Abstract: Objective　To investigate the tick species, and tick⁃derived Rickettsiales bacteria and recently emerging tick⁃derived viruses in hilly and costal mudflat wetland settings in northern Jiangsu Province, so as to provide insights into management of tick⁃borne tropical diseases in northern Jiangsu Province.  Methods　Ticks were sampled from hilly settings in Yuyi County, Huai'an City and coastal mudflat wetland settings in Jiangsu Yancheng Wetlands & Rare Birds National Nature Reserve in Tinghu District, Yancheng City on April, 2025. Following characterization of tick species, nucleic acid was isolated from ticks under a sterile condition, and tick⁃derived pathogens were detected using nested and semi⁃nested real⁃time PCR assays, including Rickettsia, Ehrlichia, Anaplasma, Yezo virus, Alongshan virus, Songling virus, Beiji nairovirus and Wetland virus. The PCR amplification products were sequenced for analysis of phylogenetic evolution and genetic characteristics.  Results　A total of 154 ticks were captured, including 114 from Huai'an City and 40 from Yancheng City, and 153 ticks were characterized as Haemaphysalis longicornis and one as H. flava. A total of 5 ticks were tested positive for Rickettsiales bacteria and viruses by semi⁃nested real⁃time PCR assay (3.25%), including 4 ticks from hilly settings in Xuyi County, Huai'an City, tested positive for Anaplasma, and one tick from coastal mudflat wetland settings in Tinghu District, Yancheng City, tested positive for Rickettsia; however, ticks were tested negative for Ehrlichia, or recently emerging Yezo virus, Alongshan virus, Songling virus, Beiji nairovirus or Wetland virus. Sequence alignment using BLASTn and phylogenetic analysis revealed that genetic differentiation occurred in four A. bovis isolates in one species of A. bovis, with two genetic clades generated, and one R. japonica variant was identified, with its nucleotide sequences highly homologous to Shandong isolates of R. japonica. Conclusions　Ticks are widely distributed in hilly and costal mudflat wetland settings in northern Jiangsu Province, and tick⁃derived pathogens have a genetic diversity. Tick⁃borne Anaplasma and Rickettsia pose a zoonotic potential.  

Key words: Tick, Rickettsia, Emerging virus, Molecular characterization, Phylogenetic evolution, Northern Jiangsu Province

摘要： 目的　了解苏北地区丘陵、沿海滩涂生境蜱种属及其携带的立克次氏体目细菌以及近年新发蜱源性病毒种类，从而为该地区蜱传热带病防控提供参考。方法　2025年4月，在江苏省淮安市盱眙县丘陵和盐城市亭湖区江苏盐城湿地珍禽国家级自然保护区沿海滩涂湿地两个生境采集蜱虫，经种属鉴定后，无菌提取蜱虫组织核酸。采用巢式和半巢式PCR法检测蜱虫携带的立克次体、埃立克体、无形体、虾夷病毒、阿龙山病毒、松岭病毒、北极内罗病毒、湿地病毒等病原体。对PCR扩增产物进行测序，对测序结果进行种系进化及遗传特征分析。结果　共采集154只蜱虫，其中自淮安市采集114只、盐城市采集40只，153只为长角血蜱、1只为褐黄血蜱。经半巢式PCR法共检出5只蜱虫阳性（3.25%），其中自淮安市盱眙县采集的4只蜱虫检出无形体、盐城市采集的1只蜱虫检出立克次体，未检出埃立克体及近年新发的虾夷病毒、阿龙山病毒、北极内罗病毒、松岭病毒和湿地病毒。经BLASTn比对及种系进化分析，1种牛无形体、4株牛无形体出现了一定程度遗传分化，形成了两个进化小分支；1种为日本立克次体变异株，与山东日本立克次体核苷酸序列高度同源。结论　苏北地区丘陵、沿海滩涂生境蜱虫分布广泛，携带的病原体遗传多样性高，无形体和立克次体具备致人兽共患病能力。

关键词: 蜱, 立克次氏体, 新发病毒, 分子鉴定, 种系进化, 苏北地区