摘要
目的对甘肃省2起传染源不明的人间鼠疫疫情分离菌株进行溯源分析,为针对鼠疫传染源隔离防控提供依据。方法采用差异区段(DFR)和规律成簇的间隔短回文重复序列(CRISPR)对2017年12月12日和2019年9月27日发生的2起人间鼠疫疫情分离的鼠疫菌进行基因分型。采用多位点可变数目串联重复序列分析(MLVA)方法确定待测鼠疫菌VNTR位点的重复数,应用BioNumerics 6.6软件中最小生成树法聚类分析确定待测菌株在甘肃省鼠疫疫源地分离鼠疫菌的系统发育树位置。结果菌株20171212缺失DFR01、DFR02、DFR03、DFR04、DFR13、DFR23,DFR分型为8型;CRISPR间区序列YPa为a1'-a2-a3-a4-a5-a6-a7-a35,YPb为b1-b2-b3-b4,YPc为c1-c2-c3,基因簇为Ca35',基因型为26';MLVA聚类分析显示菌株聚在肃北县鱼儿红牧场簇内,并成为独立分支;菌株20190927缺失DFR01、DFR13、DFR23,DFR分型为1b型;CRISPR间区序列YPa为a1-a2-a3-a4-a5-a6-a7,YPb为b1-b2-b3-b4,YPc为c1-c2-c3,基因簇为Ca7,基因型为22型;MLVA聚类分析在最小生成树的位置靠近阿克塞县当金山簇,与肃北县鱼儿红牧场簇较远。结论菌株20171212的DFR和CRISPR基因型与肃北县喜马拉雅旱獭疫源地鼠疫菌的主基因型一致,证实人间疫情病例由本地自然发生,但最小生成树中聚在肃北县鱼儿红牧场簇内,表明病例最初接触传染源地方不是盐池湾乡,而是肃北县鱼儿红牧场周边范围内。菌株20190927的DFR和CRISPR基因型与阿克塞县喜马拉雅旱獭疫源地鼠疫菌的主基因型一致,且最小生成树位置上更靠近阿克塞县当金山簇,与肃北县鱼儿红牧场簇较远,证实2019年人间疫情病例是放牧地方接触传染源。
Objective To conduct a molecular epidemiological tracing and analysis of Yersinia pestis strains isolated from two human plague outbreaks with unknown sources in Gansu Province,China.The results of this analysis would provide a basis for isolating and controlling the sources of Yersinia pestis.Methods The strains of Yersinia pestis isolated from two human plague outbreaks occurring on December 12,2017,and September 27,2019 were genotyped by the different region(DFR)and the clustered regularly interspaced short palindromic repeats(CRISPR).The repeat numbers of the variable number tandem repeat(VNTR)loci in the tested strains of Yersinia pestis were calculated by the multiple variable number tandem repeats analysis(MLVA),and the location of the phylogenetic tree of the tested strains was determined with the method of minimum spanning tree(MST)by the software BioNumerics 6.6.Results The strain of 20171212 lacked DFR01,DFR02,DFR03,DFR04,DFR13,DFR23,and the DFR type was identified as type 8.The space sequence of YPa was a1'-a2-a3-a4-a5-a6-a7-a35,the space sequence of YPb was b1-b2-b3-b4,the space sequence of YPc was c1-c2-c3,the gene cluster of CRISPR was Ca35',the genotype of CRISPR was 26'.MLVA clustering analysis showed that the strain clustered within in the cluster of Yuerhong pasture in Subei County and formed an independent branch.On the other hand,the strain of 20190927 lacked DFR01,DFR13 and DFR23,with the DFR type identified as type 1b.The space sequence of YPa was a1-a2-a3-a4-a5-a6-a7,the space sequence of YPb was b1-b2-b3-b4,the space sequence of YPc was c1-c2-c3,the gene cluster of CRSIPR was Ca7,the genotype of CRSIPR was 22 MLVA clustering analysis showed that the strain was located close to the cluster of Dangjinshan in Akesai County,and relatively distant from the cluster of Yuerhong pasture in Subei County.Conclusions The genotypes of strain 20171212 by DFR and CRISPR were consistent with the main genotypes of Y.pestis from Himalayana Marmota foci in Subei County,which confirmed that the human plague cases were naturally occurring locally.However,the strain gathered the cluster of Yuerhong pasture in Subei County,which indicated that the source of infection was not in Yanchiwan Town,but in the surrounding area of the Yuerhong pasture.The genotypes of strain 20190927 by DFR and CRISPR were in accordance with the main genotype of Y.pestis from Himalayana Marmota foci in Akesai County and were closer to the cluster of Dangjinshan in Aksai County than to.
作者
郭丽民
何爱伟
席进孝
吴斌
王鼎盛
徐大琴
张晓燕
GUO Limin;HE Aiwei;XI Jinxiao;WU bin;WANG Dingsheng;XU Daqin;ZHANG Xiaoyan(Department of Plague Control and Prevention,Gansu Provincial Center for Disease Control and Prevention,Lanzhou,Lanzhou,Gansu 730020,China;Department of Plague Control and Prevention,Jiuquan Center for Disease Control and Prevention,Jiuquan,Gansu 735000,China)
出处
《中国热带医学》
CAS
2023年第10期1077-1081,共5页
China Tropical Medicine
基金
甘肃省自然科学基金项目(No.22JR11RA185)。
