Genetic clustering and virulence of Y. pestis strains

描述(申请人提供)：鼠疫耶尔森氏菌是鼠疫的病原体，于20世纪初传入美国；因此，美国鼠疫耶尔森氏菌分离株的遗传和表型多样性相对有限。相比之下，鼠疫杆菌在前苏联(FSU)的许多国家流行了许多世纪，FSU文献中大量与鼠疫杆菌相关的出版物强烈表明，FSU的鼠疫杆菌菌株在遗传上比美国的鼠疫杆菌分离株更加多样化。在开发先进的工具和策略以应对美国和其他地方可能发生的与鼠疫菌有关的生物恐怖主义袭击时，了解菌株之间的遗传和毒力特征差异将是至关重要的。因此，我们建议开始对来自FSU高加索地区几个鼠疫疫源地的鼠疫菌株进行全面的表征，并开始描述来自FSU和其他地方的鼠疫菌株的遗传组成和毒力特征之间的关键差异。我们将致力于三个具体目标：(1)鉴定来自FSU的鼠疫杆菌菌株的基因组变异性，并进行比较MLST、PFGE和MLVA分析以进行鼠疫杆菌指纹图谱分析；(2)鉴定FSU的鼠疫杆菌分离株的质粒组分，并对选定的质粒和染色体编码的毒力基因进行基于核苷酸序列的分析；以及(3)利用微阵列和RT-PCR开始阐明主要毒力基因在FSU的鼠疫菌分离株中的流行率和表达模式。R21拨款机制非常适合支持我们提出的研究，它将帮助我们产生有关鼠疫杆菌分离株的基因组成和基因表达模式的重要信息/初始数据，以前FSU以外的研究人员无法获得这些信息，目前获得的信息也很少。生成的数据还将在我们设计适当的未来研究以及扩大我们在马里兰大学医学院的鼠疫研究计划方面发挥关键作用。

DESCRIPTION (provided by applicant): Y. pestis, the etiologic agent of plague, was introduced into the United States at the turn of the 20th century; therefore, the genetic and phenotypic diversity of American Y. pestis isolates is relatively limited. In contrast, Y. pestis has been endemic in many countries of the former Soviet Union (FSU) for many centuries and numerous Y. pestis-related publications in the FSU's literature strongly suggest that the FSU's Y. pestis strains are genetically more diverse than are American Y. pestis isolates. Understanding the genetic and virulence trait differences among strains will be of critical importance during the development of advanced tools and strategies to deal with possible Y. pestis-related bioterrorism attacks in the USA and elsewhere. Therefore, we propose to begin a comprehensive characterization of Y. pestis strains from several endemic loci of plague in the FSU's Caucasus region, and to begin delineating the critical differences between the genetic make-up and virulence traits of Y. pestis strains from the FSU and elsewhere. Three specific aims will be addressed: (1) Characterize the genomic variability of Y. pestis strains from the FSU, and perform comparative MLST, PFGE, and MLVA analyses for Y. pestis fingerprinting, (2) Characterize the plasmid compositions of the FSU's Y. pestis isolates, and perform nucleotide sequence-based analyses of selected plasmid- and chromosomally-encoded virulence genes, and (3) Begin elucidating the prevalence and the expression patterns of major virulence genes in the FSU's Y. pestis isolates, using microarrays and RT PCR The R21 grant mechanism is ideally suited for supporting our proposed studies, and it will help us to generate important information/initial data concerning the genetic make-up and gene expression patterns of Y. pestis isolates previously unavailable to investigators outside the FSU, and for which very little information is currently available. The generated data will also play a critical role in our designing appropriate future studies, and in expanding our Y. pestis research program at the University of Maryland School of Medicine.