2008-2019年德格县鼠疫疫源地鼠疫耶尔森菌MLVA分型研究

Study on MLVA Typing of Yersinia Pestis in Dege County of Sichuan Province

目的对四川省德格县鼠疫自然疫源地的24株鼠疫耶尔森菌(Y.pestis)做多位点可变数目串联重复序列(MLVA)分型研究,为四川省鼠疫菌进化研究提供科学依据。方法依据"14+12"对可变数目串联重复序列(VNTR)引物,对24株鼠疫菌进行MLVA分析,计算鼠疫菌基因在不同VNTR位点的重复数,使用Bio Numerics v7.6软件对结果进行聚类分析。结果德格县24株鼠疫菌在M15、ms09、N2896、N2117和M25这5个VNTR位点的重复数有差异,其余21个VNTR位点的重复数相同。德格县24株鼠疫菌聚类为2大群,3个小群,其中2008年、2009年和2010年的鼠疫菌株聚为Ⅰ群,2008年和2009年的鼠疫菌株为ⅠA群,2010年菌株为ⅠB群;2015年鼠疫菌株单独聚为Ⅱ群。结论德格县鼠疫菌的基因不断发生微进化,以适应新的环境,这也是该地鼠疫持续流行的驱动原因。

Objective We studied 24 strains of Yersinia pestis in Dege County of Sichuan Province by MLVA analysis so that to provide a scientific basis for plague bacteria evolution.Methods According to"14+12"VNTR primers,we analyzed 24 strains of Yersinia pestis which was isolated from Dege county by the methods of MLVA.We calculated the VNTR loci repeat numbers of yersinia pestis genes,then we analyzed it by Bio Numerics v7.6 software for cluster results.Results On M15,ms09,N2896,N2117 and M25 VNTR loci,the repeat number of 24 strainswere difference.The repeat number of other 21 VNTR loci were same.The 24 strains of Yersinia pestis which was isolated from Dege county were divided into two big groups and three small groups,among them,the plague strains of 2008,2009 and 2010 years wereⅠgroup(the plague strains of 2008 and 2009 years wereⅠA group and the plague strains of 2010 years wereⅠB group),the plague strains of 2015 years wereⅡgroup.Conclusion The microevolution of genes 24 strains is constantly so that to adapt to the new environment,also it is the engine of the plague epidemic in local area.