Tong Zongzhong, Zhou Dongsheng, Song Yajun, Zhang Ling, Pei Decui, Han Yanping, Pang Xin, Li Min, Cui Baizhong, Wang Jin, Guo Zhaobiao, Qi Zhizhen, Jin Lixia, Zhai Junhui, Du Zongmin, Wang Jun, Wang Xiaoyi, Yu Jun, Wang Jian, Huang Peitang, Yang Huanming, Yang Ruifu
Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, No. 20 Dongdajie, Fengtai, Beijing 100071, China 2Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, China 3Qinghai Institute for Endemic Diseases Prevention and Control, Xining 811602, China.
J Med Microbiol. 2005 Mar;54(Pt 3):259-268. doi: 10.1099/jmm.0.45752-0.
Plague is a natural focus-based disease, and for better understanding of this disease it is crucial to determine the molecular mechanisms of its pathogen, Yersinia pestis, for adapting to different foci. Gene inactivation, loss and acquisition are the main mechanisms that contribute to a pathogen's fitness. Determination of the whole-genome sequences of three Y. pestis strains, CO92, KIM and 91001, provided a good opportunity to probe into its genome in minute detail. Many genetic variations were found between the three strains. The present work focused on adaptive microevolutionary analysis of Y. pestis from different natural plague foci in China based on pseudogene profiles. Twenty-four mutations that led to inactivation in the corresponding genes were analysed, and a PCR-based screening method was employed to investigate the distribution of these mutations among Y. pestis isolates from different foci and also among seven strains of Yersinia pseudotuberculosis. It was found that Y. pestis isolates from the same focus had identical mutation profiles, and 260 isolates of Y. pestis were divided into eight genotypes, while Y. pseudotuberculosis harboured wild-type alleles for all the mutations. The isolates of three known biovars were grouped into distinct branches in the phylogenetic tree, which supports the proposition that biovars mediaevalis and orientalis directly arose from biovar antiqua individually. The constructed phylogenetic tree suggests that the isolates from focus B should be the oldest lineage of Y. pestis in China except for isolates from foci L and M, which might be a special lineage of Y. pestis and originated differently to the others.
鼠疫是一种自然疫源性疾病，为更好地了解这种疾病，确定其病原体鼠疫耶尔森菌适应不同疫源地的分子机制至关重要。基因失活、丢失和获得是影响病原体适应性的主要机制。对三株鼠疫耶尔森菌CO92、KIM和91001进行全基因组测序，为深入细致地探究其基因组提供了良好契机。这三株菌之间存在许多基因变异。本研究基于假基因图谱，对来自中国不同自然鼠疫疫源地的鼠疫耶尔森菌进行适应性微进化分析。分析了导致相应基因失活的24个突变，并采用基于聚合酶链反应的筛选方法，研究这些突变在来自不同疫源地的鼠疫耶尔森菌分离株以及7株假结核耶尔森菌中的分布情况。结果发现，来自同一疫源地的鼠疫耶尔森菌分离株具有相同的突变谱，260株鼠疫耶尔森菌分离株被分为8个基因型，而假结核耶尔森菌的所有突变均为野生型等位基因。三种已知生物变种的分离株在系统发育树中被归为不同分支，这支持中世纪生物变种和东方生物变种分别直接起源于古生物变种的观点。构建的系统发育树表明，除来自疫源地L和M的分离株外，来自疫源地B的分离株可能是中国鼠疫耶尔森菌最古老的谱系，疫源地L和M的分离株可能是鼠疫耶尔森菌的一个特殊谱系，其起源与其他谱系不同。
