摘要

    抗生素抗性基因（ARG）的环境选择被认为是由于经常在牲畜中使用的抗生素或金属残留物引起的。在这项研究中，我们检查了三个商业家禽养殖场，以将抗生素和金属残留物的共现模式与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种重金属和16S rRNA基因序列。 ARG的含量和类型在肥料中显着丰富，而土壤则具有最多样化的细菌群落。 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）导致与ARGs的大多数正相关。整合素和转座子与对应于9类抗生素的ARG共同出现，尤其是1类整合酶intI-1LC。冗余分析（RDA）和方差划分分析（VPA）显示，抗生素，金属，MGE和细菌分别仅解释了微生物群落中ARG的方差，分别为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。在这项研究中，金属对ARG的影响要大于所检测到的抗生素。

    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