Zhang Jun-Hua, Chen Rui-Hua, Liu Ji-Li, Shang Tian-Hao, Shen Cong
School of Ecology and Environment, Ningxia University, Yinchuan 750021, China.
School of Geography and Planning, Ningxia University, Yinchuan 750021, China.
Huan Jing Ke Xue. 2021 Jun 8;42(6):2981-2991. doi: 10.13227/j.hjkx.202011075.
Livestock breeding intensively uses veterinary antibiotics in concentrated feeding operations to improve growth and control disease. Consequently, livestock and poultry manure is an important repository of antibiotics and antibiotic resistance genes (ARGs). To understanding the distribution of antibiotics and ARGs in manure and surrounding soils of cattle farms in Ningxia, cattle manure from five breeding periods (lactation, calving, growing, pre-fattening, and post-fattening periods) and comparative soil samples were collected from the largest beef-breeding area in Ningxia. The compositions of ARGs in the samples were analyzed by UPLC-MS/MS and HT-qPCR. The results showed that:① Tetracycline, quinolone, and sulfonamide were the dominant antibiotics in cattle manure. The content of antibiotics in the manure varied greatly between different breeding periods. High amounts of antibiotics were detected during the pre-fattening and lactation periods, and the lowest amounts were detected during the calving period. ② Quinolone and tetracycline were the dominant antibiotics in the soils, and the detection rate and content of quinolone were highest. The cattle farms did not affect the distribution of antibiotics in the surrounding soils. The content of quinolone and tetracycline in the soils with cattle manure application were significantly higher than control and surrounding soils. ③ We detected 79-142 ARGs in cattle manure, with aminoglycosides the most common form. The number and relative abundance of ARGs were highest during the growing period and lowest during the calving period. The dominant ARGs were , , and across all the breeding periods. ④ There were 35-79 ARGs in the tested soils, and multidrug and aminoglycoside ARGs were dominant. The cattle farms did not affect the number and relative abundance of ARGs in the surrounding soils; however, manure application significantly affected the number and relative abundance of ARGs. ⑤ Sulfonamide and chloramphenicol ARGs are at risk of mobilization and horizontal transport. A correlation analysis showed that the relative abundances of aminoglycoside and tetracycline in cattle manure were significantly positively correlated with their contents. ⑥ Aminoglycoside, sulfonamide, chloramphenicol, and mobile genetic elements (MGEs) in manure were significantly or extremely significantly positively correlated with aminoglycosides and sulfonamides in the soils, whereas macrolides were negatively correlated with vancomycin. These results provide baseline data to inform controls on the variety and dosages of feed and veterinary drugs in cattle farms and the application of organic fertilizers in agriculture.
畜牧业在集约化饲养过程中大量使用兽用抗生素，以促进生长和控制疾病。因此，畜禽粪便成为抗生素及抗生素抗性基因（ARGs）的重要储存库。为了解宁夏养牛场粪便及周边土壤中抗生素和ARGs的分布情况，采集了宁夏最大肉牛养殖区五个养殖阶段（泌乳期、产犊期、生长期、育肥前期和育肥后期）的牛粪以及对照土壤样本。采用超高效液相色谱-串联质谱法（UPLC-MS/MS）和高通量定量聚合酶链反应（HT-qPCR）分析样本中ARGs的组成。结果表明：①四环素、喹诺酮和磺胺类是牛粪中的主要抗生素。不同养殖阶段牛粪中抗生素含量差异很大。育肥前期和泌乳期检测到大量抗生素，产犊期含量最低。②喹诺酮和四环素是土壤中的主要抗生素，喹诺酮的检出率和含量最高。养牛场对周边土壤中抗生素的分布没有影响。施用牛粪的土壤中喹诺酮和四环素含量显著高于对照土壤和周边土壤。③在牛粪中检测到79 - 142种ARGs，氨基糖苷类是最常见的形式。ARGs的数量和相对丰度在生长期最高，产犊期最低。在所有养殖阶段，主要的ARGs为 、 和 。④在测试土壤中检测到35 - 79种ARGs，多重耐药和氨基糖苷类ARGs占主导地位。养牛场对周边土壤中ARGs的数量和相对丰度没有影响；然而，施用牛粪显著影响了ARGs的数量和相对丰度。⑤磺胺类和氯霉素类ARGs存在迁移和水平转移的风险。相关性分析表明，牛粪中氨基糖苷类和四环素的相对丰度与它们的含量显著正相关。⑥牛粪中的氨基糖苷类、磺胺类、氯霉素类和可移动遗传元件（MGEs）与土壤中的氨基糖苷类和磺胺类显著或极显著正相关，而大环内酯类与万古霉素呈负相关。这些结果为控制养牛场饲料和兽药的种类及用量以及农业有机肥的施用提供了基础数据。
