新疆石河子地区犬源立克次体病流行病学调查

摘要

Rickettsia,Anaplasma and Ehrlichia of the order Rickettsiales can cause rickettsiosis,anaplasmosis,and ehrlichiosis,respectively.Rickettsiales bacteria are found in ticks worldwide.Ixodes is the major vector.The aim of this research was to screen,identify and characterize Rickettsia,Anaplasma and Ehrlichia by PCR and phylogenetic analysis in dogs.The parasite ticks and blood in dogs were collected from the pet hospitals in Shihezi City and its surrounding area.Rickettsia,Anaplasma and Ehrlichia cani 16S rRNA were detected by PCR and compared with the corresponding genes in GenBank.The 345 bp specific fragment of Rickettsia was amplified from ticks,and the specific fragments of 452 bp of Ehrlichia cani and Anaplasma were obtained.The sequencing results confirmed that these fragments were Rickettsia,Anaplasma and Ehrlichia cani,phylogenetic analyses of these products showed that canine Rickettsia,Ehrlichia and Anaplasma isolates in the study classified in the same branch with Rickettsiales bacterium (EF687768),Ehrlichia sp.Yonaguni206 (HQ697589.1),Anaplasma (KJ410247.1,KJ410248.1,KJ410249.1) and belong to the conservative clade of Rickettsia,Ehrlichia and Anaplasma,respectively,suggesting a close relationship with these foreign strains.The purpose of this study was to investigate the infection and prevalence of tick borne Rickettsia in dogs in Shihezi,and to provide epidemiological data for the prevention and treatment of rickettsiosis.%立克次体目(Rickettsiales)中的立克次体属、埃立克体属和无形体属细菌分别能引起立克次体病、埃立克体病和无形体病,硬蜱是其主要传播媒介.在石河子市部分宠物医院及周边地区采集犬血及犬体表寄生蜱,通过PCR技术扩增蜱传立克次体目细菌16S rRNA基因,对所得结果进行测序并做系统进化分析.结果表明,扩增出立克次体345 bp特异片段,无形体及犬埃立克体452 bp特异片段,测序结果证实这些片段分别为立克次体、无形体和犬埃立克体.遗传进化分析显示,犬源立克次体、埃立克体及无形体石河子流行株分别与Rickettsiales bacterium(EF687768)、Ehrlichia sp.Yonaguni206 (HQ697589.1)、Anaplasma(KJ410247.1、KJ410248.1、KJ410249.1)处于同一分支,分别属于立克次体、埃立克体、无形体的保守分支,提示与这些国内外流行株具有较近的亲缘关系.本研究基本理清了石河子地区犬中蜱传立克次体的感染和流行情况,为立克次体的防治提供了流行病学资料.