摘要
      畜禽养殖场废水中的矿物元素和抗生素抗性细菌污染物往往是生态和公共卫生问题的根源。了解山东省养猪场废水中重金属污染状况和耐药大肠杆菌（E.coli）的特征，为养猪场合理使用矿物元素添加剂、常用抗生素和季铵复合消毒剂提供指导，测定了10种矿物元素，并从废水中分离出大肠杆菌，测定了其对29种常用抗生素的耐药性和耐药基因。最后，对大肠杆菌进行了系统发育和多基因座序列分型（MLST）分析。结果表明，铁和锌污染严重，综合污染指数分别为708.94和3.13。值得注意的是，75%（12/16）的地区的平均铁含量超过了允许的限度。该省每个城市都发现了耐多药大肠杆菌。从养猪场废水中分离的大肠杆菌主要对四环素类（95.3%）、氯霉素类（77.8%）和磺酰胺类（62.2%）具有耐药性，而对喹诺酮类、四环素类、磺酰胺类、氨基糖苷类和β-内酰胺类的抗生素耐药性基因均在60%以上。克隆复合体10（CC10）在大肠杆菌分离株中普遍存在，ST10和ST48占优势。耐多药大肠杆菌分布广泛，主要为A基因型。然而，铁对抗生素耐药性影响的机制还需要在这一领域进行更多的研究。因此，有必要进一步加强铁锌污染的防治，规范抗生素和矿物元素添加剂在养猪业的使用。
Abstract
Mineral elements and antibiotic-resistant bacterial pollutants in livestock and poultry farms’ wastewater are often sources of ecological and public health problems. To understand the heavy-metal pollution status and the characteristics of drug-resistant Escherichia coli (E. coli) in swine-farm wastewater in Shandong Province and to provide guidance for the rational use of mineral-element additives, common antibiotics, and quaternary ammonium compound disinfectants on swine farms, 10 mineral elements were measured and E. coli isolated from wastewater and its resistance to 29 commonly used antibiotics and resistance genes was determined. Finally, phylogenetic and multi-locus sequence typing (MLST) analyses was performed on E. coli. The results showed serious pollution from iron and zinc, with a comprehensive pollution index of 708.94 and 3.13, respectively. It is worth noting that average iron levels in 75% (12/16) of the districts exceed allowable limits. Multidrug-resistant E. coli were found in every city of the province. The E. coli isolated from swine-farm wastewater were mainly resistant to tetracyclines (95.3%), chloramphenicol (77.8%), and sulfonamides (62.2%), while antibiotic resistance genes for quinolones, tetracyclines, sulfonamides, aminoglycosides, and β-lactams were all more than 60%. The clonal complex 10 (CC10) was prevalent, and ST10 and ST48 were dominant in E. coli isolates. Multidrug-resistant E. coli were widely distributed, with mainly A genotypes. However, the mechanism of the effect of iron on antibiotic resistance needs more study in this area. Thus, further strengthening the prevention and control of iron and zinc pollution and standardizing the use of antibiotics and mineral element additives in the swine industry are necessary.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122022138