摘要

       家畜粪便是抗生素抗性细菌 (ARB) 和抗生素抗性基因 (ARG) 的主要储存库。本研究调查了中国农村地区传统面包业新鲜和堆肥中ARB、ARGs的分布特征。采集的样品未经专业堆肥自然堆放，将施用于农田。实时定量聚合酶链反应 (qPCR) 结果显示在测试的粪便样品中存在十个目标 ARG 和两个移动遗传元件 (MGE)。四环素和磺胺类耐药基因（TRGs和SRGs）的相对丰度普遍高于大环内酯类耐药基因（MRGs），其次是喹诺酮类耐药基因（QRGs）。 sul1、sul2、tetW和MGEs（intl1、intl2）的丰度呈显着正相关。此外，目标 ARG 的分布与多西环素 (DOX)、磺胺二甲嘧啶 (SM2)、恩诺沙星 (ENR) 和泰乐菌素 (TYL) 的残留浓度有关。总的来说，共鉴定了 24 个细菌属。 SM2的ARB耐药率为17.79%~83.70%，TYL为0.40%~63.77%，DOX为0.36%~43.90%，ENR为0.00%~13.36%，具有显着的剂量效应。本研究还表明，鸡、猪和牛新鲜粪便中临床相关的 ARB 和 ARGs 的丰度显着高于堆肥，鸡和猪粪的 ARB 比例和 ARGs 丰度高于牛粪。

       Livestock manure is a major reservoir of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). This study investigated the distribution characteristics of ARB, ARGs in fresh and composted manures of traditional breading industry in rural areas in China. Samples collected were naturally piled without professional composting, and will be applied to farmland. The real-time quantitative polymerase chain reaction (qPCR) results showed the presence of ten target ARGs and two mobile genetic elements (MGEs) in the tested manure samples. The relative abundance of tetracycline and sulfonamide resistance genes (TRGs and SRGs) was generally higher than that of macrolide resistance genes (MRGs), followed by quinolone resistance genes (QRGs). There were significant positive correlations between the abundance of sul1, sul2, tetW and MGEs (intl1, intl2). In addition, the distribution of target ARGs was associated with the residual concentrations of doxycycline (DOX), sulfamethazine (SM2), enrofloxacin (ENR) and tylosin (TYL). Overall, a total of 24 bacterial genera were identified. The resistance rates of ARB were 17.79%–83.70% for SM2, followed 0.40%–63.77% for TYL, 0.36%–43.90% for DOX and 0.00%–13.36% for ENR, which showed a significant dose-effect. This study also demonstrated that the abundance of clinically relevant ARB and ARGs in chicken, swine and cow fresh manures significantly greater than that in composted manures, and chicken and swine manures had higher proportion of ARB and higher abundance of ARGs than that in cow manures.

https://www.sciencedirect.com/science/article/abs/pii/S0048969719337222