应用DiversiLab分型系统对奶制品中的阪崎肠杆菌进行同源性分析

Apply the DiversiLab typing system for epidemic analysis in Enterobacter sakazakii from dairy products

为研究奶制品污染中阪崎肠杆菌的同源性关系,并建立起阪崎肠杆菌基于重复序列的分型技术。对2005-2006年福建省出入境检验检疫局从各类奶制品中分离出的阪崎肠杆菌先进行API鉴定,然后进行DiversiLab分型。其中DiversiLab分型包括:DNA提取,rep-PCR和微电泳芯片分离检测。rep-PCR条件为:94℃预变性2 min;94℃变性30 s,55℃退火30 s,70℃延伸90 s,35个循环;最后70℃延伸3 min。结果表明:31株阪崎肠杆菌被API分成了5种不同的生物型,DiversiLab分型能将阪崎肠杆菌分为不同的亚型,但它们之间没有必然的联系。部分同一企业来源的菌株具有同源性,样品的同源性与采样地无关。DiversiLab分型系统是一种快速,高效,易于操作,高重复性,高分辨率的基因分型方法,可作为食源性污染的同源性分型工具。

To study the cognate relations of different Enterobacter sakazakii strains from dairy products, a molecular epidemiologic analysis method based on repetitive sequence was established.At first, the 31 strains of Enterobacter sakazakii isolated from various dairy products in Fujian Entry-Exit Inspection and Quarantine Bureau from 2005 to 2006 were identified by API, then typed by DiversiLab typing which includes DNA extraction, rep-PCR., separated and detected by microfluidic chip. Thermal cycling parameters were as follows： initial denaturation at 94 ℃ for 2 rain, 35 cycles of denaturation at 94 ℃ for 30 s, annealing at 55 ℃ for 30 s, extension at 70 ℃ for 90 s, and a final extension at 70℃ for 3 rain. of 31 Enterobacter sakazakii strains analyzed, all the Enterobacter sakazakii were divided into 5 biotypes by API. The Enterobacter sakazakii strains could be typed different subtypes by DiversiLab typing, but they didn＇t have the inevitable correlation with the biotypes of the API. Some of the strains from the same enterprise sources reflected homology, but the homology of the sample had nothing to do with samplingsites. DiversiLab typing system is a fast, high efficiency, feasible operating, high reproducibility and high discriminatory gene typing method. It is recommended as a epidemic analysis tool for foodborne illness.