Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, 80160, Thailand.
Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat, 80160, Thailand.
Parasit Vectors. 2021 Nov 8;14(1):569. doi: 10.1186/s13071-021-05047-z.
The distribution of phlebotomine sand flies is changing rapidly due to climate change. This issue has implications for the epidemiology of sand fly-borne diseases, especially sand fly-associated viruses. Few studies concerning sand fly-associated viruses have been conducted in Thailand. Therefore, this study aimed to perform a molecular survey of groups of pathogenic RNA viruses belonging to the Orbivirus, Phlebovirus, and Flavivirus genera and family Rhabdoviridae in sand fly samples collected from southern Thailand.
Sand flies were collected at two locations in Trang and Songkhla provinces of southern Thailand, and individual sand fly samples were processed for species identification and virus detection. The Orbivirus, Phlebovirus, and Flavivirus genera and family Rhabdoviridae molecular determination was performed by RT-PCR, and positive samples were identified by cloning and sequencing, cell culture inoculation, and phylogenetic analysis.
The results presented in this study were based on the analysis of a total of 331 female sand flies. This molecular study revealed evidence of Rhabdoviridae family virus presence in Phlebotomus papatasi (3/331, 0.9%). The findings demonstrated a new cluster of rhabdovirus that was closely related to Bactrocera dorsalis sigmavirus strain BDSV.abc5 and the lineages of insect-specific Rhabdoviridae. In addition, the Bayesian tree suggested that the common ancestor of this group was the dimarhabdovirus clade. It was assumed that the virus may have switched hosts during its evolution. However, the detection of Orbivirus, Phlebovirus, and Flavivirus genera using specific primers for RT-PCR was negative in the collected sand flies.
There is limited knowledge on the genetic diversity and ecology of Rhabdoviridae in Thailand. This is the first data regarding the circulation of Rhabdoviridae in Ph. papatasi from Thailand. We found a new cluster of rhabdoviruses that was close to the new B. dorsalis sigmavirus. It is possible that there is a great deal of diversity in this family yet to be discovered, and a more extensive survey for new rhabdoviruses may uncover viruses from a wide diversity of host taxa and broaden our understanding of the relationships among the Rhabdoviridae.
由于气候变化，白蛉的分布正在迅速变化。这一问题对白蛉传播疾病的流行病学产生了影响，尤其是与白蛉相关的病毒。在泰国，关于与白蛉相关的病毒的研究很少。因此，本研究旨在对从泰国南部采集的白蛉样本中属于呼肠孤病毒科、黄病毒科和布尼亚病毒科的一组致病性 RNA 病毒进行分子调查。
在泰国南部的桐艾府和宋卡府的两个地点采集白蛉，并对单个白蛉样本进行种属鉴定和病毒检测。通过 RT-PCR 进行呼肠孤病毒科、黄病毒科和布尼亚病毒科和弹状病毒科的分子鉴定，对阳性样本进行克隆和测序、细胞培养接种和系统发育分析进行鉴定。
本研究的结果基于对总共 331 只雌性白蛉的分析。这项分子研究表明，在白蛉属中存在弹状病毒科病毒（3/331，0.9%）。研究结果显示，一种新的弹状病毒群与果实蝇 Sigavirus 株 BDSV.abc5 和昆虫特异性弹状病毒科的谱系密切相关。此外，贝叶斯树表明该组的共同祖先属于二目病毒属。据推测，该病毒在进化过程中可能发生了宿主转换。然而，使用 RT-PCR 的特定引物在采集的白蛉中检测到呼肠孤病毒科、黄病毒科和布尼亚病毒科为阴性。
泰国对白蛉属弹状病毒科的遗传多样性和生态学知之甚少。这是首次在泰国从白蛉属中发现弹状病毒科的循环。我们发现了一个与新的果实蝇 Sigavirus 非常接近的新弹状病毒群。这个家族可能还有很多尚未被发现的多样性，更广泛的新弹状病毒调查可能会发现来自广泛宿主分类群的病毒，并扩大我们对弹状病毒科之间关系的理解。
