湖北省水产品中单增李斯特菌基因分型研究

Molecular typing of Listeria monocytogenesisisolated from the fishery products in Hubei province

目的对湖北省水产品中近几年分离的47株单增李斯特菌(Listeriamonocyt-ogenesis,LMO)16S rRNA～23S rRNA间断序列进行分子生物学研究,探讨利用该序列进行LMO检测以及对LMO进行基因分型的可能性,为建立湖北省水产品中LMO污染模型和追踪LMO污染路线提供依据。方法利用本试验设计的引物对47株LMO分离株间断序列进行PCR扩增、测序、同源性分析、构建进化树,采用水产品中常检致病菌进行特异性验证。结果47株LMO分离株与LMOstr.4b F2365〔gi:85700163〕间断序列同源性不一,各分离株间主要有碱基插入和突变现象发生;构建的进化树将47株LMO分离株分为3大类。结论LMO间断序列可对LMO分离株进行亚分型和鉴别;各分离株间断序列发生的突变、插入等变化与样本种类和样本来源地有明显关联关系。

In the present study,the 16-23S rRNA intergenic spacer region of 47 Listeria monocytogenesis （LMO） isolated from the fishery products in Heibei province was investigated in order to establish a method of detecting the presence of LMO by using this specific sequence and to perform the molecular typing of all the isolates to provide data for the pollution model and the pollution source trace line of LMO in fishery products,a couple of primers was designed based on the intergenic spacer region of LMO str 4b F2365,and, the inter-sequence genes were amplified and sequenced. Then,the homology of the isolates was analyzed and their phylogenetic tree was constructed. It was found that the homology of the inter-sequence genes varied a great deal with those of the standard strain LMO str 4b F2365[gi：8570 0163], from 93% to 100% ,with base-insertion and mutation. By the analysis from the phylogenetic tree constructed ,these 47 strains of LMO could be divided into 3 main subtypes. It is apparent that the inter-sequence of LMO can be used in the subtyping of isolates with certain differentiating ability; the diversities of the isolates may be associated with the types and origins of the samples.