东北部分地区蜱传埃立克体DNA的检测

目的 了解东北部分地区一些蜱种中是否携带埃立克体。方法 应用16SrRNA基因构建的特异性引物进行半套式PCR，检测蜱标本中埃立克体DNA，并对扩增产物进行克隆和序列测定，与基因库中已知序列进行同源性比较。结果从辽宁清原和吉林抚松、和龙、敦化、珲春的全沟硬蜱(Lpersuleatus)和森林革蜱(D．silvarum)中均扩增出了查菲埃立克体DNA，扩增片段与美国分离株(基因库M73222)相对应片段完全一致，同源性为100％；另外从吉林抚松、珲春的全沟硬蜱中扩增出了粒细胞埃立克体DNA，扩增片段与美国分离株(基因库U02521)相对应片段相差2个碱基，同源性为99.7％。结论 发现东北部分地区存在埃立克体病的病原学迹象，提示该地区可能存在埃立克体病的自然疫源地。

EHRLICHIA DNA IN TICKS FOUND IN SOME PARTS OF NORTHEAST CHINA

Objective To investigate the ticks infected by Ehrlichia in northeast China. Methods Specific primers derived from the 16 Sr RNA gene sequence were used to amplify Ehrlichia DNA from ticks by semi-nested polymerase chain reaction(PCR).The PCR products were cloned and sequenced. The sequence was compared with other Ehrlichia for homology. Results Ehrlichia chaffeensis DNA were amplified from I. Persuleatus and D. Silvarum collected from some regions in Liaoning and Jilin province. It was entirely the same in comparison to American strains(M 73222)with 100% homology. Human granulocytic Ehrlichia DNA were amplified from I.Persuleatus collected from some regions in Jilin province. It was different from American strains (U 02521) at two positions with 99.7% homology. Conclusion Ehrlichiosis pathogen mas found in some parts of northeast China. These findings demonstrate that there may be natural foci of Ehrlichiosis in northeast China.