布氏田鼠鼠疫菌102 kb pgm基因座结构研究

目的　研究布氏田鼠鼠疫菌株 1 0 2kbpgm基因座结构与其他类型鼠疫菌是否有区别 ,及其与布氏田鼠鼠疫菌株的独特特征的关系。方法　采用聚合酶链反应 (PCR)的方法 ,共设计 2 5对嵌套的引物 ,以喜玛拉雅旱獭鼠疫菌株和布氏田鼠鼠疫菌株的染色体DNA为模板 ,分段扩增该区域内的DNA ,选择差异较大的扩增片段进行克隆和测序 ,与已发表的序列比较。结果　布氏田鼠鼠疫菌株的 1 0 2kbpgm基因座一端缺失了1 952个碱基 ,即插入序列IS1 0 0。另外 ,在测序的这段基因中 ,一类似于可变数量串联重复序列 (VNTR)的区域 ,布氏田鼠鼠疫菌比已发表的序列多出几个拷贝。结论　布氏田鼠鼠疫菌株的 1 0 2kbpgm基因座序列改变了 ,一端缺失了插入序列IS1 0 0 ,这就使得它的毒力岛不容易丢失 ,保持了 pgm+表现型的稳定 ;与其毒力的关系 ,有待于进一步研究

Yersinia pestis 102 KB PGM loci m. brandti structure research

Objective To find out the differences between 102 kb pgm locus of Yersinia pestis isolated from Microtus brandti with of other types,and the characters of Yersinia pestis isolated from Microtus brandti caused by their makeup of the 102 kb pgm locus. Methods 102 kb pgm locus of Yersinia pestis isolated from Microtus brandti and Yersinia pestis isolated from Marmota himalayana were amplified by polymerase chain reation (PCR) with 25 pair of nested primers. The PCR products of one pair of primer were obviously different,and then cloned and sequenced. Sequences were searched against current protein and nucleotide databases, using BLAST. Results The 102 kb pgm locus of Yersinia pestis isolated from Microtus brandti was devoid one IS100.In addition,it had more copies than other types in the similar variable number tandem repeat sequences. Conclusion The 102 kb pgm locus of Yersinia pestis was different from that of other types.It had only one IS100 flanked it,which corresponded to the character that its pgm + phenotype was stable. Further study was needed to confirm the relationship between the diminution virulence of Yersinia pestis isolated from Microtus brandti and the loss of IS100 and other changes.