Defining virus-carrier networks that shape the composition of the mosquito core virome of a local ecosystem

Abstract

Mosquitoes are the most important vectors of emerging infectious diseases. During the past decade, our understanding of the diversity of viruses they carry has greatly expanded. Most of these viruses are considered mosquito-specific but there is increasing evidence that these viruses may affect the vector competence of mosquitoes. Metagenomics approaches have focused on specific mosquito species for the identification of what is called the core virome. Despite the fact that, in most ecosystems, multiple species may participate in virus emergence and circulation, there is a lack of understanding of the virus-carrier/host network for both vector-borne and mosquito-specific viruses. Here, we studied the core virome of mosquitoes in a diverse local ecosystem that had 24 different mosquito species. Analysis of the viromes of these 24 mosquito species resulted in the identification of 34 viruses, which included 15 novel viruses, as determined according to the species demarcation criteria of the respective virus families. Most of the mosquito species had never been analysed previously and a comparison of the individual viromes of the 24 mosquito species revealed novel relationships among mosquito species and virus families. Groups of related viruses and mosquito species from multiple genera formed a complex web in the local ecosystem. Furthermore, analyses of the virome of mixed-species pools of mosquitoes from representative traps of the local ecosystem showed almost complete overlap with the individual-species viromes identified in the study. Quantitative analysis of viruses’ relative abundance revealed a linear relationship to the abundance of the respective carrier/host mosquito species, supporting the theory of a stable core virome in the most abundant species of the local ecosystem. Finally, our study highlights the importance of using a holistic approach to investigating mosquito viromes relationships in rich and diverse ecosystems.

Broadening the <em>Chrysoviridae</em> Horizons: A New Geographical Area and Potential Arthropod Vector for the Xanthi Chryso-Like Virus

“…Vis-à-vis their topographical expansion lies an as yet unexplored potential for the spread of infectious agents conceivably obliging to humans, such as the present chrysoviruses. Moreover, these viruses are not bound to a singular arthropod genus -the XCLV apparently shares genetic similarity to Soufi chryso-like virus, previously described in the Uranotaenia unguiculata mosquito [17]. Our findings of the XCLV in the Culex arthropod might hence mean that this is not the only mosquito carrying a chrysovirus within its virome, hinting at a larger distribution of these mycoviruses throughout insect reservoirs and geographic areas alike.…”

“…This study used classical PCR and Sanger sequencing in order to investigate possible presence of West Nile virus in a population of mosquitoes in Serbia, Belgrade. We made a serendipitous detection of the uncommon XCLV, so far described in a single work by Konstantinidis and coworkers [17].…”

“…The NS5 gene-specific primers [16] are listed in Table 1, along with XCLV-specific primers for nested PCR which amplified ~750 bp of the P3 putative protease gene. These primers were designed within this study, based on the 4 XCLV sequences existing in public databases [17]. Detected PCR products were thereafter Sanger-sequenced on a Genetic analyzer 3730 (Applied Biosystems, Waltham, MA, USA).…”

Global mosquito virome profiling and mosquito spatial diffusion pathways revealed by marker-viruses

“…Characterization and identification of core-virome of mosquitoes is imperative to understand the ecological dynamics of mosquito-associated viruses [22]. Here, we redefined the core-virome in mosquitoes at different levels of mosquito genus, continent, climate, country.…”

“…Strong variance in viral compositions and abundance were observed for different seasons and host species, but not for gender. However, these studies are restricted to between two or just a few mosquito species within a particular country or district [22]. The meta-virome survey to combine all globally published mosquito virome data can draw a comprehensive map of the ISVs distribution, define more plausible core viruses and give a deep insight into the determined factors (e.g.…”