[关键词]
[摘要]
沙门氏菌是造成我国食源性疾病的常见细菌之一,也是肉类消费过程中密切监测的重点对象。在2018年~2021年期间,共计采集了南京市545份猪肉源食品样本,利用选择性培养法分离得到44株沙门氏菌,采用血清学方法和分子生物学方法(MLST)对其进行分型鉴定,并分析其耐药性。结果表明,市售样本中共计检出44株沙门氏菌,平均检出率为8.07%,其中内脏样本检出率相对最高(检出率为30.49%);血清型分析表明,检出的菌株中以鼠伤寒沙门氏菌(Salmonella. Typhimurium)、罗森氏沙门氏菌(Salmonella. Rissen)、德尔卑沙门氏菌(Salmonella. Derby)和伦敦沙门氏菌(Salmonella. London)4种血清型沙门氏菌最为常见;基因分型表明,ST19型为猪肉源中优势沙门氏菌株,占比为20.45%;检出的沙门氏菌中,38株菌株对四环素具有明显耐药性,占全部检出菌株的86.36%,而对头孢他啶、头孢噻肟和头孢西丁的耐药不超过10%。此外,对检出的1株多重耐药性沙门氏菌耐药基因分析发现,共筛查出了包括7大类抗生素及与耐药相关的基因。本实验详细分析了南京市场猪肉源食品中沙门氏菌污染状况,也为后期沙门氏菌的综合防治提供了理论依据。
[Key word]
[Abstract]
Salmonella is one of the typical bacteria causing foodborne diseases in China, which it is also the critical control object in the process of meat consumption. During 2018 to 2021, total 545 pork and pork products have been collected in this work. The selective culture method was utilized to isolate Salmonella, and the types of isolated Salmonella was identified based on serotype and nucleic acid sequence. Finally, the antibiotic susceptibility test was utilized to analyze the drug resistance of the isolated strains. The result show that a total of 44 Salmonella strains were identified among the market samples, with an average detracted rate of 8.07%, while pig viscera obtained the highest detected rate with 30.49%. Serotype analysis showed that four types strains, named S.Typhimurium, S,Rissen, S.Derby and S.London were the most common Salmonella types in pork and pork products. Genotyping results shows that the ST19 is the dominant Salmonella strain in contamination samples, nearly 20.45% in all isolated strains. Among the detected Salmonella, 38 strains showed obvious resistance to tetracycline, accounting for 86.36%. However, the resistance among all strains to ceftazidime, cefotaxime and cefoxitin was less than 10%. Besides, one multi drug resistance Salmonella strain was detected in this work. A total of 7 categories of antibiotics and related genes to resistance for this strain were successfully identified. This work provides detailed data analysis for the contamination of Salmonella in pork source food in Nanjing, Jiangsu province, and also provide the theoretical basis for the comprehensive control of Salmonella in the furthered period.
[中图分类号]
[基金项目]
南京市市场监督管理局重点科技项目(Kj2021046;Kj2020043);江苏省市场监督管理局科技计划项目(KJ207544)