Chinese Journal of Vector Biology and Control ›› 2021, Vol. 32 ›› Issue (6): 756-762.DOI: 10.11853/j.issn.1003.8280.2021.06.020

• Investigation • Previous Articles     Next Articles

Detection of Francisella strains and Francisella-like endosymbionts in ticks in some regions of China

WANG Yan-hua1, SUN Ying-wei2, MAO Ling-ling2, WANG Zi-jiang2, ZHANG Jia-yong2, ZHANG Ji-bo2, PENG Yao1, XIA Lian-xu1   

  1. 1. State Key Laboratory of Infectious Disease Prevention and Control, Ecological Medicine Research Center, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China;
    2. Liaoning Center for Disease Control and Prevention, Shenyang, Liaoning 110005, China
  • Received:2021-07-05 Online:2021-12-20 Published:2021-12-15
  • Supported by:
    Supported by the National Natural Science Foundation of China (No. 81874275)


王艳华1, 孙英伟2, 毛玲玲2, 王子江2, 张家勇2, 张稷博2, 彭遥1, 夏连续1   

  1. 1. 中国疾病预防控制中心传染病预防控制所生态医学研究中心, 传染病预防控制国家重点实验室, 北京 102206;
    2. 辽宁省疾病预防控制中心, 辽宁 沈阳 110005
  • 作者简介:王艳华,女,博士,研究员,从事细菌性感染的病原学及分子生物学研究,
  • 基金资助:

Abstract: Objective To detect Francisella strains and Francisella-like endosymbionts (FLEs) in ticks in China. Methods We selected Liaoning province, Xinjiang Uygur Autonomous Region, and Hubei province as sampling sites, which are located in Northeast, Northwest, and South Central China, respectively. A total of 715 ticks were collected, including 627 Haemaphysalis longicornis and 88 Hyalomma asiaticum ticks. For all the collected ticks, we amplified the 16S rRNA gene and tul4 gene to detect Francisella strains and FLEs. We performed sequencing and homology alignment on PCR products with amplified target fragments, and conducted a phylogenetic analysis with published sequences of Francisella and FLEs in GenBank. Results Five of 24 Ha. longicornis pools from Liaoyang, Liaoning province harbored F. tularensis, showing a minimum prevalence of 2.12% (5/236) in Ha. longicornis ticks from Liaoyang. The prevalence of FLEs was 3.39% (8/236) in Ha. longicornis from Liaoyang, 32.95% (58/176) in Ha. longicornis from Shenyang, Liaoning province, 41.86% (90/215) in Ha. longicornis from Wuhan, Hubei province, and 100% (88/88) in Hy. asiaticum from Bole, Xinjiang Uygur Autonomous Region. The phylogenic analyses based on the 16S rRNA and tul4 genes indicated that FLEs in China had high genetic diversity and significant differences with other known FLEs in the world. Conclusion It is the first time to discover FLEs in Ha. longicornis. FLEs from Ha. longicornis and Hy. asiaticum ticks in China compose a separate lineage, suggesting that these FLEs may be newly discovered.

Key words: Francisella-like endosymbiont, Francisella tularensis, Haemaphysalis longicornis, Hyalomma asiaticum, Tick, Phylogeny

摘要: 目的 了解弗朗西斯菌属和弗朗西斯菌属(类)内共生体(弗类共生体)在我国蜱中的携带情况。方法 在我国东北、西北和中南地区,分别选取辽宁省、新疆维吾尔自治区(新疆)和湖北省作为采样点,共采蜱715只,包括长角血蜱627只和亚洲璃眼蜱88只。对所有采集蜱,首先通过扩增16S rRNA基因和tul4基因来检测弗朗西斯菌属和弗类共生体。然后,对有目的片段扩增的PCR产物进行测序和同源性比对,并与网上已公布的弗朗西斯菌属和弗类共生体的序列进行系统进化分析。结果 在辽阳市采获的24组长角血蜱中有5组土拉弗朗西斯菌(土拉菌)阳性,土拉菌的最小携带率为2.12%(5/236)。辽阳、沈阳和武汉市的长角血蜱、以及新疆博乐市的亚洲璃眼蜱,弗类共生体的携带率分别为3.39%(8/236)、32.95%(58/176)、41.86%(90/215)和100%(88/88)。16S rRNA基因和tul4基因的系统进化分析均显示,中国弗类共生体具有高度的遗传多样性,和世界其他已知弗类共生体有显著差异。结论 首次在长角血蜱中发现弗类共生体。我国长角血蜱和亚洲璃眼蜱中的弗类共生体形成单独的谱系,提示这些弗类共生体可能是新发现的。

关键词: 弗类共生体, 土拉弗朗西斯菌, 长角血蜱, 亚洲璃眼蜱, 蜱, 系统进化

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