扬州市农贸市场猪肉中沙门氏杆菌的分离、鉴定及耐药性分析

Isolation,identification and drug resistance analysis of Salmonella in pork from farmer’s market in Yangzhou City

为调查扬州市农贸市场猪肉中沙门氏杆菌的流行和耐药情况,试验采集扬州市农贸市场猪肉样品393份,进行沙门氏杆菌的分离纯化、PCR鉴定和血清型鉴定,测定分离株药物敏感性,检测耐药基因,并进行多位点序列分型。结果表明:共分离到150株沙门氏杆菌,总分离率为38.2%;共鉴定8种血清型沙门氏杆菌,其中优势血清型为伦敦沙门氏杆菌。88.7%的分离菌株对多西环素耐药,对四环素(86.7%)、氨苄西林(84.0%)、阿莫西林(76.0%)、氯霉素(75.3%)和氟苯尼考(74.0%)也有较高的耐药率。92.0%的分离菌株表现出多重耐药,其中48.0%的分离菌株耐8~10种抗生素。tetA、bla;和floR 3种耐药基因检出率较高,分别占被检样品的93.8%、84.1%和50.4%,mcr-1、tet(X4)和bla;3种基因未被检出。多位点序列分型共鉴定出12种ST型,其中优势序列型(sequence type,ST)为ST155(38.7%),其次为ST469(23.3%)。说明农贸市场猪肉中沙门氏杆菌污染较为严重,应严格控制屠宰流程,并对市场定期采样监测,采取相应措施降低猪肉中沙门氏杆菌的污染。

In order to investigate the prevalence and drug resistance of Salmonella in pork from farmer’s market in Yangzhou City,393 samples of pork from farmer’s market in Yangzhou City were collected for the isolation and purification,PCR identification and serotype identification of Salmonella,and the drug susceptibility of the isolates was determined;drug resistance genes were detected,and multi-site sequence typing was performed.The results showed that 150 strains of Salmonella were isolated,with a total isolation rate of 38.2%;a total of 8 serotypes of Salmonella were identified,of which the dominant serotype was Salmonella enterica subsp.enterica serovar London.88.7%of the isolates were resistant to doxycycline;the resistance rates to tetracycline(86.7%),ampicillin(84.0%),amoxicillin(76.0%),chloramphenicol(75.3%)and florfenicol(74.0%)were high.92.0%of the isolates showed multi-drug resistance,and 48.0%of the isolates were resistant to 8-10 antibiotics.The detection rates of three drug resistance genes,tetA,bla;,and floR,were high,accounting for 93.8%,84.1%and 50.4%of the tested samples,respectively;the mcr-1,tet(X4)and bla;genes were not been detected.A total of 12 ST were identified by multi-site sequence typing,among which the dominant sequence types were ST155(38.7%),followed by ST469(23.3%).The results suggested that the pollution of Salmonella in pork in the farmer’s market was serious,and the slaughter process could be strictly controlled;the market could be regularly sampled and monitored,and corresponding measures could be taken to reduce the pollution of Salmonella in pork.