舟山海岛地区蜱媒病原体多样性及其基因同源性分析

Diversity and gene homology analysis of tick-borne pathogens in Zhoushan island

目的了解舟山海岛地区蜱类所携带的病原体多样性及其基因同源性。方法2020年4—11月,采用布旗法收集舟山海岛地区发热伴血小板减少征病例居住地周围环境中的游离蜱,采用畜体检查法采集家畜身上的寄生蜱。蜱样本提取RNA或DNA进行荧光RT-PCR检测,以嗜吞噬细胞无形体、立克次体、查菲埃里克体、新型布尼亚病毒、汉坦病毒、汉城病毒、沃尔巴克体、山羊无形体为引物进行PCR扩增初筛。扩增序列测序后进行同源性分析,以邻接法构建系统进化树。结果共采集蜱样本99只,其中游离蜱样本39只,寄生蜱样本60只。在蜱样本中检出嗜吞噬细胞无形体、立克次体、沃尔巴克体和山羊无形体核酸阳性。此次检出的沃尔巴克体与日本报道的沃尔巴克体(AB025965)同源性为98.70%;立克次体与中国云南立克次体03(KY433580)、日本立克次体LA16同源性为99.83%;嗜吞噬细胞无形体有2个进化分支:一个进化分支与安徽桐城(MK045683)及韩国济州岛(GU064903)的嗜吞噬细胞无形体同源性为100.00%,另一个进化分支与安徽金寨的嗜吞噬细胞无形体(MK045694)同源性为99.70%。结论舟山海岛地区是嗜吞噬细胞无形体、山羊无形体和日本立克次体的自然疫源地,暴露居民存在感染风险。

Objective To understand the diversity and gene homology of pathogens carried by ticks in Zhoushan island.Methods From April to November,2020,free ticks were collected by cloth flag method from the surrounding environment of the residence of patients with severe fever with thrombocytopenia syndrome in Zhoushan island,and parasitic ticks on livestock were collected by livestock examination.RNA or DNA of ticks was extracted for fluorescence RT-PCR detection,and the target genes of Anaplasma phagocytophilum,Rickettsia,Chaffeerici,novel Bunyavirus,Hantavirus,Seoul virus,Wolbachia and Anaplasma capra were screened for PCR amplification.The amplified sequence was sequenced for homology analysis,and the phylogenetic tree was constructed by adjacency method.Results A total of 99 ticks were collected,including 39 free ticks and 60 parasitic ticks.Nucleic acids of Anaplasma phagocytophilum,Rickettsia,Wolbachia and Anaplasma capra were positive by PCR detection.The homology between Wolbachia and Wolbachia reported in Japan(AB025965)was 98.70%.And the homology between Rickettsia and Rickettsia 03(KY433580)in Yunnan or Rickettsia LA16 in Japan was 99.83%.The genetic evolution of Anaplasma phagocytophilum was divided into two branches,one of which was highly homologous with Anaplasma phagocytophilum from Tongcheng,Anhui Province(MK045683)and Jeju island,Korea(GU064903)with the homology of 100.00%,and the other of which was highly homologous with Anaplasma phagocytophilum from Jinzhai,Anhui Province(MK045694)with the homology of 99.70%.Conclusions Zhoushan island is a natural foci of tick-borne pathogens such as Anaplasma phagocytophilum,Anaplasma capra and Rickettsia japonica.Exposed residents are at risk of infection.