单核细胞增生李斯特菌食品分离株的分子分型鉴定

Characterization of Listeria monocytogenes Isolates from Foods by Molecular Subtyping

单核细胞增生李斯特菌是一种重要的食源性条件致病菌,不同亚型菌株的致病力存在较大差异。本文以86株单核细胞增生李斯特菌食品分离株为研究对象,采用多重PCR的血清分型方法 ,将这些分离株分为3个血清组,即:1/2a或3a(72.1%,n=62),1/2b或3b或7(19.8%,n=17),1/2c或3c(8.1%,n=7)。采用ERICPCR亚分型方法 ,将这些分离株和4株标准菌株分为10个类群。对比ERIC-PCR的指纹图谱与血清分型结果 ,两者呈现较高的相关性。将血清分型和ERIC-PCR方法相结合,可实现不同来源单核细胞增生李斯特菌食品分离株的同源性分析。这些分型结果为该菌的流行病学调查提供数据支持。

Listeria monocytogenes is a major foodborne pathogen,which generally causes human illness including meningitis,meningoencephalitis and abortion.In this study,our aim was to characterize a total of 86 L.monocytogenes food isolates in Shanghai by serotyping and enterobacterial repetitive intergenic consensus-polymerase chain reaction （ERIC-PCR） subtyping analyses.All the isolates were serotyped by multiplex PCR assays into three serogroups：1/2a or 3a （72.1%,n =62）,1/2b or 3b or 7 （19.8%,n =17） and 1/2c or 3c （8.1%,n =7）.At the relative similarity coefficient of 0.80,86 isolates and 4 reference strains were identified into 10 clusters and 8 singletons by ERIC-PCR.It was found that the L.monocytogenes isolates sharing the same serogroup could be clustered together by ERIC-PCR at a certain relative similarity coetficient,while isolates belonging to the same serogroup could be efficiently distinguished according to diverse ERIC-PCR profiles.Furthermore,our results will provide the fundamental data for epidemiological surveillance of L.monocytogenes.