First isolation of West Nile virus in Brazil
First isolation of West Nile virus in Brazil
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DOI：
10.1590/0074-02760180332
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发表时间：
2019-01-01
期刊：
影响因子：
--
通讯作者：
Vasconcelos, Pedro Fernando da Costa
中科院分区：
文献类型：
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作者：
Martins, Lívia Caricio;Silva, Eliana Vieira Pinto da;Vasconcelos, Pedro Fernando da Costa
背景西尼罗河病毒（West Nile virus，WNV）感染的血清学证据已在巴西不同地区的马和人类宿主中报道，但该病毒从未在该国分离到。我们还进行了测序，系统发育分析和分子clock.FINDINGS组织学分析显示，从马脑组织损伤脑炎和西尼罗河病毒感染证实了免疫组化。通过逆转录定量聚合酶链反应（RT-qPCR）从脑组织中检测病毒，随后在C6/36细胞中分离病毒。对WNV全长基因组进行测序，显示分离的菌株属于谱系la。分子钟显示，巴西WNV株与2002- 2005年在美国流行的WNV株具有相同的共同祖先。主要结论本研究首次从巴西一匹患有神经系统疾病的马中分离到WNV，与2000年代初分离到的美国WNV株聚为la系。
BACKGROUND Serological evidence of West Nile virus (WNV) infection has been reported in different regions of Brazil from equine and human hosts but the virus had never been isolated in the country.OBJECTIVES We sought to identify the viral etiology of equine encephalitis in Espirito Santo state.METHODS We performed viral culture in C6/36 cells, molecular detection of WNV genome, histopathology and immunohistochemistry from horse cerebral tissue. We also carried out sequencing, phylogenetic analysis and molecular clock.FINDINGS Histopathologic analysis from horse cerebral tissue showed injury related to encephalitis and WNV infection was confirmed by immunohistochemistry. The virus was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) from brain tissue and subsequently isolated in C6/36 cells. WNV full-length genome was sequenced showing the isolated strain belongs to lineage la. The molecular clock indicated that Brazilian WNV strain share the same common ancestor that were circulating in US during 2002-2005.MAIN CONCLUSIONS Here we report the first isolation of WNV in Brazil from a horse with neurologic disease, which was clustered into lineage la with others US WNV strains isolated in beginning of 2000's decade.