度和类型在粪便中显着富集，而土壤中的细菌群落最为多样化。 Procrustes 分析显示 ARGs/MGEs 与微生物组之间存在显着相关性。与抗生素相比，镉 (Cd)、砷 (As)、锌 (Zn)、铜 (Cu) 和铅 (Pb) 与 ARG 呈正相关。整合子和转座子与对应于 9 类抗生素的 ARGs 共同出现，尤其是 Class1 整合酶 intI-1LC。冗余分析 (RDA) 和方差分区分析 (VPA) 表明，抗生素、金属、MGE 和细菌分别仅解释了微生物群落中 ARG 方差的 0.7%、5.7%、12.4% 和 21.9%。这些结果表明细菌组成和水平基因转移是影响 ARGs 组成的主要因素；与本研究中检测到的抗生素相比，金属对 ARG 谱的影响更大。

      Environmental selection of antibiotic resistance genes (ARGs) is considered to be caused by antibiotic or metal residues, frequently used in livestock. In this study we examined three commercial poultry farms to correlate the co-occurrence patterns of antibiotic and metal residues to the presence of ARGs. We quantified 283 ARGs, 12 mobile genetic elements (MGEs), 49 targeted antibiotics, 7 heavy metals and sequenced 16S rRNA genes. The abundance and type of ARG were significantly enriched in manure while soil harbored the most diverse bacterial community. Procrustes analysis displayed significant correlations between ARGs/MGEs and the microbiome. Cadmium (Cd), arsenic (As), zinc (Zn), copper (Cu) and lead (Pb) were responsible for a majority of positive correlations to ARGs when compared to antibiotics. Integrons and transposons co-occurred with ARGs corresponding to 9 classes of antibiotics, especially Class1 integrase intI-1LC. Redundancy analysis (RDA) and Variance partitioning analysis (VPA) showed that antibiotics, metals, MGEs and bacteria explain solely 0.7%, 5.7%, 12.4%, and 21.9% of variances of ARGs in the microbial community, respectively. These results suggested that bacterial composition and horizontal gene transfer were the major factors shaping the composition of ARGs; Metals had a bigger effect on ARG profile than detected antibiotics in this study.

https://www.sciencedirect.com/science/article/abs/pii/S0048969720362318