三江源地区鼠疫耶尔森菌CRISPR基因分型及流行特征研究

Research on the CRISPR genotyping and epidemic characteristics of Yersinia pestis in the Sanjiangyuan region

目的了解三江源地区鼠疫菌株分布情况,进行规律间隔成簇短回文重复序列(Clustered regularly in-terspaced short palindromic repeats)基因分型研究,为该地区鼠疫疫源地菌株鉴定溯源、科学防控提供理论依据。方法选取三江源地区310株鼠疫菌提取DNA,分别PCR扩增、测序3个CRISPR的位点YPa、YPb和YPc,所测得CRISPR序列与CRISPR Dictionary数据库最新数据进行比对,鉴定CRISPR spacer阵列并对三江源地区鼠疫菌进行基因分型。对310株鼠疫菌结合CRISPR基因型和分离宿主信息进行统计分析。结果310株鼠疫菌共发现26种spacer,分别为YPa15种、YPb8种、YPc3种;310株鼠疫菌被分成16个不同CRISPR基因型,G22型和G22-a1′型分布于整个三江源地区包括称多县、治多县、玉树市、曲麻莱县、囊谦县、杂多县、玛多县、玛沁县、同仁县、泽库县、共和县、同德县、贵德县;G24型分布于泽库县、玛多县、囊谦县、称多县;G26-a1′型主要分布于共和县、兴海县、贵德县、玛多县、称多县、杂多县,16个基因型归类为7个CRISPR类群:Cb4、Cb4′、Ca7、Ca7′、Ca8、Ca35′、Cc3′。结论三江源地区鼠疫菌CRISPR基因型具有多样性,不同疫源地基因型分布特征显著,且不同菌株基因型存在差异。

Objective To understand the distribution of Yersina pestis and conduct the Clustered Regularly Interspaced Short Palindromic Repeat(CRISPR)genotyping in Sanjiangyuan regionto provide scientific basis for Y pestis identification,tracing,plague detection and control in the region Methods The DNA was extracted from 310 strains of Y.pestis in the Sanjiangyuan region.The three CRISPR loci of YPa,YPb and YPc were amplified and sequenced by PCR respectively,and then the CRISPR sequences measured were compared with the latest data of CRISPR Dictionary database to identify CRISPR spacer array and genotype Y.pestis in the Sanjiangyuan region The CRISPR genotypes and isolated host formation of 310 strains of Y.pestis were analyzed statistically Results Twenty-six spacers including 15 of YPa,8 of YPb and 3 of YPc were observed among 310 isolates of Y.pestis.The 310 strains of Y.pestis were divided into 16 different CRISPR genotypes.G22 and G22-a1′were distributed in the entire Sanjiangyuan region,including Chengduo County,Zhiduo County,Yushu City,Qumalai County,Nangqian County,Zado County,Maduo County,Maqin County,Tongren County,Zeku County,Gonghe County,Tongde County and Guide County.G24 distributed in Zeku County,Maduo County,Nangqian County,Chengduo County;G26-a1′type is mainly distributed in Gonghe County,Xinghai County,Guide County,Maduo County,Chengduo County,Zadoi County.The 16 genotypes were grouped into seven CRISPR groups:Cb4,Cb4′,Ca7,Ca7′,Ca8,Ca35′and Cc3′.Conclusion The CRISPR have diversity genotypes of Y.pestis in Sanjiangyuan region,and the genotypes of different foci have significant distribution characteristics,and the genotypes of different strains are different.