一起沙门菌引起的食源性疾病爆发的溯源分析

目的:对一起沙门菌引起的食源性疾病爆发进行溯源分析。方法:采用GB4789法对采集的样品进行分离及鉴定,采用16S r RNA基因分型方法及PFGE分型方法对分离的菌株进行分子生物学分析,并对爆发进行溯源分析。结果:生化及血清学结果表明,该起爆发分离的菌型为伦敦沙门氏菌。16S r RNA基因分型表明爆发所分离的菌株均为肠道沙门菌肠道亚种,菌株12 sam与其他4个菌株分子发育距离较远,均为16S r RNA基因分型的TYPE1-11型;PFGE分型结果表明菌株10 sam、16 sam、27 sam及29sam的PFGE带型相似度为100%,菌株12sam跟其他菌株相似率为96%。结论:GB4789法结果表明该起爆发是由伦敦沙门氏菌引起的,16S r RNA基因分型及PFGE分型方法的结果均表明该起食源性疾病来源一致。

Source Tracing of One Outbreak of Foodborne Disease Caused by Salmonella

Objective:To trace the source of one foodborne disease outbreak caused by Salmonella using 16S rRNA genotype method and pulsed-field gel electrophoresis.Methods:The strains (10 sam, 12 sam, 16 sam, 27 samand 29 sam) from the outbreak were isolated and characterized by using GB4789 method for the culture, biochemical and serological characteristics. And two molecular typing methods were used for genotyping for the strains. Phylogenetic affiliation of the strains was studied using 16S rRNA genotype and pulsed-field gel electrophoresis (PFGE) was used by characterizing XbaI to digest genomic DNA from Salmonella enteric.Results:The strains from this outbreak were identified as London Salmonella via culture, biochemical and serological results (GB4789); they shared the same biochemical and serological characteristics. All the strains were closely associated with Salmonella enterica subsp. Enteric and classified into TYPE1-11 via 16S rRNA genotyping, but the phylogenetic distance between strain 12 sam and the other four strains (10 sam, 16 sam, 27 sam and 29 sam) was slightly further. While, The PFGE analysis revealed that the four strains (10 sam, 16 sam, 27 sam and 29 sam) shared the same banding pattern and the similarity between the strain 12sam and the other four strains was 96 %.Conclusion:Using GB4789 and two typing approaches, we showed that this foodborne disease was caused by London . 16S rRNA genotype demonstrated excellent analytical sensitivity for tracing the source of the outbreak, and also PFGE has good discriminatory power and has proven highly reliable. Results from the present study suggest,Salmonella 16S rRNA genotype coupled with PFGE could be a useful molecular diagnostic method that could enhance the current diagnostic and surveillance methods of Salmonella infections.