2019年北京市食源性单增李斯特菌的分子特征和耐药性研究

Molecular characteristics and drug resistance of foodborne Listeria monocytogenes in Beijing in 2019

目的研究2019年北京市食源性单增李斯特菌的分子特征和耐药性。方法采用多重PCR进行血清群分型,分离的56株菌株经脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)、多位点序列分析(multilocus sequence typing,MLST)鉴定,使用微量肉汤法检测菌株的耐药性。结果56株单增李斯特菌中有28株分离自冷锅串串和中式凉拌菜,1/2a,3a是主要的血清群。56株菌共分为29个PFGE带型、14个ST型,ST9、ST5、ST8、ST121是优势ST型。2株菌对环丙沙星耐药,1株菌对四环素耐药。结论冷锅串串和中式凉拌菜是单增李斯特菌污染的高危食品。北京市食品来源单增李斯特菌的ST型别与国内其他地方食品来源菌株一致,与北京市临床分离株一致。

Objective To study the molecular characteristics and antimicrobial resistance of Listeria monocytogenes isolated from food in Beijing in 2019.Methods Serogroup were typed by mutiplex PCR,the 56 strains isolated were identified by pulsed field gel electrophoresis(PFGE)and multilocus sequence analysis(MLST),and the drug resistance of the strain was detected by trace broth method.Results Among the 56 strains of Listeria monocytogenes,28 strains were isolated from cold pot strings and Chinese salad,and 1/2 a and 3 a were the main serum groups.The 56 strains were divided into 29 PFGE bands and 14 ST types,ST9,ST5,ST8 and ST121 were the main ST types,2 isolates were resistant to ciprofloxacin and 1 isolate were resistant to tetracycline.Conclusion Cold pot string and Chinese cold dishes are high risk food contaminated by Listeria monocytogenes.The ST type of Listeria monocytogenes from food sources in Beijing is consistent with that from other food sources in China and clinical isolates in Beijing.