Abstract: Objective　To identify spotted fever group rickettsiae (SFGR) isolated from Dermacentor sinicus, which were collected from the hedgehogs in the Chinese Center for Disease Control and Prevention in Changping District of Beijing, China. Methods　SFGR isolates were identified by morphological and molecular biological methods, followed by phylogenetic analysis. Results　SFGR propagated in DH82 cells and caused significant cytopathic effects. After Gimenez staining, a large number of rickettsiae were clearly seen in dark red. Sequence analysis revealed that the 16S gene of the SFGR isolates was 100% identical to that of Rickettsia sibirica strain 246 and R. sibirica strain BJ-90. Phylogenetic analysis demonstrated that the SFGR isolates were located in the same evolutionary branch as R. sibirica, which further proved that they were R. sibirica. Conclusion　The discovery of tick-born SFGR in Changping district provides etiological evidence for potential existence of the natural foci of North Asia fever in this area.

Key words: Rickettsia sibirica, Gimenez staining, Sequence analysis

摘要： 目的　对北京市昌平区中国疾病预防控制中心园区内刺猬携带的中华革蜱进行斑点热群立克次体(SFGR)的分离和鉴定。方法　采用形态学和分子生物学方法对SFGR进行鉴定,并进行系统进化特征分析。结果　SFGR对DH82细胞产生明显细胞病变;Gimenez染色后,可见较多清晰的立克次体被染成紫红色;细菌16S基因测定后,西伯利亚立克次体246株和西伯利亚立克次体BJ-90株相应核苷酸序列的同源性均为100%;系统进化分析显示,SFGR位于西伯利亚立克次体进化分支内,确认其为西伯利亚立克次体。结论　北京市昌平区存在西伯利亚立克次体,该地区存在北亚热自然疫源地的可能性。

关键词: 西伯利亚立克次体, Gimenez染色, 序列分析