联合应用分子血清分型与二元基因分型检测单核细胞增多性李斯特菌的研究

Detection of Listeria monocytogenes isolates by combinated molecular serotyping and binary gene typing

目的了解食品中单核细胞增多性李斯特菌(LM)的分子血清型分布,并探索二元基因分型方法在LM分型检测中的意义。方法对2005年-2012年间河北省分离自食品的154株LM进行分子血清分型与二元基因分型分析。结果 154株LM中,1/2a型菌株最多,占52.60%,其次为1/2c型(22.08%)、1/2b型(15.58%)和4b型(9.74%)。二元基因分型可将154株LM分为31个BT(Binary Type)型,分辨力(DI值)为92.28%。二元基因型与分子血清型综合分析,可将154株LM分为34个型别,DI值为92.56%。通过对进化树分析可见,大多数BT型仅见于一种血清型,仅少数BT型见于2种血清型,提示二元基因型和分子血清型是否存在一种紧密的关系,尚需进一步研究证明。结论分子血清分型与二元基因分型综合应用于LM的分型研究,分型能力强,且具有操作简便、快速、高通量的优势,便于推广,可应用于暴发确认与溯源检测。

Objective To investigate the molecular serotyping distribution of Listeria monocytogenes（ LM） in food,so as to explore the value of binary gene typing in the typing detection of LM. Methods A total of 154 food-borne Listeria monocytogenes isolates were typed by molecular serotyping and binary gene typing,which were collected from 2005 to 2012. Results Among the 154 LM isolates,the major serotype was 1 /2a（ 52. 60%）,followed by 1 /2c（ 22. 08%）,1 /2b（ 15. 58%） and 4b（ 9. 74%）. Binary gene typing divided 154 isolates into 31 binary types（ BTs） and the Simposon＇s index of diversity（ DI） was92. 28%. But the combination of molecular serotyping and binary gene typing divided 154 isolates into 34 BTs,the Simpson＇s index of diversity（ DI） was 92. 56%. Analyzed by the evolutionary tree,most of the BTs belonged to one serotype,but a few of the isolates belonged to two serotypes,it still need to see the relationship between binary gene typing and molecular serotyping.Conclusion Combined binary gene typing with molecular serotyping would be useful for the subtyping of Listeria monocytogenes isolates. These two methods were simple,rapid,high-throughput and easy to promote,and can be used in the outbreak identification and sourcing detection.