一起由肠炎沙门菌引起食物中毒事件的病原学检验分析

Etiological analysis of a food poisoning incident caused by Salmonella enteritidis

目的通过脉冲场凝胶电泳(pulsed-field gel electrophoresis,PFGE)技术分析一起食物中毒事件病原菌的相关性,从遗传学确定该起事件发生的原因。方法参照《感染性腹泻诊断标准》(WS 271—2007),对采集的肛拭子和可疑食物等样品进行病原菌培养、分离和鉴定。利用脉冲场凝胶电泳对分离菌株进行分子分型,采用Bio Numerics 5.1软件开展相关性分析。药敏试验的方法为微量肉汤稀释法。结果本起食物中毒事件共分离到4株肠炎沙门菌,分别分离自患者肛拭子(2株)、厨师肛拭子(1株)与可疑食物(1株)。4株分离菌对7种抗生素存在不同程度的耐药性;PFGE溯源性分析结果显示,4株分离菌呈现高度同源。结论本起食物中毒事件由食用被肠炎沙门菌污染的食物所致。分离株的多重耐药性应引起相关部门的重视。PFGE分子分型从全基因组的层面分析菌株的遗传学关系,是病原菌溯源研究的重要手段。

Objective To analyze the correlation between pathogens of a food poisoning event by pulsed field gel electrophoresis(PFGE),and to determine the cause of the event from the perspective of genetics.Methods According to the Diagnostic Criteria for Infectious Diarrhea(WS 271—2007),the anal swabs and suspect food samples collected were cultured,isolated and identified.Molecular typing of the isolated strains was performed by pulsed field gel electrophoresis,and correlation analysis was performed by Bio Numerics 5.1 software.The method of drug sensitivity test was microbroth dilution.Results A total of 4 strains of Salmonella enteritidis were isolated from the anal swab of the patient(2 strains),the cook(1 strain)and the suspicious food(1 strain).The 4 isolates had different degrees of drug resistance to 7 antibiotics.The results of PFGE traceability analysis showed that the four isolates were highly homologous.Conclusion This food poisoning incident is caused by eating food contaminated with Salmonella enteritidis.Relevant departments should pay attention to the multiple drug resistance of isolates.PFGE molecular typing is an important method of pathogen tracing to analyze the genetic relationship between bacterial strains from the whole genome level.