湖南省蜱及5种蜱传病原研究

Molecular epidemiological investigation of tick-borne bacteria in Hunan Province

蜱传病呈全球分布,危害人类和动物健康。为了研究湖南省娄底市现存蜱媒病原体,于2021—2022年在湖南省娄底市采集1395只微小牛蜱样本,提取蜱样品基因组DNA。选取蜱线粒体COI基因扩增特异性的基因片段,对微小牛蜱进行鉴定。为了对该蜱携带的病原进行检测,采用PCR方法对立克次体ompA和gltA基因,无形体groEL和23S rRNA基因,埃立克体groEL和16S rRNA基因,螺旋体16S rRNA和23S rRNA基因进行扩增,对阳性产物进行克隆测序,测序获得的基因序列进行系统发育分析来确定病原的基因型。结果显示,从蜱样本中检测出5种蜱传细菌病原,包括敬信立克次体(Candidatus Rickettsia jingxinensis)、中央无形体(Anaplasma centrale)、扁平无形体(Anaplasma platys)、米氏埃立克体(Ehrlichia minasensis)和宫本疏螺旋体(Borrelia miyamotoi)。其中敬信立克次体、米氏埃立克体和宫本疏螺旋体阳性率均为2.16%,扁平无形体阳性率为0.30%,中央无形体阳性率为5.79%。本研究利用物种鉴定与分子生物学相结合的方法,从分子流行病学角度解析这些病原体在蜱体内存在及流行情况,并且在湖南省蜱中检测到扁平无形体和宫本疏螺旋体两种人兽共患病原体,可为湖南省的虫媒疾病的研究和防控提供数据参考。

Tick-borne diseases are globally distributed and pose a threat to human and animal health.To investigate the existing tick-borne pathogens in Loudi City,Hunan Province,1395 samples of Rhi pice phalus micro plus were collected from Loudi City,Hunan Province during 2021-2022,and genomic DNA was extracted from the tick samples.The tick mitochondrial COI gene was selected for amplifying a specific gene fragment to identify the Rhipicephalus microplus.To identify the species of tick,a specific fragment of the mitochondrial COI gene was amplified using modern molecular biology methods in conjunction with morphological classification.To detect the pathogens carried by the ticks,PCR was performed to amplify the ompA and gltA genes of Rickettsiales,the groE-L and 23S rRNA genes of Anaplasma,the groE-L and 16S rRNA genes of Ehrlichia,and the 16S rRNA and 23S rRNA genes of Borrelia.The positive products were cloned and sequenced,and the resulting gene sequences were subjected to phylogenetic analysis to determine the genotype of pathogen.A total of 1395 Rhipicephalus microplus were collected,from which five pathogens including Ca.R.jingxinensis,A.centrale,A.platys,E.minasensis,and B.miyamotoi were detected.The positive rates of Ca.R.jingxinensis,E.minasensis and B.miyamotoi were all2.16%,the positive rate of A.platys was 0.3%,the positive rate of A.centrale was 5.79%.In conclusion,two zoonotic pathogens and several pathogens that can harm animal husbandry were identified in ticks in Hunan,which can provide data reference for the research and prevention of tickborne diseases in Hunan Province.