Background Culex quinquefasciatus is a notorious vector known to transmit pathogens such as Wuchereria bancrofti (causing Lymphatic filariasis) and flaviviruses such as West Nile virus in India and St. Louis Encephalitis virus in the USA. It is the vector of the Rift Valley Fever virus, also on the African continent. Mosquitoes also harbor other non-pathogenic insect-specific flaviviruses (ISFs), such as Culex flavivirus (CxFV) and Aedes flavivirus. Recent studies have implicated ISFs interfering with the vectorial efficiency of the pathogenic arbo-viruses. Methods One hundred specimens of the Cx. quinquefasciatus population in two urban areas in Kerala State, India, were screened to have an understanding of the prevalence of these flaviviruses in this vector species. Viral RNA was extracted from individual specimens and was subjected to RT-PCR towards amplification of the CxFV non-structural protein 5 (NS5) gene. Results Among the 100 specimens, 7.0% were found to be harboring CxFV infection. The phylogenetic analysis of the gene sequences showed that the virus isolates were genetically related to Kenya, with 98–99% sequence similarities. Conclusion This is the first report on the occurrence of CxFV from Cx. quinquefasciatus from India. The occurrence of these viruses in mosquitoes could play a critical role in disease vector management.

中文翻译：

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致倦库蚊（双翅目：库蚊科）中黄病毒的鉴定和分子特征：来自印度的首次报告

背景 致倦库蚊是一种臭名昭著的媒介，已知其传播病原体，如班氏乌策菌（引起淋巴丝虫病）和黄病毒，如印度的西尼罗河病毒和美国的圣路易斯脑炎病毒。它是非洲大陆裂谷热病毒的传播媒介。蚊子还携带其他非致病性昆虫特异性黄病毒 (ISF)，例如库蚊黄病毒 (CxFV) 和伊蚊黄病毒。最近的研究表明 ISF 会干扰致病性虫媒病毒的载体效率。方法 一百个 Cx 样本。对印度喀拉拉邦两个城市地区的 quinquefasciatus 种群进行了筛查，以了解这些黄病毒在该媒介物种中的流行情况。从个体样本中提取病毒 RNA，并进行 RT-PCR 以扩增 CxFV 非结构蛋白 5 (NS5) 基因。结果 100份标本中，7.0%检出CxFV感染。基因序列的系统发育分析表明，病毒分离株与肯尼亚有遗传相关性，序列相似度为 98-99%。结论 这是关于 Cx 发生 CxFV 的第一份报告。来自印度的 quinquefasciatus。这些病毒在蚊子中的出现可能在病媒管理中发挥关键作用。