新疆部分地区蜱传斑点热立克次体的分子流行病学研究

Molecular epidemiological study on the spotted fever rickettsia in Xinjiang

【目的】调查新疆地区斑点热群立克次体(spotted fever group rickettsia,SFGR)在蜱虫中的感染情况及其分布.【方法】2018年4~5月,采用人工布旗法对新疆地区10个县(市)的游离蜱和寄生于家畜体表的蜱虫进行采集并鉴定.对采集的蜱虫提取基因组,利用SFGR特异引物对提取的基因组进行PCR扩增及测序分析,用MEGA 6.0软件构建分子系统进化树.【结果】共采集蜱虫2 079只,经鉴定分析,采集的蜱种包括革蜱属、璃眼蜱属和扇头蜱属3属的7个种.扩增得到了包括拉欧蒂立克次体(Rickettsia raoultii)、斯洛伐克立克次体(Rickettsia slovaca)等在内的4种已知SFGR和2株未定种.对其阳性率进行统计结果表明,不同地区的蜱虫阳性率为40%~80%,平均阳性率为51.5%;不同蜱种间的感染率为1.1%~80%.【结论】通过对新疆地区SFGR病原的流行病学调查表明,被检地区SFGR病原阳性率较高,存在2种病原交叉感染现象,且扩增到的病原多属我国少见的人兽共患病病原.

【Objective】 To investigate the prevalence and distribution of Spotted fever group rickettsia(SFGR) in ticks in Xinjiang.【Method】 Methods Flagging for free-living ticks and off-hostcollection for parasitic ticks were conducted,during April to May,in ticks in 10 counties(cities) of Xinjiang in 2018. The genome of collected ticks was extracted,and the extracted genome was amplified and sequenced by PCR using specific primers of SFGR,and the molecular phylogenetic tree was constructed with MEGA 6.0 software.【Result】 A total of 2 079 ticks were collected,and the identified species included 7 species from 3 genera,include Dermacentor,Hyalomma,and Rhinpicephalu. Four SFGR and two Candidatus Rickettsia were obtained,including Rickettsia raoultii and Rickettsia slovaca and so on. The results showed that the positive rate of ticks in different areas was 40% ~ 80%,and the average positive rate was 51.5%.The infection rate among different tick species was 1.1%~80%.【Conclusion】 The epidemiological investigation of SFGR pathogen in Xinjiang showed that the positive rate of SFGR pathogen in the tested area was relatively high,and there was cross-infection of two kinds of pathogens,and most of the amplified pathogens were rare zoonotic pathogens in China.