目的 掌握陕西省鼠疫耶尔森菌分离株的MLVA基因分型特征,阐明不同疫情年份菌株间的遗传进化关系,为今后陕西省鼠疫的监测防治工作提供科学依据.方法 采用MLVA(14+12)方法,对分离 自陕西省鼠疫疫源地的66株鼠疫耶尔森菌进行基因分型,利用BioNumerics(Version7.6)软件对分型结果进行聚类分析.结果 66株鼠疫耶尔森菌分为A、B、C群,根据分离时间聚集成为相应群,A群包含42株菌,其中39株菌分离自2000-2001年,B群包含16株菌,其中15株分离自2006年,C群含8株菌,其中6株分离 自1987-1988年.基因型分为19种,8个基因型为多菌株基因型,其他型为单菌株基因型.结论 陕西省鼠疫菌MLVA基因型具有多态性,不同疫情年份菌株主导的基因型不同,MLVA分型能够很好区分陕西省不同年代鼠疫菌株,可用于鼠疫菌株的溯源分析.

目的 采用多位点可变数目串联重复序列(MLVA)对甘肃省鼠疫耶尔森菌(鼠疫菌)进行基因分型,探讨甘肃省鼠疫菌地区分布特征.方法 选取1962-2014年间甘肃省各市县(区)不同生态型的鼠疫菌198株,培养并提取基因组DNA.采用14+12对引物进行PCR扩增,产物进行测序,确定每对引物串联重复序列(VNTR)位点的拷贝数.应用BioNu-merics 5.10软件对菌株的VNTR位点拷贝数进行聚类分析.结果 甘肃省鼠疫菌分为10个群,群内的菌株依据分离地点继续细化为5-28个分支.10个群分别为:阿拉善黄鼠疫源地菌株聚为1个群;甘南高原疫源地菌株聚成1个群;阿克塞县菌株分成2个群,为当金山群和加尔乌宗村群;肃北县菌株分为3个群,为马场群、党城湾镇群和鱼儿红群;玉门市菌株聚集在肃北县鱼儿红群内;肃南县菌株分为3个群,为大河乡群、马蹄乡群和康乐乡群.结论 MLVA可以清晰地区分甘肃省不同鼠疫疫源地的菌株,将疫源地内菌株继续细分为不同分支,直至精确的分离地点.MLVA分型方法可用于鼠疫菌株的溯源分析.

目的 对河北省鼠疫菌株进行规律聚集间隔短回文重复序列CRISPR)基因分型.方法 利用聚合酶链式反应(PCR),采用3对CRISPR引物,对河北省分离的128株鼠疫菌进行扩增,测定扩增产物核酸序列并进行分析,确定河北省菌株CRISPR基因型.结果 128株鼠疫菌在3个CRISPR位点上有8种间隔序列,包括al、a2、a3、b1、b2、c1、c2、c3,分为2个基因型.118株鼠疫菌株为Cb2型,另外10株鼠疫菌均为新基因型(命名为Cc△1型).结论 通过CRISPR分析显示河北省鼠疫菌株遗传进化比较稳定,建立了CRISPR基因库,为鼠疫菌种群遗传进化和鼠疫防控的研究提供参考.

Objective: To study the clustered regularly interspaced short palindromic repeats (CRISPR) loci polymorphism of Yersinia pestis and its area distribution in Gansu province. Methods: A total of 203 strains of Yersinia pestis isolated from 1962 to 2014 were selected for the culture and extraction of DNA. Three pairs of CRISPR primers were used to amplify the strain DNA by PCR, and the PCR products were sequenced. The groups and genotypes of strains were determined according to the spacer and spacer arrangement of CRISPR loci in the strain. Cluster analysis was done by using the software BioNumerics 5.10. Results: A total of 16 spacers, including 9 species of YPa loci, 4 species of YPb loci and 3 species of YPc loci, were found in the 203 strains of Yersinia pestis. A new spacer of a1' was found. The 203 strains were divided into 5 CRISPR genotypes and classified into 5 CRISPR clusters (Cb2, Ca7, Ca7', CaΔ5' and Ca35'). Each cluster showed significant area-specific characteristics, Cb2 was mainly distributed in Huining country and Pingchuan district, Ca7 was mainly found in Aksai Kazak autonomous country, Ca7' was mainly found in Xiahe country, Ca35' was mainly found in Subei Mongolia autonomous county and Yumen city and CaΔ5' was mainly distributed in Sunan Yugur autonomous county. Conclusions: The strains from different plague foci in Gansu were distinguished by CRISPR, all kinds of clusters showed the obvious area specific characteristics. It is important to study the evolution of Yersinia pestis in Gansu and trace the molecular biology origin of human plague.

目的 研究河北省鼠疫菌株多位点可变数串联重复序列(multiple-locus variable-number tandem-repeat analysis,MLVA)分型特征,分析其流行病学意义.方法 采用MLVA(14+ 12)分型策略设计引物.利用聚合酶链式反应(PCR)、毛细管电泳方法和Bio Numerics软件,对河北分离的鼠疫菌进行聚类分析.结果 在选取的鼠疫菌26个可变数串联重复序列(variable number of tandem repeats,VNTR)位点中,8个VNTR位点对河北省鼠疫菌具有遗传多态性分析意义.河北省鼠疫疫源地分离到的128株鼠疫菌可分为2个群,15个基因型.结论 通过MLVA分析显示河北鼠疫菌株具有多态性,基因遗传变异相对稳定,对于未来鼠疫疫情暴发溯源和鼠疫菌种群的研究具有指导意义.