Wanjiru Tabitha, Bulimo Wallace, Langat Solomon, Kinyua Johnson, Odemba Nicholas, Yalwala Santos, Oullo David, Ochieng Richard, Ngere Francis, Kerich Gladys, Ambale Janet, Achieng Eunice, Abuom David, Egbo Timothy, Johnson Jaree, Ojwang Elly, Eads John, Garges Eric, Eyase Fredrick
Department of Emerging Infectious Diseases, Walter Reed Army Institute of Research-Africa, Nairobi, Kenya.
Centre for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya.
PLoS One. 2025 Jul 2;20(7):e0315492. doi: 10.1371/journal.pone.0315492. eCollection 2025.
Aedes aegypti is the main vector of several arboviruses including chikungunya, dengue, yellow fever and Zika. Beyond arboviruses, Aedes aegypti harbours insect-specific viruses (ISVs), which can modulate mosquito's ability to transmit diseases by interfering with viral processes and triggering immune responses. Both arboviruses and ISVs can be transmitted vertically, where viruses are passed from parent to offspring. The lack of systematic molecular and entomological surveillance, has left the diversity of viruses in local Aedes aegypti populations largely unexplored. This study aimed to characterize the viromes of Aedes aegypti mosquitoes from Kisumu, Kenya, focusing on viral diversity. Immature larvae and pupae were collected from Jua Kali area in Kisumu, reared into adults, and subjected to viral isolation by cell culture and metagenomic next-generation sequencing. RNA extraction, library preparation, and Illumina MiSeq sequencing were performed on CPE positive pools and metagenomic superpools. Initial data analysis was conducted using the CZ-ID platform, with quality control applied using PrinseqLite v0.20.4 to filter low-quality reads and remove adapters. De novo sequence assembly was performed with MEGAHIT v1.2.9, followed by BLAST analysis. Phylogenetic relationships were analyzed using the Maximum Likelihood method. A total of 2,142 female Aedes aegypti, grouped into 86 pools and 4 superpools, were analyzed using cell culture and metagenomic next-generation sequencing respectively. Dengue virus type-3 was detected in one of the 86 pool. Additionally, a variety of ISVs were identified, including Iflaviruses related to Tesano Aedes Iflavirus (TeAV), Armigeres Iflavirus, and Negeviruses related to Rabai Virus. An unclassified virus closely related to Korle-Bu Aedes virus was also detected. Our study provides insights into the viral diversity within Aedes aegypti mosquitoes in Kisumu and evidence of natural vertical transmission, specifically transovarial transmission of dengue virus type-3. Ongoing research is imperative to unravel vertical transmission mechanisms and subtleties governing ISV-arbovirus interactions across diverse environmental settings.
埃及伊蚊是包括基孔肯雅病毒、登革热病毒、黄热病病毒和寨卡病毒在内的多种虫媒病毒的主要传播媒介。除了虫媒病毒，埃及伊蚊还携带昆虫特异性病毒（ISV），这些病毒可以通过干扰病毒过程和触发免疫反应来调节蚊子传播疾病的能力。虫媒病毒和ISV都可以垂直传播，即病毒从亲代传给子代。由于缺乏系统的分子和昆虫学监测，当地埃及伊蚊种群中的病毒多样性在很大程度上尚未得到探索。本研究旨在对来自肯尼亚基苏木的埃及伊蚊的病毒组进行特征分析，重点关注病毒多样性。从未成熟幼虫和蛹中收集来自基苏木朱阿卡里地区的样本，饲养至成虫，并通过细胞培养和宏基因组下一代测序进行病毒分离。对出现细胞病变效应（CPE）阳性的样本池和宏基因组超样本池进行RNA提取、文库制备和Illumina MiSeq测序。使用CZ-ID平台进行初始数据分析，并使用PrinseqLite v0.20.4进行质量控制，以过滤低质量读数并去除接头。使用MEGAHIT v1.2.9进行从头序列组装，随后进行BLAST分析。使用最大似然法分析系统发育关系。分别使用细胞培养和宏基因组下一代测序对总共2142只雌性埃及伊蚊进行了分析，这些蚊子被分为86个样本池和4个超样本池。在86个样本池中的一个中检测到了3型登革热病毒。此外，还鉴定出了多种ISV，包括与特萨诺伊蚊伊弗病毒（TeAV）、阿氏伊蚊伊弗病毒相关的伊弗病毒，以及与拉拜病毒相关的内格病毒。还检测到一种与科勒-布伊伊蚊病毒密切相关的未分类病毒。我们的研究提供了对基苏木埃及伊蚊中病毒多样性的见解，以及自然垂直传播的证据，特别是3型登革热病毒的经卵传播。必须进行持续研究，以揭示垂直传播机制以及在不同环境中控制ISV-虫媒病毒相互作用的微妙之处。
