【摘要】 【目的】评估猪肉生产链中粪肠球菌（Enterococcus faecalis,E. faecalis）耐药情况及传播风险。【方法】从浙江省杭州市2家养猪场、1家屠宰场和2家市场中采集生猪体表、胴体及环境样品共300份。分别通过16S rDNA测序、肉汤微量稀释法（MIC）和PCR法进行菌株鉴定、耐药表型测定以及耐药基因型和毒力基因型鉴定，开展多位点序列分型（multilocus sequencing typing,MLST）分析和接合转移试验。【结果】分离得到的125株粪肠球菌对泰妙菌素、四环素和多西环素等抗生素有较高的耐药率，且养猪场分离株对抗生素的耐药率均高于屠宰场和市场。基因型鉴定结果表明，125株粪肠球菌中，10种耐药基因均有检出，其中optrA、tet(M)、tet(L)、erm(B)的检出率较高，耐药基因检出率排序为：养猪场>屠宰场>市场。已检测的毒力基因中，efaA的携带率最高，其他依次为gelE、asa1、ace、cylA、hyl、esp，毒力基因携带率排序为：养猪场>屠宰场>市场。MLST分析表明，水平传播是optrA在浙江省杭州市猪源粪肠球菌中流行的主要机制。接合转移结果显示，12株猪源菌株中，optrA可通过质粒接合作用转移到受体菌JH2-2中。【结论】作者对猪肉生产链中的粪肠球菌进行了耐药性评估与传播风险研究，为保障肉类食品安全提供了理论依据。更多还原

【Abstract】 [Objective] This study aims to evaluate the antibiotic resistance and transmission risk of Enterococcus faecalis(E. faecalis) in the pork production chain. [Method] A total of 300 samples were collected from the surface of live pigs, carcasses, and the environment in 2 pig farms, 1 slaughterhouse, and 2 markets in Hangzhou, Zhejiang. The strain identification, antibiotic resistance phenotypes, resistance genotypes, and virulence genotypes were performed by 16S rDNA sequences, broth microdilution method(MIC), and PCR. In addition, multilocus sequencing typing(MLST) and conjugational transfer tests were conducted. [Result] The 125 isolates of E. faecalis showed high resistance to antibiotics such as tiamulin, tetracycline, and doxycycline, and the isolates from pig farms showed higher antibiotic resistance rates than those from the slaughterhouse and markets. Ten antibiotic resistance genes were detected in the 125 strains of E. faecalis, and the detection rates of optrA, tet(M), tet(L), and erm(B) were higher. The detection rate of antibiotic resistance genes followed the trend of pig farm > slaughterhouse > market. Among the virulence genes tested, efaA was the most prevalent, followed by gelE, asa1, ace, cylA, hyl, and esp. Overall, the detection rate of virulence genes was the highest in pig farms, moderate in the slaughterhouse, and the lowest in markets. MLST results indicated that horizontal transmission was the main mechanism for the prevalence of optrA in pig-derived E. faecalis in Hangzhou, Zhejiang. The results of conjugation transfer tests showed that optrA in 12 pig-derived strains could be transferred to the recipient strain JH2-2 by plasmid conjugation. [Conclusion] The antibiotic resistance and transmission risk of E. faecalis in the pork production chain are assessed, which provides a theoretical basis for ensuring the safety of meat products.更多还原