应用DiversiLab分型系统对沙门氏菌进行同源性分析

Analysis on Salmonella for epidemic by DiversiLab typing system

目的:为研究食品污染中沙门氏菌间的同源性关系,建立起沙门氏菌基于重复序列的分型技术。通过建立DiversiLab基因图谱数据库,以便对将来不同来源的沙门氏菌的基因图谱进行即时比较,确定其同源性,进而追溯污染来源,切断传播途径,为预测预警保障食品安全提供科学依据,为防止食源性疾病的发生提供技术支持。同时进行血清分型,比较分析2种方法的优劣和之间的关系。方法:对2002～2010年福建省出入境检验检疫局从各类食品及饲料中分离出的沙门氏菌先进行血清分型,然后进行DiversiLab分型,其中包括:DNA提取,rep-PCR和微电泳芯片分离检测。rep-PCR条件:94℃预变性2min;94℃变性30s,50℃退火30s,70℃延伸90s,35个循环,最后70℃延伸3min。结果:23株沙门氏菌被分成6个血清型,DiversiLab分型能将相同血清型的菌株分为不同的亚型。同一企业来源的菌株具有同源性。结论:DiversiLab分型系统是一种快速、易于操作、高重复性、高分辨率的基因分型方法,可作为食源性疾病同源性分型工具。结论:DiversiLab分型的分辨率高于血清型,2种分型方法密切相关。

Objective： To study the relationship between of the Salmonella strains from food born, a molecular epidemiologic analysis method based on repetitive sequence was established. To establish DNA fingerprint databases of Salmonella by using DiversiLab typing system to compare Salmonella from different sourses with the Salmonella databases and determine its origin of the food borne disease, cut off the route of transmission. For forecasting and warning guarantee food security provide scientific basis, for preventing the food borne diseases provide technical support. Simultaneously, being serotype, comparative analysis of the two methods of quality and their correlation with serovar. Methods： At first, serotyped the Salmonella spp. which was isolated from each kind of food and feed in Fujian entry-exitinspection and quarantine bureau from 2002 to 2010, then typed by DiversiLab typing which include DNA extraction, rep-PCR, separated and detected by microfluidic chip. Thermal cycling parameters were as follows： initial denaturation at 94 % for 2 min, 35 cycles of denaturation at 94 %： for 30 s, annealing at 50 %： for 30 s, extension at 70 %： for 90 s, and a final extension at 70 %： for 3 min. Results： Of 23 Salmonella strains analyzed, all the Salmonella strains divided into 6 serovar. The same serotype strains could be typed different subtypes by DiversiLab typing. Conclusion： DiversiLab typing system is a fast, feasible operating, high reproducibility and high discriminatory gene typing method. It is recommended as a epidemic analysis tool for foodborne illness. DJversJLab typing has better discriminatory than serotyping, the two kinds of typing methods are closely related.