摘要

      猪场是一个重要的抗生素耐药基因库和供应源。然而，对于ARGs在养殖环境和随后生产的猪肉之间的传播情况知之甚少。本研究旨在调查ARGs及其相关寄主细菌是否通过食物生产链从繁殖环境传播到肉类上。分析了厦门市某大型养猪场土壤、猪粪和猪肉中ARGs的含量和丰度，比较了土壤中精氨酸和细菌群落组成。在26个靶基因中，对磺胺类药物、甲氧苄啶、氨基糖苷类药物、氯霉素、大环内酯类药物、氟苯尼考和四环素类药物的抗性基因在猪的饲养环境和猪肉中都有较高的频率。猪肉中ARGs的流行与养殖环境，特别是猪肉和粪便之间的环境惊人地一致。对6类抗生素耐药的10个代表性ARGs的相对丰度为3.01×10-1～1.55×10-6拷贝/16srRNA拷贝。抗磺胺（sulI和sulII）、氨基糖苷（aadA）和四环素（tet（A）和tet（M））的ARGs在大多数样品中含量最高。粪便和肉类样品的ARGs组成比农田土壤样品具有更高的相似性。在肉类样本中发现的肠杆菌科与以前从同一猪场分离的多重耐药细菌进一步一致。我们的研究结果强烈地表明，ARGs可以通过猪肉产业链，如饲料供应、猪饲料和猪肉生产，从猪的养殖环境向肉的扩散。

       It is well verified that pig farms are an important reservoir and supplier of antibiotic resistance genes (ARGs). However, little is known about the transmission of ARGs between the breeding environment and subsequently produced pork. This study was conducted to investigate if ARGs and associated host bacteria spread from the breeding environment onto the meat through the food production chain. We thus analyzed the occurrence and abundance of ARGs, as well as comparing both ARG and bacterial community compositions in farm soil, pig feces and pork samples from a large-scale pig farm located in Xiamen, People's Republic of China. Among the 26 target ARGs, genes conferring resistance to sulfonamide, trimethoprim, aminoglycoside, chloramphenicol, macrolide, florfenicol, and tetracycline were observed at high frequency in both the pig breeding environment and pork. The prevalence of ARGs in pork was surprisingly consistent with breeding environments, especially between the pork and feces. The relative abundance of 10 representative ARGs conferring resistance to six classes of antibiotics ranged from 3.01 × 10^-1 to 1.55 × 10^-6 copies/16S rRNA copies. The ARGs conferring resistance to sulfanilamide (sulI and sulII), aminoglycoside (aadA), and tetracycline [tet(A) and tet(M)] were most highly abundant across most samples. Samples from feces and meat possessed a higher similarity in ARG compositions than samples from the farms soil. Enterobacteriaceae found on the meat samples were further identical with previously isolated multidrug-resistant bacteria from the same pig farm. Our results strongly indicate that ARGs can be potentially spreading from pig breeding environment to meat via the pork industry chain, such as feed supply, pig feeding and pork production.

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6361818/