西沙群岛恙螨所携恙虫病东方体的序列分析

目的　用分子生物学技术鉴定西沙群岛恙虫病东方体的基因序列 ,探讨南海岛屿恙虫病疫源地的形成。方法　以巢式聚合酶链反应 (NPCR)检测西沙群岛恙螨所携恙虫病东方体的 5 6kDa蛋白基因片段 ,继而将NPCR产物克隆进pGEM-T载体并且测序 ,测序结果在国际互联网作多序列比较和进化树分析。结果　从西沙群岛收集的恙螨扩增出 5 0 7bp目的片段 ,序列分析证实与Karp株同源性 85 % ,与Gilliam株同源性 6 8% ,与Yonchon株同源性 6 7% ,与Kato株同源性 6 5 %。结论　西沙群岛的恙螨携带恙虫病东方体以Karp型为主。

Sequencing of Orientia tsutsugamushi DNA of mites from the Xisha islands

Aim To determine genotypes of Orientia tsutsugamushi of mites from the Xisha islands and to seek the formation of the endemic areas in the south sea islands Methods The DNA sequence coding 56 kDa protein of Orientia tsutsugamushi from the mites on Xisha islands was amplified by nested polymerase chain reaction(NPCR) The purified positive products was cloned into pGEM T vector and sequenced The DNA sequence was compared with various sequences on the internet for sequence homology analysis Results 507 bp DNA fragments encoding 56 kDa protein was amplified in the samples The sequence homology was 85% to Karp strain,68% to Gilliam strain,67% to Yonchon and 65% to Kato strain Conclusion Orientia tsutsugamushi existes in the mites on Xisha islands The main genotype of Orientia tsutsugamushi is Karp