Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey
Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey
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DOI：
10.1186/s13071-017-2087-7
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发表时间：
2017-03-20
影响因子：
3.2
通讯作者：
Linton, Yvonne-Marie
中科院分区：
文献类型：
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作者：
Ergunay, Koray;Litzba, Nadine;Linton, Yvonne-Marie
背景：主动媒介监测为监测新出现或再出现的媒介传播病毒的存在或传播提供了一种有效工具。本研究旨在调查黄病毒的传播。2014年和2015年，在土耳其爱琴海、色雷斯和地中海安纳托利亚地区10个省份的58个地点采集了蚊子。形态鉴定后，采用巢式和实时PCR方法对蚊虫进行筛选。检测到的病毒通过测序进一步表征。将阳性池接种到细胞系上进行病毒分离。下一代测序用于分离株的基因组特征。结果：在594个池中共捕获蚊虫15种12711只。11个池（2%）在病毒筛选试验中有反应。测序结果显示，在色雷斯一个库蚊库蚊库中发现西尼罗河病毒（WNV）。西尼罗河病毒序列与谱系1进化支1a相对应，但与土耳其原型分离物明显聚集。在10个库中，5个库和1个库分别鉴定为淡色库蚊黄病毒。在2个海伊蚊库中发现淡色库蚊，在1个环纹库中发现AV-2011型黄病毒，在爱琴海和色雷斯地区的1个爪乌带蚊库中发现一种未确定的黄病毒。检测到的昆虫特异性黄病毒的DNA形式或整合未被观察到。从土耳其伊蚊中分离出一株病毒株，暂定名为“土耳其猪黄病毒”。C6/36细胞的caspius池。病毒基因组包括10370个核苷酸和3385个氨基酸的推定多蛋白，遵循典型的黄病毒多蛋白组织。序列比较和系统发育分析表明，该毒株与葡萄牙的caspius黄毒和芬兰的Hanko病毒亲缘关系较近。确定了几个保守的结构和氨基酸基序。结论：我们在2014年和2015年对土耳其不同地区的蚊子进行了广泛的生物监测研究，发现了西尼罗河病毒和几种不同的昆虫特异性黄病毒。发现西尼罗河病毒的持续传播，具有前所未有的遗传多样性。检测到一种仅以DNA形式识别的昆虫黄病毒的可能复制形式。
Background: Active vector surveillance provides an efficient tool for monitoring the presence or spread of emerging or re-emerging vector-borne viruses. This study was undertaken to investigate the circulation of flaviviruses. Mosquitoes were collected from 58 locations in 10 provinces across the Aegean, Thrace and Mediterranean Anatolian regions of Turkey in 2014 and 2015. Following morphological identification, mosquitoes were pooled and screened by nested and real-time PCR assays. Detected viruses were further characterised by sequencing. Positive pools were inoculated onto cell lines for virus isolation. Next generation sequencing was employed for genomic characterisation of the isolates.Results: A total of 12,711 mosquito specimens representing 15 species were screened in 594 pools. Eleven pools (2%) were reactive in the virus screening assays. Sequencing revealed West Nile virus (WNV) in one Culex pipiens (s. l.) pool from Thrace. WNV sequence corresponded to lineage one clade 1a but clustered distinctly from the Turkish prototype isolate. In 10 pools, insect-specific flaviviruses were characterised as Culex theileri flavivirus in 5 pools of Culex theileri and one pool of Cx. pipiens (s. l.), Ochlerotatus caspius flavivirus in two pools of Aedes (Ochlerotatus) caspius, Flavivirus AV-2011 in one pool of Culiseta annulata, and an undetermined flavivirus in one pool of Uranotaenia unguiculata from the Aegean and Thrace regions. DNA forms or integration of the detected insect-specific flaviviruses were not observed. A virus strain, tentatively named as "Ochlerotatus caspius flavivirus Turkey", was isolated from an Ae. caspius pool in C6/36 cells. The viral genome comprised 10,370 nucleotides with a putative polyprotein of 3,385 amino acids that follows the canonical flavivirus polyprotein organisation. Sequence comparisons and phylogenetic analyses revealed the close relationship of this strain with Ochlerotatus caspius flavivirus from Portugal and Hanko virus from Finland. Several conserved structural and amino acid motifs were identified.Conclusions: We identified WNV and several distinct insect-specific flaviviruses during an extensive biosurveillance study of mosquitoes in various regions of Turkey in 2014 and 2015. Ongoing circulation of WNV is revealed, with an unprecedented genetic diversity. A probable replicating form of an insect flavivirus identified only in DNA form was detected.