Abstract:

Objective To investigate the prevalence of tick-borne spotted fever group Rickettsia (SFGR) in the western mountain area of Hebei province, China and to provide a scientific basis for the prevention and control of tick-borne SFGR. Methods One set of specific primers, designed according to the outer membrane protein A (OmpA) gene sequence of SFGR, were used to amplify the OmpA gene in DNA samples extracted from Haemaphysalis longicornis collected in the western mountain area of Hebei province, and the positive samples were subjected to sequencing and sequence analysis to establish the molecular phylogenetic tree. Results Of 1227 DNA samples, 91 (7.42%) were positive for SFGR. The phylogenetic analysis based on nucleotide sequence showed that all detected SFGR strains were clustered together with Candidatus Rickettsia hebeiii (accession numbers: HQ651815, HQ651817, HQ651818, HQ651819, HQ651823, and HQ651824) and Rickettsia sp. Fujian strain FUJ (accession number: AF169629); these strains had the highest homology with Candidatus R. hebeiii (99.02% ), followed by Rickettsia sp. Fujian strain FUJ (98.50%), Rickettsia sp. Suifen strain HLJ-054 (accession number: AF179362) and Rickettsia sp. Hulin strain HL-93 (accession number: AF179364) (98.13% ), and Rickettsia sp. Japanese strain YM (accession number: U43795) (97.92%). Conclusion Tick-borne SFGR is prevalent in the western mountain area of Hebei province. Preventive measures should be taken in time to protect humans and animals from this disease.

Key words: Spotted fever group Rickettsia, Haemaphysalis longicornis, Molecular epidemiology

摘要：

目的 调查河北省西部山区蜱类斑点热群立克次体带菌情况,为蜱传斑点热群防控提供科学依据。方法 根据已发表斑点热群立克次体OmpA外膜蛋白基因序列设计特异性引物,对河北省西部山区采集的长角血蜱进行PCR检测,并对阳性样本进行测序和序列分析,建立分子系统进化树。结果 在1227份蜱DNA样本中检测出91份阳性,阳性率为7.42%;序列分析结果显示河北省西部山区长角血蜱携带立克次体与河北株暂定种(登录号:HQ651815、HQ651817、HQ651818、HQ651819、HQ651823、HQ651824)、福建株FUJ(登录号:AF169629)同处于一个分支,与河北株立克次体暂定种同源性最高(99.02%),其次是福建株(98.50%)、黑龙江立克次体绥芬株HLJ-054(登录号:AF179362)和黑龙江立克次体虎林株HL-93(登录号:AF179364)(98.13%)、日本株YM(登录号:U43795)(97.92%)。结论 河北省西部山区蜱传斑点热群立克次体感染较为严重,应尽快制定防制措施,以免危及动物及人类健康。

关键词: 斑点热群立克次体, 长角血蜱, 分子流行病学