National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Taian 271018, People's Republic of China.
National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Taian 271018, People's Republic of China.
Sci Total Environ. 2019 Dec 10;695:133781. doi: 10.1016/j.scitotenv.2019.133781. Epub 2019 Aug 6.
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.
畜禽粪便是抗生素耐药菌（ARB）和抗生素耐药基因（ARGs）的主要储存库。本研究调查了中国农村传统养殖行业新鲜和堆肥粪便中 ARB、ARGs 的分布特征。采集的样本未经专业堆肥自然堆积，将施用于农田。实时定量聚合酶链反应（qPCR）结果显示，在测试的粪便样本中存在十种目标 ARGs 和两种移动遗传元件（MGEs）。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）的丰度之间存在显著的正相关。此外，目标 ARGs 的分布与土霉素（DOX）、磺胺甲恶唑（SM2）、恩诺沙星（ENR）和泰乐菌素（TYL）的残留浓度有关。总体而言，共鉴定出 24 个细菌属。SM2 的 ARB 耐药率为 17.79%-83.70%，其次是 TYL 的 0.40%-63.77%、DOX 的 0.36%-43.90%和 ENR 的 0.00%-13.36%，表现出显著的剂量效应。本研究还表明，鸡、猪和牛粪新鲜粪便中临床相关 ARB 和 ARGs 的丰度明显高于堆肥粪便，鸡和猪粪便中的 ARB 比例和 ARGs 丰度均高于牛粪。
