一起肠炎沙门菌引起的食物中毒检测及菌株同源性分析

检测食物中毒样品中致病菌,分析其同源性,为追踪污染源、明确病因诊断提供帮助,为控制和减少食物中毒提供依据。方法 荧光定量PCR快速筛检致病菌,参照GB 4789.4—2010《食品安全国家标准 食品卫生微生物检验 沙门氏菌检验》分离致病菌,全自动细菌鉴定仪鉴定致病菌,脉冲场凝胶电泳(PFGE)分析同源性。结果 从21份病人和从业人员粪便样品中检出8株肠炎沙门菌,9份食品样品中检出2份肠炎沙门菌,检出率分别为25.00%和6.25%；食堂用水及井水检测均未检出肠炎沙门菌等致病菌。荧光定量PCR法阳性率结果与GB 4789.4—2010方法一致。PFGE分型显示10株肠炎沙门菌的DNA条带图谱完全一致,相似性100%,聚类分析为同一型,表明菌株来自同一克隆系。结论 采用荧光定量PCR筛检能提示食物中毒样品中病原菌是否存在的信息,通过GB 4789.4—2010方法仔细寻找到目标菌,两法联合使用能快速、准确地检测出引起食物中毒的致病菌。运用PFGE对致病菌进行溯源,分析其亲缘关系,能追踪到菌株来源,有利于防止食物中毒的发生。

Determination,tracing and homology analysis of a food poisoning case caused by Salmonella enteritis

To detect the pathogens of food poisoning samples and analyze the homology, help to trace the sources of contamination and clarify etiology diagnosis, and provide the basis for the prevention and control of food poisoning.MethodsThe pathogens were screened by fluorescence quantitative PCR , isolated according to the GB method, identified by ATB method, and the homology was analyzed by PFGE.Results8 strains of Salmonella enteritis were separated from 21 patients or operators, 2 strains were from 9 food samples. The detection rate were 25.00% and 6.25% respectively. Salmonella was not detected from water samples from canteen and well. Positive rates were the same for real-time fluorescent quantitative PCR and GB method. PFGE patterns of the 10 Salmonella enteritis were the same for cluster analysis.ConclusionThe food poisoning case was caused by the same clone of Salmonella enteritis. Real-time fluorescent quantitative PCR was helpful for rapid examination for pathogenic bacteria. GB method was important for the separation of Salmonella enteritis, and the above 2 methods could increase the detection rate and shorten the time spent. PFGE method could analyze the homology of the pathogenic bacteria, trace the source and was helpful to prevent and control food poisoning.