羊及其体表蜱中SFTSV的分离培养与全基因序列分析

目的调查2012年春季江苏省某县羊及其体表蜱中发热伴血小板减少综合征病毒(SFTSV)感染情况,并对分离到的毒株进行全基因序列分析。方法采用荧光定量RT-PCR法对标本进行SFTSV核酸检测,所有阳性标本进行病毒分离并测序,序列结果用Lasergene和MEGA4软件进行拼接和分析。结果 7只羊和从羊体上采集的93只长角血蜱中,1只羊的血清和淋巴结SFTSV核酸检测呈阳性,附着于该羊体表的1只长角血蜱病毒核酸也呈阳性,通过病毒分离获得2株SFTSV毒株,JS2012-yang01(羊)和JS2012-pi01(蜱)。序列分析结果显示,JS2012-yang01和JS2012-pi01的L、M和S基因片段的核苷酸同源性分别为99.8%、99.8%、100.0%,氨基酸同源性分别为99.6%、99.6%、100.0%,进化树分析显示两株病毒处于同一亚分支。2株毒株与中国其他地区流行的SFTSV毒株核苷酸序列同源性介于95.9%⁹9.6%(L基因),94.7%99.6%(L基因),94.7%⁹9.5%(M基因)和95.0%99.5%(M基因)和95.0%⁹9.5%(S基因),与布尼亚病毒科白蛉病毒属其他毒株序列差异较大。结论该调查中分离自羊和蜱的SFTSV高度同源。蜱虫通过叮咬吸血,可能在SFTSV从动物到人的传播过程中起媒介作用。

Isolation and analysis of genomic sequences of SFTS virus from goat and tick attached to its surface

Objective To investigate the infection of severe fever with thrombocytopenia syndrome virus （SFTSV） in goats and attached ticks in a county of Jiangsu province in spring,2012; to analyze the genomic sequences of the isolated SFTSVs. Methods Real-time RT-PCR was applied to detect SFTSV nucleic acids. Positive samples were cultured for SFTSV virus iso- lation. The complete genomes of the isolated strains were sequenced and analyzed by using Lasergene and MEGA4 software. Results Of the 7 goats and 93 ticks （haemaphysalis longicornis）, the serum and ganglia lymphatica of 1 goat and 1 tick atta- ched to it were confirmed to be SFTSV nucleic acid positive. 2 SFTSV strains （JS2012-yang01 and JS2012-pi01） were isolated, and the homology of nucleotides of the two strains was 99.8%（L）, 99.8%（M） and 100%（S）, respectively; while 99.6%,99. 6 %, 100%for the homology of amino acids, respectively. Phylogenetic analysis demonstrated that they were in the same sub- genotype . The two strains and other representative strains of SFTSVs isolated from other provinces in China shared 95.9 %- 99.6%（L）, 94.7%- 99.5% （M） and 95%- 99.5% （S） for nueleotide acid homology, while they were much more different compared to other isolated bunyaviridae phlebovirus. Conclusion SFTSV viruses isolated from goat and tick are highly homol- ogous . Ticks may play an important role in the transmission of SFTSV from animals to human through biting.